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Sample records for plant density irrigation

  1. to Irrigation Intervals and Plant Density in Zuru, Northern Guinea

    African Journals Online (AJOL)

    ISSN 0794-5698. Response of Onion (Allium cepa L.) to Irrigation Intervals and Plant Density in ... The treatments were laid out in a split plot design with three replications. Irrigation ..... System and Agronomic Practice in. Tropical Climates.

  2. Drip irrigation in coffee crop under different planting densities: Growth and yield in southeastern Brazil

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    Gleice A. de Assis

    2014-11-01

    Full Text Available Irrigation associated to reduction on planting spaces between rows and between coffee plants has been a featured practice in coffee cultivation. The objective of the present study was to assess, over a period of five consecutive years, influence of different irrigation management regimes and planting densities on growth and bean yield of Coffea arabica L.. The treatments consisted of four irrigation regimes: climatologic water balance, irrigation when the soil water tension reached values close to 20 and 60 kPa; and a control that was not irrigated. The treatments were distributed randomly in five planting densities: 2,500, 3,333, 5,000, 10,000 and 20,000 plants ha-1. A split-plot in randomized block design was used with four replications. Irrigation promoted better growth of coffee plants and increased yield that varied in function of the plant density per area. For densities from 10,000 to 20,000 plants ha-1, regardless of the used irrigation management, mean yield increases were over 49.6% compared to the non-irrigated crop.

  3. Evaluation of Yield and Yield Components of Black Cumin (Nigella sativa L. under different Plant Density and Limited Irrigation Condition

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    Sh Rezvan Beidokhti

    2012-10-01

    Full Text Available Research on crop response to deficit irrigation is important to reduce agriculture water use in areas where water is limited resource. Using drought resistant landraces with irrigation scheduling based on phenological stages in semi-arid and arid regions may provide an opportunity to optimize irrigation efficiency and water savings in these regions. In order to evaluate of yield and yield components of black cumin under different plant density and limited irrigation condition an experiment was conducted in Research Farm of Islamic Azad University of Damghan during growing season of 2007-2008. The experimental treatments were arranged in split plots based on a complete randomized block design with three replications. The limited irrigation (based on phenological stages treatments were included: cutting irrigation at blooming (folded flowers, cutting irrigation at flowering stage, cutting irrigation at seed formation and normal weekly irrigation (control were allocated to the main plots and different plant density: 100, 150, 200 and 250 plant per square meter (m2 were allocated to sub plots. The results showed that the effect of limited irrigation, plant density and their interaction on plant height, number of follicle, follicle weight, number of seed, 1000 seed weight, seed yield, biological yield and harvest index Black Cumin. The highest yield and yield components was obtained in normal irrigation (control and 200 plant density and the lowest yield were obtained when irrigation cut at the blooming stage and 250 plant density. There was a significant correlation between seed yield and number (r=0.90, 1000 seed weight (r=0.95 and biological yield (r=0.97. Optimum plant density of black cumin was decreased under limited irrigation treatments. Under normal (control and limited irrigation, optimum plant density was 200 and 150 plant per (m2 respectively.

  4. Effects of different irrigation intervals and plant density on morphological characteristics, grain and oil yields of sesame (Sesamum indicum

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    parviz rezvani moghadam

    2009-06-01

    Full Text Available In order to study the effects of different irrigation intervals and plant density on morphological characteristics, grain and oil yields of sesame, an experiment was conducted at experimental station, college of agriculture, Ferdowsi University of Mashhad. Four different irrigation intervals (one, two, three and four weeks with four plant densities (20, 30, 40 and 50 plants/m2 were compared in a spilt plot arrangement based on randomized complete block design with four replications. Irrigation intervals and plant densities allocated in main plots and subplots, respectively. Different characteristics such as plant height, distance of first capsule from soil surface, number of branches per plant, number of grains per capsule, number of capsules per plant, grain yield, 1000-seed weight, harvest index and oil yield were recorded. The results showed that there were no significant difference between different irrigation intervals in terms of distance of first capsule from soil surface, number of grains per capsule, 1000-seed weight and harvest index. Different irrigation intervals had significant effects on plant height, number of branches per plant, number of capsules per plant, grain yield and oil yield. There were significant differences between different plant densities in terms of distance of first capsule from soil surface, number of branches per plant, number of graines per capsule, number of capsules per plant, grain yield, harvest index and oil yield. The highest grain yield (798/7 kg/ha and oil yield (412/8 kg/ha were obtained at one week and four weeks irrigation intervals, respectively. Between all treatments, 50 plants/m2 and one week irrigation interval produced the highest grain yield (914/7 kg/ha and oil yield (478/6 kg/ha. Because of shortage of water in Mashhad condition, the results recommended that, 50 plants/m2 and two weeks irrigation interval produced rather acceptable grain yield, with less water consumption.

  5. Responses of Grain Maize to Plant Density at Different Irrigation Regimes

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    Sara SAMADVAND

    2017-12-01

    Full Text Available In order to examine the effects of different plant densities, plant patterns and irrigation regimes on yield, yield components and harvest index of grain maize, a field experiment was conducted at Miyandoab Agricultural Research Station, Iran. A strip split plot experiment was conducted based on randomized complete block design with three replications. The results showed that the effect of plant density was significant on kernel yield, harvest index, 1,000 kernel weight. The highest kernel yield was obtained from 90,000 plants ha-1 density. Maximum grain yield (18.530 t ha-1 was obtained from furrow irrigation. However, there was no significant difference between moisture levels of 100% and 120% of field capacity. The lowest kernel yield was obtained at 80% field capacity. This study also showed that mean kernel weight and the number of kernels per row were the most determinant factors in grain yield formation. The highest and the lowest harvest indices were obtained at 120% and 80% treatments of field capacity treatment, respectively.

  6. Phenology of German Chamomile and its Changes under Different Irrigation Regimes and Plant Densities

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    Alireza PIRZAD

    2010-03-01

    Full Text Available In order to definite growth stages of Matricaria chamomilla L., 40 plants were planted with 200 200 cm distance from each other. To determine the phenology under different water stress condition and plant densities, an experiment was conducted in factorial based on randomized complete block design with two factors including irrigation at 4 levels (25, 50, 75, and 100 mm evaporation from pan class A, and plant density at 5 levels (cultivation in 30 cm rows with 5, 10, 15, 20 and 25 cm intra-row spaces with three replications. Definition of growth stages including the maximum number of nodes, sub stems and tillers were 21, 20 and 14 that were occurred at 970, 1088 and 1088 oC growth degree-days, respectively. The numbers of nodes were 28.6, 30.0, 30.2 and 27.8, of sub stem were 19.2, 18.4, 19.8 and 18.4; and of tillers were 14.8, 14.0, 15.0 and 14.4 that were obtained from irrigation at 25, 50, 75, and 100 mm evaporation from pan, respectively. In the other hand, the number of nodes as follow 28.25, 29.00, 29.75, 29.75 and 29.00; sub stem as 17.50, 20.00, 20.75, 19.00 and 17.50; and tillers were 15.00, 13.50, 14.75, 14.00 and 15.50 that were obtained from 5, 10, 15, 20 and 25 cm intra-row spacing, respectively. Differences by irrigation on GDDs values were observed at the second harvest. However the earliest observation of flower and seed receiving at the first harvest occurred on 5 cm intra-row spacing. These changes were identical by GDDs for second harvest of flower, but with mild slope of reduction. There were no differences in number of leaves and tillers among irrigation levels and plant densities.

  7. Phenology of German Chamomile and its Changes under Different Irrigation Regimes and Plant Densities

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    Alireza PIRZAD

    2010-03-01

    Full Text Available In order to definite growth stages of Matricaria chamomilla L., 40 plants were planted with 200 � 200 cm distance from each other. To determine the phenology under different water stress condition and plant densities, an experiment was conducted in factorial based on randomized complete block design with two factors including irrigation at 4 levels (25, 50, 75, and 100 mm evaporation from pan class A, and plant density at 5 levels (cultivation in 30 cm rows with 5, 10, 15, 20 and 25 cm intra-row spaces with three replications. Definition of growth stages including the maximum number of nodes, sub stems and tillers were 21, 20 and 14 that were occurred at 970, 1088 and 1088 oC growth degree-days, respectively. The numbers of nodes were 28.6, 30.0, 30.2 and 27.8, of sub stem were 19.2, 18.4, 19.8 and 18.4; and of tillers were 14.8, 14.0, 15.0 and 14.4 that were obtained from irrigation at 25, 50, 75, and 100 mm evaporation from pan, respectively. In the other hand, the number of nodes as follow 28.25, 29.00, 29.75, 29.75 and 29.00; sub stem as 17.50, 20.00, 20.75, 19.00 and 17.50; and tillers were 15.00, 13.50, 14.75, 14.00 and 15.50 that were obtained from 5, 10, 15, 20 and 25 cm intra-row spacing, respectively. Differences by irrigation on GDDs values were observed at the second harvest. However the earliest observation of flower and seed receiving at the first harvest occurred on 5 cm intra-row spacing. These changes were identical by GDDs for second harvest of flower, but with mild slope of reduction. There were no differences in number of leaves and tillers among irrigation levels and plant densities.

  8. Effect of planting density and cutting frequency on forage and grain yields of kochia (Kochia scoparia under saline water irrigation

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    mseou ziyaeii

    2009-06-01

    Full Text Available AField experiment was conducted at Research Farms of Center of Excellence for Special Crops, Ferdowsi University of Mashhad, Mashhad, Iran, in 2006 to evaluate the effect of planting density on forage and grain yield of kochia (Kochia scoparia. Experimental design was a randomized complete block with split-plot arrangement of treatments,with three replications, where different planting densities (10, 20, 30 and 40 plant m-2 were assigned to main plots and number of cutting (including a single cutting, two cutting and no cutting i.e. allowing the crop to grow until maturity allocated to sub-plots. At each harvest date (cutting the biological yield, leaf and stem dry weight, plant height, number of branches and the individual plant biomass were measured. Grain yield and thousand seed weight were also determined at the end of growing season. Result showed the highest biological yield and leaf and stem dry weights for kochia obtaind at 30 plant m-2. The total biomass, leaf and stem dry weights, plant height, number of branches were greater for the first cutting as compared to the second cutting. Planting density and cutting number interacted to affect the leaf dry weight. At physiological maturity stage there were no significant differences among planting densities for plant height and number of branches. The best planting density, in terms of biomass production and leaf and stem dry weight, was found as 30 plant m-2, while for grain production a planting density of 20 plant m-2 could be recommended. Key words: Kochia, planting density, sward, biological yield, grain production.

  9. Effects of different irrigation methods and plant densities on silage quality parameters of PR 31Y43 hybrid corn cultivar (Zea mays L. var. indentata [Sturtev.] L.H. Bailey

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    Muhammet Karasahin

    2014-03-01

    Full Text Available The yield and quality of corn silage is related to genotype as well as factors such as climate, soil conditions, altitude, planting time, plant density, irrigation, and harvesting time. This study was conducted to determine the effects of different irrigation methods (drip, subsoil drip, and subsoil capillary and different plant densities (102 040, 119 040, and 142 850 plant ha-1 on silage quality parameters of PR 31Y43 hybrid corn (Zea mays L. var. indentata [Sturtev.] L.H. Bailey in 2011 and 2012 under ecological conditions in Eskipazar-Karabuk, Turkey. Plant densities were significantly different on fresh ear ratio and plant crude protein (CP yield in both years under study. The highest fresh ear ratio values were obtained with 102 040 and 119 040 plant ha-1 densities and the highest plant CP yield with 142 850 plant ha-1. While the irrigation method x plant density interactions were significant for silage CP ratio in the first year, they were significant on fresh ear ratio in the second year. The highest fresh ear ratio values were obtained from subsoil capillary x 119 040 plant ha-1 and drip x 119 040 plant ha-1 interactions; the highest plant and silage CP ratio values were obtained from subsoil capillary x 142 850 plant ha-1 and subsoil drip x 102 040 plant ha-1 interactions. As a result of the research, high Flieg scores were obtained from each irrigation method and plant density. When plant CP yield is taken into consideration, the 142 850 plant ha-1 density is more important.

  10. Water and radiation use efficiencies of transplanted rice (Oryza sativa L.) at different plant densities and irrigation regimes under semi-arid environment

    International Nuclear Information System (INIS)

    Ahmad, S.; Ali, H.; Shad, S.A.; Zia-ul-Haq, M.; Ahmad, A.; Maqsood, M.; Khan, M.B.; Mehmood, S.; Hussain, A.

    2008-01-01

    Growth and yield of rice (Oryza sativa L.), in response to plant densities and irrigation (optimum to stress) were analyzed in terms of interception and utilization of photo-synthetically active radiation (PAR) and water use efficiency (WUE). The amount of PAR intercepted and cumulative evapotranspiration (ET) by each treatment was estimated from the measured leaf area index. The relationships between total dry matter grain yield and accumulated intercepted PAR and cumulative ET were linear. Yield differences among the treatments were attributed to the amount of PAR intercepted and water transpired their efficiencies of utilization or both. The fraction of intercepted radiation and WUE was significantly affected by the plant densities and various irrigation regimes, while, radiation utilization efficiency (RUE) and water use efficiency (WUE) for TDM varied from 1.15 g MJ-1 to 1.36 g MJ-1 and 22.6 kg per ha mm-1 to 24.3 kg per ha mm-1 during both the seasons

  11. IRRIGATION OF ORNAMENTAL PLANT NURSERY

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    Eduardo de Aguiar do Couto

    2013-01-01

    Full Text Available Airports consume significant amounts of water which can be compared to the volume consumed by mid-size cities, thus practices aimed at reducing water consumption are important and necessar y. The objective of this study was to assess the reuse potential of sewage effluent produced at a mid-size international airport for nursery irri gation. The sewage treatment system consisted of a facultative pond followed by a constructed wetland, which were monitored during one hydrological year a nd the parameters COD, pH, solids, nitrogen, phosphorus and Escherichia coli we re analyzed. Removal efficiencies of 85% and 91% were achieved for C OD and solids, respectively. Removal efficiencies for ammonia nitrogen a nd total phosphorus were 77% and 59%, respectively. In terms of E. coli concen tration, the treated effluent met the recommendations by the World Health Organization for reuse in irrigation with the advantage of providing high levels of residual nutrient. The ornamental species Impatiens walleriana was irrigated with treated sewage effluent and plant growth characteristics were evalua ted. The experiment showed that reuse can enhance plant growth without signi ficantly affecting leaf tissue and soil characteristics. This study highlighted th e importance of simple technologies for sewage treatment especially in count ries which still do not present great investment in sanitation and proved that effluent reuse for landscape irrigation can provide great savings of water and financial resources for airport environments.

  12. Densidade do sistema radicular da bananeira 'Pacovan' sob irrigação por aspersão Root system density of 'Pacovan' banana plant under sprinkler irrigation

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    Raimundo Lacerda Filho

    2004-12-01

    Full Text Available O presente trabalho foi realizado no município de Governador Dix-Sept Rosado, microrregião Açu-Apodi, no Estado do Rio Grande do Norte, tendo como objetivo verificar os efeitos do sistema de irrigação por aspersão na densidade do sistema radicular da bananeira 'Pacovan'. O delineamento experimental utilizado foi o de blocos casualizados, em esquema de parcelas subdivididas, com cinco repetições. Os tratamentos foram duas amostragens por planta, realizadas do lado contrário ao da emissão da inflorescência, formando um ângulo de 45º. Em cada amostragem, foram realizadas quatro retiradas do material de solo a distâncias de 20 cm, sendo a primeira a 30 cm e a última a 90 cm do pseudocaule. A análise dos dados demonstrou que ocorreu redução linear no peso fresco e na densidade de comprimento de raízes da bananeira em função da profundidade do solo. Em relação à distância do pseudocaule da bananeira, tanto o peso fresco quanto a densidade de comprimento de raízes não mostraram resultados significativos.The present work was conducted at Governador Dix-Sept Rosado County, microregion Açu-Apodi, in the state of Rio Grande do Norte and its objective was to study the effects of sprinkler irrigation system on the density of the root system of 'Pacovan' banana plants. The experiment followed a completely randomized block design, in a split-plot scheme, with five replications. The treatments were two sampling groups, taken per plant, and in the opposite side of the inflorescence emission, forming between them an angle of 45°. In each sampling group, four samples containing soil material were collected at intervals of 20 cm, so the first was distant 30 cm and the last 90 cm from the pseudostem. Data analysis showed that occurred a linear reduction in root fresh weight and in lenght of roots density, in replications to soil depth. For the distance from the plant pseudostem there were no significant differences between samples, both

  13. Progresso da ferrugem do cafeeiro irrigado em diferentes densidades de plantio pós-poda Progress of rust in coffee plants in various densities of cultivation in irrigated planting after pruning

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    Bernardo Reis Teixeira Lacerda Paiva

    2011-02-01

    Full Text Available Objetivou-se, no presente trabalho, avaliar o efeito de diferentes critérios para manejo da irrigação em quatro densidades de plantio, sob sistema de gotejamento na incidência e severidade da ferrugem do cafeeiro e avaliar a influência do enfolhamento na curva de progresso dessa doença. Conduziu-se, o experimento, em área experimental da Universidade Federal de Lavras MG, utilizando a cultivar Rubi MG-1192 com seis anos. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os tratamentos foram constituídos por quatro parcelas representadas pelas densidades de plantio (convencionais e adensados: 2500 (4,0x1,0 m, 3333 (3,0x1,0 m, 5000 (2,0x1,0 m, 10000 (2,0x0,5 m plantas ha-1, quatro subparcelas sendo: irrigações quando a tensão da água no solo atingiu valores de 20 e 60kPa; irrigações utilizando o manejo do balanço hídrico (calculado através do software IRRIPLUS, com turnos de irrigação fixos de três dias por semana e uma testemunha sem irrigação, perfazendo um total de 16 tratamentos. Cada subparcela foi constituída por 10 plantas, sendo consideradas como plantas úteis as seis centrais. Foram avaliadas a incidência e severidade da ferrugem e a porcentagem de enfolhamento das plantas de cafeeiros. Após análise estatística, os dados foram convertidos em área abaixo da curva de progresso da doença e do crescimento. Verificou-se que os critérios para manejo da irrigação influenciaram a curva de progresso do crescimento, porém, não interferiu na curva de progresso da incidência e da severidade da ferrugem. Os sistemas de plantios adensados favoreceram a incidência da ferrugem. Mas as densidades de plantio não interferiram no enfolhamento.The objective of this study was to evaluate the effect of different irrigation controls implemented in four planting densities on a system of drip on the incidence and severity of rust and to assess the influence of leaf growth on the progress curve of this

  14. Response of Onion ( Allium cepa L.) to Irrigation Intervals and Plant ...

    African Journals Online (AJOL)

    08 at the Teaching and Research Farm of the College of Agriculture, Zuru, Kebbi State, Nigeria. The objective was to investigate the response of onion to irrigation interval and plant population density. The treatments consisted of factorial ...

  15. Effect of different irrigation systems on root growth of maize and cowpea plants in sandy soil

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    Noha A. Mahgoub

    2017-10-01

    Full Text Available A field experiment was conducted at the Experimental Farm, Faculty of Agriculture, Suez Canal University to study the influence of different irrigation systems on root length density and specific root length of maize and cowpea plants cultivated in sandy soil. Three irrigation systems (Surface, drip and sprinkler irrigation were used in this study. The NPK fertilizers were applied as recommended doses for maize and cowpea. Root samples were collected from the soil profile below one plant (maize and cowpea which was irrigated by the three irrigation systems by using an iron box (30 cm× 20 cm which is divided into 24 small boxes each box is (5× 5 × 5 cm. At surface irrigation, root length density of cowpea reached to soil depth 30-40cm with lateral distances 5-10 cm and 15-20 cm. Vertical distribution of root length density of maize was increased with soil depth till 20-25 cm, and then it decreased till soil depth 35-40cm. Under drip irrigation, root length density of cowpea increased horizontally from 0-5cm to 10-15cm then it decreased till soil depth 25-30 cm and below this depth root length density disappeared. For the root length density and specific root length of maize under drip irrigation, the data showed that root length density and specific root length decreased with increasing in soil depth. The root length density of cowpea under sprinkler irrigation at 0-5cm disappeared from horizontal distance at 25-30 cm. The data showed that root length density of maize under sprinkler irrigation was higher at the soil top layers 0-5 cm and 5-10 cm than other layers from 10-40 cm.

  16. Irrigation water sources and irrigation application methods used by U.S. plant nursery producers

    Science.gov (United States)

    Paudel, Krishna P.; Pandit, Mahesh; Hinson, Roger

    2016-02-01

    We examine irrigation water sources and irrigation methods used by U.S. nursery plant producers using nested multinomial fractional regression models. We use data collected from the National Nursery Survey (2009) to identify effects of different firm and sales characteristics on the fraction of water sources and irrigation methods used. We find that regions, sales of plants types, farm income, and farm age have significant roles in what water source is used. Given the fraction of alternative water sources used, results indicated that use of computer, annual sales, region, and the number of IPM practices adopted play an important role in the choice of irrigation method. Based on the findings from this study, government can provide subsidies to nursery producers in water deficit regions to adopt drip irrigation method or use recycled water or combination of both. Additionally, encouraging farmers to adopt IPM may enhance the use of drip irrigation and recycled water in nursery plant production.

  17. Resposta de híbridos de milho irrigado à densidade de plantas em três épocas de semeadura Response of irrigated corn hybrids to plant density in three sowing dates

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    Paulo Regis Ferreira da Silva

    1999-04-01

    Full Text Available A determinação da densidade ótima de semeadura do milho, além de ser influenciada pelas características dos híbridos, pelo nível de fertilidade do solo e pela disponibilidade hídrica, pode também variar de acordo com a época da semeadura, uma vez que ela afeta o crescimento e desenvolvimento da planta. Com o objetivo de determinar a densidade ótima de planta em híbridos de milho com elevado potencial de rendimento de grãos, em três épocas de semeadura, com relação a rendimento de grãos, componentes do rendimento e outras características agronômicas, foram feitos quatro experimentos na região fisiográfica da Depressão Central do Rio Grande do Sul, município de Eldorado do Sul, com suplementação hídrica por aspersão. Os tratamentos constaram de quatro híbridos (Pioneer 3063, Pioneer 3207, XL 212 e Cargill 901, quatro densidades de plantas (50, 70, 90 e 110.000 pl/ha e de três épocas de semeadura (agosto, outubro e dezembro. Não há resposta à densidade de plantas dos híbridos de milho testados nas épocas de semeadura de agosto e dezembro. O aumento na densidade de plantas somente foi vantajosa na semeadura de outubro, quando se obtiveram maiores rendimentos de grãos na densidade de 70.000 pl/ha, independentemente do híbrido avaliado, nas duas estações de crescimento.Plant density response of corn besides influenced by hybrids traits, soil fertility level and water availability, could also vary with sowing date, since it affects plant growth and development. With the objective of determining the most adequate plant density of corn hybrids with high potential grain yields, in three sowing dates, in relation to grain yields, yield components and other agronomic traits, four experiments were conducted in the state of Rio Grande do Sul, Brazil, with complementary irrigation. The treatments were composed by four hybrids (Pioneer 3063, Pioneer 3207, XL 212 and Cargill 901, four plant densities (50, 70, 90 and 110

  18. Plasticity in stomatal size and density of potato leaves under different irrigation and phosphorus regimes

    DEFF Research Database (Denmark)

    Sun, Yanqi; Yan, Fei; Cui, Xiaoyong

    2014-01-01

    The morphological features of stomata including their size and density could be modulated by environmental cues; however, the underlying mechanisms remain largely elusive. Here, the effect of different irrigation and phosphorus (P) regimes on stomatal size (SS) and stomatal density (SD) of potato...... potentially enhance water-use efficiency as exemplified by the lowered leaf δ13C under fluctuating soil moisture conditions....... leaves was investigated. The plants were grown in split-root pots under two P fertilization rates (viz., 0 and 100mgkg-1 soil, denoted as P0 and P1, respectively) and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation regimes. Results showed that SS and SD were...... unresponsive to P but significantly affected by the irrigation treatment. FI plants had the largest SS, followed by DI, and PRD the smallest; and the reverse was the case for SD. Compared to FI and DI, PRD plants had significantly lower values of specific leaf area (SLA) and leaf carbon isotope discrimination...

  19. APPLICATION OF DRIP IRRIGATION ON COTTON PLANT GROWTH (Gossypium sp.

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    Syahruni Thamrin

    2017-12-01

    Full Text Available The condition of cotton planting in South Sulawesi is always constrained in the fulfillment of water. All plant growth stages are not optimal to increase production, so it is necessary to introduce good water management technology, such as through water supply with drip irrigation system. This study aims to analyze the strategy of irrigation management in cotton plants using drip irrigation system. Model of application by designing drip irrigation system and cotton planting on land prepared as demonstration plot. Observations were made in the germination phase and the vegetative phase of the early plants. Based on the result of drip irrigation design, the emitter droplet rate (EDR was 34.266 mm/hour with an operational time of 4.08 min/day. From the observation of cotton growth, it is known that germination time lasted from 6 to 13 days after planting, the average plant height reached 119.66 cm, with the number of leaves averaging 141.93 pieces and the number of bolls averaging 57.16 boll.

  20. Plasticity in stomatal size and density of potato leaves under different irrigation and phosphorus regimes.

    Science.gov (United States)

    Sun, Yanqi; Yan, Fei; Cui, Xiaoyong; Liu, Fulai

    2014-09-01

    The morphological features of stomata including their size and density could be modulated by environmental cues; however, the underlying mechanisms remain largely elusive. Here, the effect of different irrigation and phosphorus (P) regimes on stomatal size (SS) and stomatal density (SD) of potato leaves was investigated. The plants were grown in split-root pots under two P fertilization rates (viz., 0 and 100mgkg(-1) soil, denoted as P0 and P1, respectively) and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation regimes. Results showed that SS and SD were unresponsive to P but significantly affected by the irrigation treatment. FI plants had the largest SS, followed by DI, and PRD the smallest; and the reverse was the case for SD. Compared to FI and DI, PRD plants had significantly lower values of specific leaf area (SLA) and leaf carbon isotope discrimination (Δ(13)C) under P0. Midday leaf water potential (Ψleaf) and stomatal conductance (gs) was similar for DI and PRD, which was significantly lower than that of FI. Leaf contents of C, N, K, Ca and Mg were higher in PRD than in DI plants, particularly under P0. When analyzed across the three irrigation regimes, it was found that the P1 plants had significantly higher leaf contents of P and Mg, but significantly lower leaf K content compared to the P0 plants. Linear correlation analyses revealed that SS was positively correlated with Ψleaf and Δ(13)C; whereas SD was negatively correlated with Ψleaf, Δ(13)C and SLA, and positively correlated with leaf C, N and Ca contents. And gs was positively correlated with SS but negatively correlated with SD. Collectively, under low P level, the smaller and denser stomata in PRD plants may bring about a more efficient stomatal control over gas exchange, hereby potentially enhance water-use efficiency as exemplified by the lowered leaf Δ(13)C under fluctuating soil moisture conditions. Copyright © 2014 Elsevier GmbH. All rights reserved.

  1. Uptake of antibiotics from irrigation water by plants

    DEFF Research Database (Denmark)

    Azanu, David; Mortey, Christiana; Darko, Godfred

    2016-01-01

    The capacity of carrot (Daucus corota L.) and lettuce (Lactuca sativa L.), two plants that are usually eaten raw, to uptake tetracycline and amoxicillin (two commonly used antibiotics) from irrigated water was investigated in order to assess the indirect human exposure to antibiotics through...... tested concentrations of 0.1-15 mg L(-1). Tetracycline was detected in all plant samples, at concentrations ranging from 4.4 to 28.3 ng/g in lettuce and 12.0-36.8 ng g(-1) fresh weight in carrots. Amoxicillin showed absorption with concentrations ranging from 13.7 ng g(-1) to 45.2 ng g(-1) for the plant...

  2. Use of plant woody species electrical potential for irrigation scheduling.

    Science.gov (United States)

    Ríos-Rojas, Liliana; Morales-Moraga, David; Alcalde, José A; Gurovich, Luis A

    2015-01-01

    The electrical response of plants to environmental stimuli can be measured and quantitatively related to the intensity of several stimulating sources, like temperature, solar radiation, soil water content, evapotranspiration rates, sap flow and dendrometric cycles. These relations can be used to assess the influence of different environmental situations on soil water availability to plants, defined as a steady state condition between leaf transpirative flow and soil water flow to plant roots. A restricted soil water flow due to soil dryness can trigger water stress in plants, if the atmospheric evaporative demand is high, causing partial stomata closure as a physiological response to avoid plant dehydration; water stressed and unstressed plants manifest a differential electrical response. Real time plant electrical response measurements can anticipate actions that prevent the plant reaching actual stress conditions, optimizing stomata gas exchange and photosynthetic rates. An electrophysiological sensor developed in this work, allows remote real-time recording information on plant electrical potential (EP) in the field, which is highly related to EP measurements obtained with a laboratory Keithley voltmeter sensor used in an highly controlled experimental setup. Our electrophysiological sensor is a wireless, autonomous devise, which transmits EP information via Internet to a data server. Using both types of sensors (EP electrodes with a Keithley voltmeter and the electrophysiological sensor), we measured in real time the electrical responses of Persea americana and Prunus domestica plants, to induced water deficits. The differential response for 2 scenarios: irrigation and water restriction is identified by a progressive change in slope on the daily maximal and minimal electric signal values in stressed plants, and a zero-slope for similar signals for well-watered plants. Results show a correspondence between measured signals obtained by our electrophysiological

  3. Comparative effects of partial root-zone irrigation and deficit irrigation on phosphorus uptake in tomato plants

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Jensen, Christian Richardt

    2012-01-01

    The comparative effects of partial root-zone irrigation (PRI) and deficit irrigation (DI) on phosphorus (P) uptake in tomato (Lycopersicon esculentum Mill.) plants were investigated in a split-root pot experiment. The results showed that PRI treatment improved water-use efficiency (WUE) compared...... to the DI treatment. PRI-treated plants accumulated significantly higher amounts of P in their shoots than DI plants under organic maize straw N fertilisation, whereas similar levels of shoot P accumulation were observed under mineral N fertilisation. Thus, the form of N fertiliser, and thereby...... the different plant N status, affected the accumulation of P in shoots, as reflected by a higher plant N:P ratio following mineral N fertilisation than after organic N fertilisation. Compared to the DI treatment, PRI significantly increased both the physiological and agronomic efficiencies of P-use under...

  4. Advanced techniques using the plant as indicator of irrigation management

    Directory of Open Access Journals (Sweden)

    Barbara dos Santos Esteves

    2015-05-01

    Full Text Available The methodologies which are considered the most promising for irrigation management are those based on the analysis of the water status of the plants themselves. This justifies the study and improvement of indicators based on automatic and continuous measures to enable real-time monitoring data, as indices from sap flow, dendrometry and leaf turgor pressure techniques. The aim of this paper is to analyze such methodologies in order to demonstrate their principles, advantages and challenges. In conclusion, the methodologies analyzed still have many technological advances and challenges before being presented to the final user. The future research should work these tools for elaboration of technical indexes that allow their simplification, on the instrumental point of view, and the interpretation of their results.

  5. Effect of Different Irrigation and Planting Methods on Water Productivity and Health of Commercial Varieties of Potato

    Directory of Open Access Journals (Sweden)

    H. R Salemi

    2016-07-01

    Full Text Available Introduction Water crisis as a main factor of agronomy limitation exists in all over the arid and semiarid regions such as Isfahan, province which is located in the central part of the Zayandehrud River Basin (ZRB. Due to the increase in the cultivated area of potato in Fareidan Region located in the west of Isfahan province, it will be necessary to use pressurized irrigation systems to achieve the highest irrigation application efficiency and water productivity. Materials and Methods The ZRB (41,500 km2 is a closed basin with no outlet to the sea. The research was conducted in the Fareidan region of Isfahan, which is located in the west part of the ZRB. The Rozveh Agricultural Research Station (32°, 58' N, 50°, 25' E is located at the altitude of 2390 m above the sea level. This study was conducted as a randomized complete blocks design as a split strip plot layout with three replications and during two years (2007-2008. Three irrigation systems (Drip tape, Sprinkler and furrow were considered as main plots, two planting methods (one - row planting and two-row planting as split subplots and two potato cultivars (Marfuna and Agria as split-split subplots. Production (Tuber-yield, the consumption water and cultivars reactions to common diseases were evaluated in different treatments. The soil of the experimental area, according to USDA Soil Taxonomy 1994 is of silty loamy. At the soil depth of 1m, soil salinity (1.1-2.0 dS m-1, water salinity (1.24 dS m-1, soil moisture at field capacity (23 Vol. %, and bulk density (BD = 1.44 g/cm3 at the field site were measured or experimentally obtained in the Isfahan Soil and Water Laboratory. The results were subjected to an ANOVA to analyze the effects of the treatments and their interactions. The data obtained were analyzed using the compound variance analysis and the averages of different treatments were separated using the Duncan multiple range test using the statistical software (SAS Institute, Inc

  6. Performance evaluation of drip-fertigated cotton grown under different plant densities using nuclear techniques

    International Nuclear Information System (INIS)

    Janat, M.; Kalhout, A.

    2007-04-01

    Field experiment was conducted over two growing seasons to assess different planting densities of cotton variety Aleppo 118 (71.000, 57.000, 48.000, 41.000, 33.500 plants /ha), and two irrigation systems; one irrigation line per one planting row and one irrigation line per two planting rows. Nitrogen fertilizer (120 kg N/ha) as Urea (46% N) was injected through the irrigation system in six equally split applications. A labeled area (1.0 m 2 ) was established for the labeled sub plots and labeled Urea was applied to the labeled sub plots in the same manner as for unlabeled N fertilizer. Irrigation scheduling was accomplished using the direct method of neutron scattering technique. Irrigation was determined when the soil moisture content in the active root depth reached almost 80% of the field capacity. The amount of water applied for one line / one row were 6738 and 9149 m 3 /ha, whereas, for one line/two rows were 7489 and 12653 m 3 / ha for the two growing seasons 2004 and 2005 respectively. The objectives of the experiment were to evaluate the effect of different planting densities and two irrigation system on cotton yield, lint properties, dry matter yield, N-uptake, chlorophyll content and leaf area. The experimental design was randomized block design with 6 replications for each irrigation method. Results revealed that no significant differences between all different plant densities were recorded for all growth parameters tested in this study such as seed cotton yield, dry matter yield, lint properties, chlorophyll content and leaf area.(author)

  7. White mold intensity on common bean in response to plant density, irrigation frequency, grass mulching, Trichoderma spp., and fungicide Intensidade do mofobranco em feijão em função de densidade de plantas, freqüência de irrigação, cobertura vegetal do solo, Trichoderma spp. e fungicida

    Directory of Open Access Journals (Sweden)

    Trazilbo José de Paula Júnior

    2009-02-01

    Full Text Available The purpose of this study was to evaluate the efficiency of integrated managements on white mold control on common bean. Initially, in vitro testing was made to assess the antagonism of 11 Trichoderma isolates against Sclerotinia sclerotiorum and to investigate fungicides (fluazinam and procymidone inhibitory effects on those fungi. In two field experiments the following combinations were tested: irrigation frequencies (seven or 14 days, plant densities (six or 12 plants per meter, and three disease controls (untreated control, fungicide or Trichoderma spp.. In a third experiment plant densities were replaced by grass mulching treatments (with or without mulching. Fluazinam was applied at 45 and 55 days after emergence (DAE. The antagonists T. harzianum (experiments 1 and 3 and T. stromatica (experiment 2 were applied through sprinkler irrigation at 10 and 25 DAE, respectively. Most of the Trichoderma spp. were effective against the pathogen in vitro. Fluazinam was more toxic than procymidone to both the pathogen and the antagonist. Fungicide applications increased yield between 32 % and 41 %. In field one application of Trichoderma spp. did not reduce disease intensity and did not increase yield. The reduction from 12 to six plants per meter did not decrease yield, and disease severity diminished in one of the two experiments. It is concluded that of the strategies for white mold control just reduction of plant density and applications of fungicide were efficient.Objetivou-se estudar a eficácia de técnicas de manejo integrado no controle do mofo-branco em feijão. Inicialmente, foram feitos testes in vitro para avaliar o antagonismo de 11 isolados de Trichoderma contra Sclerotinia sclerotiorum e investigar os efeitos de fungicidas (fluazinam e procymidone sobre esses fungos. Em dois ensaios de campo, foram testadas estas combinações: freqüências de irrigação (sete ou 14 dias, densidades de plantas (seis ou 12 por metro e três controles

  8. Comparative effects of partial rootzone drying and deficit irrigation on growth and physiology of tomato plants

    Directory of Open Access Journals (Sweden)

    Savić Slađana

    2009-01-01

    Full Text Available The effects of partial rootzone drying (PRD, deficit irrigation (DI, and full irrigation (FI on tomato physiology were investigated. In PRD and DI plants, leaf water potential values and stomatal conductance were significantly lower, while xylem ABA concentration was greater compared to FI plants. Photosynthesis was similar for all treatments. Water use efficiency was improved by PRD and DI, which reduced fruit dry weight, but had no effect on dry weight of leaves and stems.

  9. Optimization of planting pattern plan in Logung irrigation area using linear program

    Science.gov (United States)

    Wardoyo, Wasis; Setyono

    2018-03-01

    Logung irrigation area is located in Kudus Regency, Central Java Province, Indonesia. Irrigation area with 2810 Ha of extent is getting water supply from Logung dam. Yet, the utilization of water at Logung dam is not optimal and the distribution of water is still not evenly distributed. Therefore, this study will discuss about the optimization of irrigation water utilization based on the beginning of plant season. This optimization begins with the analysis of hydrology, climatology and river discharge in order to determine the irrigation water needs. After determining irrigation water needs, six alternatives of planting patterns with the different early planting periods, i.e. 1st November, 2nd November, 3rd November, 1st December, 2nd December, and 3rd December with the planting pattern of rice-secondary crop-sugarcane is introduced. It is continued by the analysis of water distribution conducted using linear program assisted by POM-Quantity method for Windows 3 with the reliable discharge limit and the available land area. Output of this calculation are to determine the land area that can be planted based on the type of plant and growing season, and to obtaine the profits of harvest yields. Based on the optimum area of each plant species with 6 alternatives, the most optimum area was obtained at the early planting periods on 3rd December with the production profit of Rp 113.397.338.854,- with the planting pattern of rice / beans / sugarcane-rice / beans / sugarcane-beans / sugarcane.

  10. Evaluation of Irrigation Methods for Highbush Blueberry. I. Growth and Water Requirements of Young Plants

    Science.gov (United States)

    A study was conducted in a new field of northern highbush blueberry (Vaccinium corymbosum L. 'Elliott') to determine the effects of different irrigation methods on growth and water requirements of uncropped plants during the first 2 years after planting. The plants were grown on mulched, raised beds...

  11. Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent.

    Science.gov (United States)

    Barros, Kenia Kelly; do Nascimento, Clístenes Williams Araújo; Florencio, Lourdinha

    2012-01-01

    Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m(3) each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO(3)(-) found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.

  12. Nitrogen dynamics in the soil-plant system under deficit and partial root-zone drying irrigation strategies in potatoes

    DEFF Research Database (Denmark)

    Shahnazari, Ali; Ahmadi, Seyed Hamid; Lærke, Poul Erik

    2008-01-01

    Experiments were conducted in lysimeters with sandy soil under an automatic rain-out shelter to study the effects of subsurface drip irrigation treatments, full irrigation (FI), deficit irrigation (DI) and partial root-zone drying (PRD), on nitrogen (N) dynamics in the soil-plant system of potatoes...

  13. Dynamic plant uptake model applied for drip irrigation of an insecticide to pepper fruit plants

    DEFF Research Database (Denmark)

    Legind, Charlotte Nielsen; Kennedy, C. M.; Rein, Arno

    2011-01-01

    irrigation, its application for a soil-applied insecticide and a sensitivity analysis of the model parameters. RESULTS: The model predicted the measured increase and decline of residues following two soil applications of an insecticide to peppers, with an absolute error between model and measurement ranging...... from 0.002 to 0.034 mg kg fw—1. Maximum measured concentrations in pepper fruit were approximately 0.22 mg kg fw—1. Temperature was the most sensitive component for predicting the peak and final concentration in pepper fruit, through its influence on soil and plant degradation rates...

  14. Response of Silybum marianum plant to irrigation intervals combined with fertilization

    Directory of Open Access Journals (Sweden)

    SABER F. HENDAWY

    2013-05-01

    Full Text Available Hendawy SF, Hussein MS, Youssef AA, El-Mergawi RA. 2013. Response of Silybum marianum plant to irrigation intervals combined with fertilization. Nusantara Bioscience 5: 21-28. This study was investigated to evaluate the influence of different kinds of organic and bio fertilization under different irrigation intervals on the growth, production and chemical constituents of Sylibium marianum plant. Data indicated that all studied growth and yield characters were significantly affected by the duration of irrigation intervals. Fertilizer treatments had a primitive effect on growth and yield characters. The interaction between irrigation intervals and fertilizer treatments has a clear considerable effect on growth and yield characters. The obtained results indicated the favorable effect of organic and bio fertilizers which reduce the harmful effect of water stress. Different treatments had a pronounced effect on silymarin content.

  15. Rendimento da pupunheira em função da densidade de plantio, diâmetro de corte e manejo dos perfilhos no Vale do São Francisco Effect of density, cut-off diameter classes and shoot number on production and yield of irrigated plant peach palm at San Francisco River Valley

    Directory of Open Access Journals (Sweden)

    José Egidio Flori

    2004-02-01

    Full Text Available Com o objetivo de avaliar o rendimento de palmito de pupunheira irrigada em função da densidade de plantio, diâmetro de corte do estipe e o manejo dos perfilhos, instalou-se um experimento na Estação Experimental de Bebedouro da Embrapa Semi-Árido, Petrolina, PE. O delineamento utilizado foi de blocos ao acaso em parcelas subdivididas, sendo as parcelas constituídas por dois espaçamentos (2,0 x 1,0 m - E1 e 2,0 x 2,0 m - E2 e as subparcelas em arranjo fatorial 2 x 2, compreendendo dois manejos de perfilhos e duas classes de diâmetros de corte. As colheitas foram feitas a partir de 16 meses até os 69 meses após o plantio e realizadas com intervalos consecutivos de mais ou menos três meses. Pelos resultados, evidenciaram-se efeitos significativos para espaçamento, manejo de perfilhos e classe de diâmetro de corte. Não foram constatadas interações entre os tratamentos. Houve efeito significativo de espaçamento sobre o rendimento, diâmetro de corte, comprimento e peso médio do palmito. O rendimento e o peso do palmito da pupunheira foram de 545 e 434 kg ha-1 ano-1 e 147 g e 180 g nos espaçamentos E1 e E2, respectivamente. O diâmetro de corte afetou a altura da planta e peso médio do palmito. O manejo de perfilho afetou o rendimento e o peso médio do palmito, com 532 e 446 kg ha-1 e 177 e 149 g de palmito, respectivamente, no manejo de quatro e todos os perfilhos por planta. Pelos resultados, infere-se, como orientação técnica para os produtores de áreas irrigadas do Submédio São Francisco, o cultivo da pupunha no espaçamento de 2 m x 1 m, o manejo de quatro perfilhos por planta e o corte da planta com diâmetro variando de 10 a 12 cm, a 30 cm do nível do solo.The objective of this experiment was to evaluate the effect of planting density, cut-off diameter classes and shoot number on heart of palm production on irrigated peach palm. The experimental layout was a randomized split-plot design with a factorial arrangement

  16. Improved methods for irrigation and planting of major crops in waterlogged areas

    International Nuclear Information System (INIS)

    Kahlown, M.A.; Iqbal, M.; Raoof, A.

    2002-01-01

    The improved irrigation methods for wheat and cotton were evaluated in the fordwah Eastern Sadigia (South) Irrigation and Drainage Project area, during 1996-97 and 1997-98 cropping seasons, under three water table depths. Irrigation methods for wheat included 70, 95 and 120 cm Beds, with Flat Basin, as a check for comparative evaluation. Cotton had Ridge-planting on the top and side, Bed and Furrow, and Flat Basin as control. These irrigation methods were compared at water table depths of < 1 m, 1-2 and 2-3 m. The wheat variety inqalab-91, and cotton cultivar, CIM-109, were planted during the 3rd week of November and May every year. All the inputs and management practices, such as seed-rate, fertilizer, seeding method, weed control, plant-protection measures, etc. were kept common. The results on cotton indicated maximum water-use efficiency with the Bed and Furrow Method of irrigation Followed by ridge planting. The traditional Flat-planting had the lowest yield and the highest water-consumption, resulting in the minimum water-use efficiency. In harmony with cotton, the Flat Method of planting had maximum water-consumption. For wheat crop, the water-use efficiency was in descending order, with 120, 95 and 70 cm for Bed and Flat Methods. Bed planting of 95 cm had a fairly high water-use efficiency and yields were more were more comparable than Flat planting. This method had a high level of adaptabilities, especially when the groundwater was close to the root-zone and higher possibilities, especially when the groundwater was close to the root-zone and higher possibility of crop-submergence are existent during rainy spells. The results of the investigation strongly favoured the Bed and furrow methods to irrigate cotton and wheat. However, under well-drained soil conditions, Bed planting of wheat is not recommended. (author)

  17. Spatial Variation of Arsenic in Soil, Irrigation Water, and Plant Parts: A Microlevel Study

    OpenAIRE

    Kabir, M. S.; Salam, M. A.; Paul, D. N. R.; Hossain, M. I.; Rahman, N. M. F.; Aziz, Abdullah; Latif, M. A.

    2016-01-01

    Arsenic pollution became a great problem in the recent past in different countries including Bangladesh. The microlevel studies were conducted to see the spatial variation of arsenic in soils and plant parts contaminated through ground water irrigation. The study was performed in shallow tube well command areas in Sadar Upazila (subdistrict), Faridpur, Bangladesh, where both soil and irrigation water arsenic are high. Semivariogram models were computed to determine the spatial dependency of s...

  18. Effects of planting density and drought on the productivity of tea clones ( Camellia sinensis L.): Yield responses

    Science.gov (United States)

    Kigalu, Julius M.

    Tea is an important cash crop in Tanzania, contributing over US$ 45 million of annual exports and grown by over 30 000 smallholder households, and a further 10 000 people are employed by large estate producers. Over 70% of the national tea production comes from the Southern Highlands of Tanzania where expansion of tea estates under limited suitable land for tea is expected for the next two decades. Thus a client-demand driven field experiment was established in January 1993 to study and advice tea growers on the effects of plant density on the productivity and water use of young tea. The experiment comprised of two types of vegetative propagated tea plants (known as “clones”) of contrasting growth behaviour (AHP S15/10: spreading type and BBK35: erect), six plant densities (labelled D1: 8300 plants ha -1 to D6: 83 300 plants ha -1) and seven irrigation or drought levels (labelled I0: un irrigated, to I6: well irrigated condition) as the treatments. Clone AHP S15/10, with larger crop cover than clone BBK35, consistently out-yielded clone BBK35 at all densities and under both well watered and drought stressed conditions. The corresponding yields from clone BBK35 were 2620 and 5960 kg ha -1. Reciprocal of yield per plant- and asymptotic yield-density relationships were used to explain these responses to density. Yields from clone AHP S15/10 during the period of drought treatments decreased as the maximum soil water deficit increased at all densities, but there were no yield responses to drought from clone BBK35 at the low densities. The study recommends planting densities of 20 000 and 40 000 plants ha -1 for clones AHP S15/10, respectively for well irrigated conditions and a density of 20 000 plants ha -1 for both clones under un-irrigated environments.

  19. Carbon retention in the soil–plant system under different irrigation regimes

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Andersen, Mathias Neumann

    2010-01-01

    their environmental impacts. Tomato plants (Lycopersicon esculentum L., var. Cedrico) were grown in split-root pots in a climate-controlled glasshouse and were subjected to full irrigation (FI), deficit irrigation (DI) and alternate partial root-zone irrigation (PRI) at early fruiting stage. In Exp. I, each plant...... to a greater microbial activity in the two treatments; particularly the PRI induced drying and wetting cycles of the soils may cause an increase of microbial activities and respiration rate, which could lead to more C losses from the soil. However, in both experiments the total C concentration in the PRI...... in the two experiments might have affected the C retention in the soil and in the plant biomass. Nevertheless, with a same degree of water saving, PRI was superior to DI in terms of enhancing C concentration in the plant biomass, which might have contributed to a better fruit quality in tomatoes as reported...

  20. Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

    International Nuclear Information System (INIS)

    Dahal, B.M.; Fuerhacker, M.; Mentler, A.; Karki, K.B.; Shrestha, R.R.; Blum, W.E.H.

    2008-01-01

    This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from -1 where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg -1 . The arsenic content in different parts of plants are found in the order of roots > shoots > leaves > edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg -1 ) > onion bulb (0.45 mg As kg -1 ) > cauliflower (0.33 mg As kg -1 ) > rice (0.18 mg As kg -1 ) > brinjal (0.09 mg As kg -1 ) > potato ( -1 ). - The arsenic content in soil and plants is influenced by the degree of arsenic amount in irrigated water

  1. Effect of Subsurface Irrigation with Porous Clay Capsules on Quantitative and Quality of Grape Plant

    Directory of Open Access Journals (Sweden)

    H. Ghorbani Vaghei

    2016-02-01

    Full Text Available Introduction: Maintaining soil moisture content at about field capacity and reducing water loss in near root zone plays a key role for developing soil and water management programs. Clay pot or porous pipe is a traditional sub-irrigation method and is ideal for many farms in the world’s dry land with small and medium sized farms and gardens and is still used limitedly in dry lands of India, Iran, Pakistan, the Middle East, and Latin-America. Clay capsule is one of porous pipes in sub irrigation that is able to release water in near root zone with self- regulative capacity. Watering occurs only in amounts that the plants actually need (this amount is equal to field capacity and released water in near root zone without electricity or use of an automatic dispenser. Materials and Methods: A study was carried out in 2013 on the experimental field of agriculture faculty of Tarbiat Modares University, to study the effect of two irrigation types on qualitative and quantitative characters in grape production (Vitis vinifera L.. In order to provide the water requirement of grape plant were used porous clay capsules for sub irrigation with height and diameter of 12 cm and 3.5 cm and dripper with Neta film type for drip irrigation, respectively. Porous clay capsules provided from soil science group at Tarbiat Modares University. In this research, the volume of water delivered to grape plants during entire growth period in two different irrigation methods was measured separately with water-meters installed at all laterals. The water consumption, yield production and water use efficiency were evaluated and compared in two drip and porous clay irrigation systems at veraison phonological stages. In the veraison stages, cluster weight, cluster length, solid solution and pH content were measured in grape fruits. Leaf chlorophyll content and leaf water content were also measured in two irrigation systems. Results and Discussion: The results of fruit quality

  2. Techno-Economic Evaluation of Solar Irrigation Plants Installed in Bangladesh

    Directory of Open Access Journals (Sweden)

    Najmul Hoque

    2016-02-01

    Full Text Available In the summer season, irrigation sector in Bangladesh suffers a lot due to the country wide electricity crisis. Solar pump offers a clean and simple alternative to the conventional fuel fired engine or grid electricity driven pump in this regard to resolve the issue. In this paper, the techno-economic analyses of solar irrigation plants installed in Bangladesh are evaluated.  It was observed that systems were running around 70% to 80% of the rated power which was quite acceptable. A 10 hp pump was able to pump 600 liter of water per minute which was also satisfactory to irrigate the land. Average operating time was found to be 8 hour/day. It was found that the overall efficiency of the systems were in between 11.39% to 16.52% whereas the typical average value of lit/Wp/year was 9200. On the other hand, the cost of irrigation to cultivate paddy in 0.161 hectares’ land for one season was 1,750 BDT by solar irrigation which was found to be lower than that of other available modes. This charge for grid electricity based irrigation was about 3,000 to 3500 BDT per 0.161 hectares’ and 2,300 to 2,600 BDT per 0.161 hectares’ for diesel engine based irrigation. According to the current financial scheme (15% equity investment, 35% credit support and remaining 50% from government through IDCOL the average value of payback period was 5.43 years, NPV in the range from 7 to 15% and IRR was 18%. By considering 100% equity investment, however, these projects were not economically attractive. The payback period for this case was about 18 years. Study also revealed that each solar irrigation plant reduces 42.8 kg of CO2 emission per day compare to diesel engine operated pump and 2566.24 kg/day compared to grid electricity operated pump. A comprehensive effort from the Government as well as from all the stakeholders is required for further expansion of solar irrigation plants in Bangladesh. Article History: Received Sept 05, 2015; Received in revised form

  3. Phytotoxicity data safeguard the performance of the recipient plants in leachate irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, C.Y. [Department of Biology, Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Chu, L.M. [Department of Biology, Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China)]. E-mail: leemanchu@cuhk.edu.hk

    2007-01-15

    Leachates from an operating and a closed landfill were examined for their phytotoxicity by seed germination/root elongation tests using seeds of Brassica chinensis and Lolium perenne. Their EC50s ranged from 3% to 46% v/v, which varied remarkably with the operating status of the landfills. Seedlings of twelve tree species were grown in pots, which were irrigated with landfill leachate at the EC50 levels, with tap water as control. No tree mortality or growth inhibition was observed after 90 days of leachate application. Chlorophyll fluorescence measurement also showed that plants receiving leachate did not suffer from a decline in photosynthetic efficiency. Litsea glutinosa and Hibiscus tiliaceus had remarkable growth, and other non-N-fixers were not inferior to the N-fixing Acacia auriculiformis. Leachate irrigation improved soil N content, though P deficiency is still a problem. The seed bioassay provided a conservative estimate of the phytotoxicity of landfill leachate. Plants irrigated can be protected from growth inhibition when the leachate irrigation plan is designed with reference to phytotoxicity data. - Irrigated plants could be benefited by leachate when the application rate was determined according to phytotoxicity data.

  4. Phytotoxicity data safeguard the performance of the recipient plants in leachate irrigation

    International Nuclear Information System (INIS)

    Cheng, C.Y.; Chu, L.M.

    2007-01-01

    Leachates from an operating and a closed landfill were examined for their phytotoxicity by seed germination/root elongation tests using seeds of Brassica chinensis and Lolium perenne. Their EC50s ranged from 3% to 46% v/v, which varied remarkably with the operating status of the landfills. Seedlings of twelve tree species were grown in pots, which were irrigated with landfill leachate at the EC50 levels, with tap water as control. No tree mortality or growth inhibition was observed after 90 days of leachate application. Chlorophyll fluorescence measurement also showed that plants receiving leachate did not suffer from a decline in photosynthetic efficiency. Litsea glutinosa and Hibiscus tiliaceus had remarkable growth, and other non-N-fixers were not inferior to the N-fixing Acacia auriculiformis. Leachate irrigation improved soil N content, though P deficiency is still a problem. The seed bioassay provided a conservative estimate of the phytotoxicity of landfill leachate. Plants irrigated can be protected from growth inhibition when the leachate irrigation plan is designed with reference to phytotoxicity data. - Irrigated plants could be benefited by leachate when the application rate was determined according to phytotoxicity data

  5. Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis

    Science.gov (United States)

    Borzini, Letizia; Condò, Roberta; De Dominicis, Paolo; Casaglia, Adriano; Cerroni, Loredana

    2016-01-01

    Background: There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues. Objectives: To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis. Method: Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were “endodontic irrigants” and “Enterococcus faecalis” and “essential oil” and “plant extracts”. Results: Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro. Conclusion: Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space. PMID:28217184

  6. Dynamic plant uptake model applied for drip irrigation of an insecticide to pepper fruit plants.

    Science.gov (United States)

    Legind, Charlotte N; Kennedy, Coleen M; Rein, Arno; Snyder, Nathan; Trapp, Stefan

    2011-05-01

    Drip application of insecticides is an effective way to deliver the chemical to the plant that avoids off-site movement via spray drift and minimizes applicator exposure. The aim of this paper is to present a cascade model for the uptake of pesticide into plants following drip irrigation, its application for a soil-applied insecticide and a sensitivity analysis of the model parameters. The model predicted the measured increase and decline of residues following two soil applications of an insecticide to peppers, with an absolute error between model and measurement ranging from 0.002 to 0.034 mg kg fw(-1). Maximum measured concentrations in pepper fruit were approximately 0.22 mg kg fw(-1). Temperature was the most sensitive component for predicting the peak and final concentration in pepper fruit, through its influence on soil and plant degradation rates. Repeated simulations of pulse inputs with the cascade model adequately describe soil pesticide applications to an actual cropped system and reasonably mimic it. The model has the potential to be used for the optimization of practical features, such as application rates and waiting times between applications and before harvest, through the integrated accounting of soil, plant and environmental influences. Copyright © 2011 Society of Chemical Industry.

  7. Characterising root density of peach trees in a semi-arid Chernozem to increase plant density

    Science.gov (United States)

    Paltineanu, Cristian; Septar, Leinar; Gavat, Corina; Chitu, Emil; Oprita, Alexandru; Moale, Cristina; Calciu, Irina; Vizitiu, Olga; Lamureanu, Gheorghe

    2016-01-01

    The available information on root system in fully mature peach orchards in semi-arid regions is insufficient. This paper presents a study on the root system density in an irrigated peach orchard from Dobrogea, Romania, using the trench technique. The old orchard has clean cultivation in inter-row and in-row. The objectives of the study were to: test the hypothesis that the roots of fully mature peach trees occupy the whole soil volume; find out if root repulsive effect of adjacent plants occurred for the rootstocks and soil conditions; find relationships between root system and soil properties and analyse soil state trend. Some soil physical properties were significantly deteriorated in inter-row versus in-row, mainly due to soil compaction induced by technological traffic. Density of total roots was higher in-row than inter-row, but the differences were not significant. Root density decreased more intensely with soil depth than with distance from tree trunks. Root density correlated with some soil properties. No repulsive effect of the roots of adjacent peach trees was noted. The decrease of root density with distance from trunk can be used in optimising tree arrangement. The conclusions could also be used in countries with similar growth conditions.

  8. Plant height and grain yield of soybean depending on the year, irrigation and variety

    Directory of Open Access Journals (Sweden)

    Daria Galić Šubašić

    2017-01-01

    Full Text Available Three-year field trials determined the influence of the year, irrigation treatment and varieties on plant height and grain yield of soybeans in the eastern Croatia conditions. All three investigated factors, as well as their interactions, with the exception of irrigation interactions and varieties that were significant at P=0.05, show a statistically significant influence (P=0.01 on the height of soybean plants. Soybean grain yields, as well as all their interactions, affect the significance level P=0.01. The obtained values of soybean grain yields during the study (mostly greater than 3000 kg ha-1 indicate the importance of selecting appropriate varieties and irrigation treatment in adapting soybean production to adverse weather effects of the year.

  9. Does overhead irrigation with salt affect growth, yield, and phenolic content of lentil plants?

    Directory of Open Access Journals (Sweden)

    Giannakoula Anastasia

    2012-01-01

    Full Text Available Overhead irrigation of lentil plants with salt (100 mM NaCl did not have any significant impact on plant growth, while chlorophyll content and chlorophyll fluorescence parameter Fv/Fm were affected. Under such poor irrigation water quality, the malondialdehyde content in leaves was increased due to the lipid peroxidation of membranes. In seeds, the total phenolic content (TPC was correlated to their total antioxidant capacity (TAC. High performance liquid chromatography-mass spectrometry (HPLC-MS detection showed that flavonoids (catechin, epicatechin, rutin, p-coumaric acid, quercetin, kaempferol, gallic acid and resveratrol appear to be the compounds with the greatest influence on the TAC values. Catechin is the most abundant phenolic compound in lentil seeds. Overhead irrigation with salt reduced the concentration of almost all phenolic compounds analyzed from lentil seed extracts.

  10. Fate and distribution of nitrogen in soil and plants irrigated with landfill leachate.

    Science.gov (United States)

    Cheng, C Y; Chu, L M

    2011-06-01

    Landfill leachate contains a high concentration of ammoniacal substances which can be a potential supply of N for plants. A bioassay was conducted using seeds of Brassica chinensis and Lolium perenne to evaluate the phytotoxicity of the leachate sample. A soil column experiment was then carried out in a greenhouse to study the effect of leachate on plant growth. Two grasses (Paspalum notatum and Vetiver zizanioides) and two trees (Hibiscus tiliaceus and Litsea glutinosa) were irrigated with leachate at the EC50 levels for 12 weeks. Their growth performance and the distribution of N were examined and compared with columns applied with chemical fertilizer. With the exception of P. notatum, plants receiving leachate and fertilizer grew better than those receiving water alone. The growth of L. glutinosa and V. zizanioides with leachate irrigation did not differ significantly from plants treated with fertilizer. Leachate irrigation significantly increased the levels of NH(x)-N in soil. Although NO(x)-N was below 1 mg NL(-1) in the leachate sample, the soil NO(x)-N content increased by 9-fold after leachate irrigation, possibly as a result of nitrification. Leachate irrigation at EC50 provided an N input of 1920 kg N ha(-1) over the experimental period, during which up to 1050 kg N ha(-1) was retained in the soil and biomass, depending on the type of vegetation. The amount of nutrient added seems to exceed beyond the assimilative capability. Practitioners should be aware of the possible consequence of N saturation when deciding the application rate if leachate irrigation is aimed for water reuse. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Physiological and gene expression responses of sunflower (Helianthus annuus L.) plants differ according to irrigation placement.

    Science.gov (United States)

    Aguado, Ana; Capote, Nieves; Romero, Fernando; Dodd, Ian C; Colmenero-Flores, José M

    2014-10-01

    To investigate effects of soil moisture heterogeneity on plant physiology and gene expression in roots and leaves, three treatments were implemented in sunflower plants growing with roots split between two compartments: a control (C) treatment supplying 100% of plant evapotranspiration, and two treatments receiving 50% of plant evapotranspiration, either evenly distributed to both compartments (deficit irrigation - DI) or unevenly distributed to ensure distinct wet and dry compartments (partial rootzone drying - PRD). Plants receiving the same amount of water responded differently under the two irrigation systems. After 3 days, evapotranspiration was similar in C and DI, but 20% less in PRD, concomitant with decreased leaf water potential (Ψleaf) and increased leaf xylem ABA concentration. Six water-stress responsive genes were highly induced in roots growing in the drying soil compartment of PRD plants, and their expression was best correlated with local soil water content. On the other hand, foliar gene expression differed significantly from that of the root and correlated better with xylem ABA concentration and Ψleaf. While the PRD irrigation strategy triggered stronger physiological and molecular responses, suggesting a more intense and systemic stress reaction due to local dehydration of the dry compartment of PRD plants, the DI strategy resulted in similar water savings without strongly inducing these responses. Correlating physiological and molecular responses in PRD/DI plants may provide insights into the severity and location of water deficits and may enable a better understanding of long-distance signalling mechanisms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Use of infrared thermometer technique in irrigation scheduling of pomegranate (Punica granatum L. plant

    Directory of Open Access Journals (Sweden)

    Begüm TEKELİOĞLU

    2017-06-01

    Full Text Available The main objectives of this study are to assess crop water stress index (CWSI and to determine irrigation schedule of pomegranate using infrared thermometer technique. Treatments with three replications were irrigated every three and six days intervals, as much as 0.50 (S1, 0.75 (S2, 1.00 (S3, and 1.25 (S4 of Class A pan evaporation. Additionally, an unirrigated plot was also formed. The equations obtained for non-water stress baseline is Tc-Ta=0.645VPD-4.338. The equation of full water stressed upper baseline obtained from data taken from branches of pomegranate plant cut in different days is given by Tc-Ta= 0.0489VPD+2.8734. According to the results obtained, it is concluded that infrared thermometer can be used for irrigation scheduling of the pomegranate plants in Antalya conditions. When using this technique in Antalya conditions, it is suggested to keep the seasonal mean CWSI value approximately 0.12 and the index value of 0.40 can be used to start the irrigation. Additionally, it is suggested that the amount of irrigation can be determined as much as the amount of evaporation measured until the index value reaches 0.40.

  13. Influence of planting date on seed protein oil sugars minerals and nitrogen metabolism in soybean under irrigated and non-irrigated enviroments

    Science.gov (United States)

    Information on the effect of planting date and irrigation on soybean [Glycine max (L.) Merr.] seed composition in the Early Soybean Production System is deficient, and what is available is inconclusive. The objective of this research was to investigate the effects of planting date on seed protein, o...

  14. [Influences of micro-irrigation and subsoiling before planting on enzyme activity in soil rhizosphere and summer maize yield.

    Science.gov (United States)

    Zhang, Ming Zhi; Niu, Wen Quan; Xu, Jian; Li, Yuan

    2016-06-01

    In order to explore the influences of micro-irrigation and subsoiling before planting on enzyme activity in soil rhizosphere and summer maize yield, an orthogonal experiment was carried out with three factors of micro-irrigation method, irrigation depth, and subsoiling depth. The factor of irrigation method included surface drip irrigation, subsurface drip irrigation, and moistube-irrigation; three levels of irrigation depth were obtained by controlling the lower limit of soil water content to 50%, 65%, and 80% of field holding capacity, respectively; and three depths of deep subsoiling were 20, 40, and 60 cm. The results showed that the activities of catalase and urease increased first and then decreased, while the activity of phosphatase followed an opposite trend in the growth season of summer maize. Compared with surface drip irrigation and moistube-irrigation, subsurface drip irrigation increased the average soil moisture of 0-80 cm layer by 6.3% and 1.8% in the growth season, respectively. Subsurface drip irrigation could significantly increase soil urease activity, roots volume, and yield of summer maize. With the increase of irrigation level, soil phosphatase activity decreased first and then increased, while urease activity and yield increased first and then decreased. The average soil moisture and root volume all increased in the growth season of summer maize. The increments of yield and root volume from subsoiling of 40 to 20 cm were greater than those from 60 to 40 cm. The highest enzyme activity was obtained with the treatment of subsoiling of 40 cm. In terms of improving water resource use efficiency, nitrogen use efficiency, and crop yield, the best management strategy of summer maize was the combination of subsurface drip irrigation, controlling the lower limit of soil water content to 65% of field holding capacity, and 40 cm subsoiling before planting.

  15. Radionuclides and heavy metal uptake by lolium italicum plant as affected by saline water irrigation

    International Nuclear Information System (INIS)

    Ramadan, A.A.; Aly, A.I.; Helal, M.H.

    2001-01-01

    The use of saline waters to grow crops on increasingly metal polluted soils is becoming a common practice in the arid regions. Nevertheless, the effects of soil and water salinity on radionuclides and heavy metal fluxes in polluted areas are not well understood. The aim of this study was to evaluate in pot experiments the plant uptake of cesium-137, Co-60, Mn-54, Zinc, cadmium and copper from a polluted alluvial aridisol as affected by salt water irrigation. Fertilized soil material was planted in pots with L. Italicum for 18 weeks under greenhouse conditions. The plants were irrigated either with water or with salt solution of variable variable Na/Ca ratio and harvested every 5-7 weeks. In addition to elemental analysis of plants and soil extracts root length was determined by a gridline intersect method and the viable part of the roots was estimated by a root protein inex. Saline (Na) water irrigation increased cobalt-60, manganese-54 and heavy metal solubility in soil, reduced root viability and enhanced the uptake of Co-60, Mn-54, Cd, Cu, Zn and Na by L.italicum and reduced the uptake of Cs-137. Ca counteracted these effects partly. The presented results demonstrated a dual effect of salinity on radiouclides and heavy metal availability to plants and suggest a relationship between root mortality and the enhanced Co-60, Mn-54, and heavy metake ny salt stressed plants

  16. Distribution of heavy metals in plants cultivated with wastewater irrigated soils during different periods of time

    International Nuclear Information System (INIS)

    Solis, C.; Andrade, E.; Mireles, A.; Reyes-Solis, I.E.; Garcia-Calderon, N.; Lagunas-Solar, M.C.; Pina, C.U.; Flocchini, R.G.

    2005-01-01

    The Mezquital valley is a vast area near Mexico city that has been irrigated with wastewater from Mexico city for more than 50 years. At present, this water source continues to be used while new irrigation areas are being incorporated according to rural demand. This research study was conducted to evaluate the relationship between the accumulation of metals in soils and plants and the physicochemical properties of soils irrigated in this manner for 50 and 100 years, respectively. Soil properties such as pH and total organic carbon (TOC) were determined by conventional methods. Plant and soil total trace metals Fe, Co, Ni, Cu, Zn and Pb were determined using particle induced X-ray emission (PIXE). Lower pH and TOC contents were obtained for soils irrigated during 100 years, indicating a higher metal bioavailability. This is not reflected in plant content for most of the reported elements, but Zn and Pb show a higher absorption in 100 years old plots (26-79%) than in 50-year-olds plots, indicating a pH dependence

  17. Monitoring plant water status and rooting depth for precision irrigation in the vineyards of Classic Karst

    Science.gov (United States)

    Savi, Tadeja; Moretti, Elisa; Dal Borgo, Anna; Petruzzellis, Francesco; Stenni, Barbara; Bertoncin, Paolo; Dreossi, Giuliano; Zini, Luca; Martellos, Stefano; Nardini, Andrea

    2017-04-01

    The extreme summer drought and heat waves that occurred in South-Europe in 2003 and 2012 have led to the loss of more than 50% of winery production in the Classic Karst (NE Italy). The irrigation of vineyards in this area is not appropriately developed and, when used, it does not consider the actual water status and needs of plants, posing risks of inappropriate or useless usage of large water volumes. The predicted future increase in frequency and severity of extreme climate events poses at serious risk the local agriculture based on wine business. We monitored seasonal trends of pre-dawn (Ψpd) and minimum (Ψmin) leaf water potential, and stomatal conductance (gL) of 'Malvasia' grapevine in one mature (MV, both in 2015 and 2016) and one young vineyard (YV, in 2016). Moreover, we extracted xylem sap form plant stems and soil water from samples collected in nearby caves, by cryo-vacuum distillation. We also collected precipitation and irrigation water in different months. Oxygen isotope composition (δ18O) of atmospheric, plant, soil and irrigation water was analyzed to get information about rooting depth. In 2015, at the peak of summer aridity, two irrigation treatments were applied according to traditional management practices. The treatments were performed in a sub-area of the MV, followed by physiological analysis and yield measurements at grape harvest. In 2016, the soil water potential (Ψsoil) at 50 cm depth was also monitored throughout the season. Under harsh environmental conditions the apparently deep root system ensured relatively favorable plant water status in both MV and YV and during both growing seasons. The Ψsoil at 50 cm depth gradually decreased as drought progressed, reaching a minimum value of about -1.7 MPa, far more negative than Ψpd recorded in plants (about -0.5 MPa). In July, significant stomatal closure was observed, but Ψmin never surpassed the critical threshold of -1.3 MPa, indicating that irrigation was not needed. The xylem sap

  18. Water deficit imposed by partial irrigation at different plant growth stages of common bean

    International Nuclear Information System (INIS)

    Calvache, M.; Reichardt, K.

    1995-01-01

    The purpose of this study was to identify specific growth stages of common bean crop, at which the plant is less sensitive to water stress so that irrigation can be omitted without significant decrease in biological nitrogen fixation and yield. Two field experiments were conducted at a University experiments station, Tumbaco, Pichincha, Ecuador, on a sandy loam soil ( Typic durustoll ). The climate is warm and dry ( mean air temperature 16 degree Celcius and mean relative humidity 74% ) during the cropping season and rainfall of 123 mm was recorded during the cropping period. The treatments consisted of combinations of 7 irrigation regimes ( I1 = all normal watering; I2 = all stres; I3 = traditional practice; I4 = single stress at vegetation; I5 flowering; I6 = yield formation and I7 = ripening stages ) and 2 levels of applied N ( 20 and 80 kg/ ha ). Differential irrigation was started after 3 uniform irrigations for germination and crop establishment. Soil moisture was monitored with a neutron probe down to 0.60 m depth, before and 24 h after each irrigation. Biological Nitrogen Fixation was calculated using the N- 15 metodology in the 20 kg N/ ha treatment. From the yield data, it can be concluded that treatments which had irrigation deficit had lower yield than those that had suplementary irrigation. The flowering stage was the most sensitive to number of pods and grain yield. Biological Nitrogen Fixation was significantly affected by water stress at flowering and formation stages. The crop water use efficiency ( kg/ m 3 ) was the lowest at flowering period and the yield response factor ( Ky ) was higher in treatments I2 ( all stress ) and I5 (stress at flowering ). Comparing with traditional practice by farmers of the region, only treatments I1 and I7 had 13 and 10 % higher crop water use effeciency. 15 tabs., 7 refs. ( Author )

  19. Water deficit imposed by deficit irrigation at different plant growth stages of maize

    International Nuclear Information System (INIS)

    Calvache, M.; Reichardt, C.

    1995-01-01

    The purpose of this study was to identify specific growth stages of maize Crop, at which the plant is less sensitive to water stress so that irrigation can be omitted withhout significant decrease yield. The field experiment was conducted at a University experiment station, Tumbaco, Pichincha, Ecuador, during may - october 1993, on a sandy loam soil ( typic durustoll). Soil moisture was monitored with a neutron probe down to 0.70 m depth, before and 24 h after each irrigation. The actual evapotranspiration of the crop was estimated by the water - balance technique. Field water efficiency and crop water use efficiency were calculated by dividing actual grain yield by irrigation and by ETa, respectively. Nitrogen fertilizer use efficiency was calculated using N - 15 methodology in the 75 kg N/ ha treatment. From the yield data, it can be concluded that treatments which had irrigation deficit had lower yield than those that had suplementary irrigation. The flowering and yield formation stages were the most sensitive to moisture stress. Nitrogen fertilization significantly increased the grain yield. The crop water use effeciency was the lowest at the flowering and yield formation of the region, the treatments I1 and I7 had the same crop water use efficiency. The results of N - 15 labelled plots ( F1) showed that soil water deficiency significantly affects nitrogen was derived from fertilizer in treatments I3 and I7 and only 11 - 9% in the treatments I2 and I5 respectively. ( Author)

  20. Modelling energy production by small hydro power plants in collective irrigation networks of Calabria (Southern Italy)

    Science.gov (United States)

    Zema, Demetrio Antonio; Nicotra, Angelo; Tamburino, Vincenzo; Marcello Zimbone, Santo

    2017-04-01

    The availability of geodetic heads and considerable water flows in collective irrigation networks suggests the possibility of recovery potential energy using small hydro power plants (SHPP) at sustainable costs. This is the case of many Water Users Associations (WUA) in Calabria (Southern Italy), where it could theoretically be possible to recovery electrical energy out of the irrigation season. However, very few Calabrian WUAs have currently built SHPP in their irrigation networks and thus in this region the potential energy is practically fully lost. A previous study (Zema et al., 2016) proposed an original and simple model to site turbines and size their power output as well as to evaluate profits of SHPP in collective irrigation networks. Applying this model at regional scale, this paper estimates the theoretical energy production and the economic performances of SHPP installed in collective irrigation networks of Calabrian WUAs. In more detail, based on digital terrain models processed by GIS and few parameters of the water networks, for each SHPP the model provides: (i) the electrical power output; (iii) the optimal water discharge; (ii) costs, revenues and profits. Moreover, the map of the theoretical energy production by SHPP in collective irrigation networks of Calabria was drawn. The total network length of the 103 water networks surveyed is equal to 414 km and the total geodetic head is 3157 m, of which 63% is lost due to hydraulic losses. Thus, a total power output of 19.4 MW could theoretically be installed. This would provide an annual energy production of 103 GWh, considering SHPPs in operation only out of the irrigation season. The single irrigation networks have a power output in the range 0.7 kW - 6.4 MW. However, the lowest SHPPs (that is, turbines with power output under 5 kW) have been neglected, because the annual profit is very low (on average less than 6%, Zema et al., 2016). On average each irrigation network provides an annual revenue from

  1. Temporal changes of radiocesium in irrigated paddy fields and its accumulation in rice plants in Fukushima.

    Science.gov (United States)

    Yang, Baolu; Onda, Yuichi; Wakiyama, Yoshifumi; Yoshimura, Kazuya; Sekimoto, Hitoshi; Ha, Yiming

    2016-01-01

    About half of the total paddy field area, which is the dominant agricultural land in Fukushima Prefecture, was contaminated by radiocesium released by the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the temporal changes of radiocesium in soil, irrigation water, and rice plant in two adjacent rice paddies, with and without surface-soil-removal, in Fukushima Prefecture for over three years (2012-2014) after the nuclear accident. Our results showed that radiocesium migrated into 24-28 cm soil layers and that the activity concentration of radiocesium in paddy soils showed a significant reduction in 2014. The newly added radiocesium to paddies through irrigation water contributed only a maximum value of 0.15% and 0.75% of the total amount present in control and decontaminated paddies, respectively, throughout the study period. The radiocesium activity concentration in suspended sediment in irrigation water exponentially decreased, and the effective half-lives (Teff) for (137)Cs and (134)Cs were 1.3 and 0.9 years, respectively. Additionally, the average suspended sediment concentration in irrigation water increased between 2012 and 2014, suggesting that enhanced soil erosion had occurred in the surrounding environment. Radiocesium accumulation in rice plant also decreased with time in both paddies. However, the concentration ratio of radiocesium for rice plant in the decontaminated paddy increased compared with control paddy, despite approximately 96% of fallout radiocesium removed in paddy soil. Further analysis is required to clarify the reasons of high concentration ratio of radiocesium for rice plant in the decontaminated paddy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

    Energy Technology Data Exchange (ETDEWEB)

    Dahal, B.M. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria); Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna (Austria); Environment and Public Health Organization (ENPHO), P.O. Box 4102, Kathmandu (Nepal); Fuerhacker, M. [Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna (Austria); Mentler, A. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria); Karki, K.B. [Soil Science Division, Nepal Agricultural Research Council, Khumaltar, Lalitpur (Nepal); Shrestha, R.R. [UN Habitat-Nepal, UN House, Pulchwok, P.O. Box 107, Kathmandu (Nepal); Blum, W.E.H. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria)], E-mail: winfried.blum@boku.ac.at

    2008-09-15

    This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from <0.005 to 1.014 mg L{sup -1} where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg{sup -1}. The arsenic content in different parts of plants are found in the order of roots > shoots > leaves > edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg{sup -1}) > onion bulb (0.45 mg As kg{sup -1}) > cauliflower (0.33 mg As kg{sup -1}) > rice (0.18 mg As kg{sup -1}) > brinjal (0.09 mg As kg{sup -1}) > potato (<0.01 mg As kg{sup -1}). - The arsenic content in soil and plants is influenced by the degree of arsenic amount in irrigated water.

  3. Plant density affects measures of biodiversity effects

    Czech Academy of Sciences Publication Activity Database

    Stachová, T.; Fibich, P.; Lepš, Jan

    2013-01-01

    Roč. 6, č. 1 (2013), s. 1-11 ISSN 1752-9921 R&D Projects: GA ČR GD206/08/H044 Grant - others:GA JU(CZ) 138/2010/P Institutional support: RVO:60077344 Keywords : biodiversity effects * plant density * constant final yield Subject RIV: EH - Ecology, Behaviour Impact factor: 2.284, year: 2013 http://jpe.oxfordjournals.org/content/early/2012/04/27/jpe.rts015.full.pdf+html

  4. Statistical Analysis Of Heavy Metals Concentration In Watermelon Plants Irrigated By Wastewater

    Science.gov (United States)

    Khanjani, M. J.; Maghsoudi moud, A. A.; Saffari, V. R.; Hashamipor, S. M.; Soltanizadeh, M.

    2008-01-01

    Concentration of heavy metals in vegetables irrigated by urban wastewater is a cause of serious concern due to the potentials health problems of consuming contaminated produce. In this study it is tried to model the concentration of heavy metals (Cd, Cr, Cu, Fe,…) as a function of their concentration in watermelon roots and stems. Our study shows there is a good relationship between them for most of collected data. By measuring the concentration in root and stem of watermelon plant samples before harvesting, the concentration of heavy metal in watermelon's fruit can be estimated by presented mathematical models. This study shows the concentrations of heavy metals in fruits, roots and stems of watermelon plants are very high and in dangerous level when irrigated by municipal waste water.

  5. Treatment of landfill leachate by irrigation of willow coppice - Plant response and treatment efficiency

    International Nuclear Information System (INIS)

    Aronsson, Paer; Dahlin, Torleif; Dimitriou, Ioannis

    2010-01-01

    Landfill leachates usually need to be treated before discharged, and using soil-plant systems for this has gained substantial interest in Sweden and in the UK. A three-year field study was conducted in central Sweden to quantify plant response, treatment efficiency and impact on groundwater quality of landfill leachate irrigation of short-rotation willow coppice (Salix). Two willow varieties were tested and four irrigation regimes in sixteen 400-m 2 plots. The willow plants did not react negatively, despite very high annual loads of nitrogen (≤2160 kg N/ha), chloride (≤8600 kg Cl/ha) and other elements. Mean annual growth was 1.5, 9.8 and 12.6 tonnes DM/ha during years 1-3. For one of two willow varieties tested, relative leaf length accurately predicted growth rate. Irrigation resulted in elevated groundwater concentrations of all elements applied. Treatment efficiency varied considerably for different elements, but was adequate when moderate loads were applied. - Short-rotation willow coppice was successfully used for treating a strong landfill leachate in central Sweden over three years.

  6. Crop water productivity for sunflower under different irrigation regimes and plant spacing in Gezira Scheme, Sudan

    Directory of Open Access Journals (Sweden)

    Eman Rahamtalla Ahmed Elsheikh

    2015-12-01

    Full Text Available Two field experiments with Sunflower on deep cracking soil with heavy clay (vertisol were conducted at Gezira Research Station Farm during two executive winter seasons, in WadMedani, Sudan. The crop was sown in the third week of November and in the first week of December for seasons 2012 and 2013 respectively. The experimental design was split plot design with three replicates. The Sunflower hybrid tested in the study was Hysun 33. The objective of this study was to determine the effect of three different irrigation intervals of 10, 15 and 20 days and two intra-row plant spacings of 30 cm and 40 cm on yield and yield components of Sunflower. The seed yields obtained from the different treatments were in the ranges of 1890-3300 kg/ha and 1590-3290 kg/ha for the first and second season respectively. The corresponding computed on average crop water productivity was in the range of 0.31-0.43 kg/m3. The study clearly indicated that the highest seed yield was obtained when the crop was sown at 40 cm plant spacing and irrigated every 10 days. The highest crop water productivity was achieved from irrigation every15 days in both planting spacings

  7. Yield and resource use efficiency of Plukenetia volubilis plants at two distinct growth stages as affected by irrigation and fertilization.

    Science.gov (United States)

    Gong, He-De; Geng, Yan-Jing; Yang, Chun; Jiao, Dong-Ying; Chen, Liang; Cai, Zhi-Quan

    2018-01-08

    This study is to test how seedlings (vegetative) and large plants (reproductive) of an oilseed crop (Plukenetia volubilis) responded to regulated deficit irrigation techniques (conventional deficit irrigation, DI; alternative partial root-zone irrigation, APRI) in a tropical humid monsoon area. Seedlings were more sensitive to water deficit than large plants. Although APRI did better than DI in saving water for both seedlings and large plants at the same amount of irrigation, full irrigation (FI) is optimal for faster seedling growth at the expense of water-use efficiency (WUE). The seed number per unit area was responsible for the total seed oil yield, largely depending on the active process of carbon and nitrogen storages at the whole-plant level. The magnitude of the increase in total seed and seed oil yield by fertilization was similar under different irrigation regimes. Compared with FI, DI can save water, but reduced the total seed yield and had lower agronomic nutrient-use efficiency (NUE agr ); whereas APRI had similar total seed yield and NUE agr , but reduced water use greatly. Although the dual goal of increasing the yield and saving water was not compatible, maintaining a high yield and NUEagr at the cost of WUE is recommended for P. volubilis plantation in t he water-rich areas.

  8. FEATURES OF MINERAL NUTRITION FOR TOMATO PLANTS WITH DRIP IRRIGATION SYSTEM IN OPEN FIELD CONDITION

    Directory of Open Access Journals (Sweden)

    P. M. Akhmetova

    2017-01-01

    Full Text Available Dagestan is the largest region with irrigation system of agriculture in Russia. Irrigated lands provide 70% of total plant production. The field cultivation is carried on arable land in plain region of the republic. The drip irrigation as an ecologically safe technology for watering is regarded as major means for vegetable production farming. This approach maintains the propitious level of water and air in the soil without surface and deep drainage of irrigating water. These irrigated lands are expected to be used first of all for valuable and profitable crops such as tomato that is a leading crop in Dagestan. The experimental work was carried out at OOO ‘Dagagrocomplex’, Aleksandro-Nevskoye, in Tarumovskiy region. The aim of the study was to determinate the optimal dose of mineral fertilizers and the way of their application to improve the productivity without quality loss. The complex analysis of the technology for tomato production under drip irrigation through nontransplanting culture showed its high efficiency, because volume and quality of yield directly depended on soil moisture and precise supporting of mineral nutrition rates. The maximal yield of tomato fruits, 88.7-94.5 t/ha was observed with once mineral fertilizer application at a dose of N180P135K60 with soil humidity 70-80% (field moisture capacity, and also at the dose of N180P135K60 with basic application of N100 in nutrition rate. The result of the study showed that the optimization of two factors, namely soil water rate and mineral nutrition, enabled to produce additionally 39.2 t/ha. It was shown the tight connection between yielding and its quality; when yielding 95 t/ha, the increased contents of dry matter to 7.01%, sugar to 3.8% vitamin C to 18.46% were noticed. The high quality of produced output was supported by pre-watering threshold of moisture at 75-80% (field moisture capacity, when once fertilizer application at a dose of N180P135K60. 

  9. A metagenomic assessment of viral contamination on fresh parsley plants irrigated with fecally tainted river water.

    Science.gov (United States)

    Fernandez-Cassi, X; Timoneda, N; Gonzales-Gustavson, E; Abril, J F; Bofill-Mas, S; Girones, R

    2017-09-18

    Microbial food-borne diseases are still frequently reported despite the implementation of microbial quality legislation to improve food safety. Among all the microbial agents, viruses are the most important causative agents of food-borne outbreaks. The development and application of a new generation of sequencing techniques to test for viral contaminants in fresh produce is an unexplored field that allows for the study of the viral populations that might be transmitted by the fecal-oral route through the consumption of contaminated food. To advance this promising field, parsley was planted and grown under controlled conditions and irrigated using contaminated river water. Viruses polluting the irrigation water and the parsley leaves were studied by using metagenomics. To address possible contamination due to sample manipulation, library preparation, and other sources, parsley plants irrigated with nutritive solution were used as a negative control. In parallel, viruses present in the river water used for plant irrigation were analyzed using the same methodology. It was possible to assign viral taxons from 2.4 to 74.88% of the total reads sequenced depending on the sample. Most of the viral reads detected in the river water were related to the plant viral families Tymoviridae (66.13%) and Virgaviridae (14.45%) and the phage viral families Myoviridae (5.70%), Siphoviridae (5.06%), and Microviridae (2.89%). Less than 1% of the viral reads were related to viral families that infect humans, including members of the Adenoviridae, Reoviridae, Picornaviridae and Astroviridae families. On the surface of the parsley plants, most of the viral reads that were detected were assigned to the Dicistroviridae family (41.52%). Sequences related to important viral pathogens, such as the hepatitis E virus, several picornaviruses from species A and B as well as human sapoviruses and GIV noroviruses were detected. The high diversity of viral sequences found in the parsley plants

  10. Performance of irrigated green corn cultivars in different plant populations at sowing

    Directory of Open Access Journals (Sweden)

    José C. Soares Neto

    Full Text Available ABSTRACT This study aimed to evaluate the yield of green corn hybrids grown under irrigation in different plant populations at sowing. The assay was carried out in the experimental area located in the city of Arapiraca, Alagoas State, Brazil, from November 2015 to January 2016. A randomized complete block design (RCBD was used, in a 2 x 5 factorial scheme with four replicates. A double- and a single-cross hybrid (AG 1051 and BM 3061, which are suitable for green corn production, were cultivated in five spacings between plants at sowing (15.0, 17.5, 20.0, 22.5 and 25.0 cm. The characteristics photosynthetic rate (PR, ear length with rusk (HEL and without husk (UEL, husked ear weight (HEW, unhusked ear weight (UEW, percentage of marketable ears (%ME and weight of husk (HW were evaluated. The double- and single-cross hybrids AG 1051 and BM 3061 showed green ears with commercial standard. The cultivar BM 3061 showed the best results for most of the characteristics related to the performance of green corn (PR, HEL, UEL, UEW, HEW, %ME. The spacing of 17.5 cm between plants at sowing was the most indicated for irrigated green corn cultivation.

  11. Quality and Trace Element Profile of Tunisian Olive Oils Obtained from Plants Irrigated with Treated Wastewater

    Directory of Open Access Journals (Sweden)

    Cinzia Benincasa

    2012-01-01

    Full Text Available In the present work the use of treated wastewater (TWW to irrigate olive plants was monitored. This type of water is characterized by high salinity and retains a substantial amount of trace elements, organic and metallic compounds that can be transferred into the soil and into the plants and fruits. In order to evaluate the impact of TWW on the overall quality of the oils, the time of contact of the olives with the soil has been taken into account. Multi-element data were obtained using ICP-MS. Nineteen elements (Li, B, Na, Mg, Al, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo, Ba and La were submitted for statistical analysis. Using analysis of variance, linear discriminant analysis and principal component analysis it was possible to differentiate between oils produced from different batches of olives whose plants received different types of water. Also, the results showed that there was correlation between the elemental and mineral composition of the water used to irrigate the olive plots and the elemental and mineral composition of the oils.

  12. Thermal performance of different planting substrates and irrigation frequencies in extensive tropical rooftop greeneries

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Jiung [Department of Environmental Engineering and Science, Foo-Yin University, Kaohsiung (China); No. 16, Lane 29, Chen-Sing 7th Street, Niao-Song, Kaohsiung 833 (China); Lin, Hsien-Te [Department of Architecture, National Cheng Kung University, Tainan (China); No. 1, Ta-Hsueh Road, Tainan 701 (China)

    2011-02-15

    The need for the better use of scarce planetary resources has never been more evident than it is today. However, this need is poorly reflected in human housing. In recent years, there has been a growing realization of the importance of constructing human shelters that better conserve energy and water through appropriate insulation and architectural designs. Among the important advancements in these areas is the use of rooftop greeneries for both energy and water conservation. This paper performs an investigation into this topic within the specific climatic context of tropical regions. Long-term experimental results are provided from a four-floor building in Kaohsiung in the southern part of Taiwan. The study involves a fully monitored extensive rooftop greenery and examines four different plant substrates, three different irrigation regimes, and different types of drought-enduring plants to find the most efficient combination of all three in providing maximum heat insulation and water usage efficiency. The attenuation of solar radiation through the vegetation layer is evaluated, as well as the thermal insulation performance of the rooftop greenery structure. Among the substrates, burned sludge has the best thermal reduction percentage of heat amplitude under the roof slab surface (up to 84.4%). Irrigation twice a week has the best thermal reduction percentage of heat amplitude (91.6%). Among the plant types, Sansevieria trifasciata cv. Laurentii Compacta and Rhoeo spathaceo cv. Compacta are found to be suitable for extensive rooftop greeneries because they have the best coverage ratio and are most drought enduring. (author)

  13. Response of lupine plants irrigated with saline water to rhizobium inoculation using 15N-isotope dilution

    International Nuclear Information System (INIS)

    Gadalla, A.M.; El-Ghandour, I.A.; Abdel Aziz, H.A.; Hamdy, A.; Aly, M.M.

    2002-01-01

    The lupine Rhizobium symbiosis and contribution of N 2 fixation under different levels of irrigation water salinity were examined. Lysimeter experiment was established under greenhouse conditions during the year 2002-2003. In this experiment, inoculated plants were imposed to different salinity levels of irrigation water and N-fertilizer treatment. Plant height was decreased under different salinity levels, nitrogen treatments and bacterial inoculation. Similar trend was noticed with leaf area. The highest leaf area was recorded with salt tolerant bacterial inoculation (SBI) and splitting N-treatment. Highest values of N-uptake occurred after 100 day intervals under the tested factors. Relative decrease in N-uptake did not exceed 40% of those recorded with the fresh water treatment as affected by experimental factors. Nitrogen uptake by the whole plant reflected an increase at 3 dS/m salinity level of irrigation water. Relative increases were 5% and 15% for normal bacteria inoculation under single dose (NI) and splitting

  14. Modeling root length density of field grown potatoes under different irrigation strategies and soil textures using artificial neural networks

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Sepaskhah, Ali Reza; Andersen, Mathias Neumann

    2014-01-01

    ) of the eight input variables: soil layer intervals (D), percentages of sand (Sa), silt (Si), and clay (Cl), bulk density of soil layers (Bd), weighted soil moisture deficit during the irrigation strategies period (SMD), geometric mean particle size diameter (dg), and geometric standard deviation (σg......). The results of the study showed that all the nine ANN models predicted the target RLD values satisfactorily with a correlation coefficient R2>0.98. The simplest and most complex ANN architectures were 3:2:1 and 5:5:1 consisting of D, SMD, dg, and D, Bd, SMD, σg, dg as the input variables, respectively. Low...

  15. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Science.gov (United States)

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  16. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Directory of Open Access Journals (Sweden)

    Xin Liu

    Full Text Available Modelling crop evapotranspiration (ET response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1 and summer maize (scenario 2 by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  17. Impact of post-infiltration soil aeration at different growth stages of sub-surface trickle-irrigated tomato plants

    Science.gov (United States)

    Li, Yuan; Jia, Zong-xia; Niu, Wen-Quan; Wang, Jing-wei

    2016-07-01

    Sensitivity to low rhizosphere soil aeration may change over time and therefore plant response may also depend on different growth stages of a crop. This study quantified effects of soil aeration during 5 different periods, on growth and yield of trickle-irrigated potted single tomato plants. Irrigation levels were 0.6 to 0.7 (low level) or 0.7 to 0.8 (high level) of total water holding capacity of the pots. Soil was aerated by injecting 2.5 l of air into each pot through the drip tubing immediately after irrigation. Fresh fruit yield, above ground plant dry weight, plant height, and leaf area index response to these treatments were measured. For all these 4 response variables, means of post-infiltration aeration between 58 to 85 days after sowing were 13.4, 43.5, 13.7, and 37.7% higher than those for the non-aerated pots, respectively. The results indicated that: post-infiltration soil aeration can positively impact the yield and growth of sub-surface trickle-irrigated potted tomato plants; positive effects on plant growth can be obtained with aeration during the whole growth period or with aeration for partial periods; positive growth effects of partial periods of aeration appears to persist and result in yield benefit.

  18. Macronutrient uptake, accumulation and export by the irrigated 'vitória' pineapple plant

    Directory of Open Access Journals (Sweden)

    Rodinei Facco Pegoraro

    2014-06-01

    Full Text Available The nutritional state of the pineapple plant has a large effect on plant growth, on fruit production, and fruit quality. The aim of this study was to assess the uptake, accumulation, and export of nutrients by the irrigated 'Vitória' pineapple plant during and at the end of its development. A randomized block statistical design with four replications was used. The treatments were defined by different times of plant collection: at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP. The collected plants were separated into the following components: leaves, stem, roots, fruit, and slips for determination of fresh and dry matter weight at 65 ºC. After drying, the plant components were ground for characterization of the composition and content of nutrients taken up and exported by the pineapple plant. The results were subjected to analysis of variance, and non-linear regression models were fitted for the significant differences identified by the F test (p N > S > Ca > Mg > P, which corresponded to 898, 452, 134, 129, 126, and 107 kg ha-1, respectively, of total accumulation. The export of macronutrients by the pineapple fruit was in the following decreasing order: K > N > S > Ca > P > Mg, which was equivalent to 18, 17, 11, 8, 8, and 5 %, respectively, of the total accumulated by the pineapple. The 'Vitória' pineapple plant exported 78 kg ha-1 of N, 8 kg ha-1 of P, 164 kg ha-1 of K, 14 kg ha-1 of S, 10 kg ha-1 of Ca, and 6 kg ha-1 of Mg by the fruit. The nutrient content exported by the fruits represent important components of nutrient extraction from the soil, which need to be restored, while the nutrients contained in the leaves, stems and roots can be incorporated in the soil within a program of recycling of crop residues.

  19. The impact of sewage irrigation on the uptake of mercury in corn plants (Zea mays) from suburban Beijing

    International Nuclear Information System (INIS)

    Rothenberg, S.E.; Du, X.; Zhu, Y.-G.; Jay, J.A.

    2007-01-01

    The impact of sewage irrigation on the uptake and translocation of mercury (Hg) in corn plants (Zea mays) was investigated. Corn plants were harvested the same day from two nearby fields in suburban Beijing, one irrigated historically with sewage effluent, and one irrigated solely with groundwater. Hg content was analyzed in the soil, roots and stems, while percent moisture and soil organic content were analyzed in the soil samples. The concentration of Hg in the soil and roots, and the soil organic content were not significantly different between the two fields, despite the historic practice of sewage irrigation. Hg content in roots was positively correlated with soil Hg concentration (r = 0.95, n = 6). The transfer coefficients between roots and stems were significantly higher in the control site (control: 2.06, sewage-irrigated: 0.44, p < 0.05), indicating that the barrier effect of the roots was not consistent between the two fields. - Hg content in the roots of corn plants (Zea mays) was positively correlated with soil Hg content, but negatively correlated with Hg content in stems

  20. The impact of sewage irrigation on the uptake of mercury in corn plants (Zea mays) from suburban Beijing

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, S.E. [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085 (China); Environmental Science and Engineering Program, Box 951772 CHS, University of California, Los Angeles, CA 90095-1772 (United States)], E-mail: srothenb@ucla.edu; Du, X.; Zhu, Y.-G. [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085 (China); Jay, J.A. [Department of Civil and Environmental Engineering, Box 951593 Boelter Hall, University of California, Los Angeles, CA 90095-1593 (United States)

    2007-09-15

    The impact of sewage irrigation on the uptake and translocation of mercury (Hg) in corn plants (Zea mays) was investigated. Corn plants were harvested the same day from two nearby fields in suburban Beijing, one irrigated historically with sewage effluent, and one irrigated solely with groundwater. Hg content was analyzed in the soil, roots and stems, while percent moisture and soil organic content were analyzed in the soil samples. The concentration of Hg in the soil and roots, and the soil organic content were not significantly different between the two fields, despite the historic practice of sewage irrigation. Hg content in roots was positively correlated with soil Hg concentration (r = 0.95, n = 6). The transfer coefficients between roots and stems were significantly higher in the control site (control: 2.06, sewage-irrigated: 0.44, p < 0.05), indicating that the barrier effect of the roots was not consistent between the two fields. - Hg content in the roots of corn plants (Zea mays) was positively correlated with soil Hg content, but negatively correlated with Hg content in stems.

  1. Effects of Planting Dates, Irrigation Management and Cover Crops on Growth and Yield of Saffron (Crocus sativus L.

    Directory of Open Access Journals (Sweden)

    A Koocheki

    2017-08-01

    Full Text Available Introduction Saffron as a winter active plant with low water requirement is the most strategic medicinal plant in arid and semi-arid parts of Iran. This slow-growing plant has narrow leaves and no aerial stem, hence weeds can be overcome it. Moreover, because of its root and canopy structure an important part of different resources is not used by this low input crop. Therefore, the use of associated crops could be an effective way for increasing resources use efficiencies (Koocheki et al., 2016. Appropriate corm planting date is another important factor that affects saffron growth and yield. Results of some studies show that late spring is the best time for corm planting (Ghasemi-Rooshnavand, 2009; Koocheki et al., 2016. In addition, irrigation management has been evaluated in some studies, but irrigation immediately after corm planting has not been investigated previously. Therefore, the aim of this study was to investigate the effect of irrigation management, planting date and the use of some companion crops on flowering of saffron during two growth cycles. Materials and methods This experiment was carried out as a split-split plot experiment based on a Randomized Complete Block Design with three replications at Research Station, Ferdowsi University of Mashhad, Iran in 2009-2011. Experimental factors included: planting date of saffron as main factor (first of June, first of August and first of October, 2009, the irrigation management as sub factor (irrigation and no irrigation after each planting date and the companion crops as sub-sub factor [Persian clover (Trifolium resupinatum, Bitter vetch (Lathyrus sativus and control. Corm planting was done in 10×25 cm distances with 12 cm depth. In the second year irrigation was done again in the plots which were irrigated after planting in the first year at the same previous dates. Companion crops were sown after first flower picking (November, 2009, then their residue were returned to the soil in

  2. Plant densities and modulation of symbiotic nitrogen fixation in soybean

    Directory of Open Access Journals (Sweden)

    Marcos Javier de Luca

    2014-06-01

    Full Text Available Soybean nitrogen (N demands can be supplied to a large extent via biological nitrogen fixation, but the mechanisms of source/sink regulating photosynthesis/nitrogen fixation in high yielding cultivars and current crop management arrangements need to be investigated. We investigated the modulation of symbiotic nitrogen fixation in soybean [Glycine max (L. Merrill] at different plant densities. A field trial was performed in southern Brazil with six treatments, including non-inoculated controls without and with N-fertilizer, both at a density of 320,000 plants ha−1, and plants inoculated with Bradyrhizobium elkanii at four densities, ranging from 40,000 to 320,000 plants ha−1. Differences in nodulation, biomass production, N accumulation and partition were observed at stage R5, but not at stage V4, indicating that quantitative and qualitative factors (such as sunlight infrared/red ratio assume increasing importance during the later stages of plant growth. Decreases in density in the inoculated treatments stimulated photosynthesis and nitrogen fixation per plant. Similar yields were obtained at the different plant densities, with decreases only at the very low density level of 40,000 plants ha−1, which was also the only treatment to show differences in seed protein and oil contents. Results confirm a fine tuning of the mechanisms of source/sink, photosynthesis/nitrogen fixation under lower plant densities. Higher photosynthesis and nitrogen fixation rates are capable of sustaining increased plant growth.

  3. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water

    International Nuclear Information System (INIS)

    Michon, G.; Fioramonti, S.; Marty, J.R.; Benard, P.; Flanzy, M.; Delas, J.; Delmas, J.; Demias, Ch.; Huguet, C.

    1964-01-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [fr

  4. Heavy metal accumulation in soils, plants, and hair samples: an assessment of heavy metal exposure risks from the consumption of vegetables grown on soils previously irrigated with wastewater.

    Science.gov (United States)

    Massaquoi, Lamin Daddy; Ma, Hui; Liu, Xue Hui; Han, Peng Yu; Zuo, Shu-Mei; Hua, Zhong-Xian; Liu, Dian-Wu

    2015-12-01

    It is common knowledge that soils irrigated with wastewater accumulate heavy metals more than those irrigated with cleaner water sources. However, little is known on metal concentrations in soils and cultivars after the cessation of wastewater use. This study assessed the accumulation and health risk of heavy metals 3 years post-wastewater irrigation in soils, vegetables, and farmers' hair. Soils, vegetables, and hair samples were collected from villages previously irrigating with wastewater (experimental villages) and villages with no history of wastewater irrigation (control villages). Soil samples were digested in a mixture of HCL/HNO3/HCLO4/HF. Plants and hair samples were digested in HNO3/HCLO4 mixture. Inductive coupled plasma-optical emission spectrometer (ICP-OES) was used to determine metal concentrations of digested extracts. Study results indicate a persistence of heavy metal concentration in soils and plants from farms previously irrigated with wastewater. In addition, soils previously irrigated with wastewater were severely contaminated with cadmium. Hair metal concentrations of farmers previously irrigating with wastewater were significantly higher (P metal concentrations in hair samples of farmers previously irrigating with wastewater were not associated with current soil metal concentrations. The study concludes that there is a persistence of heavy metals in soils and plants previously irrigated with wastewater, but high metal concentrations in hair samples of farmers cannot be associated with current soil metal concentrations.

  5. Response of False horn plantain to different plant densities and ...

    African Journals Online (AJOL)

    The study, which was carried out at the Crops Research Institute, Kumasi, Ghana, from April 1992 to March 1995, aimed at determining (i) the optimum plant density of False horn plantain for maximum yield, and (ii) the optimum frequency of handweeding for economic returns. Results indicated that the optimum plant density ...

  6. Influência da irrigação, da densidade de plantio e da adubação nitrogenada nas características morfogênicas, estruturais e de produção do capim-tanzânia Morphogenesis and structural characteristics and production of guinea grass irrigated under different plants density and nitrogen doses

    Directory of Open Access Journals (Sweden)

    Marcela de Azevedo Magalhães

    2011-11-01

    Full Text Available O experimento foi conduzido com os objetivos de avaliar a altura do dossel com 95% de interceptação luminosa e quantificar a influência da adubação nitrogenada e da densidade de plantas nas características morfogênicas e estruturais de capim-tanzânia. Quatro doses de nitrogênio, N (0, 80, 160 e 320 kg.ha-1, foram combinadas com três densidades de plantas (9, 25 e 49 plantas.m-2, em um arranjo fatorial 4 × 3, em delineamento inteiramente casualizado com três repetições, para avaliação da produção de biomassa, e duas repetições, para avaliação das características morfogênicas e estruturais. O acúmulo de MS total durante o período experimental foi influenciado pela adubação nitrogenada e pela densidade de plantas. No período das águas, as maiores doses de nitrogênio diminuíram o intervalo de colheitas e, consequentemente, aumentaram o número de colheitas. A altura do dossel de capim-tanzânia com 95% de IL foi positivamente influenciada pela densidade de plantas nos períodos das águas e de transição água-seca e seca. A altura do capim-tanzânia com 95% de IL apresentou variações ao longo das avaliações, de modo que os valores foram maiores (próximos a 70 cm no período das águas, seguido pelos períodos de transição água-seca e seca.This experiment was carried out to evaluate canopy height of guinea grass with 95% of photosynthetic active radiation interception and quantify the nitrogen fertilization influence and plants' density on the morphogenesis and structural characteristics of Tanzania grass. Four doses of N (0, 80, 160 e 320 kg.ha-1, were arranged with three plant densities (9, 25 and 49 plants.m-2, according to 4 × 3 completely randomized design, with three repetitions. Total dry matter (DM accumulation throughout the experimental period was influenced by nitrogen fertilization and plants' density. In the rainy period, the higher nitrogen fertilization decreased the harvesting intervals, and

  7. Irrigation of Castor Bean (Ricinus communis L. and Sunflower (Helianthus annus L. Plant Species with Municipal Wastewater Effluent: Impacts on Soil Properties and Seed Yield

    Directory of Open Access Journals (Sweden)

    Vasileios A. Tzanakakis

    2011-11-01

    Full Text Available The effects of plant species (castor bean (Ricinus communis L. versus sunflower (Helianthus annus L. and irrigation regime (freshwater versus secondary treated municipal wastewater on soil properties and on seed and biodiesel yield were studied in a three year pot trial. Plant species were irrigated at rates according to their water requirements with either freshwater or wastewater effluent. Pots irrigated with freshwater received commercial fertilizer, containing N, P, and K, applied at the beginning of each irrigation period. The results obtained in this study showed that irrigation with effluent did not result in significant changes in soil pH, soil organic matter (SOM, total kjeldahl nitrogen (TKN, and dehydrogenase activity, whereas soil available P was found to increase in the upper soil layer. Soil salinity varied slightly throughout the experiment in effluent irrigated pots but no change was detected at the end of the experiment compared to the initial value, suggesting sufficient salt leaching. Pots irrigated with effluent had higher soil salinity, P, and dehydrogenase activity but lower SOM and TKN than freshwater irrigated pots. Sunflower showed greater SOM and TKN values than castor bean suggesting differences between plant species in the microorganisms carrying out C and N mineralization in the soil. Plant species irrigated with freshwater achieved higher seed yield compared to those irrigated with effluent probably reflecting the lower level of soil salinity in freshwater irrigated pots. Castor bean achieved greater seed yield than sunflower. Biodiesel production followed the pattern of seed yield. The findings of this study suggest that wastewater effluent can constitute an important source of irrigation water and nutrients for bioenergy crop cultivations with minor adverse impacts on soil properties and seed yield. Plant species play an important role with regard to the changes in soil properties and to the related factors of

  8. Presentation: 3D magnetic inversion by planting anomalous densities

    OpenAIRE

    Uieda, Leonardo; Barbosa, Valeria C. F.

    2013-01-01

    Slides for the presentation "3D magnetic inversion by planting anomalous densities" given at the 2013 AGU Meeting of the Americas in Cancun, Mexico.   Note: There was an error in the title of the talk. The correct title should be "3D magnetic inversion by planting anomalous magnetization"   Abstract: We present a new 3D magnetic inversion algorithm based on the computationally efficient method of planting anomalous densities. The algorithm consists of an iterative growth of the an...

  9. Root distribution pattern of triticale varieties under irrigated and unirrigated conditions using 32P plant injection technique

    International Nuclear Information System (INIS)

    Mahajan, J.P.; Soni, B.K.; Bhargava, B.S.

    1977-01-01

    A study on the root distribution pattern of four triticale varieties (6TA-204-3, 6TA-204-4, S-520 and S-411) under irrigated and unirrigated conditions showed that in general, there was a more profused root system in irrigated conditions than in the unirrigated ones. The lateral root distribution was adversely affected under unirrigated conditions. Root density of different varieties, in a soil segment of 15 cm diameter and 48 cm depth grown under unirrigated conditions, was in the following order : S-520 > 6 TA-204-3 > 6 TA-204-4 > S-411 while under irrigated conditions the order was : 6 TA-204-3 > S-520 > 6 TA-204-4 > S-411. (author)

  10. Energy indices in irrigated wheat production under conservation and conventional tillage and planting methods

    Directory of Open Access Journals (Sweden)

    S. M Hosseini

    2016-04-01

    Full Text Available Introduction: Conservation tillage system was recommended for soil erosion control in North America for the first time 60 years ago (Wang et al., 2006. Using this tillage system including minimum and zero tillage has been rapidly developed in recent years. Thearea covered by zero tillage in 2006 was 95 million ha all over the world (Dumanski et al., 2006. In addition to saving soil and water resources, conservation tillage system reduces energy consumption and improves energy indices by combining different tillage and planting operations. Results of research conducted in Fars province shows that conservation tillage saves fuel consumption for 77% compared to the conventional system (Afzalinia et al., 2009. Conservation tillage also reduces energy consumption from 23.6 to 42.8% in comparison to the conventional tillage (Rusu, 2005. Since energy indices would be affected by reduced input energies in conservation tillage, this research was conducted to evaluate the effect of different tillage and planting methods on energy inputs and energy indices in irrigated wheat production in Eghlid region. Materials and Methods: This research was performed to evaluate and compare the energy indices in irrigated wheat production under different tillage and planting methods. The study was conducted in the form of a randomized complete block experimental design with five treatments and three replications in Eghlid region. The treatments were included, conventional tillage and seed broadcasting (A, conventional tillage and planting with Machine Barzegar grain drill (B, reduced tillage and seeding with Roto-seeder (C, direct seeding with Jairan Sanaat grain drill (D, and direct seeding with Sfoggia direct drill (E. Experimental plots with 10 by 50 m dimensions were used in this study. Loss crop residues were taken out of the experimental plots and standing crop residues were retained in the plots. In the conventional tillage method, primary tillage was performed

  11. A study of the early detection of insect infestations and density/distribution of host plants

    Science.gov (United States)

    Hart, W. G.; Ingle, S. J.; Davis, M. R. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Significant results have been obtained in the identification of citrus, sugarcane, winter vegetables, irrigated pastures, and unimproved pastures which contain brush. Land without vegetation, lakes, roads, and waterways can also be determined. Different densities of vegetation covering some cultivated areas are apparent. The practical applications of these results are many. The abundance of host plants of pests can be determined. Avenues of entry of pests can be plotted, facilitating control or preventing entry of pest species. The boundaries of areas to be quarantined can be accurately established after viewing the S-190B data. Better cultural methods can be employed such as planning where to plant certain crops that indirectly are detrimental to those already growing. This would relate to such factors as pesticide drift or alternate hosts of major pests.

  12. The use of Skylab data to study the early detection of insect infestations and density and distribution of host plants

    Science.gov (United States)

    Hart, W. G.; Ingle, S. J.; Davis, M. R.

    1975-01-01

    The detection of insect infestations and the density and distribution of host plants were studied using Skylab data, aerial photography and ground truth simultaneously. Additional ground truth and aerial photography were acquired between Skylab passes. Three test areas were selected: area 1, of high density citrus, was located northwest of Mission, Texas; area 2, 20 miles north of Weslaco, Texas, irrigated pastures and brush-covered land; area 3 covered the entire Lower Rio Grande Valley and adjacent areas of Mexico. A color composite picture of S-190A data showed patterns of vegetation on both sides of the Rio Grande River clearly delineating the possible avenues of entry of pest insects from Mexico into the United States or from the United States into Mexico. Vegetation that could be identified with conventional color and color IR film included: citrus, brush, sugarcane, alfalfa, irrigated and unimproved pastures.

  13. Impacts of Ridge-Furrow Planting on Salt Stress and Cotton Yield under Drip Irrigation

    Directory of Open Access Journals (Sweden)

    Chitao Sun

    2017-01-01

    Full Text Available Flat (F, mini-ditch (MD, and ridge-furrow (RF are three conventional cotton planting patterns that are usually adopted around the world, yet soil and crop responses to these three patterns are poorly studied, as is their suitability for increasing yield for coastal areas in Eastern China. The effects of three planting methods on water and salt dynamics as well as on growth and lint yield of cotton (Gossypium hirsutum L. were investigated in a saline field in Bohai Rim, China, to select the best planting pattern for cultivating coastal saline fields of Eastern China. Soil moisture in the root zone with RF was 11.9% and 12.1% higher than with F and MD, whereas the electrical conductivity of a saturated soil extract (ECe in the root zone with RF was 18.0% and 13.8% lower than with MD and F, respectively, during the growth period, which indicated that RF could efficiently collect rainfall and leach salt in the root zone. After drip irrigation, the infiltration and salt-leaching depth with RF were both deeper than that with F and MD. The stand establishment of MD was the highest (80.3% due to the greenhouse effect from film mulching, and was 12.8% and 4.6% higher than that with F and RF, respectively. Growth indicators and lint yield demonstrated that RF was superior to F and MD because of the higher soil moisture and lower ECe. The lint yield was significantly higher in RF, suggesting that RF can be an optimal planting pattern for agricultural reclamation in similar saline-alkaline areas around the world.

  14. Effects of planting date and plant density on crop growth of cut chrysanthemum

    NARCIS (Netherlands)

    Lee, J.H.; Heuvelink, E.; Challa, H.

    2002-01-01

    The effects of planting date (season) and plant density (32, 48 or 64 plants m-2) on growth of cut chrysanthemum (Chrysanthemum (Indicum group)) were investigated in six greenhouse experiments, applying the expolinear growth equation. Final plant fresh and dry mass and number of flowers per plant

  15. Plant Density Effect in Different Planting Dates on Growth Indices, Yield and

    Directory of Open Access Journals (Sweden)

    F Azizi

    2013-04-01

    Full Text Available In order to determine the appropriate plant density in different planting dates for sweet corn cultivar KSC403su, an experiment was conducted using a randomized complete block design in split plot lay out with three replications at Seed and Plant Improvement Institute in Karaj in 2006. Three planting dates (22 May, 5 June and 22 June were assigned as main plots and three plant densities (65000, 75000 and 85000 plants per hectare were considered as sub plots. Effect of planting date on row/ear, 1000 kernels weight, biological yield and harvest index was significant at 1% probability level and it was significant at 5% probability level for kernels/ear row and grain yield. All traits decreased with postponement of planting date to 5 June except for row/ear, kernels/row and grain yield. More delay in planting from 22 May to 22 June caused that grain yield was decreased significantly about 32.5% (from 14.45 to 9.78 ton/ha. Effect of plant density was significant at 1% probability level for all the traits. All of the traits decreased significantly with increasing plant density except for biological yield. The highest grain yield was resulted from 65000 plants per hectare density (14.20 ton/ha. Interaction effect of planting date and plant density was significant at 5% probability level for biological yield and harvest index but it wasn’t significant for the other traits. Growth indices decreased with delay in planting date and increasing plant density. Only leaf area index increased in more plant densities. From the results of this experiment it might be resulted that appropriate planting date to produce the highest grain yield is 22 May to 5 June for sweet corn cultivar KSC403su and also the highest grain yield can obtain from 65000 plants per hectare density.

  16. Crop yield response to deficit irrigation imposed at different plant growth stages

    International Nuclear Information System (INIS)

    Kovaks, T.; Kovaks, G.; Szito, J.

    1995-01-01

    A series of field experiments were conducted between 1991 - 1994 using 7 irrigation treatments at two fertilizer levels. Nitrogen fertilizers used were labelled with 15 N stable isotope to examine the effect of irrigation on the fertilizer N use efficiency by isotope technique. The irrigation were maintained at four different growth stages of maize, soybean and potato( vegetative, flowering, yield formation and ripening ) in 4 replicates. The aim of study was to compare deficit irrigation( i.e. the water stress imposed, during one growth stage ) with normal irrigation practice included the traditional one. Two watering regimes were established : (1) normal watering when available water was within the range of 60 - 90 %, and (2) deficit irrigation, when the AW was at 30 to 60 %. Neutron probe was used for measuring the soil water status and evaporation data were recorded to determine the amount of irrigation water demand. Reference evapotranspiration ( ETo) was calculated according to Penman - Monteith. Crop water requirement ( ETm) were determined in every year. Actual evapotranspiration ( ETa) was computed using CROPWAT: FAO computer program for irrigation planning and management (1992). Every irrigation treatment was equipped with neutron access tubes in two replicates at a depth from 10 to 130 cm. tensiometers were installed at depths of 30, 50, 60 and 80 cm in one replicate of treatments and were measured on a daily basis while neutron probe measurements were used to monitor the soil water table fluctuations. The irrigation method used was a special type of low pressure drop irrigation. There were measured the amount of rainfall with irrigation water supplied and the moisture distribution profiles were drown for the different treatments. Relationships between relative yield decrease and evapotranspiration and also between the crop yield and water use were determined. 9 tabs, 9 refs, ( Author )

  17. Adapting irrigation management to water scarcity: constraints of plant growth, hydraulics and carbon assimilation.

    Science.gov (United States)

    Water shortages are responsible for the greatest crop losses around the world and are expected to worsen. In arid areas where agriculture is dependent on irrigation, various forms of deficit irrigation management have been suggested to optimize crop yields for available soil water. The relationshi...

  18. Effect Of Cowpea Planting Density On Growth, Yield And ...

    African Journals Online (AJOL)

    Effect Of Cowpea Planting Density On Growth, Yield And Productivity Of Component Crops In Cowpea/Cassava Intercropping System. ... Similarly, fresh root yield (t/ha) of cassava was influenced by cropping system and population density in 2005/2006, but not in 2004/2005 cropping season. Cassava tuber yield was ...

  19. Modeling identifies optimal fall planting times and irrigation requirements for canola and camelina at locations across California

    Directory of Open Access Journals (Sweden)

    Nicholas George

    2017-06-01

    Full Text Available In California, Brassica oilseeds may be viable crops for growers to diversify their cool-season crop options, helping them adapt to projected climate change and irrigation water shortages. Field trials have found germination and establishment problems in some late-planted canola, but not camelina at the same locations. We used computer modeling to analyze fall seedbed conditions to better understand this phenomenon. We found seedbeds may be too dry, too cold, or both, to support germination of canola during late fall. Based on seedbed temperatures only, canola should be sown no later than the last week of November in the Central Valley. Camelina has broader temperature and moisture windows for germination and can be sown from October to December with less risk, but yields of camelina are lower than canola yields. In areas without irrigation, growers could plant canola opportunistically when seedbed conditions are favorable and use camelina as a fallback option.

  20. Monitoring of Lead (Pb) Pollution in Soils and Plants Irrigated with Untreated Sewage Water in Some Industrialized Cities of Punjab, India.

    Science.gov (United States)

    Sikka, R; Nayyar, V K

    2016-04-01

    Soil and plant samples were collected from sewage and tubewell irrigated sites from three industrially different cities of Punjab (India) viz. Ludhiana, Jalandhar and Malerkotla. The extent of lead (Pb) pollution was assessed with respect to background concentration of tubewell irrigation. In sewage irrigated surface soil layer (0-15 cm), the extent of Pb accumulation was 4.61, 4.20 and 2.26 times higher than those receiving tubewell irrigation sites in Ludhiana, Jalandhar and Malerkotla, respectively. Multiple regression analysis showed that soil pH, organic carbon, calcium carbonate and clay were significant soil parameters explaining the variation in available soil Pb. The mean Pb content in plants receiving sewage irrigation was 4.56, 5.48 and 2.72 times higher than tubewell irrigation in Ludhiana, Jalandhar and Malerkotla, respectively. The content of Pb in plants receiving sewage irrigation revealed that, assuming a weekly consumption of 500-1000 g of vegetables grown on sewage irrigated soils by an adult of 70 kg body weight, the Pb intake may far exceed the World Health Organization proposed tolerable weekly intake of Pb.

  1. Physiological response of soybean genotypes to plant density

    NARCIS (Netherlands)

    Gan, Y; Stulen, [No Value; van Keulen, H; Kuiper, PJC

    2002-01-01

    Response of soybean (Glycine max (L.) Merr.) to plant density has occupied a segment of agronomic research for most of the century. Genotype differences have been noted especially in response to planting date, lodging problems and water limitation. There is limited information on the physiological

  2. Nitrogen dose and plant density effects on popcorn grain yield ...

    African Journals Online (AJOL)

    and plant densities on grain yield and yield-related plant characteristics of popcorn in Hatay, located at Southern Mediterranean region of Turkey, during 2002 and 2003. The experiment was designed in a randomized complete block design with a split-plot arrangement with three replications. Nitrogen doses of 0, 120, 180 ...

  3. Evaluation of the Effect of Different Irrigation Levels of Drip Irrigation (Tape on Yield and Yield Components of Corn

    Directory of Open Access Journals (Sweden)

    mohammad karimi

    2016-02-01

    Full Text Available Introduction: One of the serious problems in the further development of maize cultivation is increasing irrigation efficiency. Using conventional irrigation causes a shortage of water resources to increase the acreage of the crop. With regard to the development of maize cultivation, agronomic and executable methods must be studied to reduce water consumption. Using drip irrigation system is most suitable for row crops. Hamedi et al. (2005 compared drip (tape and surface irrigation systems on yield of maize in different levels of water requirement and indicated that drip irrigation increases the amount of yield to 2015 kg/ha and water use efficiency to 3 time. Kohi et al. (2005 investigated the effects of deficit irrigation use of drip (tape irrigation on water use efficiency on maize in planting of one and two rows. The results showed that maximum water use efficiency related to crop density, water requirement and planting pattern 85000, 125% and two rows, respectively with 1.46 kg/m3. Jafari and Ashrafi (2011 studied the effects of irrigation levels, plant density and planting pattern in drip irrigation (tape on corn. The results showed that the amount of irrigation water and crop density on the level of 1% and their interactions and method of planting were significant at the 5 and 10% on water use efficiency, respectively. The yield was measured under different levels of irrigation, crop density and method of planting and the difference was significant on the level of 1%. Lamm et al. (1995 studied water requirement of maize in field with silt loam texture under sub drip irrigation and reported that water use reduced to 75%; but yield of maize remained at maximum amount of 12.5 t/ha. The objective of this study was to evaluate the drip (tape irrigation method for corn production practices in the Qazvin province in Iran. Materials and Methods: In this study, yield and yield components of corn (SC 704 were investigated under different levels of

  4. Influence of pH of acid irrigation water on the transfer of elements into rice plant from soils

    International Nuclear Information System (INIS)

    Maeno, Tomokazu; Tanizaki, Yoshiyuki

    1996-01-01

    Rice plant samples were grown in 14 cultivative pots under six different pH conditions of acid irrigation water (pH: 6.5, 6.0, 4.5, 3.5, 3.0. 2.5) and ion exchange water (pH: 7.5), in order to study an influence of pH of irrigation water on the transfer of elements into rice plant from soils. The acid irrigation water was prepared by adding mixed solution of 1N H 2 SO 4 and 1N HNO 3 (1:1) to ion exchange water. The rice grain yielded was separated into three parts, i.e., polished rice, bran and chaff and they were powdered one by one. The contents of twenty five elements in the three parts of grain (14 samples each) were determined by a neutron activation analysis. It was clarified that the contents of Cu, Zn, Fe, Cr, Mg, Rb, Mo, Ni, and Cs in the polished rice increased with decreasing pH of the acid irrigation water. The contents of Se and Br, on the contrary, decreased. Significant changes of the contents were not observed for Na, Al, Sc, Mn, Cl, Ca, V and Co. The relationships between the contents of elements in the bran or chaff and pH of the acid irrigation water were not so clear as the case of polished rice. The enrichment factor of trace elements from soils was calculated for the polished rice, bran and chaff The high enrichment of Cl, Mo, Zn, Se and Cu was observed in the polished rice. Manganese and Cr were concentrated more in the bran than in the polished rice. (author)

  5. Effect of integrated plant nutrition and irrigation scheduling on yield and yield components of maize (zea mays l.)

    International Nuclear Information System (INIS)

    Randhawa, M.S.; Maqsood, M.; Wajid, S.A.; Haq, A.U.

    2012-01-01

    Effect of three irrigation schedules (4-6 irrigations) and seven integrated plant nutrition levels (control, 125-60-62 kg N-P/sub 2/O/sub 5/-K/sub 2/O ha/sup -1/, 125-60-62 kg N-P/sub 2/O/sub 5/--K/sub 2/O ha/sup -1/ + Farmyard manure at the rate 10 t ha/sup -1/, 125-60-62 kg N-P/sub 2/O/sub 5/-K/sub 2/O ha/sup -1/ + Farm yard manure at the rate 15 t ha-1, 250-120-125 kg N-P/sub 2/O/sub 5/--K/sub 2/O ha-1, 250-120-125 kg N-P/sub 2/O/sub 5/ -K/sub 2/O ha/sup -1/ + Farmyard manure at the rate 10 t ha-1 and 250-120-125 kg N-P/sub 2/O/sub 5/--K/sub 2/O ha/sup -1/ + Farmyard manure at the rate 15 t ha/sup -1/) on grain yield and its components in maize were studied during 2009 and 2010. Plant height, number of cobs plant-1, number of grain rows cob-1, number of grains cob-1, 1000-grain weight, grain weight cob-1, grain yield, stover yield and biological yield were significantly affected by irrigation schedules and integrated plant nutrition levels during both years. The crop applied with six irrigations and fertilized by integrated application of chemical fertilizers (250-120-125 kg N-P/sub 2/O/sub 5/--K/sub 2/O ha/sup -1/) and farmyard manure (15 t ha/sup -1/) produced the highest grain yield of 8.47 t ha/sup -1/ and 8.22 t ha/sup -1/ during 2009 and 2010, respectively. (author)

  6. Accumulation, mobility and plant availability of heavy metals in soils irrigated with untreated sewage effluent in Central Mexico

    International Nuclear Information System (INIS)

    Siebe-Grabach, C.

    1994-01-01

    In Irrigation District 03, Tula, Mexico, wastewater from Mexico City has been used for irrigating agricultural land since the beginning of this century. Today, approximately 85 000 ha are irrigated, alfalfa and maize being the main crops. The sewage effluent does not receive any treatment previous to its evacuation to this irrigation district, and only a part of the water is stored in the Endho Dam before being used, receiving in this way a kind or primary treatment through the sedimentation processes taking place. The reuse of wastewater for agricultural purposes represents an economic source of water and nutrients and has become an important disposal alternative for Mexico City. Nevertheless the contaminants and pathogens contained in the water represent a potential public health hazard and the production capacity of the soils. The aim of the present investigation is to determine the actual contamination levels of heavy metals (Pb, Cd, Cu, Zn) in soils, analysing the accumulation tendencies in time and space, and also to characterize their mobility and plant availability and thus their ecotoxicity. (orig.) [de

  7. Early Growth of Improved Acacia mangium at Different Planting Densities

    Directory of Open Access Journals (Sweden)

    Arif Nirsatmanto

    2016-08-01

    Full Text Available Integrating tree improvement into silvicultural practices is essential in forest plantation. Concerning this fact, Acacia mangium spacing trial planted using genetically improved seed was established in West Java. This study was aimed to evaluate the impact of ages and planting density on early growth of improved seed A. mangium in the spacing trial. Improved seed from 2 seed orchards (SSO-5 and SSO-20 and a control of unimproved seed from seed stand (SS-7 were tested together in spacing 3 × 3 m and 2 × 2 m. Height, diameter, stem volume, and stand volume were observed at 3 ages. The results showed that improved seed consistently outperformed to unimproved seed. Ages were highly significant for all traits, but the significant difference varied among traits and seed sources for planting density and the interactions. High density performed better growth than low density at first year, and they were varied in subsequent ages depending on traits and seed sources. Improved seed from less intensity selection orchard was less tolerance to high density than that from high intensity selection orchard, but the tolerance was reversed in low density. Improved seed A. mangium from different level of genetic selection has responded differently in behavior to the changes of planting density.

  8. Productive performance of soybean cultivars grown in different plant densities

    Directory of Open Access Journals (Sweden)

    Augusto Belchior Marchetti Ribeiro

    Full Text Available ABSTRACT: Plants density in soybean cultivation is an important management practice to achieve high grain yield. In this way, the objective was to evaluate the agronomic traits and grain yield in soybean in different plant densities, in two locations in the south of Minas Gerais. The experimental design was in randomized blocks, arranged in a split plot design, with three replications. Plots were composed of four population densities (300, 400, 500 and 600 thousand plants per hectare and the subplots were composed of six cultivars (‘BMX Força RR’, ‘CD 250 RR’, ‘FMT 08 - 60.346/1’, ‘NA 5909 RR’, ‘TMG 7161 RR’ and ‘V - TOP RR’ grown in Lavras and Inconfidentes, both in Minas Gerais. At the time of harvest was determined the plant height, lodging, insertion of the first pod, harvest index, number of pods per plant, number of grains, number of grains per pod and yield. Regardless of the soybean cultivar, the plant density of up to 600,000 per ha does not affect grain yield, plant height, lodging, harvest index, and number of grains per pod. The cultivars ‘V-TOP RR’ and ‘BMX FORÇA RR’ showed high grain yield and good agronomic traits in Lavras and Incofidentes.

  9. Uptake of pharmaceutical and personal care products by soybean plants from soils applied with biosolids and irrigated with contaminated water.

    Science.gov (United States)

    Wu, Chenxi; Spongberg, Alison L; Witter, Jason D; Fang, Min; Czajkowski, Kevin P

    2010-08-15

    Many pharmaceuticals and personal care products (PPCPs) are commonly found in biosolids and effluents from wastewater treatment plants. Land application of these biosolids and the reclamation of treated wastewater can transfer those PPCPs into the terrestrial and aquatic environments, giving rise to potential accumulation in plants. In this work, a greenhouse experiment was used to study the uptake of three pharmaceuticals (carbamazepine, diphenhydramine, and fluoxetine) and two personal care products (triclosan and triclocarban) by an agriculturally important species, soybean (Glycine max (L.) Merr.). Two treatments simulating biosolids application and wastewater irrigation were investigated. After growing for 60 and 110 days, plant tissues and soils were analyzed for target compounds. Carbamazepine, triclosan, and triclocarban were found to be concentrated in root tissues and translocated into above ground parts including beans, whereas accumulation and translocation for diphenhydramine and fluoxetine was limited. The uptake of selected compounds differed by treatment, with biosolids application resulting in higher plant concentrations, likely due to higher loading. However, compounds introduced by irrigation appeared to be more available for uptake and translocation. Degradation is the main mechanism for the dissipation of selected compounds in biosolids applied soils, and the presence of soybean plants had no significant effect on sorption. Data from two different harvests suggest that the uptake from soil to root and translocation from root to leaf may be rate limited for triclosan and triclocarban and metabolism may occur within the plant for carbamazepine.

  10. Predictive Control Applied to a Solar Desalination Plant Connected to a Greenhouse with Daily Variation of Irrigation Water Demand

    Directory of Open Access Journals (Sweden)

    Lidia Roca

    2016-03-01

    Full Text Available The water deficit in the Mediterranean area is a known matter severely affecting agriculture. One way to avoid the aquifers’ exploitation is to supply water to crops by using thermal desalination processes. Moreover, in order to guarantee long-term sustainability, the required thermal energy for the desalination process can be provided by solar energy. This paper shows simulations for a case study in which a solar multi-effect distillation plant produces water for irrigation purposes. Detailed models of the involved systems are the base of a predictive controller to operate the desalination plant and fulfil the water demanded by the crops.

  11. Saline irrigation water and its effect on N.use efficiency, growth and yield of Sorghum plant using 15N

    International Nuclear Information System (INIS)

    Abd El-Latteef, E.M.

    2010-01-01

    Series of pot experiments were conducted and randomly arranged under greenhouse conditions for evaluating the effect of irrigation with saline water (alternative source) in combination with different organic sources (amendments) i.e. leucaena plant residue (LU), Quail feces (QF) and chicken manure (ChM) added in different percentages against the mineral form (ammonium sulfate) either in ordinary or 15 N labeled (2 and 5% 15 N atom excess) forms, on sorghum growth and nutrients acquisition. Artificial saline water with different EC and SAR values was prepared at laboratory using computer program designed by the author with guiding of the designed Package named Artificial Saline Irrigation Water (ASIW) (Manual of Salinity Research Methods). In addition, proline acid was also sprayed (foliar) on leaves of sorghum plants at different concentrations. The experimental results indicated the positive effect of organic amendments, as compared to mineral fertilizer, and foliar application of proline acid on enhancement of plant growth and nutrient uptake. This phenomenon was pronounced under water salinity conditions. In this regard, increasing of water salinity levels induced reduction in plant growth as well as nutrients acquisition. Data of 14 N/ 15 N ratio analysis pointed out enhancement of N derived from mineral source as affected by organic amendments. At the same time, considerable amounts of N was derived from organic sources and utilized by plants. The superiority of organic sources on each others was fluctuated depending on interaction with water salinity levels and proline concentrations. In conclusion, organic additives and proline acid has an improvement effects especially under adverse condition of irrigation water salinity.

  12. Nitrogen Recovered By Sorghum Plants As Affected By Saline Irrigation Water And Organic/Inorganic Resources Using 15N Technique

    International Nuclear Information System (INIS)

    ABOU-ELKHAIR, R.A.; EL-MOHTASEM, M.O.; SOLIMAN, S.M.; GALAL, Y.G.M.; ABD EL-LATIF, E.M.

    2009-01-01

    A pot experiment was conducted in the green house of Soil and Water Department, Nuclear Research Centre, Atomic Energy Authority, Egypt, to follow up the effect of saline irrigation water, inorganic and organic fertilizers on sorghum growth and N fractions that recovered by plant organs. Two types of artificial water salinity were used; one has 3 dS m -1 salinity level with 4 and 8 SAR and the second one has 3 and 6 dS m -1 salinity levels with 6 SAR . Leucenae residue and chicken manure were applied as organic sources at rate of 2% v/v. Sorghum was fertilized with recommended doses of super phosphate and potassium sulfate at rate of 150 kg P and 50 kg K per feddan, respectively. Labelled ammonium sulfate with 5% 15 N atom excess was applied to sorghum at rate of 100 kg N fed -1 . Dry matter yield (stalks and roots) was negatively affected by increasing water salinity levels or SAR ratios. Similar trend was recorded with N uptake by either stalks or roots of sorghum plants. On the other hand, both the dry matter yield and N uptake were positively and significantly affected by incorporation of organic sources in comparison to the untreated control. In this regard, the dry matter yield and N uptake induced by incorporation of chicken manure was superior over those recorded with leucenae residues. It means, in general, that the incorporation of organic sources into the soil may maximize the plant ability to combat the hazards effects caused by irrigation with saline water. Nitrogen derived from fertilizer (% Ndff), soil (% Ndfs) and organic resources (% Ndfr) showed frequent trends as affected by water salinity and organic resources but in most cases, severe reduction of these values was recorded when plants were irrigated with saline water. In the same time, plants were more dependent on N derived from organic sources than those derived from mineral fertilizer. Superiority of one organic source over the other was related to water salinity levels and SAR ratios

  13. Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada

    International Nuclear Information System (INIS)

    Mihok, S.; Wilk, M.; Lapp, A.; St-Amant, N.; Kwamena, N.-O.A.; Clark, I.D.

    2016-01-01

    The dynamics of tritium released from nuclear facilities as tritiated water (HTO) have been studied extensively with results incorporated into regulatory assessment models. These models typically estimate organically bound tritium (OBT) for calculating public dose as OBT itself is rarely measured. Higher than expected OBT/HTO ratios in plants and soils are an emerging issue that is not well understood. To support the improvement of models, an experimental garden was set up in 2012 at a tritium processing facility in Pembroke, Ontario to characterize the circumstances under which high OBT/HTO ratios may arise. Soils and plants were sampled weekly to coincide with detailed air and stack monitoring. The design included a plot of native grass/soil, contrasted with sod and vegetables grown in barrels with commercial topsoil under natural rain and either low or high tritium irrigation water. Air monitoring indicated that the plume was present infrequently at concentrations of up to about 100 Bq/m"3 (the garden was not in a major wind sector). Mean air concentrations during the day on workdays (HTO 10.3 Bq/m"3, HT 5.8 Bq/m"3) were higher than at other times (0.7–2.6 Bq/m"3). Mean Tissue Free Water Tritium (TFWT) in plants and soils and OBT/HTO ratios were only very weakly or not at all correlated with releases on a weekly basis. TFWT was equal in soils and plants and in above and below ground parts of vegetables. OBT/HTO ratios in above ground parts of vegetables were above one when the main source of tritium was from high tritium irrigation water (1.5–1.8). Ratios were below one in below ground parts of vegetables when irrigated with high tritium water (0.4–0.6) and above one in vegetables rain-fed or irrigated with low tritium water (1.3–2.8). In contrast, OBT/HTO ratios were very high (9.0–13.5) when the source of tritium was mainly from the atmosphere. TFWT varied considerably through time as a result of SRBT's operations; OBT/HTO ratios showed no clear

  14. Aruscular mycorhizal fungi alter plant allometry and biomass - density relationships

    DEFF Research Database (Denmark)

    Zhang, Qian; Zhang, Lu; Weiner, Jacob

    2011-01-01

    Background and Aims Plant biomass–density relationships during self-thinning are determined mainly by allometry. Both allometry and biomass–density relationship have been shown to vary with abiotic conditions, but the effects of biotic interactions have not been investigated. Arbuscular mycorrhizal....... In self-thinning populations, the slope of the log (mean shoot biomass) vs. log density relationship was significantly steeper for the high AMF treatment (slope = –1·480) than for the low AMF treatment (–1·133). The canopy radius–biomass allometric exponents were not significantly affected by AMF level...

  15. EFFECTS OF PLANT DENSITY AND NPK APPLICATION ON THE ...

    African Journals Online (AJOL)

    Dr. K.E. Law-Ogbomo

    and livestock industries. Nigeria is the ... planting density and NPK fertilizer application rate on the growth and yield of D. rotundata in ..... Clay (%). 10.90. 11.00. 22.60. Silt (%). 8.60. 11.00. 23.40. Sand (%). 80.50. 78.00 .... Institute of food and.

  16. effect of plant density and land race on the growth

    African Journals Online (AJOL)

    COMPUTER UNIT

    Key words: optimum plant density sweet potato landraces and yield. ..... From this work it can be seen that improved management practices play a role in obtaining ... 22.2. 24.7. 21.4. 22.2. SED D. 5.23. 6.15. SED V. 5.23. 6.15. SED D xV. 10.46.

  17. Maximizing plant density affects broccoli yield and quality

    Science.gov (United States)

    Increased demand for fresh market bunch broccoli (Brassica oleracea L. var. italica) has led to increased production along the United States east coast. Maximizing broccoli yields is a primary concern for quickly expanding southeastern commercial markets. This broccoli plant density study was carr...

  18. Ambit determination method in estimating rice plant population density

    Directory of Open Access Journals (Sweden)

    Abu Bakar, B.,

    2017-11-01

    Full Text Available Rice plant population density is a key indicator in determining the crop setting and fertilizer application rate. It is therefore essential that the population density is monitored to ensure that a correct crop management decision is taken. The conventional method of determining plant population is by manually counting the total number of rice plant tillers in a 25 cm x 25 cm square frame. Sampling is done by randomly choosing several different locations within a plot to perform tiller counting. This sampling method is time consuming, labour intensive and costly. An alternative fast estimating method was developed to overcome this issue. The method relies on measuring the outer circumference or ambit of the contained rice plants in a 25 cm x 25 cm square frame to determine the number of tillers within that square frame. Data samples of rice variety MR219 were collected from rice plots in the Muda granary area, Sungai Limau Dalam, Kedah. The data were taken at 50 days and 70 days after seeding (DAS. A total of 100 data samples were collected for each sampling day. A good correlation was obtained for the variety of 50 DAS and 70 DAS. The model was then verified by taking 100 samples with the latching strap for 50 DAS and 70 DAS. As a result, this technique can be used as a fast, economical and practical alternative to manual tiller counting. The technique can potentially be used in the development of an electronic sensing system to estimate paddy plant population density.

  19. Active condensation of the atmospheric moisture as a self-irrigation mechanism for the ground-covering plants

    Directory of Open Access Journals (Sweden)

    Karpun Yuriy Nikolaevich

    2015-12-01

    Full Text Available Studies conducted at the Subtropical Botanical Garden of Kuban (Utch-Dere, Sochi pretty much allow to explain the abnormally high drought resistance of Liriope graminifolia Lour. and Ophiopogon japonicus Ker.-Gawl., plants that naturally grow mostly in sufficient humidity. Quite low temperatures of the leaves’ surface allow to effectively condense the atmospheric moisture and to direct it along the leaf blade to the ground. The accumulation of condensation water leads to self-irrigation, a mechanism that ensures survival of plants in case of insufficient natural precipitation in the form of rain or fog. Combined with xeromorphic leaves with a thick cuticle and thick branch roots with fusiform bulb-shaped swellings, allowing to store water, makes the named plants extremely resistant to stress factors such as prolonged summer droughts accompanied by high daytime temperatures.

  20. A comparison of E. coli persistence on basil plants and soil using drip and overhead irrigation

    Science.gov (United States)

    Introduction: It is estimated that each year in the US there are 63,153 cases of foodborne illnesses caused by E.coli O157 serotypes and 112,752 illnesses caused by non-O157 shiga-toxin producing E.coli. Irrigation water is recognized as a pre-harvest contamination source and has been linked with o...

  1. Soil moisture and plant canopy temperature sensing for irrigation application in cotton

    Science.gov (United States)

    A wireless sensor network was deployed in a cotton field to monitor soil water status for irrigation. The network included two systems, a Decagon system and a microcontroller-based system. The Decagon system consists of soil volumetric water-content sensors, wireless data loggers, and a central data...

  2. Identification of Water Usage Efficiency for Corn(Zea mays L.Lines Irrigated with Drip Irrigation Under Green House Conditions asPer Plant Water Stress Index Evaluations

    Directory of Open Access Journals (Sweden)

    Ali Beyhan UÇAK

    2017-02-01

    Full Text Available The present study was conducted as a greenhouse study under Çukurova conditions during the years2011-2012. Two different dent corn lines (5A2-B and 22K were used as the plant material of the experiments. Crop water stress index (CWSI values determined through leaf canopy temperature measurements performed ahead of irrigations were used to find outwater use efficiencies. Experiments were conducted in randomized blocks-split plots experimental design with three replications. Drip irrigation was used for irrigations and two different irrigation programs were created as of I100(supplying 100% of depleted water in every seven days and I75(applying 75% of depleted water. The amount of irrigation water applied for in the interaction of I100irrigation and corn lines (5A2-B and22K in the first and second year were respectively varied between 253.0-274.0and between 238.0-261.0mm, seasonal plant water consumptions varied between 294.0-305.0and between 284.6-302.6 mm, kernel yields varied between 2950.0-2990.0 and between 3130.0-3186.0kgha-1. With regard to (in the interaction irrigation treatments xcorn lines, the lowest and the highest CWSI values were observed in the interaction full irrigation (I100 and of the line 22K as 0.22 and in deficit irrigation treatment (I75 of the line 5A2-B as 0.41in the first year; in full irrigation treatment (I100 of the line 22K as 0.20 and in deficit irrigation treatment (I75 of the line 5A2-B as 0.36. The greatest and the lowest chlorophyll contents (in the interaction irrigation treatments x corn lines were respectively observed in I100treatment of the line 22K as 58.3 spad and in I75treatment of the line 5A2-Bas 50.9 spad in the first year; in I100treatment of the line 22K as 59.1 SPAD and in I75treatment of the line 5A2-B as 55.1 spad. While the effects of irrigation treatments on average dry matter contents of the lines were not found to be significant, significant differences were observed in water use efficiency

  3. Effect of plant growth-promoting rhizobacteria (PGPRs) on plant growth, yield, and quality of tomato (Lycopersicon esculentum Mill.) under simulated seawater irrigation.

    Science.gov (United States)

    Shen, Min; Jun Kang, Yi; Li Wang, Huan; Sheng Zhang, Xiang; Xin Zhao, Qing

    2012-01-01

    To determine the effects of three PGPRs on plant growth, yield, and quality of tomato under simulated seawater irrigation, a two consecutive seasons' field experiment was conducted in Yancheng Teachers University plot from April to June and August to October, 2011. The results showed that Erwinia persicinus RA2 containing ACC deaminase exhibited the best ability compared with Bacillus pumilus WP8 and Pseudomonas putida RBP1 which had no ACC deaminase activity to enhance marketable yields of fresh and dried fruits in tomato under simulated seawater irrigation especially under HS condition. B. pumilus WP8 had significant effects on improving tomato fruit quality under the conditions of irrigating with 1.0% NaCl solution (MS) and with 2.0% NaCl solution (HS). Na(+) contents were generally accumulated much more in tomato plant mid-shoot leaves than in fruits whatever the salt concentration. More sodium accumulation in leaves of E. persicinus RA2 and B. pumilus WP8 treatments under HS condition were found than in control. E. persicinus RA2 and B. pumilus WP8 can promote tomato growth, improve fruit quality more firmly than P. putida RBP1 during two consecutive seasons. Our study suggested that E. persicinus RA2 and B. pumilus WP8 are considered to be promising PGPR strains which are suited for application in salt marsh planting, ACC deaminase activity was not unique index on screening for PGPRs with the aim of salt stress tolerance, and plant growth promoting activities may be relevant to different growth indices and different stress conditions.

  4. Local variation in conspecific plant density influences plant-soil feedback in a natural grassland

    NARCIS (Netherlands)

    Kos, M.; Veendrick, Johan; Bezemer, T.M.

    2013-01-01

    Several studies have argued that under field conditions plant–soil feedback may be related to the local density of a plant species, but plant–soil feedback is often studied by comparing conspecific and heterospecific soils or by using mixed soil samples collected from different locations and plant

  5. Effects of Planting Date and Plant Density on Physiological Indices, Quantity and Quality Traits of Two Varieties of Marigold (Calendula officinalis L.

    Directory of Open Access Journals (Sweden)

    A Sepehri

    2016-07-01

    physiological indices, quantity and quality traits of two varieties of marigold (Calendula officinalis L., a split-factorial experiment with three replications was carried out in agricultural research station in Arak (latitude: 34o 5' N; longitude: 29o 42' E; 1757 m altitude in 2010 the growing season. Soil was silty-loamy with pH of 7.5 and EC of 0.8 Ds ms-1. The experimental factors included two planting dates (22 April and 2 May, four planting densities (26, 32, 41 and 57 plants/m2 and two varieties (sparse and compact petal. Thinning was performed 20 days after cultivation. Irrigation was carried out in 7 days intervals. For determination of growth indices, ten plants from each plot cut from crown and dried for 48 h in oven at 70°C and then weighted. The plant height, number of flowers per plant, leaf chlorophyll, leaf area index, total dry matter, seed yield, 1000 seed weight, essential oil and grain oil were measured. The extraction of the essential oil of the flower was performed using the Clevenger apparatus by steam distillation (1. Extraction of grain, oil was accomplished according to the soxhelet standard method. The data were analyzed using the statistical analysis system (SAS 9.1 and means were compared using Duncan test at P ≤ 0.05 probability. Results and Discussion Results showed that, planting date and plant density had significant effects on physiological indices, plant height, and number of flowers per plant, 1000 grain weight, chlorophyll index, oil percent and essential oil percentage of marigold. Late planting and decreasing plant density, reduced leaf area index (LAI, total dry weight (TDW and crop growth rate (CGR indices. The compact petal variety showed the highest growth indices compared with spare petal plants. On the other hand, early planting, high plant density and compact petal variety increased the growth and development of plants. The first planting date had higher leaf area index compared to second sowing date. It seems that first sowing

  6. Irrigation, Planting Date And Intra-Row Spacing Effects On Soybean Grown Under Dry Farming Systems

    OpenAIRE

    Ismail, A. M. A. [احمد محمد علي اسماعيل; Khalifa, F. M.

    1987-01-01

    Two soybean cultivars (Glycine maxima (L) Merr.) differing in maturity period, leaf size and stem height were sown five times at fortnight intervals during the rainy season at four intra—row spacings under supplementary irrigation at one site and under rainfed conditions at another site in the central rainlands of Sudan. Cultivars responded differently to the system of production. Sowing date and moisture availability were the main factors controlling soybean production. The late maturing cul...

  7. Lettuce facing microcystins-rich irrigation water at different developmental stages: Effects on plant performance and microcystins bioaccumulation.

    Science.gov (United States)

    Levizou, Efi; Statiris, George; Papadimitriou, Theodoti; Laspidou, Chrysi S; Kormas, Konstantinos Ar

    2017-09-01

    This study investigated the microcystins (MCs)-rich irrigation water effect on lettuce of different developmental stages, i.e. during a two months period, covering the whole period from seed germination to harvest at marketable size of the plant. We followed four lettuce plant groups receiving MCs-rich water (1.81μgl -1 of dissolved MCs), originating from the Karla Reservoir, central Greece: 1) from seeds, 2) the cotyledon, 3) two true leaves and 4) four true leaves stages, all of which were compared to control plants that received tap water. Lettuce growth, photosynthetic performance, biochemical and mineral characteristics, as well as MCs accumulation in leaves, roots and soil were measured. The overall performance of lettuce at various developmental stages pointed to increased tolerance since growth showed minor alterations and non-enzymatic antioxidants remained unaffected. Plants receiving MCs-rich water from the seed stage exhibited higher photosynthetic capacity, chlorophylls and leaf nitrogen content. Nevertheless, considerable MCs accumulation in various plant tissues occurred. The earlier in their development lettuce plants started receiving MCs-rich water, the more MCs they accumulated: roots and leaves of plants exposed to MCs-rich water from seeds and cotyledons stage exhibited doubled MCs concentrations compared to respective tissues of the 4 Leaves group. Furthermore, roots accumulated significantly higher MCs amounts than leaves of the same plant group. Concerning human health risk, the Estimated Daily Intake values (EDI) of Seed and Cotyledon groups leaves exceeded Tolerable Daily Intake (TDI) by a factor of 6, while 2 Leaves and 4 Leaves groups exceeded TDI by a factor of 4.4 and 2.4 respectively. Our results indicate that irrigation of lettuce with MCs-rich water may constitute a serious public health risk, especially when contaminated water is received from the very early developmental stages (seed and cotyledon). Finally, results obtained for

  8. The determination of bulk (apparent) density of plant fibres by density method

    International Nuclear Information System (INIS)

    Sharifah Hanisah Syed Abd Aziz; Raja Jamal Raja hedar; Zahid Abdullah

    2004-01-01

    The absolute density of plant fibres excludes all pores and lumen and therefore is a measure of the solid matter of the fibres. On the other hand the bulk density, which is being discussed here, includes all the solid matter and the pores of the fibres. In this work, the apparent density of the fibre was measured by using the Archimedes principle, which involves the immersion of a known weight of fibre into a solvent of lower density than the fibre. Toluene with a density of about 860 kg/m3 was chosen as a solvent. A tuft of fibre was weighed and recorded as W fa . The fibre was then immersed in toluene, which wetted the fibre, and made to rest on the weighing pan submerged in the solvent and the weight of the immersed fibre was recorded as W fs . The apparent density was then calculated using the equation. All the measurements were taken at room temperature. The fibre samples were not oven dried prior to measurement. (Author)

  9. Effects of irrigation levels on interactions among Lygus hesperus (Hemiptera: Miridae), insecticides, and predators in cotton.

    Science.gov (United States)

    Asiimwe, Peter; Naranjo, Steven E; Ellsworth, Peter C

    2014-04-01

    Variation in plant quality and natural enemy abundance plays an important role in insect population dynamics. In manipulative field studies, we evaluated the impact of varying irrigation levels and insecticide type on densities of Lygus hesperus Knight and the arthropod predator community in cotton. Three watering levels were established via irrigations timed according to three levels of percent soil water depletion (SWD): 20, 40, or 60, where 40% SWD is considered standard grower practice, 60% represents a deficit condition likely to impose plant productivity losses, and 20% represents surplus conditions with likely consequences on excessive vegetative plant production. The two key L. hesperus insecticides used were the broad-spectrum insecticide acephate and the selective insecticide flonicamid, along with an untreated check. We hypothesized that densities of L. hesperus and its associated predators would be elevated at higher irrigation levels and that insecticides would differentially impact L. hesperus and predator dynamics depending on their selectivity. L. hesperus were more abundant at the higher irrigation level (20% SWD) but the predator densities were unaffected by irrigation levels. Both L. hesperus and its predators were affected by the selectivity of the insecticide with highest L. hesperus densities and lowest predator abundance where the broad spectrum insecticide (acephate) was used. There were no direct interactions between irrigation level and insecticides, indicating that insecticide effects on L. hesperus and its predators were not influenced by the irrigation levels used here. The implications of these findings on the overall ecology of insect-plant dynamics and yield in cotton are discussed.

  10. Effect of sea salt irrigation on plant growth, yield potential and some biochemical attributes of carissa carandas

    International Nuclear Information System (INIS)

    Tayyab, A.

    2016-01-01

    Carissa carandas (varn. Karonda) is an edible and medicinal plant having ability to grow in saline and water deficit conditions, however, little is known about its salinity tolerance. Therefore, the effect of salinity on vegetative (height and volume), reproductive (number of flowers and number, size and weight of fruits) and some biochemical parameters (leaf pigments, ions, soluble sugars, proteins, and phenols) of C. carandas were studied. Plants were grown in drum pot culture and irrigated with non-saline or saline water of 0.6% and 0.8% sea salt concentrations, for a period of 30 months. Results showed that, plant height, and canopy volume decreased with increasing salinity. The chlorophyll contents and chlorophyll a/b ratio followed the similar trend as for growth, however, carotenoids increased at 0.6% sea salt and subsequently decreased in higher salinity. Unchanged soluble sugar and protein content at 0.6% sea salt, as compared to control, could be attributed to leaf osmotic adjustments which decreased with further increase in salinity. Linear increase in soluble phenols and carotenoid/chlorophyll ratio indicating a protective strategy of C. carandas to minimize photo-damage. Besides increasing Na+ and decreasing K+ contents, plant seemed to maintain K+/Na+ ratio (above 1), especially at 0.6 sea salt, which disturbed at higher salinity. Salinity adversely affected reproductive growth of C. carandas where, production of flowers, and fruits were significantly reduced. In addition, fresh and dry weights of fruits decreased with increasing salinity, but salinity did not affect fruit length and diameter. Present study provides basic information related to plant growth, fruit yield and some biochemical attributes, which suggest that C. carandas is moderately salt tolerant plant. This plant showed potential to grow on saline marginal lands using brackish water irrigation and provide biomass for edible and medicinal purposes. However, in-depth analysis of field and

  11. Relative floral density of an invasive plant affects pollinator foraging behaviour on a native plant

    Directory of Open Access Journals (Sweden)

    Amy Marie Iler

    2014-08-01

    Full Text Available Interactions between invasive and native plants for pollinators vary from competition to facilitation of pollination of native plants. Theory predicts that relative floral densities should account for some of this variation in outcomes, with facilitation at low floral densities and competition at high floral densities of the invader. We tested this prediction by quantifying pollination and female reproductive success of a native herb, Geranium maculatum, in three experimental arrays that varied in floral density of the invasive shrub Lonicera maackii: control (no L. maackii, low floral density of L. maackii, and high floral density of L. maackii. A low density of L. maackii flowers was associated with an increase in pollinator visitation rate to G. maculatum flowers and an increase in conspecific pollen deposition compared to controls and high density arrays. Increased visitation rates were not associated with an increase in the number of visitors to low density arrays, suggesting instead that a behavioural switch in visitation within the array accounted for increased pollen deposition. In contrast, the only evidence of competition in high density arrays was a shorter duration of visits to G. maculatum flowers relative to the other treatments. The number of seeds per flower did not vary among treatments, although trends in seeds per flower were consistent with patterns of pollinator foraging behaviour. Given increased pollinator visits and pollen deposition at a low density of the invader, our study indicates that complete eradication of invasives as a management or restoration technique may have unintended negative consequences for pollination of native plants.

  12. Crop growth, light utilization and yield of relay intercropped cotton as affected by plant density and a plant growth regulator

    NARCIS (Netherlands)

    Mao, L.; Zhang, L.; Zhao, X.; Liu, S.; Werf, van der W.; Zhang, S.; Spiertz, J.H.J.; Li, Z.

    2014-01-01

    Modern cotton cultivation requires high plant densities and compact plants. Here we study planting density and growth regulator effects on plant structure and production of cotton when the cotton is grown in a relay intercrop with wheat, a cultivation system that is widespread in China. Field

  13. Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada.

    Science.gov (United States)

    Mihok, S; Wilk, M; Lapp, A; St-Amant, N; Kwamena, N-O A; Clark, I D

    2016-03-01

    The dynamics of tritium released from nuclear facilities as tritiated water (HTO) have been studied extensively with results incorporated into regulatory assessment models. These models typically estimate organically bound tritium (OBT) for calculating public dose as OBT itself is rarely measured. Higher than expected OBT/HTO ratios in plants and soils are an emerging issue that is not well understood. To support the improvement of models, an experimental garden was set up in 2012 at a tritium processing facility in Pembroke, Ontario to characterize the circumstances under which high OBT/HTO ratios may arise. Soils and plants were sampled weekly to coincide with detailed air and stack monitoring. The design included a plot of native grass/soil, contrasted with sod and vegetables grown in barrels with commercial topsoil under natural rain and either low or high tritium irrigation water. Air monitoring indicated that the plume was present infrequently at concentrations of up to about 100 Bq/m(3) (the garden was not in a major wind sector). Mean air concentrations during the day on workdays (HTO 10.3 Bq/m(3), HT 5.8 Bq/m(3)) were higher than at other times (0.7-2.6 Bq/m(3)). Mean Tissue Free Water Tritium (TFWT) in plants and soils and OBT/HTO ratios were only very weakly or not at all correlated with releases on a weekly basis. TFWT was equal in soils and plants and in above and below ground parts of vegetables. OBT/HTO ratios in above ground parts of vegetables were above one when the main source of tritium was from high tritium irrigation water (1.5-1.8). Ratios were below one in below ground parts of vegetables when irrigated with high tritium water (0.4-0.6) and above one in vegetables rain-fed or irrigated with low tritium water (1.3-2.8). In contrast, OBT/HTO ratios were very high (9.0-13.5) when the source of tritium was mainly from the atmosphere. TFWT varied considerably through time as a result of SRBT's operations; OBT/HTO ratios showed no clear temporal

  14. Arbuscular mycorrhizal fungi alleviate abiotic stresses in potato plants caused by low phosphorus and deficit irrigation/partial root-zone drying

    DEFF Research Database (Denmark)

    Liu, Caixia; Ravnskov, Sabine; Lui, Fulai

    2018-01-01

    Deficit irrigation (DI) improves water use efficiency (WUE), but the reduced water input often limits plant growth and nutrient uptake. The current study examined whether arbuscular mycorrhizal fungi (AMF) could alleviate abiotic stress caused by low phosphorus (P) fertilization and DI...... or improved plant growth and P/nitrogen (N) uptake when subjected to DI/PRD and P0. However, the positive responses to AMF varied with P level and irrigation regime. Functional differences were found in ability of AMF species alleviating plant stress. The largest positive plant biomass response to M1+ and M2......+ was found under FI, both at P1 and P0 (25% increase), while plant biomass response to M1+ and M2+ under DI/PRD (14% increase) was significantly smaller. The large growth response to AMF inoculation, particularly under FI, may relate to greater photosynthetic capacity and leaf area, probably caused...

  15. Soil Nutrient Availability, Plant Nutrient Uptake, and Wild Blueberry (Vaccinium angustifolium Ait. Yield in Response to N-Viro Biosolids and Irrigation Applications

    Directory of Open Access Journals (Sweden)

    Aitazaz A. Farooque

    2012-01-01

    Full Text Available We compared the impact of surface broadcasted N-Viro biosolids and inorganic fertilizer (16.5% Ammonium sulphate, 34.5% Diammonium phosphate, 4.5% Potash, and 44.5% s and/or clay filler applications on soil properties and nutrients, leaf nutrient concentration, and the fruit yield of lowbush blueberry under irrigated and nonirrigated conditions during 2008-2009 at Debert, NS, Canada. Application rates of N-Viro biosolids were more than double of inorganic fertilizer applied at a recommended N rate of 32 kg ha−1. The experimental treatments NI: N-Viro with irrigation, FI: inorganic fertilizer with irrigation, N: N-Viro without irrigation, and F: inorganic fertilizer without irrigation (control were replicated four times under a randomized complete block design. The NI treatment had the highest OM (6.68% followed by FI (6.32%, N (6.18%, and F (4.43% treatments during the year 2008. Similar trends were observed during 2009 with the highest soil OM values (5.50% for NI treatment. Supplemental irrigation resulted in a 21% increase in the ripe fruit yield. Nonsignificant effect of fertilizer treatments on most of the nutrient concentrations in soil and plant leaves, and on ripe fruits yield reflects that the performance of N-Viro was comparable with that of the inorganic fertilizer used in this study.

  16. Using ISBA model for partitioning evapotranspiration into soil evaporation and plant transpiration of irrigated crops under semi-arid climate

    Science.gov (United States)

    Aouade, Ghizlane; Jarlan, Lionel; Ezzahar, Jamal; Er-raki, Salah; Napoly, Adrien; Benkaddour, Abdelfettah; Khabba, Said; Boulet, Gilles; Chehbouni, Abdelghani; Boone, Aaron

    2016-04-01

    The Haouz region, typical of southern Mediterranean basins, is characterized by a semi-arid climate, with average annual rainfall of 250, whilst evaporative demand is about 1600 mm per year. Under these conditions, crop irrigation is inevitable for growth and development. Irrigated agriculture currently consumes the majority of total available water (up to 85%), making it critical for more efficient water use. Flood irrigation is widely practiced by the majority of the farmers (more than 85 %) with an efficiency which does not exceed 50%. In this context, a good knowledge of the partitioning of evapotranspiration (ET) into soil evaporation and plant transpiration is of crucial need for improving the irrigation scheduling and thus water use efficiency. In this study, the ISBA (Interactions Soil-Biosphere-Atmosphere) model was used for estimating ET and its partition over an olive orchard and a wheat field located near to the Marrakech City (Centre of Morocco). Two versions were evaluated: standard version which simulates a single energy balance for the soil and vegetation and the recently developed multiple energy balance (MEB) version which solves a separate energy balance for each of the two sources. Eddy covariance system, which provides the sensible and latent heat fluxes and meteorological instruments were operated during years 2003-2004 for the Olive Orchard and during years 2013 for wheat. The transpiration component was measured using a Sap flow system during summer over the wheat crop and stable isotope samples were gathered over wheat. The comparison between ET estimated by ISBA model and that measured by the Eddy covariance system showed that MEB version yielded a remarkable improvement compared to the standard version. The root mean square error (RMSE) and the correlation coefficient (R²) were about 45wm-2 and 0.8 for MEB version. By contrast, for the standard version, the RMSE and R² were about 60wm-2 and 0.7, respectively. The result also showed that

  17. Insect density-plant density relationships: a modified view of insect responses to resource concentrations.

    Science.gov (United States)

    Andersson, Petter; Löfstedt, Christer; Hambäck, Peter A

    2013-12-01

    Habitat area is an important predictor of spatial variation in animal densities. However, the area often correlates with the quantity of resources within habitats, complicating our understanding of the factors shaping animal distributions. We addressed this problem by investigating densities of insect herbivores in habitat patches with a constant area but varying numbers of plants. Using a mathematical model, predictions of scale-dependent immigration and emigration rates for insects into patches with different densities of host plants were derived. Moreover, a field experiment was conducted where the scaling properties of odour-mediated attraction in relation to the number of odour sources were estimated, in order to derive a prediction of immigration rates of olfactory searchers. The theoretical model predicted that we should expect immigration rates of contact and visual searchers to be determined by patch area, with a steep scaling coefficient, μ = -1. The field experiment suggested that olfactory searchers should show a less steep scaling coefficient, with μ ≈ -0.5. A parameter estimation and analysis of published data revealed a correspondence between observations and predictions, and density-variation among groups could largely be explained by search behaviour. Aphids showed scaling coefficients corresponding to the prediction for contact/visual searchers, whereas moths, flies and beetles corresponded to the prediction for olfactory searchers. As density responses varied considerably among groups, and variation could be explained by a certain trait, we conclude that a general theory of insect responses to habitat heterogeneity should be based on shared traits, rather than a general prediction for all species.

  18. Density and volume measurements of reprocessing plant feed

    International Nuclear Information System (INIS)

    Platzer, R.; Carrier, M.; Neuilly, M.; Dedaldechamp, P.

    1985-05-01

    A theoretical study of the phenomenon of gas bubbles formation within a liquid led to an adaptation of the differential pressure bubbling technique for the measurement of liquid levels and densities in tanks. Experiments, carried out on a 800 liters tank with water and uranyl nitrate solutions had the double aim to study the precision attainable on volume and density measurements and to design a method for corrections of influencing factors. In parallel, procedures for transfer of known volumes through the use of siphons and for tank calibration by liquid level measurement are also investigated. The paper presents the first results obtained so far and the conclusions to be drawn for the elaboration of calibration and exploitation procedures suitables for use in reprocessing plants. The demonstration to transfer mass of solution with an accuracy of 0.1% is made [fr

  19. Wastewater use in agriculture: irrigation of sugar cane with effluents from the Cañaveralejo wastewater treatment plant in Cali, Colombia.

    Science.gov (United States)

    Madera, C A; Silva, J; Mara, D D; Torres, P

    2009-09-01

    In Valle del Cauca, south-west Colombia, surface and ground waters are used for sugar cane irrigation at a rate of 100 m3 of water per tonne of sugar produced. In addition large quantities of artificial fertilizers and pesticides are used to grow the crop. Preliminary experiments were undertaken to determine the feasibility of using effluents from the Cañaveralejo primary wastewater treatment plant in Cali. Sugar cane variety CC 8592 was planted in 18 box plots, each 0.5 m2. Six were irrigated with conventional primary effluent, six with chemically enhanced primary effluent and six with groundwater. For each set of six box plots, three contained local soil and three a 50:50 mixture of sand and rice husks. The three irrigation waters were monitored for 12 months, and immediately after harvest the sugar content of the sugar cane juice determined. All physico-chemical quality parameters for the three irrigation waters were lower than the FAO guideline values for irrigation water quality; on the basis of their sodium absorption ratios and electrical conductivity values, both wastewater effluents were in the USDA low-to-medium risk category C2S1. There was no difference in the sugar content of the cane juice irrigated with the three waters. However, the microbiological quality (E. coli and helminth numbers) of the two effluents did not meet the WHO guidelines and therefore additional human exposure control measures are required in order to minimize any resulting adverse health risks to those working in the wastewater-irrigated fields.

  20. Compatibility of Different Eucalyptus Species and Provenances Under Sewage Irrigation Using Yazd City Wastewater Treatment Plant Effluent

    Directory of Open Access Journals (Sweden)

    Mohammadhadi Rad

    2014-04-01

    92.4% and 98.6%, 95.1%, 94.4%, respectively. The species E. camaldulensis (41-zh had the best performance after the first and the second years of planting, although there was not significant difference between some of the eucalypt characteristics. Overall, the species E. camaldulensis (41-zh can be recommended for forest plantation and wood production at sites similar to the trial condition, ecologically. The species E. rubida, E. saligna and E. viminalis are also recommended for plantation and wood production, using sewage irrigation, due to their fast growing performance, although they might have high mortality at their first stage of establishment. E. sargentii is a suitable species for desertification control due to its high resistance to soil and water salinity and somewhat coldness and its fast diameter and crown growth.

  1. Effect of Post-Infiltration Soil Aeration at Different Growth Stages on Growth and Fruit Quality of Drip-Irrigated Potted Tomato Plants (Solanum lycopersicum.

    Directory of Open Access Journals (Sweden)

    Yuan Li

    Full Text Available Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conducted to quantify effects of no post-infiltration soil aeration versus aeration during 5 different periods (namely 27-33, 34-57, 58-85, 86-99, and 27-99 days after sowing, on growth and fruit quality of potted single tomato plants that were sub-surface trickle-irrigated every 2 days at 2 levels. Soil was aerated by injecting 2.5 liters of air into each pot through the drip tubing immediately after irrigation. Results showed that post-infiltration aeration, especially during the fruit setting (34-57 DAS and enlargement (58-85 DAS growth stages, can positively influence the yield, root dry weight and activity, and the nutritional (soluble solids and vitamin C content, taste (titratable acidity, and market quality (shape and firmness of the tomato fruits. Interactions between irrigation level and post-infiltration aeration on some of these fruit quality parameters indicated a need for further study on the dynamic interplay of air and water in the root zone of the plants under the conditions of this experiment.

  2. Effect of Post-Infiltration Soil Aeration at Different Growth Stages on Growth and Fruit Quality of Drip-Irrigated Potted Tomato Plants (Solanum lycopersicum).

    Science.gov (United States)

    Li, Yuan; Jia, Zongxia; Niu, Wenquan; Wang, Jingwei; Zhang, Mingzhi

    2015-01-01

    Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum) at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conducted to quantify effects of no post-infiltration soil aeration versus aeration during 5 different periods (namely 27-33, 34-57, 58-85, 86-99, and 27-99 days after sowing), on growth and fruit quality of potted single tomato plants that were sub-surface trickle-irrigated every 2 days at 2 levels. Soil was aerated by injecting 2.5 liters of air into each pot through the drip tubing immediately after irrigation. Results showed that post-infiltration aeration, especially during the fruit setting (34-57 DAS) and enlargement (58-85 DAS) growth stages, can positively influence the yield, root dry weight and activity, and the nutritional (soluble solids and vitamin C content), taste (titratable acidity), and market quality (shape and firmness) of the tomato fruits. Interactions between irrigation level and post-infiltration aeration on some of these fruit quality parameters indicated a need for further study on the dynamic interplay of air and water in the root zone of the plants under the conditions of this experiment.

  3. The influence of the forerunner plant and the irrigation on some quality indicators of the wheat plant (Triticum aestivum L. in their growth conditions on the acid soils in the North-Western Romania

    Directory of Open Access Journals (Sweden)

    Ileana ARDELEAN

    2010-05-01

    Full Text Available The paper sustains the importance of the forerunner plant concerning the quality of the wheat (Triticum aestivum L. and is based on the research carried out during 2006-2008 on a long term trial placed on the brown luvic (acid soils from Oradea in 1990. In non-irrigating and irrigating conditions as well the smallest protein, wet gluten and dry gluten values were obtained in wheat mono-crop; the values increased in the forerunner plant, wheat-maize and the biggest values were registered in the forerunner plant, wheat-maize-soybean.

  4. Reproductive sink of sweet corn in response to plant density and hybrid

    Science.gov (United States)

    Improvements in plant density tolerance have played an essential role in grain corn yield gains for ~80 years; however, plant density effects on sweet corn biomass allocation to the ear (the reproductive ‘sink’) is poorly quantified. Moreover, optimal plant densities for modern white-kernel shrunke...

  5. Use of Irrigation to Extend the Seeding Window for Final Reclamation at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    TRW Environmental Safety

    2000-01-01

    The U.S. Department of Energy has implemented a program to investigate the feasibility of various techniques for reclaiming lands disturbed during site characterization at Yucca Mountain. As part of this program, two studies were conducted in 1997 to assess the effects of combinations of seeding date (date that seeds are planted) and supplemental irrigation on densities of native plant species at Yucca Mountain. Study objectives were to (1) determine whether the traditional seeding window (October-December) could be extended through combinations of seeding date and irrigation date, (2) determine which combination of seeding date and irrigation was most successful, and (3) assess the effects of irrigation versus natural precipitation on seedling establishment. In the first study, a multi-species seed mix of 16 native species was sown into plots on four dates (12/96, 2/97, 3/97, and 4/97). Irrigation treatments were control (no irrigation) or addition of 80 mm of supplemental water applied over a one month period. Plant densities were sampled in August and again in October, 1997. In the second study, Larrea tridentata and Lycium andersonii, two species that are common at Yucca Mountain, but difficult to establish from seed, were sown together into plots in January and August, 1997. Half the plots were irrigated with approximately 250 mm of water between August 18 and September 11, while the remaining plots received no irrigation (control). Plant densities were sampled in October, 1997. The August census for the multi-species mix study showed irrigated plots that were sown in February, March and April had higher plant densities and more species than plots that were not irrigated. Irrigation had no effect on plant densities on plots that were seeded in December. Plots were used again in October following 18 mm of precipitation in September. Densities of three species, Ambrosia dumosa, Hymenoclea salsola, and L. tridentata, (warm-season species) were lower on irrigated

  6. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water; Etude experimentale de la contamination radioactive par l'eau d'irrigation de certaines plantes cultivees

    Energy Technology Data Exchange (ETDEWEB)

    Michon, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Barbier, G.; Le Blaye, P.; Brossard, M. [Station Centrale d' Agronomie, 78 - Versailles (France); Fioramonti, S.; Marty, J.R. [Station Agronomique de Toulouse, 31 (France); Benard, P.; Flanzy, M. [Station Centrale de Technologie des Produits Vegetaux, 11 - Narbonne (France); Delas, J.; Delmas, J.; Demias, Ch. [Station d' Agronomie de Bordeaux (Pont de la Maye), 33 (France); Huguet, C. [Station Agronomique d' Avignon, 84 (France)

    1964-07-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [French] Ce rapport fait suite aux rapports CEA no 1860 et 2159 et rapporte les resultats obtenus pendant les annees 1961 et 1962. Ces resultats confirment dans l'ensemble ceux precedemment obtenus tout en augmentant la variete des legumes etudies. La vigne et les prairies artificielles ont egalement fait l'objet d'etudes. La grande dispersion des valeurs limites du coefficient r (rapport entre la quantite de radioelements dans un kg de produits recoltes a la quantite de radioelements presente dans un litre d'eau d'irrigation) en rapport avec la nature des sols, le type vegetal, etc.., ne permet pas de degager de conclusions generales. Chaque cas de rejet necessite une etude particuliere dont le schema est donne. En tout etat de cause l'on doit s'attendre a ce que dans la plupart des cas ces etudes conduisent a une diminution des normes actuellement utilisees. (auteurs)

  7. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water; Etude experimentale de la contamination radioactive par l'eau d'irrigation de certaines plantes cultivees

    Energy Technology Data Exchange (ETDEWEB)

    Michon, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Barbier, G; Le Blaye, P; Brossard, M [Station Centrale d' Agronomie, 78 - Versailles (France); Fioramonti, S; Marty, J R [Station Agronomique de Toulouse, 31 (France); Benard, P; Flanzy, M [Station Centrale de Technologie des Produits Vegetaux, 11 - Narbonne (France); Delas, J; Delmas, J; Demias, Ch [Station d' Agronomie de Bordeaux (Pont de la Maye), 33 (France); Huguet, C [Station Agronomique d' Avignon, 84 (France)

    1964-07-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [French] Ce rapport fait suite aux rapports CEA no 1860 et 2159 et rapporte les resultats obtenus pendant les annees 1961 et 1962. Ces resultats confirment dans l'ensemble ceux precedemment obtenus tout en augmentant la variete des legumes etudies. La vigne et les prairies artificielles ont egalement fait l'objet d'etudes. La grande dispersion des valeurs limites du coefficient r (rapport entre la quantite de radioelements dans un kg de produits recoltes a la quantite de radioelements presente dans un litre d'eau d'irrigation) en rapport avec la nature des sols, le type vegetal, etc.., ne permet pas de degager de conclusions generales. Chaque cas de rejet necessite une etude particuliere dont le schema est donne. En tout etat de cause l'on doit s'attendre a ce que dans la plupart des cas ces etudes conduisent a une diminution des normes actuellement utilisees. (auteurs)

  8. Study of the Effects Irrigation Water Sanity and pH on Production and Relative Absorption of some Elements Nutrient by the Tomato Plant

    OpenAIRE

    Hossein Afshari; Shahram Ashraf; Abdol G. Ebadi; Sara Jalali; Hossein Abbaspour; Morteza S. Daliri; Seyed R. Toudar

    2011-01-01

    Problem statement: This study was conducted to examine the effects of irrigation water pH and sanity on the growth and absorption of P, Na, Ca, K by tomato. Approach:The study includes two sanity and pH factors and is consisted from 12 treatment and three repetitions. Tomato seeding grown in foam trays were transplanted in the joune 2010 to bags filled with perte in an Greenhouse at Damghan Islamic Azad University of Iran. Plant were divided into groups then irrigated with the targeted sane a...

  9. How Planting Density Affects Number and Yield of Potato Minitubers in a Commercial Glasshouse Production System

    NARCIS (Netherlands)

    Veeken, van der A.J.H.; Lommen, W.J.M.

    2009-01-01

    Commercial potato minituber production systems aim at high tuber numbers per plant. This study investigated by which mechanisms planting density (25.0, 62.5 and 145.8 plants/m2) of in vitro derived plantlets affected minituber yield and minituber number per plantlet. Lowering planting density

  10. Maize yield and quality in response to plant density and application of a novel plant growth regulator

    NARCIS (Netherlands)

    Zhang, Q.; Zhang, L.; Evers, J.B.; Werf, van der W.; Zhang, W.; Duan, L.

    2014-01-01

    Farmers in China have gradually increased plant density in maize to achieve higher yields, but this has increased risk of lodging due to taller and weaker stems at higher plant densities. Plant growth regulators can be used to reduce lodging risk. In this study, for the first time, the performance

  11. Alleviatory activities in mycorrhizal tobacco plants subjected to increasing chloride in irrigation water

    Directory of Open Access Journals (Sweden)

    Ali Reza Safahani Langeroodi

    2017-03-01

    Full Text Available The effects of presence and absence of arbuscular mycorrhizal (AM+ and AM- fungus (AMF Glomus intraradices on agronomic and chemical characteristics of field-grown tobacco (Nicotiana tabacum L. Virginia type (cv. K-326 plants exposed to varying concentrations of chloride 10, 40, 70 and 100 mg Cl L–1 (C1-C4 were studied over two growing seasons (2012-2013. Mycorrhizal plants had significantly higher uptake of nutrients in shoots and number of leaves regardless of intensities of chloride stress. The cured leaves yields of AM+ plants under C2-C4 chloride stressed conditions were higher than AM- plants. Leaf chloride content increased in line with the increase of chloride level, while AMF colonised plants maintained low Cl content. AM+ plants produced tobacco leaves that contained significantly higher quantities of nicotine than AM- plants. AM inoculation ameliorated the chloride stress to some extent. Antioxidant enzymes like superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase as well as non-enzymatic antioxidants (ascorbic acid and glutathione also exhibited great variation with chloride treatment. Chloride stress caused great alterations in the endogenous levels of growth hormones with abscisic acid showing increment. AMF inoculated plants maintained higher levels of growth hormones and also allayed the negative impact of chloride. The level of 40 mg L–1 in combination with arbuscular mycorrhizal can be considered as the acceptable threshold to avoid adverse effects on Virginia tobacco.

  12. Impact of irrigation with high arsenic burdened groundwater on the soil–plant system: Results from a case study in the Inner Mongolia, China

    International Nuclear Information System (INIS)

    Neidhardt, H.; Norra, S.; Tang, X.; Guo, H.; Stüben, D.

    2012-01-01

    Consequences of irrigation by arsenic (As) enriched groundwater were assigned in the Hetao Plain, part of Chinas’ Inner Mongolia Autonomous Region. Examinations followed the As flow path from groundwater to soil and finally plants. A sunflower and a maize field were systematically sampled, each irrigated since three years with saline well water, characterized by elevated As concentrations (154 and 238 μg L −1 ). The annual As input per m 2 was estimated as 120 and 186 mg, respectively. Compared to the geogenic background, As concentrations increased toward the surface with observed enrichments in topsoil being relatively moderate (up to 21.1 mg kg −1 ). Arsenic concentrations in plant parts decreased from roots toward leaves, stems and seeds. It is shown that the bioavailability of As is influenced by a complex interplay of partly counteracting processes. To prevent As enrichment and soil salinization, local farmers were recommended to switch to a less problematic water source. - Highlights: ► We examined influences of irrigation with As burdened water at two fields. ► As distribution within soil–plant system in Hetao Plain, PR China. ► Three years of flood irrigation with As containing groundwater. ► Annual As inputs per m 2 were estimated as 120 mg and 186 mg, respectively. ► Contents in topsoil and plants are partly elevated, but not critical yet. - Recent irrigation with groundwater raises the risk of As entering the local food chain in one of the oldest crop producing areas in the People’s Republic of China.

  13. Common bean growth, N uptake and seed production in sandy loam soil as affected by application of plant residues, nitrogen and irrigation level

    International Nuclear Information System (INIS)

    Abdallah, A.A.G.

    2002-01-01

    Field experiment was conducted at the experimental farm, Inshas, atomic energy authority, egypt. Common bean seeds e.v. Nebrasks were cultivated in sandy loan soil using drip irrigation system prepared for this purpose. Two water regimes, i.e., 100% (793.0 m 3 /fed.) and 65% (513.0 m 3 /fed.) of maximum available water were used in main plots. Where in sub plots two fertilizers types were applied i.e., soybean plant residues which contains N 15 labelled as an organic matter without any addition of any fertilizer and nitrogen as chemical fertilizer without using organic matter. The obtained results indicated that, application of plant residues was superior for total seed yield comparing to nitrogen fertilization treatments. This N source with irrigation level of 793.33 m 3 /fed. had a slight increase in total seed yield comparing with (513.0 m 3 /fed.). Irrigation level of 513.0 m 3 /fed. (65% MAW) as well as application of soybean plant residues showed the highest value of water use efficiency. The highest value of N seed percentage was obtained irrigation level with (513.0 m 3 /fed.). Soybean plant residues improved and increased seeds N content, and total seeds protein content. Both N chemical and irrigation level (65% Maw) recorded highest values with N 15 % atom excess. This result has been obtained at two growth stages and seed yield. The same trend of N 15 % atom excess reflected N utilized with both growth stages and seed yield

  14. Effects of elevated ozone on leaf {delta}{sup 13}C and leaf conductance of plant species grown in semi-natural grassland with or without irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeggi, M. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, CH-8046 Zurich (Switzerland)]. E-mail: maya.jaeggi@psi.ch; Saurer, M. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Volk, M. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, CH-8046 Zurich (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, CH-8046 Zurich (Switzerland)

    2005-03-01

    Stable carbon isotope ratios ({delta}{sup 13}C) and leaf conductance (g{sub s}) were measured (2002, 2003) in Holcus lanatus L., Plantago lanceolata L. Ranunculus friesianus (Jord.), and Trifolium pratense L. at two levels of ozone (O{sub 3}) with or without irrigation. In non-irrigated control plots, R. friesianus showed the least negative {delta}{sup 13}C, and the smallest response to the treatments. Irrigation caused more negative {delta}{sup 13}C, especially in H. lanatus. Irrespective of irrigation, O{sub 3} increased {delta}{sup 13}C in relationship to a decrease in g{sub s} in P. lanceolata and T. pratense. The strongest effect of O{sub 3} on {delta}{sup 13}C occurred in the absence of irrigation, suggesting that under field conditions lack of moisture in the top soil does not always lead to protection from O{sub 3} uptake. It is concluded that in species such as T. pratense plants can maintain stomatal O{sub 3} uptake during dry periods when roots can reach deeper soil layers where water is not limiting. - Under natural field conditions, lack of precipitation may not protect semi-natural vegetation from O{sub 3} effects on leaf gas exchange.

  15. Effects of elevated ozone on leaf δ13C and leaf conductance of plant species grown in semi-natural grassland with or without irrigation

    International Nuclear Information System (INIS)

    Jaeggi, M.; Saurer, M.; Volk, M.; Fuhrer, J.

    2005-01-01

    Stable carbon isotope ratios (δ 13 C) and leaf conductance (g s ) were measured (2002, 2003) in Holcus lanatus L., Plantago lanceolata L. Ranunculus friesianus (Jord.), and Trifolium pratense L. at two levels of ozone (O 3 ) with or without irrigation. In non-irrigated control plots, R. friesianus showed the least negative δ 13 C, and the smallest response to the treatments. Irrigation caused more negative δ 13 C, especially in H. lanatus. Irrespective of irrigation, O 3 increased δ 13 C in relationship to a decrease in g s in P. lanceolata and T. pratense. The strongest effect of O 3 on δ 13 C occurred in the absence of irrigation, suggesting that under field conditions lack of moisture in the top soil does not always lead to protection from O 3 uptake. It is concluded that in species such as T. pratense plants can maintain stomatal O 3 uptake during dry periods when roots can reach deeper soil layers where water is not limiting. - Under natural field conditions, lack of precipitation may not protect semi-natural vegetation from O 3 effects on leaf gas exchange

  16. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

    Science.gov (United States)

    Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

    2017-01-01

    Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may be more complex. Transport rates can only limit growth when they are below a rate corresponding to maximum plant uptake. Our first objective was to compare Chrysanthemum growth performance for three water-based growing systems with different irrigation. We compared; multi-point irrigation into a pond (DeepFlow); one-point irrigation resulting in a thin film of running water (NutrientFlow) and multi-point irrigation as droplets through air (Aeroponic). Second objective was to compare press pots as propagation medium with nutrient solution as propagation medium. The comparison included DeepFlow water-rooted cuttings with either the stem 1 cm into the nutrient solution or with the stem 1 cm above the nutrient solution. Measurements included fresh weight, dry weight, length, water supply, nutrient supply, and oxygen levels. To account for differences in radiation sum received, crop performance was evaluated with Radiation Use Efficiency (RUE) expressed as dry weight over sum of Photosynthetically Active Radiation. The reference, DeepFlow with substrate-based propagation, showed the highest RUE, even while the oxygen supply provided by irrigation was potentially growth limiting. DeepFlow with water-based propagation showed 15-17% lower RUEs than the reference. NutrientFlow showed 8% lower RUE than the reference, in combination with potentially limiting irrigation supply of nutrients and oxygen. Aeroponic showed RUE levels similar to the reference and Aeroponic had non-limiting irrigation supply of water, nutrients, and oxygen. Water-based propagation affected the subsequent

  17. Sources and doses of nitrogen in the production of sunflower plants irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Reginaldo G. Nobre

    Full Text Available ABSTRACT The cultivation of sunflower allows its use as bio-fuel and alternative forage. It is a viable alternative in the semiarid regions. Current study evaluates the effect of saline water use, sources and doses of nitrogen fertilization on the production of sunflower in the experiment conducted in drainage lysimeters between May and August 2012, under protected conditions, at Pombal - PB Brazil. The experiment consisted of a randomized block design, with a 2 x 3 x 4 factorial arrangement and three replications. The treatments consisted of two levels of electrical conductivity of water - ECw (0.3 and 3.0 dS m-1, three sources of nitrogen (urea, ammonium sulfate and calcium nitrate and four levels of N (40, 80, 120 and 160% of recommended dose - 100 mg kg-1, for trials in pots. Dry mass of chapter (DMC, mass of achenes (MAc, the number of viable seeds (MVS, total number of seeds (TNS and internal (DCI and external (DCE diameter of chapter. Irrigation with water of ECw=3.0 dS m-1 negatively affected all variable evaluated. Doses of N 104 and 160% of recommended dose for trials in pots, resulted in the highest DMC, TNS, DCE and DCI. N sources and the interaction between factors did not affect significantly any of the variable evaluated.

  18. Upgrading secondary wastewater plant effluent by modified coagulation and flocculation, for water reuse in irrigation

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Ghaneian

    2017-09-01

    Full Text Available In this study, the feasibility of using coagulation, flocculation, and sedimentation (CF-S for advanced treatment of secondary effluent released from the Yazd Intermittent Cycle Extended Aeration System was investigated. Four coagulants including ferric chloride (FeCl3, polyaluminum chloride (PAC, ferrous sulfate (FeSo4, and potassium ferrate (K2FeSo4 along with Gflog C-150 as flocculant polymer were used. In this study, returned chemical sludge was considered as a modification. Preliminary CF-S processes showed that FeSO4 and K2FeO4 had low removal efficiencies. Thus, these two coagulants were abandoned and CF-S processes were continued only with PAC and FeCl3 coagulants which had higher efficiencies in the removal of biological oxygen demand (BOD5, chemical oxygen demand (COD, total suspended solids (TSS, and turbidity. Removal efficiency was higher when half of the chemical producing sludge was returned as compared with using both coagulants simultaneously along with 2 mg L−1 of C-150 as flocculant. In the optimum dosage, when half of PAC and FeCl3 sludge were returned, the volume of produced sludge was reduced by 40% and 28%, respectively, as compared without returned sludge. For the PAC coagulant in the optimum dosage with half of the sludge returned, all 2012 EPA standards of irrigation were met for both ‘processed and non-processed type’ agricultural crops.

  19. Reuse of treated waste water for the irrigation of ornamental plants. The case of Pistoia; Riuso di acque reflue depurate di specie ornamentali: l'impianto pilota di Pistoia

    Energy Technology Data Exchange (ETDEWEB)

    Gori, R.; Lubello, C. [Florence Univ., Florence (Italy). Dipt. di Ingegneria Civile

    1999-12-01

    After a brief introduction on irrigation waste water reuse, the paper deals with the case of Pistoia (italy), the most important nursery area in Italy, which has developed an experiment for evaluating the effects of waste water treatment plant effluent irrigation. The better physiological and growth parameters of plants irrigated with the effluent shows that it could be a valid alternative of water and fertilizer nutrients resources for ornamental plants. [Italian] Dopo una breve introduzione sul riuso delle acque reflue a fini irrigui, il lavoro affronta il caso di Pistoia, sede della maggiore area vivaistica italiana, che utilizza le acque reflue dal 1998 con una sperimentazione volta a verificare gli effetti dell'irrigazione con l'effluente dell'impianto di depurazione centrale. Le piante cosi' irrigate hanno mostrato parametri di crescita e fisiologici generalmente migliori di quelli riscontrati sulle piante irrigate con i metodi tradizionali.

  20. Yield gains of coffee plants from phosphorus fertilization may not be generalized for high density planting

    Directory of Open Access Journals (Sweden)

    Samuel Vasconcelos Valadares

    2014-06-01

    Full Text Available Inconclusive responses of the adult coffee plant to phosphorus fertilization have been reported in the literature, especially when dealing with application of this nutrient in high density planting systems. Thus, this study was carried out for the purpose of assessing the response of adult coffee plants at high planting density in full production (in regard to yield and their biennial cycle/stability to the addition of different sources and application rates of P in the Zona da Mata region of Minas Gerais, Brazil. The experiment with coffee plants of the Catucaí Amarelo 6/30 variety was carried out over four growing seasons. Treatments were arranged in a full factorial design [(4 × 3 + 1] consisting of four P sources (monoammonium phosphate, simple superphosphate, natural reactive rock phosphate from Algeria (Djebel-Onk, and FH 550®, three P rates (100, 200, and 400 kg ha-1 year-1 of P2O5, and an additional treatment without application of the nutrient (0 kg ha-¹ year-¹. A randomized block experimental design was used with three replicates. The four seasons were evaluated as subplots in a split plot experiment. The P contents in soil and leaves increased with increased rates of P application. However, there was no effect from P application on the yield and its biennial cycle/stability regardless of the source used over the four seasons assessed.

  1. Organic Highbush Blueberry Production Systems Research – Management of Plant Nutrition, Irrigation Requirements, and Weeds

    Science.gov (United States)

    A 0.4 ha planting of blueberry was established in October 2006 to evaluate the effects of cultivar (Duke and Liberty), bed type (flat versus raised beds), weed management (sawdust mulch and hand-weed control; sawdust+compost mulch with acetic acid, flaming, and hand control used as needed; and weed ...

  2. Organic blueberry production systems: management of plant nutrition, irrigation requirements, and weeds

    Science.gov (United States)

    A long-term systems trial was established to evaluate management practices for organic production of northern highbush blueberry (Vaccinium corymbosum L.). The factorial experiment included two planting bed treatments (flat and raised beds), source and rate of fertilizer (feather meal and fish emuls...

  3. Effect of plant population density on the growth and yield of sorghum ...

    African Journals Online (AJOL)

    Improvement of resource use efficiency and yields is probably possible through the use of appropriate plant densities. Field trials were therefore conducted to study the effects of four plant densities, varying from 2.0 to 12.5 plants m-2 on water and radiation use and performance of two Masakwa sorghum varieties grown on ...

  4. Optimized Subsurface Irrigation System: The Future of Sugarcane Irrigation

    Directory of Open Access Journals (Sweden)

    M. H. J. P. Gunarathna

    2018-03-01

    Full Text Available Climate change may harm the growth and yield of sugarcane (Saccharum officinarum L. without the introduction of appropriate irrigation facilities. Therefore, new irrigation methods should be developed to maximize water use efficiency and reduce operational costs. OPSIS (optimized subsurface irrigation system is a new solar-powered automatic subsurface irrigation system that creates a phreatic zone below crop roots and relies on capillarity to supply water to the root zone. It is designed for upland crops such as sugarcane. We investigated the performance of OPSIS for irrigating sugarcane and evaluated its performance against sprinkler irrigation under subtropical conditions. We conducted field experiments in Okinawa, Japan, over the period from 2013 to 2016 and took measurements during spring- and summer-planted main crops and two ratoon crops of the spring-planted crop. Compared with sprinkler irrigation, OPSIS produced a significantly higher fresh cane yield, consumed less irrigation water and provided a higher irrigation water use efficiency. We conclude that OPSIS could be adopted as a sustainable solution to sugarcane irrigation in Okinawa and similar environments.

  5. Effects of plant density and proportion on the interaction between wheat with alexandergrass plants

    Directory of Open Access Journals (Sweden)

    Leonardo Bianco de Carvalho

    2011-01-01

    Full Text Available Determination of competitive relationships among plant species requires appropriate experimental designs and method of analysis. The hypothesis of this research was that two species growing in coexistence show different growth and development due to their relative competitiveness. This research aims to measure the relative competitiveness of wheat crop compared to Alexandergrass by the interpretation of plant density and proportional effects using replacement series experiments. Monocultures were cultivated in densities of 1, 3, 5, 10 and 15 plants per pot and analyzed by regression of dry mass data. Mixture experiment was cultivated in wheat:Alexandergrass proportions of 0:6, 1:5, 2:4, 3:3, 4:2, 5:1 and 6:0 plants per pot and analyzed by graphical interpretation of growth and production characteristics. Both experiments were carried out in randomized complete block design with four replicates. Alexandergrass was more sensitive to intraspecific competition than wheat. Alexandergrass was lightly more competitive than wheat. Number and weight of spikes and number of tillers were the wheat characteristics more affected by Alexandergrass interference.

  6. Changes in growth, physiological parameters and the hormonal status of Myrtus communis L. plants irrigated with water with different chemical compositions.

    Science.gov (United States)

    Acosta-Motos, José Ramón; Ortuño, María Fernanda; Álvarez, Sara; López-Climent, María Fernanda; Gómez-Cadenas, Aurelio; Sánchez-Blanco, María Jesús

    2016-02-01

    Myrtus communis, an important Mediterranean ornamental shrub, was used to study the effect of irrigation water with different chemical compositions in the plant response. A treatment with NaCl was used to establish the plant resistance to high salinity at long term. Plants were subjected to four irrigation treatments with drainage for three months: Control (0.8 dS m(-1)); two treatments using reclaimed water (RWs): RW1 (2.0 dS m(-1)) and RW2 (5.0 dS m(-1)); and NaCl (10.0 dS m(-1)). High levels of electric conductivity of RWs not affected plant growth, while NaCl decreased leaf dry weight. Coinciding with the accumulation of Na(+) and Cl(-) in the roots, soil water potential decreased, which hinders the mobilization of water to the leaves, decreasing leaf water potential. The osmotic adjustment in the NaCl treatment was due to Na(+) and Cl(-) ions, although the proline could contribute as an Osmo compatible solute, increasing the turgor plants. Also changes in cell walls rigidity minimize the negative effects on the water balance; however, a higher lipid peroxidation was observed in these plants. Stomatal closure was associated with a decrease in K(+) and an increase in abscisic acid. NaCl produced an increase in salicylic acid and did not affect jasmonic acid contents at the end of the experiment. Similar behavior in soil and leaf water potentials, although less pronounced than in NaCl, was shown in RW2 plants. The abscisic acid increased in the RW2 with respect to the control and a decrease in stomatal conductance was observed at the end of the experiment. Plants irrigated with RW1 behaved similarly to the control. Copyright © 2015. Published by Elsevier GmbH.

  7. Risk assessment and vertical distribution of thallium in paddy soils and uptake in rice plants irrigated with acid mine drainage.

    Science.gov (United States)

    Huang, Xuexia; Li, Ning; Wu, Qihang; Long, Jianyou; Luo, Dinggui; Zhang, Ping; Yao, Yan; Huang, Xiaowu; Li, Dongmei; Lu, Yayin; Liang, Jianfeng

    2016-12-01

    The objective of this paper is to assess the influence of irritating paddy fields with acid mine drainage containing thallium (Tl) to rice plant-soil system and potential health risks for local residents. Vertical distribution of Tl, pH, organic matter (OM), and cation exchange capacity (CEC) in 24 paddy soil profiles around Yunfu pyrite mine area was investigated. Rice plant samples were collected from the corresponding soil sampling site. The results showed that Tl concentrations in paddy soils at 0-60 cm depth range from 3.07 to 9.42 mg kg -1 , with a mean of 5.74 mg kg -1 , which were significantly higher than the background value of soil in China (0.58 mg kg -1 ). On the whole, Tl contents in paddy soil profiles increased quickly with soil depth from 0 to 30 cm and decreased slowly with soil depth from 30 to 60 cm. The soil Tl content was significant negatively correlated with soil pH. The mean content of Tl in the root, stem, leaf, and rice was 4.36, 1.83, 2.74, and 1.42 mg kg -1 , respectively, which exceeded the proposed permissible limits for foods and feedstuffs in Germany. The Tl content in various tissues of the rice plants followed the order root > leaf > stem (rice), which suggested that most Tl taken up by rice plants retained in the root, and a little migrated to the leaf, stem, and rice. Correlation analysis showed that Tl content in root was significant positively correlated with Tl content in leaf and rice. The ranges of hazard quotient (HQ) values were 4.08∼24.50 and 3.84∼22.38 for males and females, respectively. Males have higher health risk than females in the same age group. In childhood age groups (2 to <21 years) and adult age groups (21 to <70 years), the highest health risk level was observed in the 11 to 16 age group and 21 to 50 age group, respectively. The findings indicated that regular irrigation with Tl-bearing acid mine drainage led to considerable contamination of Tl in paddy soil and rice plant. Local government

  8. Phytophthora ×stagnum nothosp. nov., a New Hybrid from Irrigation Reservoirs at Ornamental Plant Nurseries in Virginia

    Science.gov (United States)

    Yang, Xiao; Richardson, Patricia A.; Hong, Chuanxue

    2014-01-01

    A novel Phytophthora species was frequently recovered from irrigation reservoirs at several ornamental plant production facilities in eastern Virginia. Initial sequencing of the internal transcribed spacer (ITS) region of this species generated unreadable sequences due to continual polymorphic positions. Cloning and sequencing the ITS region as well as sequencing the mitochondrially encoded cytochrome c oxidase 1 and beta-tubulin genes revealed that it is a hybrid between P. taxon PgChlamydo as its paternal parent and an unknown species genetically close to P. mississippiae as its maternal parent. This hybrid has some diagnostic morphological features of P. taxon PgChlamydo and P. mississippiae. It produces catenulate hyphal swellings, characteristic of P. mississippiae, and chlamydospores, typical of P. taxon PgChlamydo. It also produces both ornamented and relatively smooth-walled oogonia. Ornamented oogonia are another important diagnostic character of P. mississippiae. The relatively smooth-walled oogonia may be indicative of oogonial character of P. taxon PgChlamydo. The new hybrid is described here as Phytophthora ×stagnum. PMID:25072374

  9. Modeling of two-phase flow in membranes and porous media in microgravity as applied to plant irrigation in space

    Science.gov (United States)

    Scovazzo, P.; Illangasekare, T. H.; Hoehn, A.; Todd, P.

    2001-01-01

    In traditional applications in soil physics it is convention to scale porous media properties, such as hydraulic conductivity, soil water diffusivity, and capillary head, with the gravitational acceleration. In addition, the Richards equation for water flux in partially saturated porous media also contains a gravity term. With the plans to develop plant habitats in space, such as in the International Space Station, it becomes necessary to evaluate these properties and this equation under conditions of microgravitational acceleration. This article develops models for microgravity steady state two-phase flow, as found in irrigation systems, that addresses critical design issues. Conventional dimensionless groups in two-phase mathematical models are scaled with gravity, which must be assigned a value of zero for microgravity modeling. The use of these conventional solutions in microgravity, therefore, is not possible. This article therefore introduces new dimensionless groups for two-phase models. The microgravity models introduced here determined that in addition to porous media properties, important design factors for microgravity systems include applied water potential and the ratio of inner to outer radii for cylindrical and spherical porous media systems.

  10. A model exploring whether the coupled effects of plant water supply and demand affect the interpretation of water potentials and irrigation management

    OpenAIRE

    Spinelli, GM; Shackel, KA; Gilbert, ME

    2017-01-01

    © 2017 Elsevier B.V. Water potential is a useful predictive tool in irrigation scheduling as it, or a component, is associated with physiological responses to water deficit. Increasing atmospheric demand for water increases transpiration and decreases water potential for the same stomatal conductance. However, based on supply by the soil-plant-atmosphere-continuum, decreasing soil water potential should decrease stomatal conductance and thus transpiration but also decrease water potential. Su...

  11. Performance of 'Rocha' and 'Santa Maria' pears as affected by planting density

    Directory of Open Access Journals (Sweden)

    Mateus da Silveira Pasa

    2015-02-01

    Full Text Available The objective of this work was to evaluate the performance of 'Rocha' and 'Santa Maria' pears at two planting densities. The experiment was carried out during the 2011/2012, 2012/2013, and 2013/2014 growing seasons, in one-year-old orchards (2011/2012 of 'Rocha' and 'Santa Maria' pears, trained in a central-leader system and planted in two densities (2,000 and 4,000 trees per hectare. The assessed parameters were: production per hectare, production per tree, yield efficiency, number of fruit per tree, average fruit weight, trunk diameter increment, fruit firmness, and soluble solid contents. The cumulative yield of 'Rocha' is greater at the higher planting density, whereas the yield efficiency of 'Santa Maria' increases at the lower planting density, as the trees get more mature. Trunk diameter of 'Rocha' also increases at the lower planting density. However, fruit quality parameters in both cultivars are little affected by planting density.

  12. Human health risk assessment of pharmaceuticals and personal care products in plant tissue due to biosolids and manure amendments, and wastewater irrigation.

    Science.gov (United States)

    Prosser, R S; Sibley, P K

    2015-02-01

    Amending soil with biosolids or livestock manure provides essential nutrients in agriculture. Irrigation with wastewater allows for agriculture in regions where water resources are limited. However, biosolids, manure and wastewater have all been shown to contain pharmaceuticals and personal care products (PPCPs). Studies have shown that PPCPs can accumulate in the tissues of plants but the risk that accumulated residues may pose to humans via consumption of edible portions is not well documented. This study reviewed the literature for studies that reported residues of PPCPs in the edible tissue of plants grown in biosolids- or manure-amended soils or irrigated with wastewater. These residues were used to determine the estimated daily intake of PPCPs for an adult and toddler. Estimated daily intake values were compared to acceptable daily intakes to determine whether PPCPs in plant tissue pose a hazard to human health. For all three amendment practices, the majority of reported residues resulted in hazard quotients plants to concentrations of PPCPs that would not be considered relevant based on concentrations reported in biosolids and manure or unrealistic methods of exposure, which lead to artificially elevated plant residues. Our assessment indicates that the majority of individual PPCPs in the edible tissue of plants due to biosolids or manure amendment or wastewater irrigation represent a de minimis risk to human health. Assuming additivity, the mixture of PPCPs could potentially present a hazard. Further work needs to be done to assess the risk of the mixture of PPCPs that may be present in edible tissue of plants grown under these three amendment practices. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Experimental effects of herbivore density on above-ground plant biomass in an alpine grassland ecosystem

    OpenAIRE

    Austrheim, Gunnar; Speed, James David Mervyn; Martinsen, Vegard; Mulder, Jan; Mysterud, Atle

    2014-01-01

    Herbivores may increase or decrease aboveground plant productivity depending on factors such as herbivore density and habitat productivity. The grazing optimization hypothesis predicts a peak in plant production at intermediate herbivore densities, but has rarely been tested experimentally in an alpine field setting. In an experimental design with three densities of sheep (high, low, and no sheep), we harvested aboveground plant biomass in alpine grasslands prior to treatment and after five y...

  14. Light response of sunflower and canola as affected by plant density, plant genotype and N fertilization.

    Science.gov (United States)

    Soleymani, A

    2017-08-01

    Crop response to light is an important parameter determining crop growth. Three field (split plots) experiments were conducted to investigate the effects of plant density, plant genotype and N fertilization on the light absorption and light extinction of sunflower (Helianthus annuus L.) and canola (Brassica napus L.). A detailed set of plant growth, light absorption and crop yield and oil related parameters were determined. Light was measured at noon during the sunny days with clear sky. In experiment I, although the plant density (PD) of 14 resulted in the highest rate of sunflower light absorption (31.37%) and light extinction (0.756), the highest rate of grain yield and grain oil yield was resulted at PD12 at 3639 and 1457.9kg/ha, respectively; as well as by genotype SUP.A. In experiment II (canola), PD80 resulted in the highest rate of light absorption (13.13%), light extinction (0.63), grain yield (2189.4kg/ha) and grain oil yield (556.54kg/ha). This was also the case for Genotype H. In experiment III (canola), although N150 resulted in the highest rate of light absorption (10.74%) and light extinction (0.48), the highest rate of grain yield (3413.6kg/ha) and grain oil yield (891.86kg/ha) was resulted at N100 as well as by Genotype H401. Results indicate how light properties, crop growth and yield of sunflower and canola can be affected by plant and environmental parameters, which are also of practical use by farmers. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Effect of maize intercrop plant densities on yield and β-carotene ...

    African Journals Online (AJOL)

    Effect of maize intercrop plant densities on yield and β-carotene contents of orange-fleshed sweetpotatoes. ... African Crop Science Journal ... 88,888 plants ha-1), at Ngetta Zonal Agricultural Research and Development Institute in Uganda.

  16. EFFECT OF COVER CROPS ON SOIL ATTRIBUTES, PLANT NUTRITION, AND IRRIGATED TROPICAL RICE YIELD

    Directory of Open Access Journals (Sweden)

    ANDRE FROES DE BORJA REIS

    2017-01-01

    Full Text Available In flood plains, cover crops are able to alter soil properties and significantly affect rice nutrition and yield. The aims of this study were to determine soil properties, plant nutrition, and yield of tropical rice cultivated on flood plains after cover crop cultivation with conventional tillage (CT and no-tillage system (NTS at low and high nitrogen (N fertilization levels. The experimental design was a randomized block in a split-split-plot scheme with four replications. In the main plots were cover crops sunhemp (Crotalaria juncea and C. spectabilis, velvet bean (Mucuna aterrima, jackbean (Canavalia ensiformis, pigeon pea (Cajanus cajan, Japanese radish (Raphanus sativus, cowpea (Vigna unguiculata and a fallow field. In the subplots were the tillage systems (CT or NTS. The nitrogen fertilization levels in the sub-subplots were (10 kg N ha-1 and 45 kg N ha-1. All cover crops except Japanese radish significantly increased mineral soil nitrogen and nitrate concentrations. Sunhemp, velvet bean, and cowpea significantly increased soil ammonium content. The NTS provides higher mineral nitrogen and ammonium content than that by CT. Overall, cover crops provided higher levels of nutrients to rice plants in NTS than in CT. Cover crops provide greater yield than fallow treatments. Rice yield was higher in NTS than in CT, and greater at a higher rather than lower nitrogen fertilization level.

  17. The Effect of Drought Stress and Plant Density on Biochemical and Physiological Characteristics of Two Garlic (Allium sativum L. Ecotypes

    Directory of Open Access Journals (Sweden)

    Sh Akbari

    2017-03-01

    Full Text Available Introduction Drought stress is the most important growth limiting factor for crop production. Sugar accumulation under drought stress strengthens and stabilizes cell membranes and maintains the water absorption and turgid property. Under stress conditions, proline will also maintain the turgor pressure and decreased the damages caused to plant membrane. Although proline concentrations may have undesirable effects on plant growth, because of deflecting photosynthetic resources to the processes that are not involved in plant growth. Chloroplasts and its pigments are also affected by drought stress. Density is one of the factors that has a significant impact on plant growth. Garlic is one of the edible plants which has generated considerable interest throughout human history because of its pharmaceutical properties. This study aimed to determine the effects of drought stress and plant density on some biochemical and physiological treats of two garlic ecotypes and determining the more resistant ecotype. Materials and Methods The study was carried out in 2011-2012 in a farm land at the south east of Semnan city. The experimental layout was a split-plot factorial with a randomized complete block design in three replications. The treatments were comprised of three factors: irrigation regimes (60%, 80% and 100% of estimated crop evapotranspiration (ETC that were assigned as the main plot and the factorial combination of 3 levels of planting density (30, 40 and 50 plants. m-2 and two ecotypes (Tabas and Toroud made up the sub-plots. The water requirement was calculated based on FAO-56 crop water requirements instruction. FAO-56 Penman-Monteith equation was used to calculate evapotranspiration. To calculate the content of soluble sugar, proline and leaves pigment, the samples were collected in a random way from the youngest fully expended leaves one month before the final harvest. Relative water content was estimated by measuring dry weight, fresh weight

  18. Application of Pesticide Phytoremediation in Irrigated Rice Fields System Using Eceng Gondok (Eichhornia crassipes) Plants

    Science.gov (United States)

    Febriani, Ika Kartika; Hadiyanto

    2018-02-01

    The problem of environmental pollution especially urban water pollution becomes major issue in Indonesia. The cause of water pollution is not only from industrial factory waste disposal but also other causes which become pollution factor. One cause of water pollution is the existence of agricultural activities with the use of the amount of pesticides that exceed the threshold. As regulated in Government Regulation No. 82/2001 on Water Quality Management and Water Pollution Control, it is necessary to manage water quality and control water pollution wisely by taking into account the interests of current and future generations as well as the ecological balance. To overcome the problem of water pollution due to agricultural activities, it is necessary to conduct research on phytoremediation technique by utilizing eceng gondok plant. It is excepted that using this phytoremediation technique can reduce the problem of water pollution due to the use of pesticides on agricultural activities.

  19. Application of Pesticide Phytoremediation in Irrigated Rice Fields System Using Eceng Gondok (Eichhornia crassipes Plants

    Directory of Open Access Journals (Sweden)

    Kartika Febriani Ika

    2018-01-01

    Full Text Available The problem of environmental pollution especially urban water pollution becomes major issue in Indonesia. The cause of water pollution is not only from industrial factory waste disposal but also other causes which become pollution factor. One cause of water pollution is the existence of agricultural activities with the use of the amount of pesticides that exceed the threshold. As regulated in Government Regulation No. 82/2001 on Water Quality Management and Water Pollution Control, it is necessary to manage water quality and control water pollution wisely by taking into account the interests of current and future generations as well as the ecological balance. To overcome the problem of water pollution due to agricultural activities, it is necessary to conduct research on phytoremediation technique by utilizing eceng gondok plant. It is excepted that using this phytoremediation technique can reduce the problem of water pollution due to the use of pesticides on agricultural activities.

  20. Arsenic-resistant and plant growth-promoting Firmicutes and γ-Proteobacteria species from industrially polluted irrigation water and corresponding cropland.

    Science.gov (United States)

    Qamar, N; Rehman, Y; Hasnain, S

    2017-09-01

    The aim of the study was to explore irrigation water polluted with industrial waste and corresponding cropland to screen bacteria for As detoxification and plant growth promotion. Plant growth-promoting (PGP) As-resistant cropland bacteria were isolated from contaminated irrigation water and corresponding agricultural soil. Phylogenetic analysis revealed that the isolates belonged to two distinct bacterial lineages; Firmicutes and γ-Proteobacteria. Maximum As(V) resistance was exhibited by Klebsiella pneumoniae T22 and Klebsiella oxytoca N53 (550 mmol l -1 ), whereas maximum resistance against As(III) was exhibited by K. oxytoca N53 (200 mmol l -1 ). Maximum As(V) reduction was shown by K. pneumoniae T22 (6·7 mmol l -1 ), whereas maximum As(III) oxidation was exhibited by Bacillus subtilis T23 (4·8 mmol l -1 ). As resistance genes arsB and ACR3 were detected in many of the isolates through polymerase chain reaction. Many of these isolates exhibited PGP traits such as hydrogen cyanide and auxin production as well as phosphate solubilization. The bacterial strains were able to enhance Triticum aestivum growth both in the absence and presence of As, and statistically significant increase in shoot and root lengths was observed especially in case of Acinetobacter lwoffii T24 and Citrobacter freundii N52-treated plants. Cropland bacteria have the ability to support plant growth. Bacteria of croplands irrigated with industrially polluted water develop resistance against toxicants. These bacteria are helpful for the plant growth in such contaminated lands. The bacteria capable of both As detoxification and plant growth promotion, such as A. lwoffii T24 and C. freundii N52, are ideal for remediation and reclamation of polluted lands for agriculture purposes. © 2017 The Society for Applied Microbiology.

  1. Growth limitation of Lemna minor due to high plant density

    NARCIS (Netherlands)

    Driever, S.M.; Nes, van E.H.; Roijackers, R.M.M.

    2005-01-01

    The effect of high population densities on the growth rate of Lemna minor (L.) was studied under laboratory conditions at 23°C in a medium with sufficient nutrients. At high population densities, we found a non-linear decreasing growth rate with increasing L. minor density. Above a L. minor biomass

  2. Effect of Weed Interference on Yield and Agronomical Characteristics of Fenugreek (Trigonella foenum gracum in Different Plant Density under Birjand Conditions

    Directory of Open Access Journals (Sweden)

    R Baradaran

    2016-02-01

    Full Text Available Introduction Iran is among the countries with a climate appropriate for growing a wide range of herbs, and can be a great source of producing and exporting plants. Fenugreek (Trigonella foenum gracum is one of the oldest plant and it is an annual herbaceous plant of the Fabaceae family (Fabaceae which are dry, brown or reddish-yellow to gray to over 5.3 mm. Seeds of this plant are used as a spice and its leaves are used as a vegetable. Among the most important factors in farming, it is important to use appropriate planting density. Therefore, if all the necessary conditions, including the right, but density is inappropriate, it will not get the optimum yield per unit area. The effective management of weeds increase the performance of weed management practices, reduce weed population and the costs associated with it over time. Weeds compete with crops for a variety of sources such as light, water and minerals. Given that the best time weeding the weeds and the most appropriate density of fenugreek is not much information available, this study aimed to determine the appropriate density of weed infested and fenugreek was used. Materials and Methods In order to determine the effects of weed interference and appropriate density of fenugreek, a field trial was conducted in research farm of Birjand Islamic Azad University during the spring of year 2011. The experiment was a factorial based on randomized complete block design. The treatments were fenugreek density at 10, 20 and 40 plants m-2 and weed interference in five levels included weed-free to maturity, 20, 40 and 60 days after emergence, and no weeding. Fenugreek seeds (spherical, brown of pure seed before planting desert of preparation and sterilization by benomyl and then do planting trees and irrigation was done immediately. Irrigation was applied every seven days. During the study, pests and diseases were completely controlled. Weed control was done manually in three stages. Traits such as

  3. Desenvolvimento vegetativo do pepino enxertado irrigado com água salina Vegetative development on grafted cucumber plants irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Marcos Vinícius Folegatti

    2000-09-01

    Full Text Available A salinização dos solos em ambiente protegido devido ao excesso de fertilizantes e falta de lixiviação tem resultado na redução da produtividade das culturas. Este trabalho teve o objetivo de avaliar os efeitos da irrigação com água salina no desenvolvimento vegetativo do pepino enxertado cultivado em ambiente protegido. Foram utilizadas águas de diferentes salinidades (S1=1,58; S2=3,08 e S3=5,13 dS m-1, lâminas de água de irrigação (L0=1,00 x ETc e L1=1,25 x ETc e freqüências de aplicação da lâmina L1 (F1=em todas as irrigações e F2=quando a lâmina de água de irrigação acumulada em L0 atingia 100 mm. Os resultados demonstraram que a altura das plantas, área foliar unitária e índice de área foliar foram afetados linearmente pela salinidade da água, não apresentando diferença para as diferentes lâminas e frequências de aplicação de L1.Greenhouse soil salinization by excessive fertilization and lack of leaching has been a common cause of cucumber yield reduction in Brazil. The aim of this work was to evaluate the effects of irrigation with saline water on the vegetative development of grafted cucumber plants in a greenhouse. Three water salinities (S1=1.58; S2=3.08 e S3=5.13 dS m-1, two irrigation water depths (L0=1.00 x ETc e L1=1.25 x ETc and two application frequencies of L1 (F1=in all irrigations and F2=when the irrigation water depth of L0 reached 100 mm were used. Irrigation water depths and frequencies of L1 were grouped and, therefore, the experimental design was in a factorial scheme 3x3, with randomized blocks. Results showed that plant height, unit leaf area and leaf area index were linearly affected by water salinity. No differences were observed for the various irrigation water depths and frequencies of L1 application.

  4. Branch Development of Five-Year-Old Betula alnoides Plantations in Response to Planting Density

    Directory of Open Access Journals (Sweden)

    Chun-Sheng Wang

    2018-01-01

    Full Text Available Branch development in the lower part of stem is critical to both early stem growth and wood quality of the most valuable section of tree, and its regulation through planting density has always been greatly concerned. Here the effect of planting density on branch development was examined in a five-year-old plantation of Betula alnoides with six planting densities (625, 833, 1111, 1250, 1667, and 2500 stems per hectare (sph in Guangdong Province, South China. Branch quantity (number, proportion, and density, morphology (diameter, length, and angle, position (height and orientation, and branch status (dead or alive were investigated for 54 dominant or co-dominant trees under six treatments of planting density after the growth of each tree was measured. Factors influencing branch development were also explored by mixed modelling. The results showed that the mean tree heights of 1250 and 1667 sph treatments were higher than those of other planting density treatments. The quantity of live branches decreased with increasing planting density. However, planting density had no significant effect on the number of all branches, and there existed no remarkable difference in branch number and proportion among four orientations. As for branch morphology, only the largest branch diameter had a significantly negative correlation with planting density. In addition, high planting density significantly increased the height of the largest branch within the crown. Mixed effects models indicated that branch diameter, length, and angle were closely correlated with each other, and they were all in positively significant correlation to the branch height at the stem section below six meters. It was concluded that properly increasing planting density will promote natural pruning, improve early branch control, and be beneficial for wood production from the most valuable section of the stem.

  5. Morphological analysis of plant density effects on early leaf area growth in maize

    NARCIS (Netherlands)

    Bos, H.J.; Vos, J.; Struik, P.C.

    2000-01-01

    The mechanisms of density-related reduced leaf area per plant in non-tillering maize (Zea mays) were investigated. Maize cv. Luna crops with a wide range of plant densities were grown in the field at Wageningen for two years. Half of the plots were shaded (50% transmittance). Detailed measurements

  6. Effects of plant density on forage production in five populations of ...

    African Journals Online (AJOL)

    Kleingrass (Panicum coloratum L.) forage yield evaluation plots are often established at a density of 6.0 plants m-2 to accommodate mechanical transplanting and harvesting equipment. However, forage crops are usually established from seed at higher plant densities. Experiments were conducted to determine if ...

  7. The effects of planting density and cultural intensity on loblolly pine crown characteristics at age twelve

    Science.gov (United States)

    Madison Akers; Michael Kane; Robert Teskey; Richard Daniels; Dehai Zhao; Santosh Subedi

    2012-01-01

    Twelve-year old loblolly pine (Pinus taeda L.) stands were analyzed for the effects of planting density and cultural intensity on tree and crown attributes. Four study installations were located in the Piedmont and Upper Coastal Plain regions of the U.S. South. The treatments included six planting densities (740, 1480, 2220, 2960, 3700, 4440 trees...

  8. Effects of deficit irrigation and partial root-zone drying on soil and plant water status, stomatal conductance, plant growth and water use efficiency in tomato during early fruiting stage

    DEFF Research Database (Denmark)

    Liu, Fulai; Shahnazari, Ali; Jacobsen, S.-E.

    2008-01-01

    The effects of 'partial root-zone drying' (PRD), compared with full irrigation (FI) and deficit irrigation (DI), on soil and plant water status, plant growth and water use efficiency (WUE) were investigated in potted tomatoes (Lycopersicon esculentum L., var. Cedrico) at the early fruiting stage...... system, and the irrigated side of the plants was reversed when volumetric soil water content ( ) of the dry side had decreased to 6%. of FI was about 14%. of DI decreased during the first 4-5 days after the onset of treatment (DAT) and was about 7% and 6% thereafter for DI-70 and DI-50, respectively....... of the wet side in PRD-70 declined during 3-6 DAT and was lower than that of FI by 4-6% thereafter. in both wet and dry sides of PRD-50 was slightly lower than that for PRD-70. After 5 DAT, midday leaf water potential was significantly lower in DI and PRD than in FI plants. FI plants had the highest leaf...

  9. Effect of Drought Stress on Growth and Morphological Characteristics of Two Garlic (Allium sativum L. Ecotypes in Different Planting Densities

    Directory of Open Access Journals (Sweden)

    shiva akbari

    2017-10-01

    underground organs and leaf area from measured samples of treatments were used. Results and Discussion The results showed that the highest value of maximum leaf area index (LAI, maximum total dry matter accumulation (TDM, maximum crop growth rate (CGR and maximum of net assimilation rate (NAR were observed at 100% ETc with the value of 5.537, 387.53 gr.m-2, 10.47 gr m-2day-1 and 4.92 gr.m-2leaf.day-1 respectively; and by applying the irrigation treatment of 80% ETc these values decreased to 3.745, 262.60 gr.m-2, 6.31 gr.m-2day-1 and 3.71 gr.m-2leaf.day-1 respectively. Drought stress can decrease cell development and division and plant photosynthesis, and thus, it can decrease leaf area index and consequently decrease light absorption, photosynthetic area, dry matter and crop growth rate. Difference between ecotypes in terms of number of leaves, maximum total dry matter accumulation and maximum crop growth rate was significant. Maximum crop growth rate (CGR in Toroud ecotype was higher than Tabas ecotype but number of leaves and maximum concentration of total dry matter (TDM in Tabas ecotype were higher than corresponding values in Toruod ecotype. The effect of planting density on maximum leaf area index (LAI, maximum total dry matter (TDM and maximum net assimilation rate (NAR was significant. The highest value of maximum leaf area index (5.017 and maximum total dry matter (358.57 g.m-2 concentration were obtained from 50 plant.m-2 density. The highest value of maximum net assimilation rate (4.61 was obtained from 30 plant.m-2 density. It could be because of having leaves exposed to more light and less shading. Conclusion Applying drought stress at the irrigation treatment of 80% ETc decreased studied growth characteristics of garlic. Therefore, it is recommended that garlic should be avoided from facing drought stress and its water requirement must be met as much as possible. In general, under drought stress, two studied ecotypes did not have any preference related to the

  10. Effect of increased plant density and fertilizer dose on the yield of rice variety IR-6

    International Nuclear Information System (INIS)

    Amin, M.; Khan, M.A.; Khan, E.A.; Ramazan, M.

    2004-01-01

    An experiment to evaluate the effect of increased plant density and fertilizer dose on yield of rice variety IR-6 was conducted at the farm of Faculty of Agriculture, Gomal University Dera Ismail Khan. Increase plant density significantly increase number of panicles per square meter, sterility and straw yield while increased fertilizer dose of NPK increase plant height, sterility, normal kernels, and 1000 grain weight. Interaction of increased plant density and fertilizer dose was found to be non significant except sterility percentage and straw yield. However efforts are required for increasing yield per unit area of rice. (author)

  11. Hydroponic vs. Soilless Media: Interaction with Plant Density

    OpenAIRE

    Pinnock, Derek R.; Bugbee, Bruce

    2000-01-01

    Water stress can cause early heading in some plant species. ‘Super Dwarf’ rice was grown in hydroponic culture and soilless media to determine if a slight water stress, caused by the soilless media, would cause earlier heading.

  12. Fate of fertilizer nitrogen in soil-plant system under irrigating condition. Pt.1: Effect of nitrogen level

    International Nuclear Information System (INIS)

    Chen Qing; Wen Xianfang; Zheng Xingyun; Pan Jiarong

    1997-01-01

    Three nitrogen fertilization levels including optimum rate of nitrogen applied (N1.0, 150 kg N·ha -1 ), 150% of optimum rate (N1.5, 225 kg N·ha -1 ) and 50% of optimum rate (N0.5, 75 kg N·ha -1 ) were selected to determine the fate of nitrogen in soil plant system by 15 N technique in 1994∼1995 field experiment which was conducted in Shijiazhuang. The results showed that under irrigated condition the nitrogen use efficiencies (NUE) of ammonium bicarbonate by winter wheat in fertilized treatments were 38.5%, 32.3% and 22.4% respectively, while the highest NUE of winter wheat was found in N0.5 treatment due to a relatively high fertility. The highest yield (6.8 x 10 3 kg grain·ha -1 , 14.7 x 10 3 kg top·ha -1 ) was obtained in N1.0 treatment, but nitrogen uptake and grain yield in N1.5 treatment were lower than those of other fertilizer treatments and there was no significant difference between N0.0 and N1.5 in grain yield. the highest residue of fertilizer N was determined in N1.5 treatment, of which 46% existed in the top layer of the soil (0∼50 cm). There was no significant difference in residual fertilizer N in soil between the other two treatments (31.28% in N0.5, 31.12% in N1.0). In 15 N balance calculation, the unaccounted part of applied N which was leaching down 50 cm in the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, 36.56%, 31.25% in N0.5, N1.5 treatments, respectively. It is very important to control residual N in order to prevent N pollution and promote the growth of next crop

  13. Effect of Organic Fertilizers and Plant Density on Qualititative Characteristics of Balangu (Lallenamntia royleana Benth.

    Directory of Open Access Journals (Sweden)

    A Roohi Nogh

    2017-10-01

    Full Text Available Introduction Recently, the impact of chemical farming and the negative consequences on the environment and human health are on rise in Iran. Organic farming is gaining attention and increasing globally because it is eco-friendly, safe and has benefits for human health. The use of organic fertilizers in agriculture improves soil structure. Plant spacing and fertilizer applications have significant influence on the growth and yield in crop production. Optimum plant spacing ensures the proper use of land, as well as growth and nutrition in plants. Balangu (Lallemantia royleana Benth. is a medicinal plant from Lamiaceae family, containing essential oils and mucilage. The most important feature of this plant is the mucilage of the seeds. The seeds are a good source of fiber, oil and protein, and have medicinal and nutritional properties. Using the appropriate plant density and environmental friendly methods like organic fertilizers can improve the quality and quantity of medicinal plants production. Materials and Methods In order to study the effect of organic fertilizers and plant density on the qualitative characteristics of Balangu (Lallemantia royleana Benth. as a medicinal plant, an experiment was conducted at the Research Station of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during the growing season of 2011-2012. Soil samples were collected from the 15 cm depth of each experimental plots for laboratory analysis. This experiment was carried out as factorial layout based on randomized complete block design with three replications. Treatments were included five levels of fertilizer (cow manure, sheep manure, chicken manure, municipal solid waste compost and control and three levels of plant density (20, 30 and 40 plant m-2. The studied traits were included amount of mucilage, swelling factor, swelling per gram mucilage, mucilage and seed yield. Data were analyzed with SAS software. The F test was used to test the significance

  14. Phytoextraction of 55-year-old wastewater-irrigated soil in a Zn-Pb mine district: effect of plant species and chelators.

    Science.gov (United States)

    Tai, YiPing; Yang, YuFen; Li, ZhiAn; Yang, Yang; Wang, JiaXi; Zhuang, Ping; Zou, Bi

    2017-07-16

    Untreated water from mining sites spreads heavy metal contamination. The present study assessed the phytoextraction performance of heavy metal-accumulating plants and the effects of chemical chelators on cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) removal from paddy fields that have been continuously irrigated with mining wastewater from mines for 55 years. Outdoor pot experiments showed that the total Pb, Zn, and Cd content was lower in the rhizosphere soil of Amaranthus hypochondriacus than in that of Sedum alfredii, Solanum nigrum, and Sorghum bicolor. The aboveground biomass (dry weight) and relative growth rate of A. hypochondriacus were significantly higher than that of the other three species (P phytoextraction effect.

  15. EFFECT OF ALTERNATING WETTING AND DRYING IRRIGATION METHODS ON PHOTOSYNTHESIS AND TEMPERATURE OF RICE AND WEED PLANTS.

    Science.gov (United States)

    Reduced input systems such as alternating wetting and drying (AWD) and furrow irrigation can potentially reduce water costs and limit the release of greenhouse gases in rice production, but also can introduce unwanted crop stresses that compromise crop yield and quality, as well as introducing compl...

  16. Using container weights to determine irrigation needs: A simple method

    Science.gov (United States)

    R. Kasten Dumroese; Mark E. Montville; Jeremiah R. Pinto

    2015-01-01

    Proper irrigation can reduce water use, water waste, and incidence of disease. Knowing when to irrigate plants in container nurseries can be determined by weighing containers. This simple method is quantifiable, which is a benefit when more than one worker is responsible for irrigation. Irrigation is necessary when the container weighs some target as a proportion of...

  17. The factors controlling species density in herbaceous plant communities: An assessment

    Science.gov (United States)

    Grace, J.B.

    1999-01-01

    This paper evaluates both the ideas and empirical evidence pertaining to the control of species density in herbaceous plant communities. While most theoretical discussions of species density have emphasized the importance of habitat productivity and disturbance regimes, many other factors (e.g. species pools, plant litter accumulation, plant morphology) have been proposed to be important. A review of literature presenting observations on the density of species in small plots (in the vicinity of a few square meters or less), as well as experimental studies, suggests several generalizations: (1) Available data are consistent with an underlying unimodal relationship between species density and total community biomass. While variance in species density is often poorly explained by predictor variables, there is strong evidence that high levels of community biomass are antagonistic to high species density. (2) Community biomass is just one of several factors affecting variations in species density. Multivariate analyses typically explain more than twice as much variance in species density as can be explained by community biomass alone. (3) Disturbance has important and sometimes complex effects on species density. In general, the evidence is consistent with the intermediate disturbance hypothesis but exceptions exist and effects can be complex. (4) Gradients in the species pool can have important influences on patterns of species density. Evidence is mounting that a considerable amount of the observed variability in species density within a landscape or region may result from environmental effects on the species pool. (5) Several additional factors deserve greater consideration, including time lags, species composition, plant morphology, plant density and soil microbial effects. Based on the available evidence, a conceptual model of the primary factors controlling species density is presented here. This model suggests that species density is controlled by the effects of

  18. The effect of plant density on epiphytic macroinvertebrates ...

    African Journals Online (AJOL)

    The effect of variations in the density of a submerged macrophyte,Lagarosiphon ilicifolius, on epiphytic macroinvertebrate community structure in the shallow waters of a sheltered bay of Lake Kariba were investigated. The body size class distributions of a mayfly, Cloeon (Ephemeroptera: Baetidae), and the damselfly family, ...

  19. Potato yield and quality as a function of the plant density

    Directory of Open Access Journals (Sweden)

    Eero Varis

    1975-05-01

    Full Text Available The effects of potato plant density on yield quantity and quality were investigated at the Hankkija Plant Breeding Institute from 1971-73, using seed rates of 1600, 3200 and 4800 kg/ha, and seed sizes of 40, 80 and 120 g. The varieties used were Ijsselster and Record. The number of stems per m2 rose with increasing seed rate and with increasing seed size. Stem number increased with seed rate faster for small seed than for large. The response in stem number was greater for Ijsselster than for Record. The number of stems per seed tuber fell as the plant density rose. The number of tubers per m2 altered in the same direction as the number of stems, but less responsively. The reason for this was that the number of tubers per stem decreased with increasing plant density. The tuber yield showed a continual increase with increasing plant density. At the lowest stem densities (less than 20—25 stems/m2 small seed gave better results than other sizes, but at the higher plant densities, the importance of seed size faded away and the yield was dependant on the plant density alone. Net yield (gross yield 2 x seed rate, however, was higher the smaller the seed used, whatever the stem density. Tuber size decreased when plant density increased, the proportion of large tubers diminishing most, especially when small seed was used. The proportion of small tubers altered more for Ijsselster than for Record. Seed size and seed rate did not on average significantly affect the proportion of Class I potatoes, though small seed gave results slightly better than other sizes. The starch content of the yield rose when the seed rate was increased (16.0-16.3 -16.5 % and fell with increasing seed size (16.5 16.2 16.1 %. The maximum variation was 15.8-16.7 %. The specific gravity distribution improved with increasing plant density. Raw discolouration of the tubers did not alter significantly as the plant density rose. Blackening of the tubers decreased with increasing plant

  20. Arsenic adsorption and plant availability in an agricultural soil irrigated with As-rich water: Effects of Fe-rich amendments and organic and inorganic fertilisers.

    Science.gov (United States)

    Arco-Lázaro, Elena; Pardo, Tania; Clemente, Rafael; Bernal, Ma Pilar

    2018-03-01

    The use of As-rich water for irrigation in agricultural soils may result in As accumulation in soil and crops, with the consequent risk of its entry into the food chain. The effectiveness of three different Fe-based materials (a commercial iron oxide (Bayoxide ® ), lamination slag (a by-product of the hot rolling of steel) and a commercial red mud derivative (ViroBind™)) used as soil amendments to minimise the impact of irrigation with As-rich water in an agricultural soil-plant system was evaluated in a pot experiment. Simultaneously, the influence of organic and inorganic fertilisation (olive oil mill waste compost versus NPK fertiliser) on the effectiveness of iron oxide in As adsorption processes was also assessed. The As adsorption capacity of the amendments was determined in a preliminary batch experiment using sorption isotherms. Then, a pot experiment was carried out in a growth chamber using an agricultural soil (arenosol) from Segovia province (central Spain), amended with the different materials, in which Lactuca sativa (lettuce) was grown for two months. The As adsorption capacity was higher in the commercial iron oxide and in the red mud derivative, which fitted the Freundlich model (no saturation), than in the lamination slag, which fitted the Langmuir model (limited adsorption). All the materials decreased the pore water As concentration compared to the control (by 29-80%), but only iron oxide reduced As availability in the soil, and none of the amendments decreased the As concentration in plant leaves. The combination of iron oxide and compost did not significantly improve plant growth, but increased nutrients (N, K, Ca, Na and Mg) concentrations and availability in the soil and their concentration in the plants, relative to the other treatments and the control. Therefore, this seems to be a viable option to prevent As leaching and improve the plant nutritional status. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Combined effects of patch size and plant nutritional quality on local densities of insect herbivores

    NARCIS (Netherlands)

    Bukovinszky, T.; Gols, R.; Kamp, A.; De Oliveira-Domingues, F.; Hambäck, P.A.; Jongema, Y.; Bezemer, T.M.; Dicke, M.; Van Dam, N.M.; Harvey, J.A.

    2010-01-01

    Plant–insect interactions occur in spatially heterogeneous habitats. Understanding how such interactions shape density distributions of herbivores requires knowledge on how variation in plant traits (e.g. nutritional quality) affects herbivore abundance through, for example, affecting movement rates

  2. EFFECT OF MAIZE INTERCROP PLANT DENSITIES ON YIELD ...

    African Journals Online (AJOL)

    ACSS

    protein maize (Zea mays L.) in combating vitamin A and protein malnutrition, small land holdings by rural poor farmers still ... A cet effet, l'association des cultures doublée d'une densité optimale des plants dans les systems ..... their foliar area to lessen water loss. Also ..... Valenzuela, H.R., O'Hair, S.K. and Schaffer, B. 1991 ...

  3. Irrigation Requirement Estimation using MODIS Vegetation Indices and Inverse Biophysical Modeling; A Case Study for Oran, Algeria

    Science.gov (United States)

    Bounoua, L.; Imhoff, M.L.; Franks, S.

    2008-01-01

    Human demand for food influences the water cycle through diversion and extraction of fresh water needed to support agriculture. Future population growth and economic development alone will substantially increase water demand and much of it for agricultural uses. For many semi-arid lands, socio-economic shifts are likely to exacerbate changes in climate as a driver of future water supply and demand. For these areas in particular, where the balance between water supply and demand is fragile, variations in regional climate can have potentially predictable effect on agricultural production. Satellite data and biophysically-based models provide a powerful method to quantify the interactions between local climate, plant growth and water resource requirements. In irrigated agricultural lands, satellite observations indicate high vegetation density while the precipitation amount indicates otherwise. This inconsistency between the observed precipitation and the observed canopy leaf density triggers the possibility that the observed high leaf density is due to an alternate source of water, irrigation. We explore an inverse process approach using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), climatological data, and the NASA's Simple Biosphere model, SiB2, to quantitatively assess water demand in a semi-arid agricultural land by constraining the carbon and water cycles modeled under both equilibrium (balance between vegetation and prevailing local climate) and nonequilibrium (water added through irrigation) conditions. We postulate that the degree to which irrigated lands vary from equilibrium conditions is related to the amount of irrigation water used. We added water using two distribution methods: The first method adds water on top of the canopy and is a proxy for the traditional spray irrigation. The second method allows water to be applied directly into the soil layer and serves as proxy for drip irrigation. Our approach indicates that over

  4. Transfer mechanisms in cultivated soils of waste radionuclides from electronuclear power plants in the system river--irrigated soil--underground water level

    Energy Technology Data Exchange (ETDEWEB)

    Saas, A; Grauby, A

    1974-12-31

    From symposinm on environmentl behavior of radionuclides released in the nuclear industry; Aix-en-Provence, France (14 May 1973). The location of nuclear power plants by rivers whose waters are used for irrigation and industrial and domestic consumption necessities a profound study of the river-irrigated soil- ground water system. Mechanisms of radionuclide transport in cultivated soil are considered under three principal aspects: the effect of the quality of the river water, of the irrigation channels, and of the ground water level on the mobility of the radionuclides in the soil; the influence of the type of soil (the four types of soils considered are acid brown soil, calcic brown soil, chalky brown soil, and chalky alluvial soil); and the distribution of radionuclides in the soil (hydrosoluble forms can contminate the ground water level and these are the forms in which they are taken up by plants. A study was made on the following nuclides: /sup 22/Na, /sup 137/Cs, /sup 85/Sr, /Sup 54/Mn, /Sup 59/Fe, /Sup 60/ Co, /sup 65/Zn, /sup 124/Sb, /sup 141 in the cultivated soils permit the evaluation of the risks of contmination of the food chain and of the underground water. This study also showed new perspectives of the behavior of radionuclides as a function of their contmination of the organo-mineral wastes of industrial and domestic origin. This pollution interfers largely with the formation of stble complexes carried by the river to irrigated soils. The quality of the water determines the distribution of the radionuclides in the profile. The hydrosoluble complex persists in the soil and migrates toward the underground water level if they are not biodegradable. The stability of these forms as a function of the soil pH and of its physicochemical characteristics, as well as that of the radionuclides considered, permit the formulation of a new balance of the radionuclides in soils. The formulation of new proposals for the contml of nuclear sites is discussed. (tr-auth)

  5. Yield components and quality of intercropped cotton in response to mepiquat chloride and plant density

    NARCIS (Netherlands)

    Mao, Lili; Zhang, Lizhen; Evers, J.B.; Werf, van der Wopke; Liu, Shaodong; Zhang, Siping; Wang, Baomin; Li, Zhaohu

    2015-01-01

    Cotton yield is greatly improved by moderately increasing plant density and modifying the cotton plants to have a compact structure, which is also required by the increasing demand for mechanized harvest. However, in cotton strip intercropped with wheat, only limited knowledge on yield response

  6. Effects of Plant Density and NPK Application on the Growth and ...

    African Journals Online (AJOL)

    Studies were conducted at Evboneka, Edo State, Nigeria in a forest zone to examine the effect of increasing plant population and NPK application on the growth and tuber yield of Dioscorea rotundata (Poir) cv “Obiaoturugo”. This study involved three trials. The first was conducted in 2010 involving five plant densities (10000 ...

  7. Genotype and planting density effects on rooting traits and yield in cotton (Gossypium hirsutum L.)

    NARCIS (Netherlands)

    Zhang, L.Z.; Li, B.G.; Yan, G.T.; Werf, van der W.; Spiertz, J.H.J.; Zhang, S.P.

    2006-01-01

    Root density distribution of plants is a major indicator of competition between plants and determines resource capture from the soil. This experiment was conducted in 2005 at Anyang, located in the Yellow River region, Henan Province, China. Three cotton (Gossypium hirsutum L.) cultivars were

  8. Effect of planting density and growing media on growth and yield of strawberry

    International Nuclear Information System (INIS)

    Tariq, R.; Qureshi, K.M.; Hassan, I.; Rasheed, M.; Qureshi, U.S.

    2013-01-01

    Strawberry (Fragaria ananasa), belonging to Rosaceae family, is a rich source of vitamins and minerals with delicate flavors. It is perishable crop which is exceedingly in demand for its taste, profitability, high yield and good quality. To make the plant growth successful in the container, the requirement of special media is very important step because plant growth is largely depended on the physiochemical properties of the growing media used. Winter strawberry production in a greenhouse using high plant densities and various media may be a viable alternative to open-field production system. Planting density can be increased thrice by using different production systems. Studies were conducted to see the impact of different planting densities and media on growth and yield of strawberry. The treatments were T 1 = Control, with normal planting distance of 30 cm x 60 cm and growing media silt, sand and farm yard manure (FYM); T 2 = 15 cm 2 x 30 cm and silt, sand and FYM; T 3 = 30 cm x 60 cm and coir; T 4 = 15 cm x 30 cm and coir; T 5 = 30 cm x 60 cm and peat moss; T 6 = 15 cm x 30 cm and 5 6 peat moss. Results showed that plants grown at low planting distance on all growth media showed more pronounced results as compared to high planting distance. Plants grown in peat moss at both planting densities moderately increased the plant height, canopy size, leaf area, number of fruits, fruit size, fruit weight and titratable acidity. A significant increase in fresh and dry weight of leaves, number of leaves, fruit yield in term of fruit number, fruit size and fruit weight, and fruit quality with high ascorbic acid contents were observed. On the other hand, plants grown in silt, sand and FYM (1 : 1 : 1) at both planting densities showed significant increment in vegetative growth resulting in early flowering with more flowers per plant, better fruit setting and fruit set percentage, greater fruit size and weight but fruit number per plant was reduced which lowered the overall

  9. Substrates and irrigation levels for growing desert rose in pots

    Directory of Open Access Journals (Sweden)

    Ronan Carlos Colombo

    Full Text Available ABSTRACT In the past decades, desert rose has become a very popular ornamental plant, especially among collectors, due to its exotic and sculptural forms. However, it has been grown on a commercial scale only recently, and little is known about how to best manage it as a container-grown plant, or even which potting medium (substrate to recommend. Therefore, the aim of this study was to investigate the interactions between potting media and irrigation levels for growing desert rose as a potted ornamental plant. The experiment was conducted in a greenhouse using a 6 x 2 factorial arrangement with six replications, six potting media and two irrigation levels. The mixes were characterized by measuring their physical properties, specifically the density and water retention capacity (WRC, as well as chemical properties, such as the pH and electrical conductivity (EC. After 210 days, plant growth and plant water consumption were evaluated and measured. A lower dry density for the vermiculite mixes was observed in comparison to that for the sand mixes. However, WRC ranged from 428 to 528 mL L-1 among the mixes, values considered close to ideal. In general, plant growth exhibited higher increases in mixes consisting of coconut fiber + sand or vermiculite, regardless of the irrigation level. Mixes of vermiculite + coconut fiber and sand + coconut fiber can be used to grow desert rose in pots, as long as irrigation is used to maintain the moisture content of the potting medium (mix between 60-70% and 80-90% of the WRC.

  10. Plant quality and conspecific density effects on Anaphothrips obscurus (Thysanoptera: Thripidae) wing diphenism and population ecology.

    Science.gov (United States)

    Reisig, Dominic D; Godfrey, Larry D; Marcum, Daniel B

    2010-04-01

    Factors that influence thysanopteran wing diphenism are not well known. In these studies, the impact of food quality, mediated through nitrogen addition, and conspecific density was explored on the wing diphenism of an herbivorous thrips species (Anaphothrips obscurus Müller) (Thysanoptera: Thripidae). In the first study, nitrogen was added to timothy grass (Phleum pretense L.) (Poales: Poaceae) transplants, and naturally occurring thrips populations were caged on the plants. Thrips abundance and foliar nutrients were assessed every 2 wk. A separate factorial experiment in growth chambers explored the impact of both plant nitrogen addition and thrips abundance on wing diphenism. Thrips density was manipulated by adding either 3 or 40 thrips to potted and caged timothy. Thrips abundance and foliar nutrients were measured 58 d after treatment placement. Plant quality directly affected thrips wing diphenism independent of thrips density in both experiments. Near the end of the field cage experiment, density may have indirectly impacted wing diphenism. In both experiments, plant quality and thrips density interacted to affect thrips population abundance. Plant quality alone can affect thrips wing diphenism, but it remains unclear whether density alone can affect thrips wing diphenism. This is a unique and understudied system that will be useful to examine generalized theories on the negative interaction between reproduction and dispersal.

  11. Seasonal population dynamics of Homalodisca vitripennis (Hemiptera: Cicadellidae) in sweet orange trees maintained under continuous deficit irrigation.

    Science.gov (United States)

    Krugner, Rodrigo; Groves, Russell L; Johnson, Marshall W; Flores, Arnel P; Hagler, James R; Morse, Joseph G

    2009-06-01

    A 2-yr study was conducted in a citrus orchard (Citrus sinensis L. Osbeck cultivar Valencia) to determine the influence of plant water stress on the population dynamics of glassy-winged sharpshooter, Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop evapotranspiration rate (ET(c)) and continuous deficit-irrigation regimens at 80 and 60% ET(c). Microclimate and plant conditions monitored included temperature and humidity in the tree canopy, leaf surface temperature, water potential, and fruit quality and yield. Glassy-winged sharpshooter population densities and activity were monitored weekly by a combination of visual inspections, beat net sampling, and trapping. Glassy-winged sharpshooter populations were negatively affected by severe plant water stress; however, population densities were not linearly related to decreasing water availability in plants. Citrus trees irrigated at 60% ET(c) had significantly warmer leaves, lower xylem water potential, and consequently hosted fewer glassy-winged sharpshooter eggs, nymphs, and adults than trees irrigated at 80% ET(c). Citrus trees irrigated at 100% ET(c) hosted similar numbers of glassy-winged sharpshooter stages as trees irrigated at 60% ET(c) and a lower number of glassy-winged sharpshooter nymphs than the 80% ET(c) treatment, specifically during the nymphal density peak in mid-April to early July. Irrigation treatments did not affect populations of monitored natural enemies. Although the adult glassy-winged sharpshooter population was reduced, on average, by 50% in trees under severe water stress, the total number of fruit and number of fruit across several fruit grade categories were significantly lower in the 60% ET(c) than in the 80 and 100% ET(c) irrigation treatments.

  12. Power density forecasting device for nuclear power plant

    International Nuclear Information System (INIS)

    Fukuzaki, Takaharu; Kiguchi, Takashi.

    1978-01-01

    Purpose: To attain effective reactor operation in a bwr type reactor by forecasting the power density of the reactor after adjustment and comparing the same with the present status of the reactor by the on-line calculation in a short time. Constitution: The present status for the reactor is estimated in a present status decision section based on a measurement signal from the reactor and it is stored in an operation result collection section. The reactor status after the forecasting is estimated in a forecasting section based on a setting signal from a forecasting condition setting section and it is compared with the result value from the operation results collection section. If the forecast value does not coincide with the result value in the above comparison, the setting value in the forecast condition setting section is changed in the control section. The above procedures are repeated so as to minimize the difference between the forecast value and the result value to thereby exactly forecast the reactor status and operate the reactor effectively. (Moriyama, K.)

  13. Varying plant density and harvest time to optimize cowpea leaf yield and nutrient content

    Science.gov (United States)

    Ohler, T. A.; Nielsen, S. S.; Mitchell, C. A.

    1996-01-01

    Plant density and harvest time were manipulated to optimize vegetative (foliar) productivity of cowpea [Vigna unguiculata (L.) Walp.] canopies for future dietary use in controlled ecological life-support systems as vegetables or salad greens. Productivity was measured as total shoot and edible dry weights (DW), edible yield rate [(EYR) grams DW per square meter per day], shoot harvest index [(SHI) grams DW per edible gram DW total shoot], and yield-efficiency rate [(YER) grams DW edible per square meter per day per grams DW nonedible]. Cowpeas were grown in a greenhouse for leaf-only harvest at 14, 28, 42, 56, 84, or 99 plants/m2 and were harvested 20, 30, 40, or 50 days after planting (DAP). Shoot and edible dry weights increased as plant density and time to harvest increased. A maximum of 1189 g shoot DW/m2 and 594 g edible DW/m2 were achieved at an estimated plant density of 85 plants/m2 and harvest 50 DAP. EYR also increased as plant density and time to harvest increased. An EYR of 11 g m-2 day-1 was predicted to occur at 86 plants/m2 and harvest 50 DAP. SHI and YER were not affected by plant density. However, the highest values of SHI (64%) and YER (1.3 g m-2 day-1 g-1) were attained when cowpeas were harvested 20 DAP. The average fat and ash contents [dry-weight basis (dwb)] of harvested leaves remained constant regardless of harvest time. Average protein content increased from 25% DW at 30 DAP to 45% DW at 50 DAP. Carbohydrate content declined from 50% DW at 30 DAP to 45% DW at 50 DAP. Total dietary fiber content (dwb) of the leaves increased from 19% to 26% as time to harvest increased from 20 to 50 days.

  14. Study on the radioactivity and soil-to-plant transfer factor of 226Ra, 234U and 238U radionuclides in irrigated farms from the northwestern Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Hamarneh, Ibrahim F.; Alkhomashi, N.; Almasoud, Fahad I.

    2016-01-01

    The present study addresses the soil-to-plant transfer factors (TFs) of 226 Ra, 234 U and 238 U for 13 types of vegetables and agricultural crops planted under semi-arid environment in the northwestern part of Saudi Arabia. Crop plants along with plant-growing soils were collected from selected farms, which are irrigated from the non-renewable Saq aquifer, and investigated for their radioactivity content by means of alpha spectrometry after applying a radiochemical separation procedure. Hence, TF data for plant roots, green parts (stem and leaves) and fruits were calculated and contrasted to those reported in the literature. Substantial differences were observed in the TFs of Ra and U radioisotopes among plant species. In crop fruits, eggplant exhibited the highest uptake of 226 Ra (TF value of 0.11), while beans (0.16) have the highest TF for 234 U and 238 U. The geometric mean TF values indicated that the crop roots tend to accumulate Ra and U about four to six-folds higher than fruits. The relation between TF values and soil concentrations showed a weak correlation. Activity ratios between radionuclides in crop plants indicated the preferential translocation of U in fruits than Ra even though Ra is more available for root uptake. The fruit/root (F/R) ratios obtained for the investigated plants shown that pepper had the smallest F/R ratios (0.07 ± 0.01, 0.12 ± 0.02 and 0.11 ± 0.02 for 226 Ra, 234 U and 238 U, respectively), while the highest F/R ratios were observed in potatoes (0.71 ± 0.15, 0.44 ± 0.10 and 0.40 ± 0.08 for 226 Ra, 234 U and 238 U, respectively). The TF and F/R ratios data of natural radionuclides in the study region can hopefully improve the scientific knowledge for future studies. - Highlights: • Ra and U isotopes were measured in soils and plant crops in farms in Saudi Arabia. • Ra and U activities in plant roots (R) slightly exceeded that in their fruits (F). • Ra/U activity ratios showed preferential translocation of U

  15. Effect of supplementary irrigation at high ambient temperatures on sunburn, plant physiology, soil and canopy environment of ‘Granny Smith’ apple

    CSIR Research Space (South Africa)

    Mupambi, G

    2017-01-01

    Full Text Available Pulsing irrigation is a supplementary irrigation strategy whereby South African apple growers aim to reduce tree stress during a heat wave by applying additional water to the orchard floor using microsprinklers. The aim of this research...

  16. Forage yield and nutritive value of Tanzania grass under nitrogen supplies and plant densities

    Directory of Open Access Journals (Sweden)

    Fabrício Paiva de Freitas

    2012-04-01

    Full Text Available The objective of this experiment was to evaluate the nitrogen and plant density influence on the yield, forage dissection and nutritive value of Tanzania grass (Panicum maximum Jacq.. The design was of completely randomized blocks with three replications in a factorial arrangement with four nitrogen levels (0, 80, 160 or 320 kg/ha N and three plant densities (9, 25 or 49 plants/m². The plots were cut at 25 cm from soil level when the canopy reached 95% of light interception. The total dry matter forage yield and dry matter forage yield per harvest increased linearly with the nitrogen fertilization. The leaf and stem yield had the same response. The senesced forage yield was quadratically influenced by the nitrogen. The stems ratio in the morphologic composition was high in the high nitrogen levels and in the low plant densities. The leaf:stem ratio showed high values in this trial, but it was increased in plots without nitrogen and high plant density. The pre-grazing height was reduced with the increase in plant density. The nutritive value was favored by the nitrogen fertilization, which increased the crude protein level and reduced neutral detergent fiber and lignin. These factors increased the leaf and stem in vitro digestibility of organic matter. Nitrogen fertilization increases the forage yield of Tanzania grass under rotational grazing. After the establishment, plant density has little influence on the Tanzania grass yield and its forage dissection. The harvest with 95% light interception improves the structure and nutritive value of Tanzania grass pastures.

  17. Physiological and biochemical responses to the exogenous application of proline of tomato plants irrigated with saline water

    Directory of Open Access Journals (Sweden)

    B. Kahlaoui

    2018-01-01

    Full Text Available In scope of crop salinity tolerance, an experiment was carried out in a field using saline water (6.57 dS m−1 and subsurface drip irrigation (SDI on two tomato cultivars (Solanum lycopersicum, cv. Rio Grande and Heinz-2274 in a salty clay soil. Exogenous application of proline was done by foliar spray at two concentrations: 10 and 20 mg L−1, with a control (saline water without proline, during the flowering stage. Significant higher increases in proline and total soluble protein contents, glutamine synthetase (GS, EC6.3.1.2 activities and decreases in proline oxidase (l-proline: O2 Oxidoreductase, EC1.4.3.1 activities were detected in both tomato cultivars when irrigated with saline water (6.57 dS m−1 and exogenously applied by the lower concentration of proline. Taking in consideration the obtained results, it was concluded that the foliar spray of low concentration of proline can increase the tolerance of both cultivars of tomato to salinity under field conditions.

  18. Effect of planting density on fruit size, light-interception and photosynthetic activity of vertically trained watermelon (Citrullus lanatus (Thunb.) Matsum. et Nakai) plants

    International Nuclear Information System (INIS)

    Watanabe, S.; Nakano, Y.; Okano, K.

    2003-01-01

    Summary The effect of planting density on fruit size of vertically trained watermelon (Citrullus lanatus (Thunb.) Matsum. et Nakai) plants was investigated with regard to light - interception characteristics and photosynthetic production. Watermelon plants, grafted on bottle gourd, were grown in a glasshouse at different planting densities. Two vines per plant were allowed to grow and trained vertically. One hand-pollinated fruit per plant was set around the 15th node on either vine. The solar radiation and photosynthetic rate of individual leaves during fruit development period were determined by an integrated solarimeter film and a portable photosynthesis system, respectively. Fruit size was significantly decreased as the planting density increased, whereas soluble solids content of the fruits was affected little. The solar radiation and the photosynthetic rate of the individual leaves gradually decreased as the leaf position became lower at all planting densities on account of shading; those at lower leaves tended to decrease as the planting density increased. Fruit size was closely related to both the total solar radiation and the photosynthetic production per plant. In conclusion, the difference in fruit size among the planting densities is attributed to the photosynthetic productivity of the whole plant, which is mainly a function of the total solar radiation. This paper appears to be the first trial relating the influence of light interception and photosynthetic rates in high density plantings of vertically trained watermelon plants on fruit size

  19. The Effect of Plant Density on Photosynthesis and Growth Indices of Henna (Lowsonia inermis L. Ecotypes

    Directory of Open Access Journals (Sweden)

    A Pasandi Pour

    2018-05-01

    Full Text Available Introduction One of the most important factors to obtain the maximum performance or yield in every climatic condition and for each plant varieties is determining the optimum plant density. Henna (Lowsonia inermis L. is a perennial plant with high value in terms of having medicinal properties and industrial applications. The dye which is derived from green leaves of henna is used for decorating the body with intricate designs and the principle coloring matter is lawsone, 2-hydroxy-1, 4-naphthoqunone. The main purpose of this study was to evaluate the agro-physiological reaction of different henna ecotypes to different planting densities in Kerman weather conditions. Materials and Methods The study was carried out as a factorial experiment based on complete randomized block design with three replications in Shahid Bahonar University in 2015. The experiment consisted of four plant densities (25, 33, 50 and 100 plants m-2 and three ecotypes (Shahdad, Roodbar and Bam. Due to its small seeds and germination problems the planting method used was transplanting. In this study, growth indices such as leaf area index (LAI, crop growth rate (CGR, relative growth rate (RGR, leaf area ratio (LAR, specific leaf area (SLA, specific leaf weight (SLW, leaf area duration (LAD and biomass duration (BMD were calculated. The net photosynthesis, stomatal conductance and transpiration rate were measured in the middle of growing period by photosynthesis meter (CI-340 model, CID Bio- Science companies, USA. At the end, the results were analyzed using the SAS v. 9.1 and MSTATC software’s and diagrams were drawn by Excel software. Results and Discussion The results showed that the studied ecotypes were significantly different in terms of CGR, RGR and stomatal conductance. The highest average of CGR belonged to Shahdad ecotype while there was no significant difference between Roodbar and Bam ecotypes in this case. Shahdad ecotype with the RGR of 0.018 g.g.day had the

  20. Medicinal Plants Density Along an Altitudinal Gradient in and Around Ayubia National Park

    International Nuclear Information System (INIS)

    Tariq, A.; Adnan, M.; Begum, S.

    2016-01-01

    Medicinal plants are an essential source of livelihood for many rural populations and are currently facing several threats of extinction in temperate Himalaya, such as excessive grazing and collection along altitudinal gradients. The present study was designed to investigate the species density of medicinal plants at different mid-altitude levels (2200, 2300, 2400, and 2500 m above the sea level (a.s.l.) between two forest-use types and to examine the possible association between medicinal plant densities and forest-stand structural variables along the altitudinal gradient. Factorial design analysis of variance showed that the densities of all medicinal plants differed significantly between the forest-use types (p<0.00) and elevation (p<0.00). Moreover, a significant interaction (p<0.04) was also observed between the forest-use types and elevation. In the old-growth forest, density of medicinal plants was 290/40 m/sup 2/ at the higher altitude (2500 m a.s.l.), approximately 1.5-fold less than the 475/40 m/sup 2/ density observed at lower altitude (2200 m a.s.l.). However, in derived woodland, density of medicinal plants at higher altitude was approximately 4-fold less than that at the lower altitude. At these altitudinal levels, medicinal plants densities, such as Valeriana jatamansi, were significantly higher under old-growth forest compared to derived woodland, where they were almost nonexistent. A rapid vulnerability assessment has also shown that Valeriana jatamansi and Viola canescens were highly vulnerable species. Litter cover was the influential variable that was most likely related to medicinal plant density. In conclusion, abundance of medicinal plants decreased along mid-altitude levels in both of the forest-use types. However, this decrease was extremely marked in the derived woodland, and this decline may be due to human activity. Hence, these factors must be considered in future studies to suggest protective measures that can be applied along

  1. Effects of Plant Density on Sweet and Baby Corn (Hybrid KSC 403 Yield and Yield Components

    Directory of Open Access Journals (Sweden)

    H Bavi

    2016-07-01

    Full Text Available Introduction Sweet corn is the one of the most important types of corn. There is a high amount of sugar in the endosperm of sweet corn than dent corn. Baby corn is the ear of corn that is being harvested in the silking stage before the end of pollination. This crop has an interesting using methods as salad, conserve production and vegetative consumption. Both two sweet and baby corn is obtained from one plant in different growth stages and could be harvested from one corn hybrid. Best yield and quality of baby corn is obtained from sweet corn hybrids, because of high amounts of sugar in the grains and ears. Sweet corn and baby corn could be harvested at early dough stage (with about 30 % of humidity and early silking stage before the pollination is completed, respectively. Plant density is the most important factor in growing corn, especially in sweet and baby corn. Khuzestan province is one of the main regions of corn production in Iran. In Khuzestan, forage and silage corn have the most production among the summer crops. Corn is planted in two planting date in Khuzestan: early spring and early summer. Spring corn planting produces little grain yield due to Simultaneity of silking stage with hot early summer days. Because of little production and little research about sweet and baby corn, this study was performed and designed. Materials and Methods In order to investigate the effects of plant density and harvesting method on sweet corn and baby corn yield, an experiment was performed during 2012-13, in research farm of Ramin Agriculture and Natural Resources University of Khuzestan, located in southwest of Iran. In this experiment, four plant densities (7, 9, 11 and 13 plants.m-2 and two harvesting methods (baby corn and sweet corn were investigated in an RCB statistical design with four replications. The KSC 403 hybrid was used and investigated in the experiment, as a sweet corn hybrid. Statistical analysis was performed using SAS 9.1 through

  2. Ring Irrigation System (RIS) design through customer preference representation

    OpenAIRE

    Ridwan Infandra I.Z.; Rianmora Suchada; Werawatganon Siwat

    2018-01-01

    In agricultural field, irrigation is one of the most interesting considerations affecting the rate of plant growth and development. Micro-irrigation as the dripping or sprinkle method is one of the irrigation types that applies the small amount of water for fulfilling the humidity requirement. The most important factors affecting the demand of water for plants are soil conditions and effect of climatic factors. With less human labour required, to improve the irrigation method from the recent ...

  3. Performance of five plant species in removal of nitrogen and phosphorus from an experimental phytoremediation system in the Ningxia irrigation area.

    Science.gov (United States)

    Chen, Chongjuan; Zhao, Tiancheng; Liu, Ruliang; Luo, Liangguo

    2017-09-10

    Agricultural non-point source (ANPS) pollution is an important contributor to elevated nitrogen (N) and phosphorus (P) in surface waters, which can cause serious environmental problems. Considerable effort has therefore gone into the development of methods that control the ANPS input of N and P to surface waters. Phytoremediation has been extensively used because it is cost-effective, environmentally friendly, and efficient. The N and P loads from agricultural drainage are a potential threat to the water quality of the Yellow River in Ningxia, China. Yet, phytoremediation has only rarely been applied within the Ningxia irrigation area. In an experimental set-up, five species (Ipomoea aquatica, IA; Lactuca sativa, LS; Oryza sativa, OS; Typha latifolia, TL; Zizania latifolia, ZL) were evaluated for their ability to reduce N and P loads over 62 days and five observation periods. Total N and P concentrations, plant biomass, and nutrient content were measured. The results showed that OS, LS, and IA performed better than ZL and TL in terms of nutrients removal, biomass accumulation, and nutrients storage. The highest overall removal rates of N and P (57.7 and 57.3%, respectively) were achieved by LS treatment. In addition, plant uptake contributed significantly to nutrient removal, causing a 25.9-72.0% reduction in N removal and a 54.3-86.5% reduction in P removal. Thus, this study suggests that OS, LS, and IA would be more suitable than ZL and TL for controlling nutrient loads in the Ningxia irrigation area using phytoremediation.

  4. Root activity pattern of banana under irrigated and rain conditions

    International Nuclear Information System (INIS)

    Sobhana, A.; Aravindakshan, M.; Wahid, P.A.

    1989-01-01

    Root morphology by excavation method and root activity pattern by 32 P soil-injection technique have been studied in banana var., Nendran under rainfed/irrigated conditions. The number of roots, length and diameter of roots and dry weight of roots were found to be more for the rainfed banana crop compared to the irrigated. The results of the radiotracer studies indicated that about 60 per cent of the active roots of irrigated banana lie within 20 cm distance and about 90 per cent of the total root activity is found within 40 cm distance from the plant. In the case of rainfed crop about 85 per cent of the active roots were found within a radius of 40 cm around the plant. Active roots were found to be more concentrated at 15 to 30 cm depth under rainfed conditions while the density of active roots was more or less uniform along the profile upto a dpeth of 60 cm in irrigated banana. (author). 4 refs., 3 figs

  5. Influence of planting density and nitrogen fertilization on the yield of Morus alba var. tigreada

    International Nuclear Information System (INIS)

    Noda, Yolai; Martín, G. J.

    2014-01-01

    An experiment was carried out to evaluate the effect of planting density (12 500, 25 000 and 37 500 plants/ha) and nitrogen fertilization (100, 300 and 500 kg N/ha/year) on the yield and bromatological composition of Morus alba var. tigreada. The dry matter yield of the total (DMYTB) and edible biomass (DMYEB), and the yield of the leaves (DMYL) and the fresh stems (DMYFS) were measured during two years. The crude fiber (CF) and crude protein (CP) percentages were also calculated. There was interaction of the factors (p < 0,05) in the DMYFS; the highest values were obtained when the maximum planting density was combined with the three doses of N (0,37; 0,35 and 0,32 kg DM/plant), as well as when combining 25 000 plants/ha with 300 and 500 kg N/ha/year (0,27 and 0,34 kg DM/plant, respectively). In the variables DMYTB, DMYEB and DMYL there was no interaction of the studied factors. The highest values of total and edible biomass and leaves were reached with 37 500 plants (4,43; 2,37 and 2,03 kg DM/plant ) and the maximum dose of N (3,16;1,89 and 1,68 kg DM/plant). It is concluded that the best results regarding the yield of mulberry were obtained with the density of 37 500 plants/ha; its combination with the lowest dose of N produced high yields of fresh stems, which constitutes an important component of the biomass consumed by livestock. (author)

  6. Estimation of Wheat Plant Density at Early Stages Using High Resolution Imagery

    Directory of Open Access Journals (Sweden)

    Shouyang Liu

    2017-05-01

    Full Text Available Crop density is a key agronomical trait used to manage wheat crops and estimate yield. Visual counting of plants in the field is currently the most common method used. However, it is tedious and time consuming. The main objective of this work is to develop a machine vision based method to automate the density survey of wheat at early stages. RGB images taken with a high resolution RGB camera are classified to identify the green pixels corresponding to the plants. Crop rows are extracted and the connected components (objects are identified. A neural network is then trained to estimate the number of plants in the objects using the object features. The method was evaluated over three experiments showing contrasted conditions with sowing densities ranging from 100 to 600 seeds⋅m-2. Results demonstrate that the density is accurately estimated with an average relative error of 12%. The pipeline developed here provides an efficient and accurate estimate of wheat plant density at early stages.

  7. Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

    Science.gov (United States)

    Nemec, Kristine T.; Allen, Craig R.; Danielson, Stephen D.; Helzer, Christopher J.

    2014-01-01

    In recent decades, agricultural producers and non-governmental organizations have restored thousands of hectares of former cropland in the central United States with native grasses and forbs. However, the ability of these grassland restorations to attract predatory invertebrates has not been well documented, even though predators provide an important ecosystem service to agricultural producers by naturally regulating herbivores. This study assessed the effects of plant richness and seeding density on the richness and abundance of surface-dwelling (ants, ground beetles, and spiders) and aboveground (ladybird beetles) predatory invertebrates. In the spring of 2006, twenty-four 55 m × 55 m-plots were planted to six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Natural Resources Conservation Service Conservation Reserve Program mix, CP25), at low and high seeding densities. Ants, ground beetles, and spiders were sampled using pitfall traps and ladybird beetles were sampled using sweep netting in 2007–2009. The abundance of ants, ground beetles, and spiders showed no response to seed mix richness or seeding density but there was a significant positive effect of richness on ladybird beetle abundance. Seeding density had a significant positive effect on ground beetle and spider species richness and Shannon–Weaver diversity. These results may be related to differences in the plant species composition and relative amount of grass basal cover among the treatments rather than richness.

  8. Ecological and evolutionary consequences of tri-trophic interactions: Spatial variation and effects of plant density.

    Science.gov (United States)

    Abdala-Roberts, Luis; Parra-Tabla, Víctor; Moreira, Xoaquín; Ramos-Zapata, José

    2017-02-01

    The factors driving variation in species interactions are often unknown, and few studies have made a link between changes in interactions and the strength of selection. We report on spatial variation in functional responses by a seed predator (SP) and its parasitic wasps associated with the herb Ruellia nudiflora . We assessed the influence of plant density on consumer responses and determined whether density effects and spatial variation in functional responses altered natural selection by these consumers on the plant. We established common gardens at two sites in Yucatan, Mexico, and planted R. nudiflora at two densities in each garden. We recorded fruit output and SP and parasitoid attack; calculated relative fitness (seed number) under scenarios of three trophic levels (accounting for SP and parasitoid effects), two trophic levels (accounting for SP but not parasitoid effects), and one trophic level (no consumer effects); and compared selection strength on fruit number under these scenarios across sites and densities. There was spatial variation in SP recruitment, whereby the SP functional response was negatively density-dependent at one site but density-independent at the other; parasitoid responses were density-independent and invariant across sites. Site variation in SP attack led, in turn, to differences in SP selection on fruit output, and parasitoids did not alter SP selection. There were no significant effects of density at either site. Our results provide a link between consumer functional responses and consumer selection on plants, which deepens our understanding of geographic variation in the evolutionary outcomes of multitrophic interactions. © 2017 Botanical Society of America.

  9. Morphogenesis of Tanzania guinea grass under nitrogen doses and plant densities

    Directory of Open Access Journals (Sweden)

    Thiago Gomes dos Santos Braz

    2011-07-01

    Full Text Available The objective of this work was to evaluate effects of nitrogen fertilization and plant density on morphogenesis of Tanzania guinea grass. It was used a random block design with 12 treatments and two replications in a 4 × 3 factorial arrangement, with four doses of nitrogen (N (without N application, 80, 160 or 320 kg/ha.year and three plant densities (9, 25 or 49 plants/m². Harvest was performed at 25 cm from the ground when the canopy intercepted 95% of the incident light. Rates of leaf appearance and pseudostem elongation were positively and linearly influenced by nitrogen, whereas phillochron and leaf life span were influenced linearly and negatively. Leaf elongation responded positively to two factors, whereas leaf senescence rate and number of live leaves were not influenced by the factors evaluated. Number of total, basal and aerial tillers were greater at the density of 9 plants/m² and at the nitrogen dose of 320 kg/ha.year. Nitrogen increases production of leaves and tillers in Tanzania guinea grass defoliated at 95% of light interception, but high density of plants reduces the number of tiller per bunch.

  10. Interactions between fluvial forces and vegetation size, density and morphology influence plant mortality during experimental floods

    Science.gov (United States)

    Stella, J. C.; Kui, L.; Manners, R.; Wilcox, A. C.; Lightbody, A.; Sklar, L. S.

    2015-12-01

    Introduction and methods Fluvial disturbance is a key driver of riparian vegetation dynamics in river corridors. Despite an increasing understanding of ecohydraulic interactions between plants and fluvial forces, the interactive influences of plant morphology and sediment supply on plant mortality, a key demographic factor, are largely unknown. To better understand these processes, we designed and conducted a series of flume experiments to: (1) quantify effects of plant traits that interact with flow and sediment transport on plant loss to scour during floods; and (2) predict plant dislodgement for different species across a range of plant sizes, patch densities, and sediment condition (equilibrium transport versus sediment deficit). We ran ten experimental floods in a 28 m long × 0.6 m wide × 0.71 m tall flume, using live, 1-3 year-old tamarisk and cottonwood seedlings with contrasting morphologies with varied combinations of size and density. Results and discussion Both sediment supply and plant traits (morphology and composition) have significant impacts on plant vulnerability during floods. Sediment deficit resulted in bed degradation and a 35% greater risk of plant loss compared to equilibrium sediment conditions. The probability of plant dislodgement in sparse patches was 4.5 times greater than in dense patches. Tamarisk plants and patches had greater frontal area, basal diameter and longer roots compared to cottonwood across all seedling heights. These traits, as well as its lower crown position reduced tamarisk's vulnerability to scour by 75%. Compared with cottonwood, tamarisk exhibits better resistance to floods, due to its greater root biomass and longer roots that stabilize soil, and its greater frontal area and lower crown that effectively trap sediment. These traits likely contribute to riverscape-scale changes in channel morphology that are evident where tamarisk has invaded native riparian communities, and explain the persistence of tamarisk

  11. The Effects of Drought Stress on Yield, Yield Components and Anti-oxidant of Two Garlic (Allium sativum L. Ecotypes with Different Planting Densities

    Directory of Open Access Journals (Sweden)

    shiva akbari

    2016-07-01

    Full Text Available Introduction Drought stress reduces plant growth by affecting various physiological and biochemical processes, such as photosynthesis, respiration, translocation, ion uptake, carbohydrates, nutrient metabolism and growth promoters. Garlic (Allium sativum L. is an annual bulb crop that has been cultivated since ancient times and was used as a spice and condiment for many centuries. Garlic is an important plant because of its pharmaceutical properties. The optimum yield of this bulb crop depends on well-managed irrigation, fertilization and cultivation practices. In the final and middle stages of growth, garlic is sensitive to water stress and low irrigation is unsuitable in these stages. This experiment was established to study the influence of drought stress and planting density on yield and its components and the non-enzymatic anti-oxidant content of two different garlic ecotypes. Materials and methods This study was conducted in 2011-2012 in a farmland at the south east of Semnan city. The experimental layout was a split-plot factorial with a randomized complete block design with three replications. The treatments were comprised of three factors: irrigation rates (60%, 80% and 100% of estimated crop evapotranspiration (ETC as the main plot and the factorial combination of three levels of planting density (30, 40 and 50 plants.m-2 and two ecotypes (Tabas and Toroud as the sub-plots. To estimate the crop water requirement, different meteorological parameters were collected from Semnan weather station and were used based on FAO-56 water irrigation calculation instructions. After harvesting, ten garlic plants were sampled randomly in each plot and bulb yield components were measured. To calculate the leaves anti-oxidant content, DPPH method was used. The statistical significances of mean values were assessed by analysis of variance and LSD tests at p≤0.05. All calculations were performed using SAS and Mstat-C softwares. Results and discussion

  12. Manejo da irrigação associada a coberturas mortas vegetais no cultivo orgânico da beterraba Irrigation management and mulching in organic beet planting

    Directory of Open Access Journals (Sweden)

    Daniel F. de Carvalho

    2011-04-01

    Full Text Available Práticas agrícolas orgânicas, como a cobertura do solo com palha, foram testadas em área irrigada por gotejamento na Baixada Fluminense, no Estado do Rio de Janeiro. O cultivo de inverno da beterraba nesta região é favorecido por temperaturas mais amenas, coincidindo com a época de maior disponibilidade do produto no Estado. No cultivo da beterraba, foram adotados três tipos de cobertura do solo e seis lâminas de irrigação (0; 29; 48; 78; 100 e 148% da ETc determinadas com base no balanço de água no solo utilizando a técnica da TDR. O delineamento estatístico adotado foi blocos casualizados, com seis tratamentos e quatro repetições. Sob cobertura morta de Pennisetum purpureum, de Gliricidia sepium e na ausência de cobertura morta, os valores máximos relativos de EUA, no cultivo de beterraba, foram de 21,00; 32,90 e 17,90 kg m-3, respectivamente. A maior e a menor lâmina de irrigação acumulada para cada tipo de manejo foram de 2.746 e 951 m³ ha-1 nas parcelas sem cobertura morta. Em comparação, as parcelas com cobertura do solo reduziram em 34,5 e 10,5% as lâminas acumuladas, respectivamente. Os valores acumulados de nitrogênio nas partes das plantas foram maiores no cultivo sob cobertura morta de G. sepium, indicando vantagens desta prática cultural associada à irrigação por gotejamento.Organic farming practices, like mulching, were tested in drip irrigated area in Baixada Fluminense, state of Rio de Janeiro, Brazil. In this region, the winter crop of sugar beet is favored by mild temperatures, coinciding with the period of higher product availability in the State. For the beet planting were used three soil management practices (different conditions of coverage. In each one, six irrigation depth(0, 29, 48, 78, 100 and 148% of ETc, estimated based on soil water balance using TDR technique were applied through drip of different flow rates. Moreover, it was also included a plot without irrigation. The statistical

  13. Effect of Plant Density and Weed Interference on Yield and Yied Components of Grain Sorghum

    Directory of Open Access Journals (Sweden)

    S. Sarani

    2018-01-01

    Full Text Available Introduction Weed control is an essential part of all crop production systems. Weeds reduce yields by competing with crops for water, nutrients, and sunlight. Weeds also directly reduce profits by hindering harvest operations, lowering crop quality, and producing chemicals which are harmful to crop plants. Plant density is an efficient management tool for maximizing grain yield by increasing the capture of solar radiation within the canopy, which can significantly affect development of crop-weed association. The response of yield and yield components to weed competition varies by crop and weeds species and weeds interference duration. The objective of the present study was to evaluate the effect of weed interference periods and plant density on the yield and yield components of sorghum. Materials and Methods In order to study the effect of plant density and weeds interference on weeds traits, yield and yield components of sorghum (Var. Saravan, an experiment was conducted as in factorial based on a randomized complete block design with three replications at the research field of Islamic Azad University, Birjand Branch in South Khorasan province during year of 2013. Experimental treatments consisted of three plant density (10, 20 and 30 plants m-2 and four weeds interference (weed free until end of growth season, interference until 6-8 leaf stage, interference until stage of panicle emergence, interference until end of growth season. Measuring traits included the panicle length, number of panicle per plant, number of panicle per m2, number of seed per panicle, 1000-seed weight, seed yield, biological yield, number and weight of weeds per m2. Weed sampling in each plot have done manually from a square meter and different weed species counted and oven dried at 72 °C for 48 hours. MSTAT-C statistical software used for data analysis and means compared with Duncan multiple range test at 5% probability level. Results and Discussion Results showed that

  14. Physiological quality of soybean seeds under different yield environments and plant density

    Directory of Open Access Journals (Sweden)

    Felipe A. Baron

    Full Text Available ABSTRACT Yield potential of agricultural fields associated with plant spatial arrangement could determine the physiological quality of soybean (Glycine max L. seeds. Thus, this study aimed to evaluate the physiological quality of soybean seeds from different yield environments and plant densities. Experiments were carried out in Boa Vista das Missões-RS, Brazil, during the 2014/2015 growing season. Yield environments were delineated by overlapping yield maps from the 2008, 2009/2010 and 2011/2012 growing seasons. The experimental design was a randomized complete block in a 2 x 5 factorial arrangement with two yield environments (low and high and five plant densities, with four replicates. Two varieties were tested: Brasmax Ativa RR (10, 15, 20, 25 and 30 plants m-1 and Nidera 5909 RR (5, 10, 15, 20 and 25 plants m-1. After harvested, the seeds were analysed as following: first count index, germination, abnormal seedlings, dead seeds, electrical conductivity, accelerate aging test, root length, hypocotyl length and seedling length. The spatial variability of seed vigor in the production field could be reduced by adjusting plant density, but the adjustment should consider the variety. Harvest according to yield environment is a strategy to separate lots of seeds with higher vigor, originated from high-yield environments.

  15. Narrow row and crossed lines associated with different plant densities of soybean

    Directory of Open Access Journals (Sweden)

    Alvadi Antonio Balbinot Junior

    2015-10-01

    Full Text Available The spatial arrangement of soybean plants affects the intraspecific competition for light, water and nutrients, which can change the biomass production, incidence of pests, diseases and weeds, plant lodging, and grain yield. This work aimed to evaluate the agronomic performance under different row spacing, plant densities and crossed rows. Two field experiments were carried out in Campo Mourão, Paraná State, Southern Brazil, using the randomized complete block experimental design, in a 3x3x2 factorial arrangement, with four replications. The treatments were formed by the combination of three row spacings (0.30, 0.45, and 0.60 m, three plant densities (300,000; 450,000; and 600,000 plants ha-1, and two row design (crossed or parallel rows. For all variables, interaction of the experimental factors was not significant. The row spacing of 0.45 m provided the highest grain yield in relation to 0.30 and 0.60 m. The density of 300,000 plants ha-1 showed higher yield of soybeans in late sowing. The crossed lines did not increase the productive performance in soybean.

  16. AGROCLIMATIC DETERMINANTS OF IRRIGATION NEEDS

    Directory of Open Access Journals (Sweden)

    Leszek Łabędzki

    2016-05-01

    Full Text Available The paper is a review of the so far used in Poland methods and criteria for assessing the needs of irrigation for planning purposes, the assessment because of the agroclimatic conditions and taking into account the soil water retention. Irrigation needs of the most are determined taking into account crop water deficits. This is the factor that is characterized by a shortage of precipitation in relation to the water requirements of crops. Some methods use only the meteorological parameters that determine the state of the atmosphere-soil-plant system, and some also take into account soil water retention and its availability for plants.

  17. Effect of Irrigation CutOff on Flowering Stage and Foliar Application of Spermidine on Some Quantitative and Qualitative Characteristics of Various Ecotypes of Cumin

    Directory of Open Access Journals (Sweden)

    Sarah Bakhtari

    2017-02-01

    Full Text Available Introduction: Medicinal plants play major roles in human health. . Cumin (Cuminum cyminum L. is an annual plant that commonly cultivated in arid and semiarid regions of Iran. The crop has a wide range of uses including medicinal, cosmetic and food industry. Cumin occupies about 26% of the total area devoted to medicinal plants in Iran. However, cumin is seriously affected by the Fusarium wilt and blight diseases. The diseases usually increase under warm and wet conditions. It was demonstrated that the peak of the disease incidence is occurring at the flowering stage and irrigation cutoff at this time may be reduced the diseases density. Materials and methods: In order to evaluate the effects of irrigation cutoff in flowering stage and foliar application of spermidine on some characteristics of various ecotype of cumin, an experiment was conducted in a split-split-plot arrangement in randomized complete block design with three replications at the research farm of Shahid Bahonar University of Kerman at 2014. The experimental treatments were irrigation in two levels (complete irrigation and cutoff the irrigation in flowering stage assigned to main plots, foliar application of spermidine in three levels (0, 1 and 2 Mm as a subplot and cumin ecotypes in three levels (Kerman, Khorasan and Esfahan that was randomized in sub-subplot. Plots size under the trial was 4 m × 3 m so as to get 50 cm inter row spacing in six rows. The ideal density of the crops was considered as 120 plant m-2. As soon as the seeds were sown, irrigation was applied every 10 days. Foliar application of spermidine was done at three stages (after thinning, before flowering stage and in the middle of flowering stage. No herbicides and chemical fertilizers were applied during the expriments. Results and discussion: In this study the number of branches, umbels per plant, 1000-seed weight, seed yield per plant and hectare, harvest index, essential oil percentage and yield, infected

  18. Plant Density Effect on Grain Number and Weight of Two Winter Wheat Cultivars at Different Spikelet and Grain Positions

    OpenAIRE

    Li, Yong; Cui, Zhengyong; Ni, Yingli; Zheng, Mengjing; Yang, Dongqing; Jin, Min; Chen, Jin; Wang, Zhenlin; Yin, Yanping

    2016-01-01

    In winter wheat, grain development is asynchronous. The grain number and grain weight vary significantly at different spikelet and grain positions among wheat cultivars grown at different plant densities. In this study, two winter wheat (Triticum aestivum L.) cultivars, 'Wennong6' and 'Jimai20', were grown under four different plant densities for two seasons, in order to study the effect of plant density on the grain number and grain weight at different spikelet and grain positions. The resul...

  19. Effects of tillage operations and plant density on leaf spot disease ...

    African Journals Online (AJOL)

    Two seasons experiments conducted in 2002 and 2003 revealed that Tillage operations significantly influenced leafspot disease severity; Percentage lodging 3.14; 2.08 and Grain yield 3.02; 3.84 in 2002 and 2003 respectively. Plant density also had significant difference on leafspot disease severity; Percentage lodging ...

  20. Effect of Plant Density and Land Race on the Growth and Yield of ...

    African Journals Online (AJOL)

    Field study was conducted at National Root Crops Research Institute out station Nyanya Research farm located at Zhewun Jidna Nasarawa State during 2007 and 2008 cropping seasons. The aim was to determine the effect of optimum plant population Density of sweet potato land races under improved management ...

  1. 55-61 Effect of Plant Density on Morphological Characteristics, Yield a

    African Journals Online (AJOL)

    characteristics of Napier grass due to plant density during the establishment year. However, the ... resulting in slow growth rates, poor fertility and high rates of mortality (Osuji et al., ...... matter digestibility in vitro of leaf and stem of buffel grass ...

  2. The effect of plant density with different row spacing on quality of the ...

    African Journals Online (AJOL)

    This research was aimed to assess the influence of density with different row spacing on sunflower crop in two different locations in southern Italy. The experiment was laid out in a randomized block design with four replicates. It involved the comparison of sunflower grown in the field on 25 m2 (5 x 5 m) plots at three plant ...

  3. Increasing plant density in eastern United States broccoli production systems to maximize marketable head yields

    Science.gov (United States)

    Increased demand for fresh market broccoli (Brassica oleracea L. var. italica) has led to increased production along the eastern seaboard of the United States. Maximizing broccoli yields is a primary concern for quickly expanding eastern commercial markets. Thus, a plant density study was carried ...

  4. The effect of planting density on the wood quality of South African ...

    African Journals Online (AJOL)

    This paper presents the results of a wood property and sawn board quality study performed on disc samples and sawlogs taken from a 23-year-old Eucalyptus grandis Nelder 1a spacing trial at J.D.M. Keet plantation near Tzaneen. Ten trees from each of four markedly different planting densities were chosen to provide ...

  5. Early impact of oil palm planting density on vegetative and oil yield variables in West Africa

    Directory of Open Access Journals (Sweden)

    Bonneau Xavier

    2014-07-01

    Full Text Available A range of various different planting distances (from 7.5 to 9.5 m between oil palms were tested using an equilateral triangle design in a plantation density experiment which was settled in an oil palm commercial plantation in Nigeria. Climatic conditions were quite stable, with two seasons and around 2000 mm of annual rainfall. The soil was of desaturated ferralitic type, sandy on the surface, deep and without coarse elements. The early impact of plantation density was analysed at eight years after planting. Some early signs of depressive effect on yields were found for high planting densities (180 and 205 p/ha. Such a negative impact was not severe enough to counteract the effects of a higher number of palms per hectare. As a consequence, a gradient could be observed as yields (in tons of bunches per hectare increased with density. We can anticipate that the competition effect between palms will increase over time with high densities, so that the counteracting point ought to be reached in a few years. A thinning treatment has been included in the protocol. Thinning was carried out at the end of the eight-year period.

  6. Herbivore-specific, density-dependent induction of plant volatiles: honest or "cry wolf" signals?

    Directory of Open Access Journals (Sweden)

    Kaori Shiojiri

    Full Text Available Plants release volatile chemicals upon attack by herbivorous arthropods. They do so commonly in a dose-dependent manner: the more herbivores, the more volatiles released. The volatiles attract predatory arthropods and the amount determines the probability of predator response. We show that seedlings of a cabbage variety (Brassica oleracea var. capitata, cv Shikidori also show such a response to the density of cabbage white (Pieris rapae larvae and attract more (naive parasitoids (Cotesia glomerata when there are more herbivores on the plant. However, when attacked by diamondback moth (Plutella xylostella larvae, seedlings of the same variety (cv Shikidori release volatiles, the total amount of which is high and constant and thus independent of caterpillar density, and naive parasitoids (Cotesia vestalis of diamondback moth larvae fail to discriminate herbivore-rich from herbivore-poor plants. In contrast, seedlings of another cabbage variety of B. oleracea (var. acephala: kale respond in a dose-dependent manner to the density of diamondback moth larvae and attract more parasitoids when there are more herbivores. Assuming these responses of the cabbage cultivars reflect behaviour of at least some genotypes of wild plants, we provide arguments why the behaviour of kale (B. oleracea var acephala is best interpreted as an honest signaling strategy and that of cabbage cv Shikidori (B. oleracea var capitata as a "cry wolf" signaling strategy, implying a conflict of interest between the plant and the enemies of its herbivores: the plant profits from being visited by the herbivore's enemies, but the latter would be better off by visiting other plants with more herbivores. If so, evolutionary theory on alarm signaling predicts consequences of major interest to students of plant protection, tritrophic systems and communication alike.

  7. Effect of Plant Density and Nitrogen Fertilizeron Morphological Traits, Seed and Essential Oil Yield and Essential Oil Content of Ajowan (Carum copticum L.

    Directory of Open Access Journals (Sweden)

    S.Ali Tabatabaei

    2017-08-01

    Full Text Available Introduction: Ajowan (Carum copticum Benth. & Hook. is an annual herbaceous essential oil bearing plant belonging to the Apiaceae family, which grows in India, Iran, and Egypt. Ajowan seeds have essential oil as an active substance, which is used in pharmaceutical industry as a diuretic, antivomiting, analgesic, antiasthma, antispasmodic and a carminative. Nitrogen is a part of all living cells and is a necessary part of all proteins, enzymes and metabolic processes involved in the synthesis and transfer of energy. Also, nitrogen is a part of chlorophyll, the green pigment of the plant that is responsible for photosynthesis. Generally, proper agronomic management including suitable plant density has a high influence on growth and yield of medicinal plants. In this regard, Kloss et al., (2012 highlighted the need for strategies to improve crop growth, make irrigation more efficient and sustainable and conserve farmlands. In addition, yield is influenced by inter-row spacing and sowing density. Ghilavizadeh et al., (2013 have reported that application of suitable amount of nitrogen fertilizer and plant density of 25 plan/m2 increased seed yield, essential oil yield and essential oil content of ajowan. In another research, Borumand Rezazadeh et al., (2009 reported that the plant density of 50 plant/m2 have produced the highest seed yield, essential oil yield and essential oil content. Generally, with regard to importance of medicinal plants and the necessity of understanding their crop and the impact of plant density and nitrogen fertilizer on the performance of these plants, this study was conducted to investigate the impact of these factors on some traits of ajowan. Materials and Methods: In order to evaluate the effect of plant density and nitrogen fertilizer on different traits of ajowan (Carum copticum L., an experiment was conducted using factorial based on randomized complete block design with three replications at Agricultural and Natural

  8. Estratégias de irrigação com água salina na mamoneira Irrigation strategies with saline water in castor oil plant

    Directory of Open Access Journals (Sweden)

    Maria Eugênia da Costa

    2013-03-01

    Full Text Available Este experimento foi realizado em campo para avaliar estratégias de irrigação com água salina no crescimento e na produção da mamoneira (BRS Energia, além de identificar eventuais estádios de maior tolerância à salinidade e monitorar alguns atributos químicos do solo. Os tratamentos consistiram da irrigação com águas de CE 0,53; 2,09; 3,66 dS m-1 de acordo com a fase de desenvolvimento da cultura, totalizando cinco estratégias de irrigação com água salina e uma testemunha. As avaliações de crescimento foram realizadas aos 20; 40; 60; 80; 100 dias após a semeadura (DAS. As coletas de solo foram realizadas concomitantemente às avaliações de crescimento, nas camadas 0-0,10; 0,10-0,30; 0,30-0,50 m. A irrigação contínua com água de CE 3,66 dS m-1 reduziu a altura de planta, o comprimento de racemo terciário, o número de frutos por área útil e a produtividade de frutos. Essa estratégia aumentou acentuadamente os teores de Na+ e a CE do solo no final do ciclo. Por outro lado, a irrigação com água salina começando aos 45 DAS não prejudicou as variáveis de crescimento e os componentes de produção. Essa estratégia minimizou os impactos negativos sobre a salinidade/sodicidade do solo no final do ciclo. Comportamento similar foi observado para a irrigação contínua com água de CE 2,09 dS m-1 (mistura de águas com CE de 0,53 e 3,66 dS m-1. A mamoneira não apresentou tolerância diferenciada à salinidade em função da fase de desenvolvimento, embora tenha sido prejudicada quando aumentaram a intensidade e a duração do estresse salino.This experiment was conducted under field conditions to evaluate irrigation strategies with saline water on growth and production of castor oil plant (cv. BRS Energia, identify eventual stages with higher tolerance to salinity and monitor some soil chemical attributes. The treatments consisted of irrigations with water of EC 0.53; 2.09; 3.66 dS m-1 according to the development

  9. Improved plant nitrogen nutrition contributes to higher water use efficiency in tomatoes under alternate partial root-zone irrigation

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Andersen, Mathias Neumann

    2010-01-01

    stomatal conductance during the treatment. At the end of the experiment, N accumulation and 15N recovery was highest in FI, intermediate in PRI and lowest in DI. In addition, PRI plants consistently allocated more N into the upper and middle leaf layers than in the FI and DI treatments. The improved N...... nutrition and distribution in the canopy may indicate that PRI plants have a greater photosynthetic capacity than DI plants; this is confirmed by the observed positive linear relationship between specific leaf N content and δ13C. It is concluded that PRI improves N nutrition and optimises N distribution...

  10. Experimental evidence that density dependence strongly influences plant invasions through fragmented landscapes.

    Science.gov (United States)

    Williams, Jennifer L; Levine, Jonathan M

    2018-04-01

    Populations of range expanding species encounter patches of both favorable and unfavorable habitat as they spread across landscapes. Theory shows that increasing patchiness slows the spread of populations modeled with continuously varying population density when dispersal is not influence by the environment or individual behavior. However, as is found in uniformly favorable landscapes, spread remains driven by fecundity and dispersal from low density individuals at the invasion front. In contrast, when modeled populations are composed of discrete individuals, patchiness causes populations to build up to high density before dispersing past unsuitable habitat, introducing an important influence of density dependence on spread velocity. To test the hypothesized interaction between habitat patchiness and density dependence, we simultaneously manipulated these factors in a greenhouse system of annual plants spreading through replicated experimental landscapes. We found that increasing the size of gaps and amplifying the strength of density dependence both slowed spread velocity, but contrary to predictions, the effect of amplified density dependence was similar across all landscape types. Our results demonstrate that the discrete nature of individuals in spreading populations has a strong influence on how both landscape patchiness and density dependence influence spread through demographic and dispersal stochasticity. Both finiteness and landscape structure should be critical components to theoretical predictions of future spread for range expanding native species or invasive species colonizing new habitat. © 2018 by the Ecological Society of America.

  11. Conspecific and Heterospecific Plant Densities at Small-Scale Can Drive Plant-Pollinator Interactions

    Czech Academy of Sciences Publication Activity Database

    Janovský, Z.; Mikát, M.; Hadrava, J.; Horčičková, E.; Kmecová, K.; Požárová, D.; Smyčka, J.; Herben, Tomáš

    2013-01-01

    Roč. 8, č. 10 (2013), s. 1-11, e77361 E-ISSN 1932-6203 Institutional support: RVO:67985939 Keywords : animal mutualistic networks * local-density size * landscape Subject RIV: EF - Botanics Impact factor: 3.534, year: 2013

  12. Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina.

    Science.gov (United States)

    de Wysiecki, María Laura; Arturi, Marcelo; Torrusio, Sandra; Cigliano, María Marta

    2011-01-01

    A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996-2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and

  13. Biomass of tree species as a response to planting density and interspecific competition

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2014-04-01

    Full Text Available Planting trees is an important way to promote the recovery of degraded areas in the Caatinga region. Experiments (E1, E2, and E3 were conducted in a randomized blocks design, with three, three, and five replicates, respectively. The objectives were to evaluate biomass of the shoots of: a gliricidia (G and sabiá (S, as a response to planting density; b G, S, and neem (N in competition; c G, and S in agroforestry. E1 was conducted in split-plots, and planting densities (400, 600, 800, 1000, and 1200 plants ha-1 as subplots. E2 consisted of a factorial comprising the following plots: GGG, NGN, SGS, NNN, GNG, SNS, SSS, GSG, NSN (each letter represents a row of plants. E3 was conducted with G and S in agroforestry experiment. The trees were harvested after 54, 42, and 27 months old, in E1, E2 and E3, respectively. In E1, G presented higher green biomass of the stems and leaf at smaller densities than S, but lower green biomass of branches at most densities. The species did not differ for mean stem dry biomass and leaf dry biomass, but G showed higher branch dry biomass at most densities. Higher planting densities increased green and dry biomass of stems, branches, and leaves in S, but decreased those characteristics in G, with the exception of leaf dry mass, which was not influenced by density. In E2, the behavior of each species was identical in plots containing the same or different species. Griricidia showed the highest green biomass of stems and branches, and the highest values for geren biomass of the leaf were observed for gliricidia and neem. The highest stem, branch, and leaf dry biomass values were obtained for G, S, and N, respectively. In E3, G was superior for stem and leaf green biomass, and for stem and branch dry biomass. There were no differences between species for the other biomass values.

  14. Greenhouse evaluation of deficit irrigation on the growth of tomato ...

    African Journals Online (AJOL)

    Deficit irrigation is considered to be an important approach for crop cultivation in dry regions where water resources are scarce. Deficit irrigation can be used also to decrease the level of infections by some moisturedependent plant pests and diseases such as root-knot nematode disease. Therefore, deficit irrigation at levels ...

  15. Scheduling irrigation for jujube ( Ziziphus jujuba Mill. ) | Zhang ...

    African Journals Online (AJOL)

    This study was performed to select suitable indicator for scheduling the irrigation of jujube (Ziziphus jujuba Mill.) grown in the Loess Plateau. The relationships between plant-based indicators and soil matrix potential as well as meteorological factors of jujube under deficit irrigation compared with well irrigation were ...

  16. Evaluation some Forage Legumes in Limited Irrigation Condition

    Directory of Open Access Journals (Sweden)

    Hassan Moniri Far

    2015-11-01

    Full Text Available Forage legumes respond differently to limited irrigation regimes. Their evaluation may, thus, help to select drought tolerant types for limited irrigation conditions. In this study four type of forage legume were studied for two years in Tikma-Dash Research Station of East Azarbaijan Agricultural and Natural Research Center, Tabriz, Iran, in a randomized complete block design using split-plot experiment in 2011-2013 years. Irrigation regimes (without irrigation, one irrigation and two irrigations were assigned to main plots and four forage types (hairy vetch, grass pea, Pannonica sativa and lathyrus were assigned to subplots. The results of analysis of variance showed that the effect of irrigation on plant height, number of shoots, leaf area and plant fresh and dry weights were not significant. Howere, legume types affected these traits significantly (P≤0.01. The effect of irrigation levels and legume types on protein content of hay were significant (P

  17. Effect of Irrigation Intervals, Type of Fertilizers and Harvesting Time on Essence Content and Yield of Three Medicinal Plants: Lavender (lavandula angustifolia, Rosemary (Rosemarinus officinalis and Hyssop (Hyssopus officinalis in Mashhad Condition.

    Directory of Open Access Journals (Sweden)

    A Koocheki

    2012-12-01

    Full Text Available In order to investigate the effect of fertilizer types and irrigation regimes on quality criteria of three medicinal plants: Lavander, Rosemary and Hyssop, an experiment was conducted at Research Field of Faculty of Agriculture, Ferdowsi University of Mashhad, during two growing years of 2007-2009. A split plot design with three replications was used. Treatments were three irrigation intervals (10, 20, 30 days as main plots and six fertilizers: including (control, Nitroxin (5lit/ha, nitrogen fertilizer (50 and 100 (kg/ha, cow manure (10 and 20 ton/ha and three medicinal plants as sub-subplots. Animal manure and chemical fertilizer were applied at the time of transferring seedlings to the field and Nitroxin was used with the first irrigation. Results indicated that the effect of irrigation intervals on yield of essential oil in all species was significant (p≤0.01. The highest essential oil content was from Rosemary (1.5% but the highest yield of essential oil was obtained from three species, Lavander (10kg/ha, Rosemary (7kg/ha and Hyssop (12kg/ha with application of biological fertilizer. Application of fertilizer affected significantly (P

  18. Efeito do manejo da irrigação e de populações de plantas sobre o rendimento do algodoeiro herbáceo Effect of irrigation management and plant population on herbaceous cotton yield

    Directory of Open Access Journals (Sweden)

    Francisco Assis de Oliveira

    1999-12-01

    Full Text Available Objetivou-se estudar, num solo aluvial, franco siltoso, no vale do Açu, no Rio Grande do Norte, o efeito do momento da última irrigação e da população de plantas sobre a altura das plantas e a produtividade do algodoeiro herbáceo (Gossypium hirsutum L.r. latifolium Hutch, cultivar Acala del cerro. Os tratamentos foram definidos pelos momentos da última irrigação aos 65, 80, 95 e 110 dias após a emergência e pela população com 30.000, 60.000, 90.000 e 120.000 plantas/ha. Usou-se o delineamento experimental em blocos ao acaso, com parcelas subdivididas, e quatro repetições. A altura das plantas aumentou com o retardamento da última irrigação e com o tamanho das populações. Houve efeito (P In an alluvial soil, silt loam, of Açu valley, in the state of Rio Grande do Norte, Brazil, a research was carried out to study the effect of time of the last irrigation and plant population on yield and plant height of the herbaceous cotton (Gossypium hirsutum L.r. latifolium Hutch cultivar Acala del cerro. Treatments consisted of times of the last irrigation at 65, 80, 95 and 110 days after emergence and populations with 30,000, 60,000, 90,000 and 120,000 plants/ha. The experimental plan was a randomized complete blocks in a split-plot design, with four replications. Delaying time of last irrigation increased height and plant populations. A significant effect (P <= 0.01 of interaction between time of last irrigation and plant population was found for cotton yield. The highest cotton yield (4,090 kg/ha was obtained with the interaction between time of last irrigation at 95 days and in population of 90,000 plants/ha. Irrigation times at 65 and 80 days were considered too early, and at 110 days too late for cotton yields.

  19. Tillage and planting density affect the performance of maize hybrids in Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Tika Baladur Karki

    2015-12-01

    Full Text Available To find out whether the different tillage methods at different planting densities affect the performance of maize hybrids, an experiment was carried out at National Maize Research Program, Rampur during spring season of 2013 and 2014. The experiment was laid out in strip plot design with three replications having 12 treatments. The vertical factor was tillage with conservation tillage (No Tillage + residue=NT and conventional tillage (CT and the horizontal factor were genotypes (Rampur Hybrid-2 and RML-32/RML-17 and in split planting geometries (75cm × 25cm =53333 plants/ha, 70cm × 25cm=57142 plant/ha and 60cm ×25cm= 66666 plants/ha. In both the years, the highest number of cobs (73,177 and 67638/ha was recorded at planting density of 66666/ha. NT had the highest no of kernel rows/cob (14.01 as against 12.12 in CT in 2014. The highest number of kernels (27.3 and 29.29 per row was recorded in NT during 2013 and 2014 respectively. Similarly, in 2014, the highest number of kernels were found in RML-32/RMl-17 (29.17/row and planting density of 53333/ha (28.46/row. In 2013, RML-32/RML-17 produced the highest test weight of 363.94g over the Rampur hybrid-2 with 362.17g. Significantly the highest grain yield of 9240.00 kg/ha in 2013 and 7459.80 kg/ha in 2014 at planting geometry of 65cm ×25cm were recorded. No effects was found by tillage methods for grain yields of maize in 2013, but was found in 2014 (7012.18 kg in NT compared to 6037.59 kg/ha in CT. NT and wider spaced crop matured earlier in both the years; however Rampur hybrid-2 matured earlier to RML-32/RML-17 in 2013. In 2014, harvest index of 47.85 % was recorded in planting geometry of 66666/ha, the highest benefit cost ratio of 1.36 was worked out in NT and 1.46 at the density of 66666/ha. The highest value of 2.46% of soil organic matter was recorded in NT as compared to 2.43% in CT.

  20. Interaction Effects between Light Level and Plant Density on Plant Growth, Development and External Quality in Year-around Cut Chrysanthemum

    NARCIS (Netherlands)

    Lee, J.H.; Heuvelink, E.; Bakker, M.J.

    2009-01-01

    Aims of this study are to analyze growth pattern and development Of Cut chrysanthemum and test simple regression models in relation to light level and plant density. Cut chrysanthemum (Chrysanthemum morifolium), cv. Reagan Improved, was grown at four different plant densities of 16, 32, 64 or 80

  1. Crescimento inicial de duas cultivares de cafeeiro adensado influenciado por níveis de irrigação localizada Initial growth of two high-density coffee tree cultivars influenced by drip irrigation levels

    Directory of Open Access Journals (Sweden)

    Márcio S. Santana

    2004-12-01

    , steam diameter, plant height and plagiotropic branches number. At 316 dat irrigated treatments had similar type of growth but they were significantly higher than the non-irrigated one. Irrigas system has proved to be an option for an adequate water management with null maintenance. IAPAR-59 and Obatã cultivars had significant differences with all growth variable evaluated favoring the last one.

  2. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30–70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below...

  3. Drip Irrigation for Commercial Vegetable and Fruit Production

    OpenAIRE

    Maughn, Tiffany; Allen, Niel; Drost, Dan

    2017-01-01

    Drip irrigation is a highly efficient irrigation method well suited to many fruit and vegetable row crops. Drip tubing or tape discharges water to the soil through emitters positioned close to the plant. The drip tubing can be placed uncovered on the soil surface, under plastic mulch, buried in the soil, or suspended above the ground (e.g., on a trellis system). Water application rate is relatively low and irrigations are usually frequent. Properly designed and maintained drip-irrigation syst...

  4. Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant.

    Science.gov (United States)

    Shi, Pei-Jian; Xu, Qiang; Sandhu, Hardev S; Gielis, Johan; Ding, Yu-Long; Li, Hua-Rong; Dong, Xiao-Bo

    2015-10-01

    The relationship between spatial density and size of plants is an important topic in plant ecology. The self-thinning rule suggests a -3/2 power between average biomass and density or a -1/2 power between stand yield and density. However, the self-thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log-linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self-thinning rule to improve light interception.

  5. The effect of plant density and nitrogen fertilizer on light interception and dry matter yield in hemp (Cannabis sativa L.

    Directory of Open Access Journals (Sweden)

    mohamad reza asghari poor

    2009-06-01

    Full Text Available The effect of plant density and nitrogen fertilizer on canopy light interception and on flowering was investigated in hemp (Cannabis sativa L. cv. ‘Kompolti’ Crop grown at initial densities of 50, 150 and 250 plants/m2 at the Mashhad and 30, 90 and 150 plants/m2 at the Shirvan. Nitrogen fertilizer was applied before and 45 days after sowing at a rates of 50 and 200 kg/ha at the Mashhad, and 50, 150 and 250 kg/ha at the Shirvan. Rate of canopy development increased with increasing plant density and nitrogen fertilizer in both sites. At the Mashhad, interception of 90% of light was attained at 380 to 665 degree days (base 2°C from emergence for the crop grown at different densities. At Shirvan, rate of canopy development was slower. Interception of 90% of light was attained at 586 degree days from emergence for the crop grown at 30 plants/m2 and at 712 degree days for the crop grown at 150 plants/m2, probably as a result of cold weather. Nitrogen fertilizer in a similar way as plant density increased light interception. Maximum light interception did not depend on plant density and nitrogen fertilizer and was about 95%. In both sites, the flowering date was later with increasing plant density. Dates of 75% flowering for the initial densities of 50, 150 and 250 plants/m2 in Mashhad and 30, 90 and 150 plants/m2 in Shirvan were, respectively 26 August, 1, 6, 6, 11 and 12 September. Independent of plant density, canopy light interception started to decline at about 150 degree days after flowering, reaching 58 to 75% at about 700 degree days post-flowering. Morphological characteristics at both sites were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained in Mashhad at 250 plant/m-2 and in Shirvan at 150 plant m-2 when 200 kg N ha-1 in Mashhad and 250 kg N/ha in Shirvan was used. Above ground dry matter increased at both sites with increasing plant density and

  6. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation pot...

  7. Effect of planting methods, seed density and nitrogen phosphorus (NP) fertilizer levels on sweet corn (Zea maYs L.)

    International Nuclear Information System (INIS)

    Amin, M.; Razzaq, A.; Ullah, R.

    2006-01-01

    A field experiment was conducted to evaluate the effect of planting methods, seed density and nitrogen phosphorus (NP) fertilizer levels on emergence m/sup -2/ growth and grain yield of sweet corn. The fertilizer and interaction of fertilizer x seed density had significant negative effect with increasing level while seed density had a positive effect with increased density on emergence per m/sup 2/. Increased seed density significantly reduced plant growth which increased with application of higher fertilizer dose. The grain yield was improves by ridge planting methods, increased seed density and increased fertilizer levels. The highest grain yield (3,553.50 kg ha/sup-1/) of sweet corn plants was recorded in ridge planting method with highest NP fertilizer level of 300:150 kg ha/sup 1/ and 4 seeds hill/sup -1/. The lowest grain yield (3,493.75 kg ha/sup -1/) of sweet corn was observed in flat sowing planting method with 120:75 NP level and 2 seeds hill/sup -1/ seed density. The ridge planting rank first then furrow and flat planting methods on basis of grain yield per hectare. The sweet corn plant yield was high with 4 seeds hill/sup -1/ compared with 2 seeds hill/sup -1/. (author)

  8. Organic highbush blueberry production systems research – management of plant nutrition, irrigation requirements, weeds, and economic sustainability

    Science.gov (United States)

    A 0.4 ha planting was established in October 2006 to evaluate the effects of cultivar (Duke and Liberty), bed type ("flat ground" and raised beds), weed management [sawdust mulch and hand weed control; compost plus sawdust mulch with acetic acid, flaming, and hand control used as needed; and landsca...

  9. Grey mould development in greenhouse tomatoes under drip and furrow irrigation

    OpenAIRE

    Aissat , Kamel; Nicot , Philippe ,; Guechi , Abdelhadi; Bardin , Marc; Chibane , Mohamed

    2008-01-01

    Several methods can be used to provide water to plants in cropping systems where irrigation is necessary. For instance, drip irrigation has recently received much attention due to its advantages for water conservation. The type of irrigation can also impact the development of several pathogens responsible for soilborne diseases. Here, we studied the effect of drip irrigation and furrow irrigation on the development of grey mould, caused by the airborne fungus Botrytis cinerea, on tomato plant...

  10. Determination of coefficient defining leaf area development in different genotypes, plant types and planting densities in peanut (Arachis hypogeae L.).

    Science.gov (United States)

    Halilou, Oumarou; Hissene, Halime Mahamat; Clavijo Michelangeli, José A; Hamidou, Falalou; Sinclair, Thomas R; Soltani, Afshin; Mahamane, Saadou; Vadez, Vincent

    2016-12-01

    Rapid leaf area development may be attractive under a number of cropping conditions to enhance the vigor of crop establishment and allow rapid canopy closure for maximizing light interception and shading of weed competitors. This study was undertaken to determine (1) if parameters describing leaf area development varied among ten peanut ( Arachis hypogeae L.) genotypes grown in field and pot experiments, (2) if these parameters were affected by the planting density, and (3) if these parameters varied between Spanish and Virginia genotypes. Leaf area development was described by two steps: prediction of main stem number of nodes based on phyllochron development and plant leaf area dependent based on main stem node number. There was no genetic variation in the phyllochron measured in the field. However, the phyllochron was much longer for plants grown in pots as compared to the field-grown plants. These results indicated a negative aspect of growing peanut plants in the pots used in this experiment. In contrast to phyllochron, there was no difference in the relationship between plant leaf area and main stem node number between the pot and field experiments. However, there was genetic variation in both the pot and field experiments in the exponential coefficient (PLAPOW) of the power function used to describe leaf area development from node number. This genetic variation was confirmed in another experiment with a larger number of genotypes, although possible G × E interaction for the PLAPOW was found. Sowing density did not affect the power function relating leaf area to main stem node number. There was also no difference in the power function coefficient between Spanish and Virginia genotypes. SSM (Simple Simulation model) reliably predicted leaf canopy development in groundnut. Indeed the leaf area showed a close agreement between predicted and observed values up to 60000 cm 2  m -2 . The slightly higher prediction in India and slightly lower prediction in

  11. CS-137 transfer factors soil-plant and density of hyphae in soil of spruce forests

    International Nuclear Information System (INIS)

    Klemt, E.; Deuss, H.; Drissner, J.; Krapf, M.; Miller, R.; Zibold, G.

    1999-01-01

    Samples of soil and plants were taken at spruce stand sites in southern Baden-Wuerttemberg. Fern always had the highest aggregated Cs-137 transfer factor (T ag ) varying between 0.01 and 0.27 m 2 kg -1 . There is a tendency for higher T ag s in soils with thicker raw humus layers, lower pH, lower cation exchange capacity (CEC) in the O h horizon, and lower clay content below the organic deposit. The density of hyphae is determined by the season and its weather conditions and it usually decreases continuously from O f to top B horizon. In analyzing our data no correlation between aggregated or horizon-specific transfer factors of different plants and density of hyphae could be found. Refs. 5 (author)

  12. Effects of sowing date and plant density on morphological triats, yield and yield components of sweet corn (Zea mays L.

    Directory of Open Access Journals (Sweden)

    A. Rahmani

    2016-04-01

    Full Text Available In order to evaluate the effect of sowing date and plant density on the morphological triats, yield and yield components of sweet corn (Zea mays L. var SC. 403 an experiment was conducted at the Khorasan Razavi Agricultural Research and Natural Resources Center, Mashhad, Iran during 2008. This experiment was carried out as split plot based on RCBD with four replications. The sowing date (14th June, 3th July and 24th July and plant densities (66600, 83300 and 111000 plants.ha-1 were arranged in main and sub plots, respectively. The results showed significant differences between different sowing dates for plant height, ear height, and no. of leaves/plant, no. of leaves above ear, stem diameter, dehusked ear yield, can grains yield, no. of grain rows/ear, ear length, ear diameter, kernel depth, no. of ear.plant-1, 1000 kernel weight, ear harvest index and plant harvest index. The highest and the lowest can grains yield with 18.27 and 0.930 ton ha-1 was belonged to 14th June and 24th July sowing date, respectively. Although, delay in sowing date, led to decrease of growth period and also decrease of temperature can lead to improper transfer of photosynthetic materials and cause to grains yield decrease. The plant density had significant effects on husked ear yield, dehusked ear yield and forage yield. The highest can grains yield was harvested from the highest plant density (8.862 t.ha-1 and the lowest can grains yield derived from the lowest plant density (66600 plants.ha-1 with 7.692 t.ha-1. Finally, the interaction of sowing date and plant density was significant only for harvest index. Therefore, the sowing date 14th June and the highest plant density (111000 plants.ha-1, is recommended for summer sowing date of sweet corn in Mashhad with maximum and better can grains production.

  13. Evaluation of population density and distribution criteria in nuclear power plant siting

    International Nuclear Information System (INIS)

    Young, M.

    1994-06-01

    The NRC has proposed revisions to 10 CFR 100 which include the codification of nuclear reactor site population density limits to 500 people per square mile, at the siting stage, averaged over any radial distance out to 30 miles, and 1,000 people per square mile within the 40-year lifetime of a nuclear plant. This study examined whether there are less restrictive alternative population density and/or distribution criteria which would provide equivalent or better protection to human health in the unlikely event of a nuclear accident. This study did not attempt to directly address the issue of actual population density limits because there are no US risk standards established for the evaluation of population density limits. Calculations were performed using source terms for both a current generation light water reactor (LWR) and an advanced light water reactor (ALWR) design. The results of this study suggest that measures which address the distribution of the population density, including emergency response conditions, could result in lower average individual risks to the public than the proposed guidelines that require controlling average population density. Studies also indicate that an exclusion zone size, determined by emergency response conditions and reactor design (power level and safety features), would better serve to protect public health than a rigid standard applied to all sites

  14. Inoculum density of Glomus mosseae and growth of onion plants in unsterilized bituminous coal spoil

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.G.

    1988-01-01

    The effect of inoculum, density (number of vesicular-arbuscular mycorrhizal (VAM) propagules g/sup -1/ of inoculum) on the growth of onions (Allium cepa L.) infected by Glomus mosseae (Nicol and Gerd). Gerdemann and Trappe, Comb nov in unsterilized coal spoil containing indigenous VAM fungi, including G. mosseae, was investigated. The amount of onion roots converted to mycorrhizas by inoculant fungus, estimated by a gridline intersect method, increased with inoculum density (..gamma..0.62, P0.05) until a plateau was reached. Onion growth responses also increased significantly (P<0.05) with the amount of VAM inoculum present in the coal spoil. The initial linear relationship between inoculum propagules (MPN estimates), percent colonization of onion roots and onion shoot dry weight became quadratic as the number of infection propagules increased. VAM infection had no significant effect on root:shoot ratios. Similarly there was no significant interaction (P>0.05) between the inoculum density, VAM-colonized root mass and the onion root:shoot fresh weight ratios. The amount of the windswept bituminous coal spoil bound to VAM (presumably because of VAM external hyphae) also increased as inoculum density increased (..gamma..0.63, P<0.05). There was a stronger correlation (ga0.85, P<0.05) between the amount of spoil adhered per plant and the root fresh wt plant/sup -1/ indicating that root effects were primarily responsible for increasing spoil adherence. There were negative correlations (P<0.05) between root fresh wt plant/sup -1/ (..gamma..-0.68), inoculum density (..gamma..-0.589), percent root elngth infected (..gamma..-0.73) and the amount of spoil adhered g/sup -1/ root fresh wt. The possible exploitation of VAM in revegetation of bituminous coal spoil is discussed. 25 refs., 2 tabs.

  15. Translocations of 2,4-D-14C Herbicides In Weed And Rice Plant On Irrigated Rice Field System

    International Nuclear Information System (INIS)

    Chairul, Sofnie M.; Idawati; Mulyadi

    2000-01-01

    The investigation of translocation 2,4-D herbicides using 14 C as tracer on irradiated rice plant system. Condition of the soil was two kinds, that is normal soil and soil 30% up normal. The soil of rice field was spray with 1μCi of 2,4-D non labelled, one week after planting. A part of rice plant and weed was determined the radioactivity after 0, 2, 4, 8, and 10 weeks after spraying. The result showed that radioactivity maximum after zero week was in root and leaf of weeds, the second weeks in root of rice, the forth weeks in rice stick, and eighth weeks in leaf of rice. This result occur at normal condition soil of solid 30 % up normal soil. The residues of 2.4-D in rice was 4,24x10 -3 ppb at normal soil and 3.16x10 -3 ppb at solid 30% up normal soil. This result still lower than rate of WHO/FAO, that is 0,05 ppm

  16. UF6 Density and Mass Flow Measurements for Enrichment Plants using Acoustic Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Good, Morris S.; Smith, Leon E.; Warren, Glen A.; Jones, Anthony M.; Ramuhalli, Pradeep; Roy, Surajit; Moran, Traci L.; Denslow, Kayte M.; Longoni, Gianluca

    2017-09-01

    A key enabling capability for enrichment plant safeguards being considered by the International Atomic Energy Agency (IAEA) is high-accuracy, noninvasive, unattended measurement of UF6 gas density and mass flow rate. Acoustic techniques are currently used to noninvasively monitor gas flow in industrial applications; however, the operating pressures at gaseous centrifuge enrichment plants (GCEPs) are roughly two orders magnitude below the capabilities of commercial instrumentation. Pacific Northwest National Laboratory is refining acoustic techniques for estimating density and mass flow rate of UF6 gas in scenarios typical of GCEPs, with the goal of achieving 1% measurement accuracy. Proof-of-concept laboratory measurements using a surrogate gas for UF6 have demonstrated signatures sensitive to gas density at low operating pressures such as 10–50 Torr, which were observed over the background acoustic interference. Current efforts involve developing a test bed for conducting acoustic measurements on flowing SF6 gas at representative flow rates and pressures to ascertain the viability of conducting gas flow measurements under these conditions. Density and flow measurements will be conducted to support the evaluation. If successful, the approach could enable an unattended, noninvasive approach to measure mass flow in unit header pipes of GCEPs.

  17. Modeling the growth of individuals in plant populations: local density variation in a strand population of Xanthium strumarium (Asteraceae).

    Science.gov (United States)

    Weiner, J; Kinsman, S; Williams, S

    1998-11-01

    We studied the growth of individual Xanthium strumarium plants growing at four naturally occurring local densities on a beach in Maine: (1) isolated plants, (2) pairs of plants ≤1 cm apart, (3) four plants within 4 cm of each other, and (4) discrete dense clumps of 10-39 plants. A combination of nondestructive measurements every 2 wk and parallel calibration harvests provided very good estimates of the growth in aboveground biomass of over 400 individual plants over 8 wk and afforded the opportunity to fit explicit growth models to 293 of them. There was large individual variation in growth and resultant size within the population and within all densities. Local crowding played a role in determining plant size within the population: there were significant differences in final size between all densities except pairs and quadruples, which were almost identical. Overall, plants growing at higher densities were more variable in growth and final size than plants growing at lower densities, but this was due to increased variation among groups (greater variation in local density and/or greater environmental heterogeneity), not to increased variation within groups. Thus, there was no evidence of size asymmetric competition in this population. The growth of most plants was close to exponential over the study period, but half the plants were slightly better fit by a sigmoidal (logistic) model. The proportion of plants better fit by the logistic model increased with density and with initial plant size. The use of explicit growth models over several growth intervals to describe stand development can provide more biological content and more statistical power than "growth-size" methods that analyze growth intervals separately.

  18. Sustainable irrigation in fruit trees

    Directory of Open Access Journals (Sweden)

    Cristos Xiloyannis

    2010-09-01

    Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

  19. Sustainable irrigation in fruit trees

    Directory of Open Access Journals (Sweden)

    Cristos Xiloyannis

    Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

  20. Optimization of Nitrogen Rate and Planting Density for Improving Yield, Nitrogen Use Efficiency, and Lodging Resistance in Oilseed Rape

    OpenAIRE

    Khan, Shahbaz; Anwar, Sumera; Kuai, Jie; Ullah, Sana; Fahad, Shah; Zhou, Guangsheng

    2017-01-01

    Yield and lodging related traits are essential for improving rapeseed production. The objective of the present study was to investigate the influence of plant density (D) and nitrogen (N) rates on morphological and physiological traits related to yield and lodging in rapeseed. We evaluated Huayouza 9 for two consecutive growing seasons (2014–2016) under three plant densities (LD, 10 plants m−2; MD, 30 plants m−2; HD, 60 plants m−2) and four N rates (0, 60, 120, and 180 kg ha−1). Experiment wa...

  1. Studying Geographical Distribution Map of Weeds of Irrigated Wheat Fields of Ardabil Province

    Directory of Open Access Journals (Sweden)

    B Soheili

    2013-12-01

    Full Text Available In order to identify the density and abundance of weeds in irrigated wheat fields of Ardabil Province, 76 samples of irrigated wheat fields based on cultivation area from all counties of Ardabil province for six years (2001-2006 were selected. The genus and species of weeds from each sampling fields and their population indices density, frequency and uniformity of each species were calculated by using Thomas method. Geographic coordinates of field (Latitude, Altitude and Elevation were the main coverage and were determined by using GPS. These data were used for producing weed maps using GIS in irrigated wheat fields of Ardabil province. Results showed that bedstraw (Galium tricurnatum, Fumitory(Fumaria vaillantiand wildradish (Raphanus raphanistrum were dominant broad leaf weed species and wild oats (Avena fatua, rye (Secale cereal and mouse foxtail(Alopecurus myosuroides dominant grassy weeds species in irrigated wheat fields of Ardabil province. Bindweed (Convolvulus arvensis, Canada thistle(Cirsium arvenseand Acroptilon repens were the most important disturbing plants prior to harvesting in irrigated wheat fields of Ardabil province.

  2. Effects of plant density on recombinant hemagglutinin yields in an Agrobacterium-mediated transient gene expression system using Nicotiana benthamiana plants.

    Science.gov (United States)

    Fujiuchi, Naomichi; Matsuda, Ryo; Matoba, Nobuyuki; Fujiwara, Kazuhiro

    2017-08-01

    Agrobacterium-mediated transient expression systems enable plants to rapidly produce a wide range of recombinant proteins. To achieve economically feasible upstream production and downstream processing, it is beneficial to obtain high levels of two yield-related quantities of upstream production: recombinant protein content per fresh mass of harvested biomass (g gFM -1 ) and recombinant protein productivity per unit area-time (g m -2 /month). Here, we report that the density of Nicotiana benthamiana plants during upstream production had significant impacts on the yield-related quantities of recombinant hemagglutinin (HA). The two quantities were smaller at a high plant density of 400 plants m -2 than at a low plant density of 100 plants m -2 . The smaller quantities at the high plant density were attributed to: (i) a lower HA content in young leaves, which usually have high HA accumulation potentials; (ii) a lower biomass allocation to the young leaves; and (iii) a high area-time requirement for plants. Thus, plant density is a key factor for improving upstream production in Agrobacterium-mediated transient expression systems. Biotechnol. Bioeng. 2017;114: 1762-1770. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Expression of β-glucosidase increases trichome density and artemisinin content in transgenic Artemisia annua plants.

    Science.gov (United States)

    Singh, Nameirakpam Dolendro; Kumar, Shashi; Daniell, Henry

    2016-03-01

    Artemisinin is highly effective against multidrug-resistant strains of Plasmodium falciparum, the aetiological agent of the most severe form of malaria. However, a low level of accumulation of artemisinin in Artemisia annua is a major limitation for its production and delivery to malaria endemic areas of the world. While several strategies to enhance artemisinin have been extensively explored, enhancing storage capacity in trichome has not yet been considered. Therefore, trichome density was increased with the expression of β-glucosidase (bgl1) gene in A. annua through Agrobacterium-mediated transformation. Transgene (bgl1) integration and transcript were confirmed by molecular analysis. Trichome density increased up to 20% in leaves and 66% in flowers of BGL1 transgenic plants than Artemisia control plants. High-performance liquid chromatography, time of flight mass spectrometer data showed that artemisinin content increased up to 1.4% in leaf and 2.56% in flowers (per g DW), similar to the highest yields achieved so far through metabolic engineering. Artemisinin was enhanced up to five-fold in BGL1 transgenic flowers. This study opens the possibility of increasing artemisinin content by manipulating trichomes' density, which is a major reservoir of artemisinin. Combining biosynthetic pathway engineering with enhancing trichome density may further increase artemisinin yield in A. annua. Because oral feeding of Artemisia plant cells reduced parasitemia more efficiently than the purified drug, reduced drug resistance and cost of prohibitively expensive purification process, enhanced expression should play a key role in making this valuable drug affordable to treat malaria in a large global population that disproportionally impacts low-socioeconomic areas and underprivileged children. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  4. Expression of Beta-glucosidase increases trichome density and artemisinin content in transgenic Artemisia annua plants

    Science.gov (United States)

    Singh, Nameirakpam Dolendro; Kumar, Shashi; Daniell, Henry

    2015-01-01

    Artemisinin is highly effective against multidrug-resistant strains of Plasmodium falciparum, the etiological agent of the most severe form of malaria. However, a low level of accumulation of artemisinin in Artemisia annua is a major limitation for its production and delivery to malaria endemic areas of the world. While several strategies to enhance artemisinin have been extensively explored, enhancing storage capacity in trichome has not yet been considered. Therefore, trichome density was increased with the expression of β glucosidase (bgl1) gene in A. annua through Agrobacterium-mediated transformation. Transgene (bgl1) integration and transcript was confirmed by molecular analysis. Trichome density increased up to 20% in leaves and 66% in flowers of BGL1 transgenic plants than Artemisia control plants. High-performance liquid chromatography (HPLC, MS-TOF) data showed that artemisinin content increased up to 1.4% in leaf and 2.56% in flowers (g-1DW), similar to the highest yields achieved so far through metabolic engineering. Artemisinin was enhanced up to 5-fold in BGL1 transgenic flowers. The present study opens the possibility of increasing artemisinin content by manipulating trichomes density, which is a major reservoir of artemisinin. Combining biosynthetic pathway engineering with enhancing trichome density may further increase artemisinin yield in A. annua. Because oral feeding of Artemisia plant cells reduced parasitemia more efficiently than the purified drug, reduced drug resistance and cost of prohibitively expensive purification process, enhanced expression should play a key role in making this valuable drug affordable to treat malaria in a large global population that disproportionally impacts low-socioeconomic areas and underprivileged children. PMID:26360801

  5. Effect of plant density and mixing ratio on crop yield in sweet corn/mungbean intercropping.

    Science.gov (United States)

    Sarlak, S; Aghaalikhani, M; Zand, B

    2008-09-01

    In order to evaluate the ear and forage yield of sweet corn (Zea mays L. var. Saccarata) in pure stand and intercropped with mung bean (Vigna radiata L.), a field experiment was conducted at Varamin region on summer 2006. Experiment was carried out in a split plot design based on randomized complete blocks with 4 replications. Plant density with 3 levels [Low (D1), Mean (D2) and High (D3) respecting 6, 8 and 10 m(-2) for sweet corn, cultivar S.C.403 and 10, 20 and 30 m(-2) for mung bean cultivar, Partow] was arranged in main plots and 5 mixing ratios [(P1) = 0/100, (P2) = 25/75, (P3) = 50/50, (P4) = 75/25, (P5) = 100/0% for sweet corn/mung bean, respectively] were arranged in subplots. Quantitative attributes such as plant height, sucker numbers, LER, dry matter distribution in different plant organs were measured in sweet corn economical maturity. Furthermore the yield of cannable ear corn and yield components of sweet corn and mung bean were investigated. Results showed that plant density has not any significant effect on evaluated traits, while the effect of mixing ratio was significant (p ratio of 75/25 (sweet corn/mung bean) could be introduced as the superior mixing ratio; because of it's maximum rate of total sweet corn's biomass, forage yield, yield and yield components of ear corn in intercropping. Regarding to profitability indices of intercropping, the mixing ratio 75/25 (sweet corn/mung bean) in low density (D1P2) which showed the LER = 1.03 and 1.09 for total crop yield before ear harvesting and total forage yield after ear harvest respectively, was better than corn or mung bean monoculture.

  6. Comparison of Manual and Automatic Irrigation of Pot Experiments

    DEFF Research Database (Denmark)

    Haahr, Vagner

    1975-01-01

    An air-lift principle for transport of water was adapted for automatic irrigation of experimental pots originally constructed for manual irrigation by the weighing method. The two irrigation techniques were compared in an experiment with increasing amounts of nitrogen fertilizer to spring barley....... Productions of grain and straw and chemical composition were almost the same after the two irrigation methods, and it was concluded that the laborious manual watering could be replaced by automatic irrigation. Comparison of the yield from individual plants in the pots showed a large difference between centre...... plants and border plants independent of irrigation principle. The increase in yield per pot with increasing N fertilization was at the highest N level caused only by an increase in yield of the border plants....

  7. Effects of Plant Density and Nitrogen Fertilizer on Quantity and Quality of Forage Corn in Daregaz Region (Iran

    Directory of Open Access Journals (Sweden)

    N. Saadatzadeh

    2011-01-01

    Full Text Available In order to evaluate the effects of plant density and nitrogen on quantity and quality of forage corn an experiment was conducted in Daregaz region in cropping season 2008 – 2009. The experimental design was a split – plot based on randomized complete block with three replications. The main plots were four levels of nitrogen (0 , 75, 150 and 225 kg/ha and sub plots were three levels of plant density (75000, 100000 and 125000 plant/ha. The results showed that increasing nitrogen levels and plant density, plant height, percentage crude protein and total protein production (ton/ha were increased. By increasing plant density, stem diameter, leaf and ear weight decreased while they increased with increased nitrogen levels. The highest forage yield obtained at nitrogen level 150 kg/ha (46 ton/ha and 100000 plant per hectare (40.27 ton/ha. The highest total protein production (7 ton/ha obtained at nitrogen level of 150 kg/ha and plant density of 125000 plant/ha.

  8. Effect of sowing date and plant density on grain and flower yield of Pot Marigold (Calendula officinalis L.

    Directory of Open Access Journals (Sweden)

    mohamad javad seghatol eslami

    2009-06-01

    Full Text Available Pot marigold (Calendula officinalis L. is a medicinal herb whose dried flower heads are used to heal wounds. In order to study the effects of sowing dates and plant density on grain and flower yield of pot marigold, an experiment was conducted at Agricultural Research Center of Islamic Azad University, Birjand Branch in 2005. Three sowing dates (30 March, 14 April and 30 April and three plant densities (plant distances on row were 10, 20 and 30 centimeters were compared in a split- plot experiment based on a randomized complete block design with 3 replications. Seed and flower yields were significantly different at planting dates and plant densities. Sowing date had significant effects on flower and seed harvest index. The latest sowing dates had the highest flower and seed harvest index. Plant density had not significant effect on flower harvest index, but the effect on seed harvest index, was significant. In total our result showed that the first sowing date with 25 plants/m2 had the highest grain and flower yield. Keywords: Marigold, sowing date, plant density, medicinal plant.

  9. Effects of plant density and cultivar on yield responses in onions (Allium cepa L. grown from seeds

    Directory of Open Access Journals (Sweden)

    Jan Rumpel

    2013-12-01

    Full Text Available Two field experiments were conducted to study the effect of plant density on yield, size grading and maturity of onion bulbs grown from seeds. In the first experiment carried out during 1991-1993, three onion cultivars (Hysam F1 , Mercato F1 and Sochaczewska were sown for intended densities of 20, 40, 60, 80,100 and 140 plants m-2, whereas in the second one, in 1996, six onion cultivars (Spirit F1, Summit F1, Hyduro F1, Armstrong F1, Renate F1 and Robusta were sown for intended densities of 40, 60 and 80 plants m-2. The onions were grown on beds, 1,35 m wide, in 4 rows per bed (27+27+27+54 cm. Marketable yield increased with plant density, and depending on year was highest at 80 or 100 plants m-2. The average marketable yield of the 1991-1993 experiment increased from 20.5 t·ha-1 at 20 plants m-2 to 32.8 t·ha-1 at 80 plants m-2, whereas that of the 1996 experiment increased from 48,9 t-ha-1 at 40 plants m-2 to 59.0 t·ha-1 at 80 plants m-2, respectively. Yield of large bulbs decreased with density and was highest at 20-40 plants m-2, oposite to the yield of small bulbs, which was highest at the highest density of 140 plants·m-2. The medium bulb yield increased with density, at the some way as compared the total marketable yield. No greater effect of cultivar on bulb size grades was found and the existing differences were proportional to the total marketable yield . Plant density hastened maturity of onions, and at density of 140 plants m-2 the leaf fall-over occurred 9-10 days earlier as compared at density of 20 plants m-2. The cultiwars used. can be placed in the following order of decreasing productivity: 1 . Mercato F1, 2. Hysam F1 and 3. Sochaczewska, - in the first expeiiment (1991-93 and 1. Annstrong F1, 2. Spirit F1, 3. Robusta, 4. Renate F1, 5. Hyduro F1 and 6. Summit F1 - in the second experiment (1996, respectively.

  10. Effect of Increase in Plant Density on Stem Yield and Sucrose Content in Two Sweet Sorghum Cultivars

    Directory of Open Access Journals (Sweden)

    A Soleymani

    2011-01-01

    Full Text Available Abstract In order to evaluate the effect of increase plant density on stalk yield and sucrose content in two sweet sorghum cultivars, an experiment was conducted at Research Farm of Isfahan University located at Zaghmar village. A split plot layout within a randomized complete block design with tree replication was used. Main plots were plant densities (100, 200, 300, 400, 500 and 600 thousand plant/ha and subplots were cultivars (Rio and Keller. The effect of plant density at hard dough harvest stage on plant height, stem diameter, number of tillers, stem fresh weight and juice yield were significant but had no significant effect on brix, sucrose percentage and purity. The highest juice yield and purity were produced by 400 thousand plants/ha. Keller was significantly superior for plant height, stem diameter, stem fresh weight, juice yield and brix at hard dough harvest stage as compared to Rio. Number of tiller per plant of Rio was significantly more than Keller. There were no significant difference between two cultivars for sucrose percentage and purity but sucrose percentage in Keller had highest as compared to Rio. Maximum stem fresh weight, juice yield, sucrose percentage and purity were obtained at hard dough harvest stag. On the basis of the results obtained, 400 thousand plant/ha plant density, Keller cultivar and hard dough harvest stage might be suitable for sweet sorghum production under the condition similar to the present study. Keywords: Sweet sorghum, Stem yield, Sucrose percentage, Harvesting stages

  11. Effects of Row Spacing and Plant Density on Yield and Yield Components of Sweet Corn in Climatic Conditions of Isfahan

    Directory of Open Access Journals (Sweden)

    N. Khodaeian

    2013-06-01

    Full Text Available To evaluate the effects of row spacing and plant density on yield and yield components of sweet corn, variety KSC403, an experiment was conducted in Research Farm of Isfahan University of Technology, Isfahan, Iran, in 2007, as randomized complete block design with a split-plot layout and three replications. The main plots were allocated to two row spacing (60 and 75 cm and the sub-plots accommodated four levels of plant density (50000, 70000, 90000 and 110000 plants per ha. There was significant increase in leaf area index, shoot dry weight, 100-grain fresh weight and grain fresh yield, as row width was decreased from 75 to 60 cm but the plant height was decreased. There was no significant effect of row spacing on number of rows per ear, number of grains per row and number of grains per ear. Plant height, leaf area index, shoot dry weight per m2 and number of ears per m2 were increased with an increase in plant density. The number of rows per ear, number of grains per row, number of grains per ear, 100-grain fresh weight and grain fresh yield were significantly higher under plant densities of 90000 and 110000 as compared to 50000 and 70000 plants per ha. There was significant interaction between row spacing and plant density for leaf area index, shoot dry weight, number of grains per ear, 100-grain fresh weight and grain fresh yield. Under all plant densities, the grain fresh yield was higher in 60-cm row width compared to 70-cm row width. However, the difference between these two row spacing was not significant in plant densities of 50000 and 110000 plants per ha. The highest grain fresh yield (33940 kg/ha was achieved under row spacing 60 cm and 70000 plants per ha and the least grain fresh yield (20750 kg/ha was obtained in under 75 cm row width and 110000 plants per ha. Considering the obtained results of this experiment, to have maximum grain fresh yield of sweet corn under Isfahan climate, the row spacing of 60 cm and plant density of

  12. The Effect of Planting Pattern and Density on Yield and Yield Components of Sesame (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    A Koocheki

    2017-06-01

    Full Text Available Introduction Crop density enhancement is a method to increase yield per unit area. The spatial distribution of plants is related to radiation absorption. Therefore, it could play an effective role in photosynthesis and yield, since Crop Growth Rate (CGR is a function of used radiation energy in photosynthesis. Totally, increasing radiation absorption efficiency and yield need sufficient leaf area and suitable distribution of leaves in canopy. Ahmad et al., (2002 planted sesame with different inter row- spacing (30, 45 and 60 cm, they reported that the maximum plant height and economic yield were obtained from inter row- spacing of 45 cm. Rahnama and Bakhshandeh (2006 planted sesame with different inter row- spacing (37.5, 50 and 60 cm and the results showed that the number of capsules per plant, seed weight as well as seed oil per plant, increased with increasing inter row- spacing. Karasan et al., (2007 reported that decreasing inter row- spacing resulted in seed yield enhancement and reduction in number of capsules per plant. Material and Methods An experiment using split-plot based on randomized complete blocks design was performed. The experiment was carried with three replications in two years (2012 and 2013 at the agricultural research station of Ferdowsi University of Mashhad. For this purpose, the main plot was the density per square meter with three levels (30, 40 and 50 plants per square meter and the sub main plot was planting pattern (rectangle, square and rhombic. The size of each plot was 2×3 meters. The distance between plots and blocks were 0.5 and 1 meter, respectively. Intra row- spacing for rectangle planting pattern for densities of 30, 40 and 50 plants per square meter was 6, 5 and 4 cm, respectively. In square and rhombic planting patterns, 2 lines was planted in each row and inter row- spacing for densities of 30, 40 and 50 plants per square meter were 18, 16 and 14 cm. economic yield measured at the end of growth season

  13. Effects of irrigation on the seasonal abundance of Empoasca vitis in north-Italian vineyards.

    Science.gov (United States)

    Fornasiero, D; Duso, C; Pozzebon, A; Tomasi, D; Gaiotti, F; Pavan, F

    2012-02-01

    The effect of irrigation on the abundance of Empoasca vitis (Göthe) populations was investigated in four vineyards located in northeastern Italy. In two experiments, we compared leafhopper population densities in plots irrigated (micro-spray irrigation system) or nonirrigated. In another experiment, we studied the effect of various irrigation systems on E. vitis populations over two successive seasons. In particular, five treatments were compared: control (not irrigated), traditional drip system, three types of subirrigation varying in distance from the row (40, 135, and 95 cm). In this vineyard, stem water potential was monitored with a pressure chamber. E. vitis population densities were affected by irrigation, with higher densities of this pest recorded on irrigated vines. Highest E. vitis densities were detected in drip irrigation plots compared with nonirrigated plots where water stress was highest. Moderate water stress (subirrigation plots) was associated with intermediate leafhopper densities. Implications for integrated pest management are discussed.

  14. Demographic models reveal the shape of density dependence for a specialist insect herbivore on variable host plants.

    Science.gov (United States)

    Miller, Tom E X

    2007-07-01

    1. It is widely accepted that density-dependent processes play an important role in most natural populations. However, persistent challenges in our understanding of density-dependent population dynamics include evaluating the shape of the relationship between density and demographic rates (linear, concave, convex), and identifying extrinsic factors that can mediate this relationship. 2. I studied the population dynamics of the cactus bug Narnia pallidicornis on host plants (Opuntia imbricata) that varied naturally in relative reproductive effort (RRE, the proportion of meristems allocated to reproduction), an important plant quality trait. I manipulated per-plant cactus bug densities, quantified subsequent dynamics, and fit stage-structured models to the experimental data to ask if and how density influences demographic parameters. 3. In the field experiment, I found that populations with variable starting densities quickly converged upon similar growth trajectories. In the model-fitting analyses, the data strongly supported a model that defined the juvenile cactus bug retention parameter (joint probability of surviving and not dispersing) as a nonlinear decreasing function of density. The estimated shape of this relationship shifted from concave to convex with increasing host-plant RRE. 4. The results demonstrate that host-plant traits are critical sources of variation in the strength and shape of density dependence in insects, and highlight the utility of integrated experimental-theoretical approaches for identifying processes underlying patterns of change in natural populations.

  15. Low crop plant population densities promote pollen-mediated gene flow in spring wheat (Triticum aestivum L.).

    Science.gov (United States)

    Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C

    2009-12-01

    Transgenic wheat is currently being field tested with the intent of eventual commercialization. The development of wheat genotypes with novel traits has raised concerns regarding the presence of volunteer wheat populations and the role they may play in facilitating transgene movement. Here, we report the results of a field experiment that investigated the potential of spring wheat plant population density and crop height to minimize gene flow from a herbicide-resistant (HR) volunteer population to a non-HR crop. Pollen-mediated gene flow (PMGF) between the HR volunteer wheat population and four conventional spring wheat genotypes varying in height was assessed over a range of plant population densities. Natural hybridization events between the two cultivars were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) families. PMGF was strongly associated with crop yield components, but showed no association with flowering synchrony. Maximum observed PMGF was always less than 0.6%, regardless of crop height and density. The frequency of PMGF in spring wheat decreased exponentially with increasing plant population density, but showed no dependence on either crop genotype or height. However, increasing plant densities beyond the recommended planting rate of 300 cropped wheat plants m(-2) provided no obvious benefit to reducing PMGF. Nevertheless, our results demonstrate a critical plant density of 175-200 cropped wheat plants m(-2) below which PMGF frequencies rise exponentially with decreasing plant density. These results will be useful in the development of mechanistic models and best management practices that collectively facilitate the coexistence of transgenic and nontransgenic wheat crops.

  16. Impact of Bee Species and Plant Density on Alfalfa Pollination and Potential for Gene Flow

    Directory of Open Access Journals (Sweden)

    Johanne Brunet

    2010-01-01

    Full Text Available In outcrossing crops like alfalfa, various bee species can contribute to pollination and gene flow in seed production fields. With the increasing use of transgenic crops, it becomes important to determine the role of these distinct pollinators on alfalfa pollination and gene flow. The current study examines the relative contribution of honeybees, three bumble bee species, and three solitary bee species to pollination and gene flow in alfalfa. Two wild solitary bee species and one wild bumble bee species were best at tripping flowers, while the two managed pollinators commonly used in alfalfa seed production, honeybees and leaf cutting bees, had the lowest tripping rate. Honeybees had the greatest potential for gene flow and risk of transgene escape relative to the other pollinators. For honeybees, gene flow and risk of transgene escape were not affected by plant density although for the three bumble bee species gene flow and risk of transgene escape were the greatest in high-density fields.

  17. Ghana - Agriculture - Irrigation

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

  18. Effects of Plant Density and Nitrogen Fertilizer on Dry Flower Yield and Essential Oil Content of Chamomile (Matricaria chamomilla

    Directory of Open Access Journals (Sweden)

    Gh. Sharafi

    2013-06-01

    Full Text Available Chamomile is a valuable medicinal plant and is used as spice and herbal medicine. Application of agronomical methods has important role in increasing quantitative and qualitative traits of this medicinal plant. Fertilizer management is an important factor in successful cultivation of medicinal plants, which could have positive effects on their quantitative and qualitative indices. This experiment was conducted in order to determine the effects of plant density and nitrogen (N fertilizer on dry flower yield and essential oil content of chamomile (Matricaria chamomilla using factorial randomized complete blocks design with three replications. Three N rates from urea source (0, 100 and 200 kg/ha and three plant densities (28.6, 40 and 66.7 plants per m2 were considered. The results showed that the highest single plant yield was produced in the lowest plant density (28.6 plants per m2 and application of 100 kg/ha N. The highest dry flower yield of 474.1 kg/ha and essential oil content of 0.2% was produced in 25 cm row width and fixed plant spacing of 10 cm (40 plants per m2 and application of 100 kg/ha N.

  19. Root canal irrigants

    OpenAIRE

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

  20. IRRIGATION USING SOLAR PUMP

    OpenAIRE

    Prof. Nitin P.Choudhary*1 & Ms. Komal Singne2

    2017-01-01

    In this report the described design of a PV and soil moisture sensor based automated irrigation system is introduced. This project aims to provide a human friendly, economical and automated water pumping system which eliminates the problems of over irrigation and helps in irrigation water optimization and manage it in accordance with the availability of water. Our project not only tries to modernize the irrigation practices and ensure the optimum yield by carefully fulfilling the requirements...

  1. First-year plant density of seeded vegetation on amended lead-zinc chat tailing

    International Nuclear Information System (INIS)

    Norland, M.R.; Veith, D.L.

    1991-01-01

    Mining of lead and zinc sulfides began in the Kansas portion of the Tri-State Mining District in 1976 and continued until the 1950s when a decrease in the demand for lead and zinc forced operations to shut down. As a result of this shallow underground mining, chat tailing and other mine wastes were deposited on the soil surface or as mine waste piles. In 1983, the U.S. EPA added 285 km of Cherokee County, Kansas, to the National Priorities List due to the risks to human health and the environment by heavy metal contamination. In 1985, the EPA declared the Cherokee County portion of the Tri-State District to be a Superfund Site and began remedial action investigations at the Galena, Kansas subsite. The Bureau of Mines is evaluating site stabilization techniques in Galena, to minimize wind and water erosion, infiltration and percolation through the mine wastes. Vegetation and the use of locally available organic wastes are being tested as site stabilization techniques. A 4x3x3 factorial experiment arranged in a randomized complete block was initiated in 1990. Four organic waste materials (composted yard waste, composted cattle manure, spent mushroom compost and turkey litter) were applied with inorganic fertilizer. Control plots were included in the design. A total of 39 combinations were assigned to 2.5 by 4 m test plots at random and each combination was replicated three times. All experimental plots were seeded with a mix of introduced or native and cool or warm season grasses and leguminous forbs. First-year results of this long-term study suggest that the type of organic waste material used as a soil amendment has a significant effect on first-year plant density. Applications of composted cattle manure, composted yard waste and spent mushroom compost resulted in mean plant densities of 90, 83 and 76 plants M-2 which are significantly higher than the mean plant density of control plots and plots amended with turkey litter, 37 and 21 plants M-2

  2. Irrigation in endodontic treatment.

    Science.gov (United States)

    Basrani, Bettina

    2011-01-01

    The primary endodontic treatment goal is to optimize root canal disinfection and to prevent reinfection. Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal system. In this review of the literature, various irrigants and the interactions between irrigants are discussed and new delivery systems are introduced.

  3. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Science.gov (United States)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-12-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

  4. Leaf Senescence, Root Morphology, and Seed Yield of Winter Oilseed Rape (Brassica napus L. at Varying Plant Densities

    Directory of Open Access Journals (Sweden)

    Ming Li

    2017-01-01

    Full Text Available In this study, the yield and yield components were studied using a conventional variety Zhongshuang 11 (ZS 11 and a hybrid variety Zhongyouza 12 (ZYZ 12 at varying plant densities. The increase in plant density led to an initial increase in seed yield and pod numbers per unit area, followed by a decrease. The optimal plant density was 58.5 × 104 plants ha−1 in both ZS 11 and ZYZ 12. The further researches on physiological traits showed a rapid decrease in the green leaf area index (GLAI and chlorophyll content and a remarkable increase in malondialdehyde content in high plant density (HPD population than did the low plant density (LPD population, which indicated the rapid leaf senescence. However, HPD had higher values in terms of pod area index (PAI, pod photosynthesis, and radiation use efficiency (RUE after peak anthesis. A significantly higher level of dry matter accumulation and nitrogen utilization efficiency were observed, which resulted in higher yield. HPD resulted in a rapid decrease in root morphological parameters (root length, root tips, root surface area, and root volume. These results suggested that increasing the plant density within a certain range was a promising option for high seed yield in winter rapeseed in China.

  5. Growth Analysis of Fenugreek (Trigonella foenum- graecum L. under Various Levels of Nitrogen and Plant Density

    Directory of Open Access Journals (Sweden)

    L Bazrkar-Khatibani

    2018-02-01

    Full Text Available Introduction Fenugreek (Trigonella foenum-graecum L. is a specific condiment crop mostly grown for its edible parts, and is used as a green fodder and fresh vegetable. The seeds have medicinal value solely against digestive disorders, whereas its leaves are rich source of minerals and nutrients. The growth and yield of fenugreek is particularly affected by the application of nitrogen fertilizer and planting arrangement. Plant growth is a process of biomass accumulation which in turn is derived out of the interaction of the respiration, photosynthesis, water relations, long-distance transport, and mineral nutrition processes. Growth is the most important process in predicting plant reactions to environment. Irradiance, temperature, soil-water potential, nutrient supply and enhanced concentrations of atmospheric carbon dioxide are among some external components influencing crop growth and development. Growth analysis is a useful tool in studying the complex interactions between plant growth and the environment, clarifying and interpreting physiological responses. Plants total dry matter (TDM production and accumulation can be appraised via relative growth rate (RGR and crop growth rate (CGR which are the most important growth indices. Leaf area index (LAI is a factor of crop growth analysis that accounts for the potential of the crop to assimilate light energy and is a determinant component in understanding the function of many crop management practices. Materials and Methods A field investigation was conducted in a paddy field at Shaft County (Guilan Province for eight consecutive months (from November 2009 to June 2010, to study the effect of four levels of nitrogen fertilizer (0, 25, 50 and 75 Kg N ha-1 and four levels of planting density (60, 80,100, and 120 plants m-2 on the growth indices of fenugreek (Trigonella foenum graecum L. crop. The soil for the experiment was loam in texture and strongly acidic in reaction (pH 4.5. Sixteen treatment

  6. WHEAT LEAF RUST SEVERITY AS AFFECTED BY PLANT DENSITY AND SPECIES PROPORTION IN SIMPLE COMMUNITIES OF WHEAT AND WILD OATS

    Science.gov (United States)

    While it is generally accepted that dense stands of plants exacerbate epidemics caused by foliar pathogens, there is little experimental evidence to support this view. We grew model plant communities consisting of wheat and wild oats at different densities and proportions and exp...

  7. Scheduling of Irrigation and Leaching Requirements

    Directory of Open Access Journals (Sweden)

    Amer Hassan Al-haddad

    2015-03-01

    Full Text Available Iraq depends mainly on Tigris and Euphrates Rivers to provide high percentage of agricultural water use for thousands years. At last years, Iraq is suffering from shortage in water resources due to global climate changes and unfair water politics of the neighboring countries, which affected the future of agriculture plans for irrigation, added to that the lack of developed systems of water management in the irrigation projects and improper allocation of irrigation water, which reduces water use efficiency and lead to losing irrigation water and decreasing in agricultural yield. This study aims at studying the usability of irrigation and leaching scheduling within the irrigating projects and putting a complete annual or seasonal irrigation program as a solution for the scarcity of irrigation water, the increase of irrigation efficiency, lessening the salinity in the projects and preparing an integral irrigation calendar through field measurements of soil physical properties and chemical for project selected and compared to the results of the irrigation scheduling and leaching with what is proposed by the designers. The process is accomplished by using a computer program which was designed by Water Resources Department at the University of Baghdad, with some modification to generalize it and made it applicable to various climatic zone and different soil types. Study area represented by large project located at the Tigris River, and this project was (Al-Amara irrigation project. Sufficient samples of project's soil were collected so as to identify soil physical and chemical properties and the salinity of soil and water as well as identifying the agrarian cycles virtually applied to this project. Finally, a comparison was conducted between the calculated water quantities and the suggested ones by the designers. The research results showed that using this kind of scheduling (previously prepared irrigation and leaching scheduling with its properties

  8. Effect of Irrigation with Wastewater on Certain Soil Physical and Chemical properties

    Directory of Open Access Journals (Sweden)

    Farzad Rohani Shahraki

    2005-03-01

    Full Text Available Depending on effluent characteristics, irrigation with wastewater plant effluent can be either beneficial or harmful. To investigate the effects of nine years of irrigation with North Isfahan Wastewater Treatment Plant effluent on physical and chemical properties of soil, a study was carried out using a randomized complete block design with three replications. Treatments included: 1 raw wastewater; 2 effluent from primary settling basin; 3 final plant effluent and 4 well water. To investigate soil physical and chemical properties, samples were taken from depths of 0-5 cm and 5-10 cm from each plot. The results showed that raw wastewater COD and SS were higher than the Iranian Standard limits for use in irrigation. So were BOD5 and turbidity of effluent from primary sedimentation tanks. From the results obtained, the raw wastewater may be considered to be of medium quality. However, regarding other parameters such as EC, SAR, Na and Pb, the quality of the raw wastewater was considerably higher than that of well water. All treatments showed medium infiltrability with respect to chloride concentration. The concentration of lead in well water was higher than in treated wastewater. It should be noted that lead concentration in all samples was less than the standard limits. The average soil bulk density and percentage of moisture in FC did not follow any specific trend. The results indicate that the soil irrigated with effluent over the nine years had a lower bulk density, a higher percentage of moisture, and a lower infiltration compared to adjacent soil not irrigated with wastewater. Analysis of variance for all results did not confirm any significant differences among treatments.

  9. Plant density-dependent variations in bioactive markers and root yield in Australian-grown Salvia miltiorrhiza Bunge.

    Science.gov (United States)

    Li, Chun Guang; Sheng, Shu Jun; Pang, Edwin C K; May, Brian; Xue, Charlie Chang Li

    2011-04-01

    The plant density-dependent variations in the root yield and content, and the yield of biomarkers in Australian grown Salvia miltiorrhiza Bunge, a commonly used Chinese medicinal herb for the treatment of cardiovascular diseases, were investigated in a field trial involving six different plant densities. The key biomarker compounds cryptotanshinone, tanshinone I, tanshinone IIA, and salvianolic acid B were quantified by a validated RP-HPLC method, and the root yields were determined per plant pair or unit area. There were significant variations (pplant densities. Positive linear correlations were observed between the contents of the three tanshinones, whereas negative linear correlations were revealed between the contents of the tanshinones and salvianolic acid B. The highest root yield per plant pair was achieved when the plants were grown at 45×30 cm or 45×40 cm, whereas the highest root production par unit area was obtained for a plant density of 30×30 cm. The highest contents of the three tanshinones and the most abundant production of these tanshinones per unit area were achieved when the plants were grown at 30×30 cm. However, the highest content of salvianolic acid B was found for a density of 45×40 cm, while its highest yield per unit area was obtained for densities of 30×40 cm or 45×30 cm. The findings suggest that the plant density distinctly affects the root yield and content and the yield of tanshinones and salvianolic acid B in Australian grown S. miltiorrhiza, which may be used as a guide for developing optimal agricultural procedures for cultivating this herb. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  10. Water quality and irrigation [Chapter 10

    Science.gov (United States)

    Thomas D. Landis; Kim M. Wilkinson

    2009-01-01

    Water is the single most important biological factor affecting plant growth and health. Water is essential for almost every plant process: photosynthesis, nutrient transport, and cell expansion and development. In fact, 80 to 90 percent of a seedling's weight is made up of water. Therefore, irrigation management is the most critical aspect of nursery operations....

  11. Optimization of Nitrogen Rate and Planting Density for Improving Yield, Nitrogen Use Efficiency, and Lodging Resistance in Oilseed Rape

    Directory of Open Access Journals (Sweden)

    Shahbaz Khan

    2017-05-01

    Full Text Available Yield and lodging related traits are essential for improving rapeseed production. The objective of the present study was to investigate the influence of plant density (D and nitrogen (N rates on morphological and physiological traits related to yield and lodging in rapeseed. We evaluated Huayouza 9 for two consecutive growing seasons (2014–2016 under three plant densities (LD, 10 plants m−2; MD, 30 plants m−2; HD, 60 plants m−2 and four N rates (0, 60, 120, and 180 kg ha−1. Experiment was laid out in split plot design using density as a main factor and N as sub-plot factor with three replications each. Seed yield was increased by increasing density and N rate, reaching a peak at HD with 180 kg N ha−1. The effect of N rate was consistently positive in increasing the plant height, pod area index, 1,000 seed weight, shoot and root dry weights, and root neck diameter, reaching a peak at 180 kg N ha−1. Plant height was decreased by increasing D, whereas the maximum radiation interception (~80% and net photosynthetic rate were recorded at MD at highest N. Lodging resistance and nitrogen use efficiency significantly increased with increasing D from 10 to 30 plants m−2, and N rate up to 120 kg ha−1, further increase of D and N decreased lodging resistance and NUE. Hence, our study implies that planting density 30 plants m−2 can improve yield, nitrogen use efficiency, and enhance lodging resistance by improving crop canopy.

  12. Biochar enhances yield and quality of tomato under reduced irrigation

    DEFF Research Database (Denmark)

    Saleem Akhtar, Saqib; Li, Guitong; Andersen, Mathias Neumann

    2014-01-01

    tBiochar is an amendment that can be used for enhancing soil water storage which may increase cropproductivity. The objective of this study was to investigate the effects of biochar on physiology, yield andquality of tomato under different irrigation regimes. From early flowering to fruit maturity...... stages, theplants were subjected to full irrigation (FI), deficit irrigation (DI) and partial root-zone drying irrigation(PRD) and two levels of biochar (0% and 5% by weight). In FI, the plants were irrigated daily to pot waterholding capacity while in DI and PRD, 70% of FI was irrigated on either...... the whole or one side of the pots,respectively. In PRD, irrigation was switched between sides when the soil water content of the dry sidedecreased to 15%. The results showed that addition of biochar increased the soil moisture contents in DIand PRD, which consequently improved physiology, yield, and quality...

  13. Agronomic and physiological impacts of irrigation frequency on green basil (Ocimum basilicum L.)

    OpenAIRE

    Gao, Peng; Dodd, Ian

    2015-01-01

    Water scarcity is a major factor restricting agricultural production and irrigation globally, with sustainable agricultural development calling for less irrigation water use and more production per unit of water applied. Improved understanding of plant physiological responses to water stress, and the effect of irrigation frequency on plant biomass production and quality, may help to optimize irrigation scheduling. Glasshouse-grown basil (Ocimum basilicum L.) received three different irrigatio...

  14. Plant diversity increases with the strength of negative density dependence at the global scale

    Science.gov (United States)

    LaManna, Joseph A.; Mangan, Scott A.; Alonso, Alfonso; Bourg, Norman; Brockelman, Warren Y.; Bunyavejchewin, Sarayudh; Chang, Li-Wan; Chiang, Jyh-Min; Chuyong, George B.; Clay, Keith; Condit, Richard; Cordell, Susan; Davies, Stuart J.; Furniss, Tucker J.; Giardina, Christian P.; Gunatilleke, I.A.U. Nimal; Gunatilleke, C.V. Savitri; He, Fangliang; Howe, Robert W.; Hubbell, Stephen P.; Hsieh, Chang-Fu; Inman-Narahari, Faith M.; Janik, David; Johnson, Daniel J.; Kenfack, David; Korte, Lisa; Kral, Kamil; Larson, Andrew J.; Lutz, James A.; McMahon, Sean M.; McShea, William J.; Memiaghe, Herve R.; Nathalang, Anuttara; Novotny, Vojtech; Ong, Perry S.; Orwig, David A.; Ostertag, Rebecca; Parker, Geoffrey G.; Phillips, Richard P.; Sack, Lawren; Sun, I-Fang; Tello, J. Sebastian; Thomas, Duncan W.; Turner, Benjamin L.; Vela Diaz, Dilys M.; Vrska, Tomas; Weiblen, George D.; Wolf, Amy; Yap, Sandra; Myers, Jonathan A.

    2017-01-01

    Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.

  15. Space/age forestry: Implications of planting density and rotation age in SRIC management decisions

    Energy Technology Data Exchange (ETDEWEB)

    Merriam, R.A.; Phillips, V.D.; Liu, W.

    1993-12-31

    Short-rotation intensive-culture (SRIC) of promising tree crops is being evaluated worldwide for the production of methanol, ethanol, and electricity from renewable biomass resources. Planting density and rotation age are fundamental management decisions associated with SRIC energy plantations. Most studies of these variables have been conducted without the benefit of a unifying theory of the effects of growing space and rotation age on individual tree growth and stand level productivity. A modeling procedure based on field trials of Eucalyptus spp. is presented that evaluates the growth potential of a tree in the absence and presence of competition of neighboring trees in a stand. The results of this analysis are useful in clarifying economic implications of different growing space and rotation age decisions that tree plantation managers must make. The procedure is readily applicable to other species under consideration for SRIC plantations at any location.

  16. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, nutrient concentrations, and plant nutrition and growth

    Science.gov (United States)

    Liming agents in irrigation water, typically associated with carbonates and bicarbonates of calcium and magnesium, contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient availability imbalan...

  17. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, and nutrient concentrations; and plant nutrition and growth

    Science.gov (United States)

    Liming agents (LA) in irrigation water, typically associated with carbonates and bicarbonates of calcium (Ca) and magnesium (Mg), contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient avail...

  18. The Regularity of Optimal Irrigation Patterns

    Science.gov (United States)

    Morel, Jean-Michel; Santambrogio, Filippo

    2010-02-01

    A branched structure is observable in draining and irrigation systems, in electric power supply systems, and in natural objects like blood vessels, the river basins or the trees. Recent approaches of these networks derive their branched structure from an energy functional whose essential feature is to favor wide routes. Given a flow s in a river, a road, a tube or a wire, the transportation cost per unit length is supposed in these models to be proportional to s α with 0 measure is the Lebesgue density on a smooth open set and the irrigating measure is a single source. In that case we prove that all branches of optimal irrigation trees satisfy an elliptic equation and that their curvature is a bounded measure. In consequence all branching points in the network have a tangent cone made of a finite number of segments, and all other points have a tangent. An explicit counterexample disproves these regularity properties for non-Lebesgue irrigated measures.

  19. Optimization of modern irrigation for biosaline agriculture

    International Nuclear Information System (INIS)

    Shahid, S.A.; Hasbini, B.

    2007-01-01

    Supplementation water is a must to offset the water requirement to produce profitable crops in most arid and semiarid zones, where fresh water resources are insufficient to meet the pressure of irrigated agriculture. This necessitates the use of poor quality water resources. These waters if not properly managed and used can cause serious soil related problems (salinity, sodicity, destruction of soil structure) in addition to decline in crop yields. Biosaline agriculture (using saline water on saline soils to grow salt-tolerant crops) becomes the only option for the farmer when both soil and water resources are saline and the water resource is scarce. In this regards key design considerations must be taken into account when irrigating with salty waters to optimize water uses and to reduce subsequent soil salinity development. Sprinkler irrigation systems are commonly used in irrigation of large-scale irrigational production systems. However they tend to concentrate salts on the leaves of plants. For this reason discharge and degree of overlap between consecutive sprinkler heads, are key design parameters when applying salty waters. Trickle irrigation is the most efficient system and is gaining importance in the GCC countries in the agriculture and landscape irrigation. The objective of this study was to optimize modern irrigation systems through development of design standards for drip (emitters spacing) and sprinkler irrigation systems (single head jet and overlapping) by applying saline water. The effect of emitter spacing (drip) and overlapping (sprinkler) were tested for the formation of salt contours in soil. The leaching ratio (LR) is the overall soil sanity within rhizosphere divided by the average irrigation water salinity. In this study LR is used to evaluate the effectiveness of irrigation systems in developing soil sanity. From the present investigations it is concluded that when using saline water for irrigation, the soil sanity development can be

  20. The Effects of Two Different Deficit Irrigation Managements on the Root Length of Maize

    Directory of Open Access Journals (Sweden)

    M. Gheysari

    2015-06-01

    Full Text Available The response of root to water stress is one of the most important parameters for researchers. Study of growth and distribution of root under different irrigation managements helpsresearchersto a better understanding of soil water content, and the availability of water and nutrition in water stress condition. To investigate the effects of four levels of irrigation under two different deficit irrigation managements on the root length of maize, a study was conducted in 2009. Irrigation managements included fixed irrigation interval-variable irrigation depth (M1 and variable irrigation interval-fixed irrigation depth (M2. Maize plants were planted in 120 large 110-liter containers in a strip-plot design in a randomized complete block with three replications. Root data sampling was done after root washing in five growth stages. The results showed that the effect of irrigation levels on root length was significant (P

  1. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    Directory of Open Access Journals (Sweden)

    Jochen Hemming

    2009-04-01

    Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.

  2. Density-dependency and plant-soil feedback: former plant abundance influences competitive interactions between two grassland plant species through plant-soil feedbacks

    NARCIS (Netherlands)

    Xue, W.; Bezemer, T.M.; Berendse, Frank

    2018-01-01

    Backgrounds and aims Negative plant-soil feedbacks (PSFs) are thought to promote species coexistence, but most evidence is derived from theoretical models and data from plant monoculture experiments. Methods We grew Anthoxanthum odoratum and Centaurea jacea in field plots in monocultures and in

  3. Effects of reindeer density on vascular plant diversity on North Scandinavian mountains

    Directory of Open Access Journals (Sweden)

    Johan Olofsson

    2005-04-01

    Full Text Available We studied the effects of reindeer grazing on species richness and diversity of vascular plants on dolomite influenced low alpine sites in the species rich northern part of the Scandes using 8 sites with different reindeer densities. Two sites were situated inside Malla Strict Nature Reserve, where reindeer grazing have been totally prohibited since 1981, and strongly restricted since 1950s. The six other sites were located in other species rich hotspot sites standardized to be as similar to the dolomite-influenced sites in Malla Strict Reserve as possible but varying in reindeer densities commonly found in the Fennoscandian mountain chain. Each site with a habitat complex especially rich in rare vascular plants (the Dryas heath – low herb meadow complex was systematically sampled in four plots of 2 m x 10 m. The plots were divided to 20 squares of 1 m x 1 m, and complete species lists of vascular plants were compiled for each of the squares. The first DCA (detrended correspondence analysis axis was strongly related to an index of reindeer grazing, indicating that grazing has a strong impact on the composition of the vegetation. None of the characteristics indices of biodiversity (species richness, evenness or Shannon-Wiener H’ was correlated with reindeer density. The local abundances of categories consisting of relatively rare plants (Ca favored plants and red listed plants of Finland showed significant, positive correlation with the intensity of reindeer grazing. We conclude that even though the density of reindeer has no influence on the total species richness or diversity of vascular plants, reindeer may still be important for regional biodiversity as it seems to favour rare and threatened plants. Moreover, our results imply that standard diversity indices may have limited value in the context of conservation biology, as these indices are equally influenced by rarities and by trivial species.Abstract in Swedish / Sammandrag: Vi

  4. Density-dependent reproductive and vegetative allocation in the aquatic plant Pistia stratiotes (Araceae

    Directory of Open Access Journals (Sweden)

    Flávia Freitas Coelho

    2005-09-01

    Full Text Available Pistia stratiotes is an aquatic macrophyte that grows in temporary-ponds in the southern Pantanal, Brazil. It reproduces both sexually and asexually and is usually observed forming dense mats on the water surface, a condition favored by the plant’s vegetative reproduction coupled with an ability for rapid growth. In this study we examined the effect of densely crowded conditions on the production of reproductive and vegetative structures. In addition, we verified whether there is a trade-off between clonal growth and investment in sexual reproductive structures, and whether there is an allocation pattern with plant size. Individual plant biomass and the number of the rosettes producing sexual reproductive structures and vegetative growth structures both increased with density. Increase in plant size resulted in increased proportional allocation to sexual reproductive structures and vegetative growth structures. Allocation of biomass to reproduction did not occur at the expense of clonal growth. Thus, the density response appears as a increase of rosettes producing sexual reproductive structures and vegetative growth structures. Therefore, long leaves and stolons may be adaptive under densely crowded conditions where competition for light is intense. An important aspect in the study of trade-offs is the size-dependency of the allocation patterns .Usually, larger plants produce more biomass. Therefore, larger plants can allocate more biomass to both vegetative and sexual reproduction than smaller plants and thus show a positive correlation between both traits rather than the expected negative one. Rev. Biol. Trop. 53(3-4: 369-376. Epub 2005 Oct 3.Pistias strariotes es una macrófita acuática que crece en charcas estacionales en el Pantanal sureño de Brasil. Se reproduce tanto sexual como asexualmente y se obsrva generalmente que forma densas parches sobre la superficie del agua, una condicion que favorecida por la reproduccion vegetativa de la

  5. Growth and Flowering Responses of Cut Chrysanthemum Grown under Restricted Root Volume to Irrigation Frequency

    Directory of Open Access Journals (Sweden)

    Viyachai Taweesak

    2014-01-01

    Full Text Available Influences of irrigation frequency on the growth and flowering of chrysanthemum grown under restricted root volume were tested. Chrysanthemum cuttings (Chrysanthemum morifolium “Reagan White” were grown in seedling tray which contained coconut peat in volumes of 73 and 140 cm3. Plants were irrigated with drip irrigation at irrigation frequencies of 4 (266 mL, 6 (400 mL, and 8 (533 mL times/day to observe their growth and flowering performances. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. Plants grown in 140 cm3 substrates and irrigated 6 times/day produced the tallest plant of 109.25 cm. Plants irrigated 6 and 8 times/day had significantly higher level of phosphorus content in their leaves than those plants irrigated 4 times/day. The total leaf area, number of internodes, leaf length, and leaf width of chrysanthemums grown in 140 cm3 substrate were significantly higher than those grown in 73 cm3 substrate. The numbers of flowers were affected by both irrigation frequencies and substrate volumes. Chrysanthemums irrigated 8 times/day had an average of 19.56 flowers while those irrigated 4 times/day had an average of 16.63 flowers. Increasing irrigation frequency can improve the growth and flowering of chrysanthemums in small substrate volumes.

  6. The effects of landscape position on plant species density: Evidence of past environmental effects in a coastal wetland

    Science.gov (United States)

    Grace, J.B.; Guntenspergen, G.R.

    1999-01-01

    Here we propose that an important cause of variation in species density may be prior environmental conditions that continue to influence current patterns. In this paper we investigated the degree to which species density varies with location within the landscape, independent of contemporaneous environmental conditions. The area studied was a coastal marsh landscape subject to periodic storm events. To evaluate the impact of historical effects, it was assumed that the landscape position of a plot relative to the river's mouth ('distance from sea') and to the edge of a stream channel ('distance from shore') would correlate with the impact of prior storm events, an assumption supported by previous studies. To evaluate the importance of spatial location on species density, data were collected from five sites located at increasing distances from the river's mouth along the Middle Pearl River in Louisiana. At each site, plots were established systematically along transects perpendicular to the shoreline. For each of the 175 Plots, we measured elevation, soil salinity, percent of plot recently disturbed, percent of sunlight captured by the plant canopy (as a measure of plant abundance), and plant species density. Structural equation analysis ascertained the degree to which landscape position variables explained variation in species density that could not be explained by current environmental indicators. Without considering landscape variables, 54% of the variation in species density could be explained by the effects of salinity, flooding, and plant abundance. When landscape variables were included, distance from shore was unimportant but distance from sea explained an additional 12% of the variance in species density (R2 of final model = 66%). Based on these results it appears that at least some of the otherwise unexplained variation in species density can be attributed to landscape position, and presumably previous storm events. We suggest that future studies may gain

  7. Effects of seedbed preparation, irrigation, and water harvesting of seedling emergence at the Nevada Test Site

    International Nuclear Information System (INIS)

    Winkel, V.K.; Ostler, W.K.; Gabbert, W.D.; Lyon, G.E.

    1994-02-01

    Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with plutonium. As part of a cleanup effort, both the indigenous vegetation and the top 5--10 cm of soil may be removed, and the soil may or may not be replaced. Technologies must be developed to stabilize and revegetate these lands. A study was developed to determine adaptable plant species, methods to prepare seedbeds for direct seeding and water harvesting, and proper irrigation rates. Plots were cleared of indigenous vegetation, and then prepared with various seedbed/water harvesting treatments including, pitting, land imprinting, and mulching. Other plots were treated with large water harvesting structures. Three irrigation treatments were superimposed over the seedbed/water harvesting treatments. Seedling emergence data was collected, and the treatment combinations compared. Supporting meteorological and soil data were collected with an automatic data-logger. Specific data included precipitation, and air temperature. In a year of above-average precipitation, irrigation did not generally aid germination and emergence of seeded species, and only slightly increased densities of species from the native seedbank. With the exception of increased shrub seedling densities in desert strips, there were no strong seedbed preparation/water harvesting treatment effects. In years of above-average rainfall, mulching and water harvesting treatments, irrigation may not be necessary to insure adequate germination and emergence of adapted perennial grasses, forbs, and shrubs in the Mojave/Great Basin Transition Desert. Future collection of survival data will determine whether a maintenance irrigation program is necessary to ensure establishmnent of native plants

  8. Armenia - Irrigation Infrastructure

    Data.gov (United States)

    Millennium Challenge Corporation — This study evaluates irrigation infrastructure rehabilitation in Armenia. The study separately examines the impacts of tertiary canals and other large infrastructure...

  9. Adding a small hydroelectric power plant to the irrigation system of the Liddes community. Feasibility study; Installation d'une petite centrale hydraulique sur le reseau d'irrigation de la commune de Liddes. Etude de faisabilite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This final report prepared for the Swiss Federal Office of Energy (SFOE) examines the possibility of generating electric power with an irrigation system in the southwestern Swiss Alps. The water of the mountain torrent of Palasuit is collected at an altitude of 1620 m above sea-level in a reservoir. It is then passed through a pipeline to the distribution reservoir at 1450 m above sea-level. Among the various schemes studied, the most promising one comprises a Pelton turbine with 2 injectors that utilises a net height-difference of 162 meters. The resulting flow amounts to 150 l/s producing 197 kW of power. In order to achieve this flow, some sections of the pipeline must be replaced by ducts of a larger diameter. If the community of Liddes would obtain the permission to generate power during the whole year, the production would amount to 574,000 kWh/year and the resulting cost 0.090 CHF/kWh.

  10. Bayesian Belief Networks Approach for Modeling Irrigation Behavior

    Science.gov (United States)

    Andriyas, S.; McKee, M.

    2012-12-01

    Canal operators need information to manage water deliveries to irrigators. Short-term irrigation demand forecasts can potentially valuable information for a canal operator who must manage an on-demand system. Such forecasts could be generated by using information about the decision-making processes of irrigators. Bayesian models of irrigation behavior can provide insight into the likely criteria which farmers use to make irrigation decisions. This paper develops a Bayesian belief network (BBN) to learn irrigation decision-making behavior of farmers and utilizes the resulting model to make forecasts of future irrigation decisions based on factor interaction and posterior probabilities. Models for studying irrigation behavior have been rarely explored in the past. The model discussed here was built from a combination of data about biotic, climatic, and edaphic conditions under which observed irrigation decisions were made. The paper includes a case study using data collected from the Canal B region of the Sevier River, near Delta, Utah. Alfalfa, barley and corn are the main crops of the location. The model has been tested with a portion of the data to affirm the model predictive capabilities. Irrigation rules were deduced in the process of learning and verified in the testing phase. It was found that most of the farmers used consistent rules throughout all years and across different types of crops. Soil moisture stress, which indicates the level of water available to the plant in the soil profile, was found to be one of the most significant likely driving forces for irrigation. Irrigations appeared to be triggered by a farmer's perception of soil stress, or by a perception of combined factors such as information about a neighbor irrigating or an apparent preference to irrigate on a weekend. Soil stress resulted in irrigation probabilities of 94.4% for alfalfa. With additional factors like weekend and irrigating when a neighbor irrigates, alfalfa irrigation

  11. Grazing damage to plants and gastropod and grasshopper densities in a CO 2-enrichment experiment on calcareous grassland

    Science.gov (United States)

    Ledergerber, Stephan; Thommen, G. Heinrich; Baur, Bruno

    Plant-herbivore interactions may change as atmospheric CO 2 concentrations continue to rise. We examined the effects of elevated atmospheric CO 2 and CO 2-exposure chambers on the grazing damage to plants, and on the abundances of potential herbivores (terrestrial gastropods and grasshoppers) in a calcareous grassland in the Jura mountains of Switzerland (village of Nenzlingen). Individuals of most plant species examined showed slight grazing damage. However, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in the extent of grazing damage. Similarly, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in either gastropod or grasshopper density. Experimental plots with and without chambers did not differ in the number of gastropods. However, the densities of gastropods and grasshoppers and extent of grazing damage to plants were generally lower in the experimental area than in the grassland outside the experimental field.

  12. ASPECTS OF DRIP IRRIGATION ON SLOPES

    Directory of Open Access Journals (Sweden)

    Oprea Radu

    2010-01-01

    Full Text Available Nowadays, water and its supply raise problems of strategic importance, of great complexity, being considered one of the keys to sustainable human development. Drip irrigation consists in the slow and controlled administration of water in the area of the root system of the plants for the purposes of fulfilling their physiological needs and is considered to be one of the variants of localized irrigation. Water is distributed in a uniform and slow manner, drop by drop, in a quantity and with a frequency that depend on the needs of the plant, thanks to the exact regulation of the water flow rate and pressure, as well as to the activation of the irrigation based on the information recorded by the tensiometer with regard to soil humidity. This method enables the exact dosage of the water quantity necessary in the various evolution stages of the plant, thus eliminating losses. By applying the irrigation with 5 liters of water per linear meter, at a 7 days interval, in the month of august, for a vine cultivated on a slope, in layers covered with black film and irrigated via dropping, soil humidity immediately after irrigation reaches its highest level, but within the limits of active humidity, on the line of the irrigation band. Three days later, the water content of the soil in the layer is relatively uniform, and, after this interval, it is higher in the points situated at the basis of the film. This technology of cultivation on slopes favors the accumulation, in the soil, of the water resulted from heavy rains and reduces soil losses as a result of erosion.

  13. Selectivity and weed control efficacy of some herbicides applied to sprinkler irrigated rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Cavero, J; Zaragoza, C; Cirujeda, A; Anzalone, A; Faci, J M; Blanco, O

    2011-07-01

    Sprinkler irrigation can reduce the irrigation water needed to grow rice. However, most available information on weed control with herbicides is related to flood irrigated rice because this is the main growing method. Field experiments were conducted at Zaragoza (Spain) during two years to study weed control and tolerance of sprinkler irrigated rice to several herbicides. The main weeds were Atriplex prostrata Boucher ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. and Sonchus oleraceus L. Rice cv Guadiamar was tolerant to preemergence (PRE) application of clomazone at 0.36 kg ha{sup -}1 and oxadiazon at 0.5 kg ha{sup -}1. PRE application of pendimethalin at 1.32 kg ha{sup -}1 combined with clomazone at 0.36 kg ha{sup -}1 decreased rice yield. Postemergence (POST) application of bentazon at 1.6 kg ha{sup -}1 + MCPA at 0.25 kg ha{sup -}1 did not injure rice but POST application of azimsulfuron at 0.025 kg ha{sup -}1 produced visual crop injury. Only treatments that controlled grassy weeds since rice was planted and by more than 80% at harvest time lead to acceptable rice yield (> 5,000 kg ha{sup -}1). Clomazone applied PRE at 0.36 kg ha{sup -}1 provided good control of grassy weeds (> 80%) and the highest rice yield, so it is recommended as a selective and efficacious PRE treatment for weed control of annual weeds in sprinkler irrigated rice. The perennial purple nutsedge was difficult to control at high plant densities (> 150 plants m{sup -}2) and the recommended herbicide is azimsulfuron applied at POST at 0.02 kg ha{sup -}1. (Author) 37 refs.

  14. Variable-density ground-water flow and paleohydrology in the Waste Isolation Pilot Plant (WIPP) region, southeastern New Mexico

    International Nuclear Information System (INIS)

    Davies, P.B.

    1989-01-01

    Variable-density groundwater flow was studied near the Waste Isolation Pilot Plant in southeastern New Mexico. An analysis of the relative magnitude of pressure-related and density-related flow-driving forces indicates that density-related gravity effects are not significant at the plant and to the west but are significant in areas to the north, northeast, and south. A regional-scale model of variable-density groundwater flow in the Culebra Dolomite member of the Rustler Formation indicates that the flow velocities are relatively rapid west of the site and extremely slow east and northeast of the site. In the transition zone between those two extremes, which includes the plant, velocities are highly variable. Sensitivity simulations indicates that the central and western parts of the region, including the plant, are fairly well isolated from the eastern and northeastern boundaries. Vertical-flux simulations indicate that as much as 25% of total inflow to the Culebra could be entering as vertical flow, with most of this flow occurring west of the plant. A simple cross-sectional model was developed to examine the flow system as it drains through time following recharge during a past glacial pluvial. This model indicates that the system as a whole drains very slowly and that it apparently could have sustained flow from purely transient drainage following recharge of the system during the Pleistocene

  15. Plant Killing by Mutualistic Ants Increases the Density of Host Species Seedlings in the Dry Forest of Costa Rica

    OpenAIRE

    Amador-Vargas, Sabrina

    2012-01-01

    Some species of plant-mutualistic ants kill the vegetation growing in the vicinities of their host plant, creating an area of bare ground (clearing). The reduced competition in the clearing may facilitate the establishment of host species sprouts (clones and seedlings), which in turn benefits the ants with additional food and shelter (“sprout-establishment hypothesis”). To test this hypothesis, the density and origin of Acacia collinsii sprouts growing inside clearings and in the vicinities o...

  16. Effects Of Elevated Ozone On Leaf {delta} {sup 13} C And Leaf Conductance Of Plant Species Grown In Semi-Natural Grassland With Or Without Irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeggi, M.; Saurer, M.; Volk, M. [Agroscope-FAL (Switzerland); Fuhrer, J. [Agroscope-FAL (Switzerland)

    2005-03-01

    At the Swiss prealpine site Le Mouret (754 m a.s.l. 46deg 45min N / 7deg 10min E), semi-natural grassland species were kept under ambient or elevated ozone, paired with or without additional irrigation. Two of the four investigated grassland species showed an additive increase in {sup 13}C-values under drought and elevated ozone conditions. (author)

  17. NUTRIENT CONTENT IN SUNFLOWERS IRRIGATED WITH OIL EXPLORATION WATER

    Directory of Open Access Journals (Sweden)

    ADERVAN FERNANDES SOUSA

    2016-01-01

    Full Text Available Irrigation using produced water, which is generated during crude oil and gas recovery and treated by the exploration industry, could be an option for irrigated agriculture in semiarid regions. To determine the viability of this option, the effects of this treated water on the nutritional status of plants should be assessed. For this purpose, we examined the nutritional changes in sunflowers after they were irrigated with oil - produced water and the effects of this water on plant biomass and seed production. The sunflower cultivar BRS 321 was grown for three crop cycles in areas irrigated with filtered produced water (FPW, reverse osmosis - treated produced water (OPW, or ground water (GW. At the end of each cycle, roots, shoots, and seeds were collected to examine their nutrient concentrations. Produced water irrigation affected nutrient accumulation in the sunflower plants. OPW irrigation promoted the accumulation of Ca, Na, N, P, and Mg. FPW irrigation favored the accumulation of Na in both roots and shoots, and biomass and seed production were negatively affected. The Na in the shoots of plants irrigated with FPW increased throughout the three crop cycles. Under controlled conditions, it is possible to reuse reverse osmosis - treated produced water in agriculture. However, more long - term research is needed to understand its cumulative effects on the chemical and biological properties of the soil and crop production.

  18. An Evaluation of the Plant Density Estimator the Point-Centred Quarter Method (PCQM Using Monte Carlo Simulation.

    Directory of Open Access Journals (Sweden)

    Md Nabiul Islam Khan

    Full Text Available In the Point-Centred Quarter Method (PCQM, the mean distance of the first nearest plants in each quadrant of a number of random sample points is converted to plant density. It is a quick method for plant density estimation. In recent publications the estimator equations of simple PCQM (PCQM1 and higher order ones (PCQM2 and PCQM3, which uses the distance of the second and third nearest plants, respectively show discrepancy. This study attempts to review PCQM estimators in order to find the most accurate equation form. We tested the accuracy of different PCQM equations using Monte Carlo Simulations in simulated (having 'random', 'aggregated' and 'regular' spatial patterns plant populations and empirical ones.PCQM requires at least 50 sample points to ensure a desired level of accuracy. PCQM with a corrected estimator is more accurate than with a previously published estimator. The published PCQM versions (PCQM1, PCQM2 and PCQM3 show significant differences in accuracy of density estimation, i.e. the higher order PCQM provides higher accuracy. However, the corrected PCQM versions show no significant differences among them as tested in various spatial patterns except in plant assemblages with a strong repulsion (plant competition. If N is number of sample points and R is distance, the corrected estimator of PCQM1 is 4(4N - 1/(π ∑ R2 but not 12N/(π ∑ R2, of PCQM2 is 4(8N - 1/(π ∑ R2 but not 28N/(π ∑ R2 and of PCQM3 is 4(12N - 1/(π ∑ R2 but not 44N/(π ∑ R2 as published.If the spatial pattern of a plant association is random, PCQM1 with a corrected equation estimator and over 50 sample points would be sufficient to provide accurate density estimation. PCQM using just the nearest tree in each quadrant is therefore sufficient, which facilitates sampling of trees, particularly in areas with just a few hundred trees per hectare. PCQM3 provides the best density estimations for all types of plant assemblages including the repulsion process

  19. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    2017-01-01

    . We argue that the effect has historical origins: irrigation allowed landed elites in arid areas to monopolize water and arable land. This made elites more powerful and better able to oppose democratization. Consistent with this conjecture, we show that irrigation dependence predicts land inequality...

  20. Effective colostomy irrigation.

    Science.gov (United States)

    Mazier, W P; Dignan, R D; Capehart, R J; Smith, B G

    1976-06-01

    The ultimate goal of the cone method of colostomy irrigation is to return patients with colostomies to their former role in society with confidence in themselves to the extent that having a colostomy is not considered a handicap. The results have generally been excellent. We believe all patients with stomas should be afforded the opportunity to attempt colostomy irrigation.

  1. Effects of planting times and plant densities of top-shoot cuttings on multiplication of breeder seed potato

    Directory of Open Access Journals (Sweden)

    Md. Abdullah Al Mamun

    2016-01-01

    Full Text Available Top-shoot cuttings were planted with the whole tuber (as a control at different dates using three spacings at the Horticultural Research Farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University to evaluate the performance of top-shoots as planting material and to determine the optimum time of planting and the optimum spacing for top-shoot cuttings as planting material for breeder seed production. The survival of top shoot cuttings was more than 97.8% irrespective of the planting time and plant spacing. Significant variations were found among the treatment combinations for plant height at 45 and 60 days after planting (DAP, foliage coverage at 45 and 60 DAP, number of branches per plant, number of tubers per plant, individual tuber weight, tuber yields per plant and per hectare yield. The highest mean yield (46.57 t/ha was produced by whole tubers planted on 10 November with 50 × 10 cm spacing which was similar to whole tubers planted on 1 November with 50 × 10 cm spacing. On the other hand, plants from top-shoot cuttings yielded 34.82 t/ha in T3S2 followed by T1S1 (33.34 t/ha, T3S3 (30.70 t/ha. The total yield of potato increased 122.8% from a single, early crop due to taking two repeated cuttings compared with 89.6% from a single late crop. Early planting of top-shoot cuttings with closer spacing (50 × 10 cm and 50 × 15 cm is recommended for the multiplication of breeder seed potato.

  2. Effects of plant diversity on the concentration of secondary plant metabolites and the density of arthropods on focal plants in the field

    NARCIS (Netherlands)

    Kostenko, O.; Mulder, Patrick P. J.; Courbois, Matthijs; Bezemer, T. Martijn

    2017-01-01

    1.The diversity of the surrounding plant community can directly affect the abundance of insects on a focal plant as well as the size and quality of that focal plant. However, to what extent the effects of plant diversity on the arthropod community on a focal plant are mediated by host plant quality

  3. Grower demand for sensor-controlled irrigation

    Science.gov (United States)

    Lichtenberg, Erik; Majsztrik, John; Saavoss, Monica

    2015-01-01

    Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

  4. Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

    Directory of Open Access Journals (Sweden)

    Haibing He

    2014-01-01

    Full Text Available Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM, furrow irrigation with nonmulching (FIN, and drip irrigation with plastic mulching (DI. Compared with the conventional flooding (CF treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN, lower maximum quantum yield (Fv/Fm, and lower effective quantum yield of PSII photochemistry (ΦPSII. And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC. Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

  5. Produção e fisiologia de plantas de cajueiro anão precoce sob condições de sequeiro e irrigado Production and physiology of dwarf cashew plants under rainfed and irrigated conditions

    Directory of Open Access Journals (Sweden)

    Aiala V Amorim

    2011-10-01

    Full Text Available A exploração do cajueiro sob condições de irrigação tem-se mostrado bastante promissora, especialmente no estado do Ceará, porém a resposta dessa cultura ao regime hídrico depende do genótipo. Objetivouse, com este trabalho, comparar respostas fisiológicas e bioquímicas (teores de solutos orgânicos e inorgânicos e trocas gasosas, tal como a produtividade de plantas de cajueiro anão precoce (Anacardium occidentale L. sob dois regimes hídricos (sequeiro e irrigado. O experimento foi conduzido no Campo Experimental da Embrapa Agroindústria Tropical, em Pacajus CE, no período de agosto de 2006 a janeiro de 2007. As plantas foram submetidas a dois tratamentos: um sem irrigação e outro com água de poço com condutividade elétrica (CEa de 0,5 dS m-1. As respostas fisiológicas foram avaliadas mensalmente e os dados de produção foram obtidos no período de novembro a janeiro. Os teores foliares de N-aminossolúveis e prolina foram mais elevados nas plantas cultivadas em condições de sequeiro do que naquelas irrigadas, porém não houve diferença significativa entre os tratamentos para as trocas gasosas, teores de carboidratos solúveis, K+, Na+ e Cl-. Entretanto, com exceção da fotossíntese, todas as variáveis estudadas apresentaram alterações com as épocas de coleta. Apesar das alterações em algumas variáveis ao longo do experimento, a produtividade das plantas não foi afetada pelo estresse hídrico.The exploitation of cashew under irrigated conditions has been very promising, especially in the state of Ceará, however, the response of this crop to the water regime depends on the genotype. This work attempts to compare the physiological and biochemical responses (content of organic and inorganic solutes and gas exchange and yield of precocious dwarf cashew (Anacardium occidentale L plants under two water regimes (irrigated and rainfed. The experiment was conducted at the experimental field of Embrapa Agroind

  6. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  7. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NARCIS (Netherlands)

    Chukalla, Abebe Demissie; Krol, Martinus S.; Hoekstra, Arjen Ysbert

    2015-01-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and

  8. Biomass conversion and expansion factors in Douglas-fir stands of different planting density: variation according to individual growth and prediction equations

    International Nuclear Information System (INIS)

    Marziliano, P.A.; Menguzzato, G.; Scuderi, A.; Scalise, C.; Coletta, V.

    2017-01-01

    Aim of study: We built biomass expansion factors (BCEFs) from Douglas-fir felled trees planted with different planting densities to evaluate the differences according tree size and planting density. Area of study: The Douglas-fir plantation under study is located on the northern coastal chain of Calabria (Tyrrhenian side) south Italy. Materials and methods: We derived tree level BCEFs, relative to crown (BCEFc), to stem (BCEFst = basic density, BD) and total above-ground (BCEFt) from destructive measurements carried out in a Douglas-fir plantation where four study plots were selected according to different planting densities (from 833 to 2500 trees per hectare). The measured BCEFs were regressed against diameter at breast height and total height, planting density, site productivity (SP) and their interactions to test the variation of BCEFs. Analysis of variance (ANOVA) and the post hoc Tukey comparison test were used to test differences in BCEFt, BCEFc and in BD between plots with different planting density. Main results: BCEFs decreased with increasing total height and DBH, but large dispersion measures were obtained for any of the compartments in the analysis. An increasing trend with planting density was found for all the analyzed BCEFs, but together with planting density, BCEFs also resulted dependent upon site productivity. BCEFt average values ranged between 1.40 Mg m-3 in planting density with 833 trees/ha (PD833) to 2.09 Mg m-3 in planting density with 2500 trees/ha (PD2500), which are in the range of IPCC prescribed values for Douglas-fir trees. Research highlights: Our results showed that the application of BCEF to estimate forest biomass in stands with different planting densities should explicitly account for the effect of planting density and site productivity.

  9. Biomass conversion and expansion factors in Douglas-fir stands of different planting density: variation according to individual growth and prediction equations

    Energy Technology Data Exchange (ETDEWEB)

    Marziliano, P.A.; Menguzzato, G.; Scuderi, A.; Scalise, C.; Coletta, V.

    2017-11-01

    Aim of study: We built biomass expansion factors (BCEFs) from Douglas-fir felled trees planted with different planting densities to evaluate the differences according tree size and planting density. Area of study: The Douglas-fir plantation under study is located on the northern coastal chain of Calabria (Tyrrhenian side) south Italy. Materials and methods: We derived tree level BCEFs, relative to crown (BCEFc), to stem (BCEFst = basic density, BD) and total above-ground (BCEFt) from destructive measurements carried out in a Douglas-fir plantation where four study plots were selected according to different planting densities (from 833 to 2500 trees per hectare). The measured BCEFs were regressed against diameter at breast height and total height, planting density, site productivity (SP) and their interactions to test the variation of BCEFs. Analysis of variance (ANOVA) and the post hoc Tukey comparison test were used to test differences in BCEFt, BCEFc and in BD between plots with different planting density. Main results: BCEFs decreased with increasing total height and DBH, but large dispersion measures were obtained for any of the compartments in the analysis. An increasing trend with planting density was found for all the analyzed BCEFs, but together with planting density, BCEFs also resulted dependent upon site productivity. BCEFt average values ranged between 1.40 Mg m-3 in planting density with 833 trees/ha (PD833) to 2.09 Mg m-3 in planting density with 2500 trees/ha (PD2500), which are in the range of IPCC prescribed values for Douglas-fir trees. Research highlights: Our results showed that the application of BCEF to estimate forest biomass in stands with different planting densities should explicitly account for the effect of planting density and site productivity.

  10. Comportamento de cultivares de cafeeiro em diferentes densidades de plantio The behavior of coffee cultivars under different plant densities

    Directory of Open Access Journals (Sweden)

    Edison Martins Paulo

    2005-01-01

    Full Text Available Avaliou-se em Adamantina, na Região da Alta Paulista, em São Paulo, entre maio de 1995 e junho de 2000, o crescimento e quatro produções de cafeeiros das cultivares de porte baixo Catuaí Amarelo IAC 47 e Obatã IAC 1669-20 de Coffea arabica L., submetidas às densidades de plantio de 2.500, 5.000, 7.519 e 10.000 plantas ha-1, com uma planta por cova. Estudou-se também a população de 2.500 plantas.ha-1 em covas com duas plantas com 2,0 m de distância na linha de plantio. Adotou-se o delineamento estatístico de blocos ao acaso com três repetições, com parcelas subdivididas, onde as parcelas foram as populações e as subparcelas, as cultivares. Os resultados permitiram inferir que, no período estudado, o aumento da densidade influenciou positivamente a altura e negativamente o diâmetro do caule e da base da copa dos cafeeiros, mas não a altura da inserção do primeiro ramo plagiotrópico a partir do nível do solo. O aumento da população de cafeeiros acarretou menor produção de café beneficiado por planta, mas concorreu para o aumento da produtividade no período de 1997 a 2000. O plantio de duas mudas de café por cova acarretou também diminuição do diâmetro do caule e da produção individual dos cafeeiros. Observou-se na cultivar Catuaí Amarelo IAC 47 maior diâmetro da base da copa e maior crescimento em altura, enquanto a cv. Obatã IAC 1669-20 evidenciou seu maior diâmetro do caule. As cultivares Catuaí Amarelo IAC 47 e Obatã IAC 1669-20 não diferiram entre si quanto à produção individual e à produtividade de café beneficiado no quadriênio (1997-2000.This experiment was developed at Adamantina, west region of the State of São Paulo, Brazil, during May of 1995 to June of 2000. The plant growth and productivity of two coffee cultivars Catuaí Amarelo IAC 47 and Obatã IAC 1669-20, were evaluated considering to plant densities of 2.500, 5.000, 7.519 and 10.000 plants ha-1. The density of 2500 also was

  11. A simulation study on the interactive effects of radiation and plant density on growth of cut chrysanthemum

    NARCIS (Netherlands)

    Lee, J.H.; Heuvelink, E.; Challa, H.

    2002-01-01

    In the present study, we used a photosynthesis-driven crop growth model to determine acceptable plant densities for cut chrysanthemum throughout the year at different intensities of supplementary light. Dry matter partitioning between leaves, stems, and flowers was simulated as a function of crop

  12. Planting density and silvicultural intensity impacts on loblolly pine stand development in the western gulf coastal plain through age 8

    Science.gov (United States)

    Michael B. Kane; Dehai Zhao; John W. Rheney; Michael G. Messina; Mohd S. Rahman; Nicholas Chappell

    2012-01-01

    Commercial plantation growers need to know how planting density and cultural regime intensity affect loblolly pine plantation productivity, development and value to make sound management decisions. This knowledge is especially important given the diversity of traditional products, such as pulpwood, chip-n-saw, and sawtimber, and potential products, such as bioenergy...

  13. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

    Science.gov (United States)

    Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

  14. Effects of ten years treated wastewater drip irrigation on soil ...

    African Journals Online (AJOL)

    SWEET

    soil contamination and the cumulative impact of wastewater, we compared two plots, all under orange- ... A slight increase in the concentration of soil enteric bacteria and soil fungal densities was ..... could be used for fruit tree irrigation.

  15. Predicting deep percolation with eddy covariance under mulch drip irrigation

    Science.gov (United States)

    Ming, Guanghui; Tian, Fuqiang; Hu, Hongchang

    2016-04-01

    Water is essential for the agricultural development and ecological sustainability of the arid and semi-arid oasis with rare precipitation input and high evaporation demand. Deep percolation (DP) defined as excess irrigation water percolating below the plant root zone will reduce irrigation water use efficiency (WUE). But the DP was often ignored in mulch drip irrigation (MDI) which has reached the area of 1.6 million hectares in Xinjiang, the northwest of China. In this study DP experiments were conducted at an agricultural experiment station located within an irrigation district in the Tarim River Basin for four cotton growing periods. First it was detected the irrigation water infiltrated into the soil layers below 100cm and the groundwater level responded to the irrigation events well. Then DP below 100cm soil layers was calculated using the soil water balance method with the aid of eddy covariance (with the energy balance closure of 0.72). The negative DP (groundwater contribution to the crop-water use through capillary rising) at the seedling and harvesting stages can reach 77mm and has a good negative correlation with the groundwater level and positive correlation with potential evaporation. During the drip irrigation stage approximately 45% of the irrigation became DP and resulted in the low irrigation WUE of 0.6. The DP can be 164mm to 270mm per year which was positive linearly correlated to irrigation depth and negative linear correlated to irrigation interval. It is better to establish the irrigation schedule with small irrigation depth and given frequently to reduce deep percolation and meet crop needs.

  16. [Effects of different colored plastic film mulching and planting density on dry matter accumulation and yield of spring maize.

    Science.gov (United States)

    Zhang, Lin Lin; Sun, Shi Jun; Chen, Zhi Jun; Jiang, Hao; Zhang, Xu Dong; Chi, Dao Cai

    2018-01-01

    In order to investigate the effect of different colored plastic film mulching and planting density on spring maize dry matter accumulation and yield in the rain-fed area of the Northeast China, a complete combination field experiment which was comprised by three types of mulching (non-mulching, transparent plastic film mulching and black plastic film mulching) and five densities (60000, 67500, 75000, 82500 and 90000 plants·hm -2 ), was conducted to analyze the water and heat effect, dry matter accumulation and yield of spring maize (Liangyu 99). The results showed that, compared with the other mulching treatments, the black plastic film mulching treatment significantly increased the maize dry matter accumulation and maize biomass by 3.2%-8.2%. In mature stage, the biomass increased firstly and then decreased with the increasing plant density. When planting density was 82500 plants·hm -2 , the biomass was the highest, which was 5.2%-28.3% higher than that of other plant density treatments. The mean soil temperature in prophase of transparent plastic film mulching treatment was 0.4-2.7 ℃ higher than that of other treatments, which accelerated the maize growth process and augmented the dry matter transportation amount (T), dry matter transportation efficiency (TE) and contribution rate of dry matter transportation to the grain yield (TC) of maize stalk and leaf. The T, TE, TC of leaf and leaf-stalk under 60000 plants·hm -2 treatment were the highest. The highest T, TE, TC of stalk were observed under 75000 plants·hm -2 treatment. In heading period, the water consumption and daily water consumption intensity of maize under the treatment of black film mulching were the largest, which were 9.4%-10.6% and 10.6%-24.5% higher than that of other mulching treatments, respectively. The highest water consumption and daily water consumption intensity were both obtained under 90000 plants·hm -2 treatment, which increased by 6.8%-15.7% and 7.0%-20.0% compared with other

  17. Scheduling irrigation for jujube (Ziziphus jujuba Mill.)

    African Journals Online (AJOL)

    USER

    2010-08-30

    Aug 30, 2010 ... indicators for diagnosing plant water information, but it is troublesome to measure leaf water potential using a pressure chamber (Turner, 1981). It is also difficult to achieve automatic and continuous records with the pressure chamber. Definition of threshold values of soil moisture for irrigation management ...

  18. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2015-01-01

    The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P......, K, Mg and micronutrients, and in addition 120 kg N/ha in the gun irrigated treatments and 36 kg N/ha in the drip-fertigated. For the latter, portion of 20 kg N/ha was applied whenever plant N concentration approached a critical value as simulated by the Daisy model. As a result differences in soil...

  19. A specialist root herbivore reduces plant resistance and uses an induced plant volatile to aggregate in a density dependent manner

    Science.gov (United States)

    1. Leaf-herbivore attack often triggers induced resistance in plants. However, certain specialist herbivores can also take advantage of the induced metabolic changes. In some cases, they even manipulate plant resistance, leading to a phenomenon called induced susceptibility. Compared to above-ground...

  20. Unsaturated flow dynamics during irrigation with wastewater: field and modelling study

    Science.gov (United States)

    Martinez-Hernandez, V.; de Miguel, A.; Meffe, R.; Leal, M.; González-Naranjo, V.; de Bustamante, I.

    2012-04-01

    To deal with water scarcity combined with a growing water demand, the reuse of wastewater effluents of wastewater treatment plants (WWTP) for industrial and agricultural purposes is considered as a technically and economically feasible solution. In agriculture, irrigation with wastewater emerges as a sustainable practice that should be considered in such scenarios. Water infiltration, soil moisture storage and evapotranspiration occurring in the unsaturated zone are fundamental processes that play an important role in soil water balance. An accurate estimation of unsaturated flow dynamics (during and after irrigation) is essential to improve wastewater management (i.e. estimating groundwater recharge or maximizing irrigation efficiency) and to avoid possible soil and groundwater affections (i.e. predicting contaminant transport). The study site is located in the Experimental Plant of Carrión de los Céspedes (Seville, Spain). Here, treated wastewater is irrigated over the soil to enhance plants growth. To obtain physical characteristics of the soil (granulometry, bulk density and water retention curve), soil samples were collected at different depths. A drain gauge passive capillary lysimeter was installed to determine the volume of water draining from the vadose zone. Volumetric water content of the soil was monitored by measuring the dielectric constant using capacitance/frequency domain technology. Three soil moisture probes were located at different depths (20, 50 and 70 cm below the ground surface) to control the variation of the volumetric water content during infiltration. The main aim of this study is to understand water flow dynamics through the unsaturated zone during irrigation by using the finite element model Hydrus-1D. The experimental conditions were simulated by a 90 cm long, one dimensional solution domain. Specific climatic conditions, wastewater irrigation rates and physical properties of the soil were introduced in the model as input parameters

  1. Crescimento inicial do cafeeiro irrigado com água salina e salinização do solo Initial growth of coffee plants irrigated with saline water and soil salinization

    Directory of Open Access Journals (Sweden)

    Vladimir B. Figueirêdo

    2006-03-01

    Full Text Available A cultura do cafeeiro (Coffea arabica L. vem-se expandindo para regiões ainda pouco exploradas, em que o uso da irrigação com água salina possa ser fator limitante. Nesse contexto, avaliou-se o crescimento inicial do cafeeiro, conduzido em casa de vegetação do Departamento de Engenharia da Universidade Federal de Lavras (UFLA, submetendo-o a níveis crescentes de salinidade da água de irrigação. O delineamento utilizado foi inteiramente casualizado com 6 tratamentos (S0 = 0,0 dS m-1, S1 = 0,6 dS m-1, S2 = 1,2 dS m-1, S3 = 1,8 dS m-1, S4 = 2,4 dS m-1 e S5 = 3,0 dS m-1 e 4 repetições. A reposição de água foi realizada com base na curva característica do solo, pela leitura da tensão de água por blocos de resistência, retornando o conteúdo de água à capacidade de campo. Verificou-se que os tratamentos influenciaram significativamente as características da planta e que a salinidade da água a partir de 1,2 dS m-1 prejudicou o crescimento e, em alguns casos, provocou a morte das plantas. A área foliar foi a variável mais prejudicada. Ao final do experimento o solo foi classificado como salino-sódico.The coffee crop is expanding to new areas with not enough studies about its response to saline irrigation water. The initial growth of coffee plant was evaluated, in greenhouse at the Engineering Department of the Federal University of Lavras (UFLA, under different levels of irrigation water salinity. The completely randomized design was used with 6 treatments (S0 = 0.0 dS m-1, S1 = 0.6 dS m-1, S2 = 1.2 dS m-1, S3 = 1.8 dS m-1, S4 = 2.4 dS m-1 and S5 = 3.0 dS m-1 and 4 replications. The irrigation was accomplished according to soil water retention curve and resistance block reading, restoring the soil water content to its field capacity. It was verified that water salinity affected the plants characteristics significantly. The water salinity above 1.2 dS m-1 caused damage to plant development resulting, in some cases, in death of

  2. Interspecies Interactions in Relation to Root Distribution Across the Rooting Profile in Wheat-Maize Intercropping Under Different Plant Densities

    Directory of Open Access Journals (Sweden)

    Yifan Wang

    2018-04-01

    Full Text Available In wheat-maize intercropping systems, the maize is often disadvantageous over the wheat during the co-growth period. It is unknown whether the impaired growth of maize can be recovered through the enhancement of the belowground interspecies interactions. In this study, we (i determined the mechanism of the belowground interaction in relation to root growth and distribution under different maize plant densities, and (ii quantified the “recovery effect” of maize after wheat harvest. The three-year (2014–2016 field experiment was conducted at the Oasis Agriculture Research Station of Gansu Agricultural University, Wuwei, Northwest China. Root weight density (RWD, root length density (RLD, and root surface area density (RSAD, were measured in single-cropped maize (M, single-cropped wheat (W, and three intercropping systems (i wheat-maize intercropping with no root barrier (i.e., complete belowground interaction, IC, (ii nylon mesh root barrier (partial belowground interaction, IC-PRI, and (iii plastic sheet root barrier (no belowground interaction, IC-NRI. The intercropped maize was planted at low (45,000 plants ha−1 and high (52,000 plants ha−1 densities. During the wheat/maize co-growth period, the IC treatment increased the RWD, RLD, and RSAD of the intercropped wheat in the 20–100 cm soil depth compared to the IC-PRI and IC-NRI systems; intercropped maize had 53% lower RWD, 81% lower RLD, and 70% lower RSAD than single-cropped maize. After wheat harvest, the intercropped maize recovered the growth with the increase of RWD by 40%, RLD by 44% and RSAD by 11%, compared to the single-cropped maize. Comparisons among the three intercropping systems revealed that the “recovery effect” of the intercropped maize was attributable to complete belowground interspecies interaction by 143%, the compensational effect due to root overlap by 35%, and the compensational effect due to water and nutrient exchange (CWN by 80%. The higher maize plant

  3. Ideotype population exploration: growth, photosynthesis, and yield components at different planting densities in winter oilseed rape (Brassica napus L.).

    Science.gov (United States)

    Ma, Ni; Yuan, Jinzhan; Li, Ming; Li, Jun; Zhang, Liyan; Liu, Lixin; Naeem, Muhammad Shahbaz; Zhang, Chunlei

    2014-01-01

    Rapeseed is one of the most important edible oil crops in the world and the seed yield has lagged behind the increasing demand driven by population growth. Winter oilseed rape (Brassica napus L.) is widely cultivated with relatively low yield in China, so it is necessary to find the strategies to improve the expression of yield potential. Planting density has great effects on seed yield of crops. Hence, field experiments were conducted in Wuhan in the Yangtze River basin with one conventional variety (Zhongshuang 11, ZS11) and one hybrid variety (Huayouza 9, HYZ9) at five planting densities (27.0×10(4), 37.5×10(4), 48.0×10(4), 58.5×10(4), 69.0×10(4) plants ha(-1)) during 2010-2012 to investigate the yield components. The physiological traits for high-yield and normal-yield populations were measured during 2011-2013. Our results indicated that planting densities of 58.5×10(4) plants ha(-1) in ZS11 and 48.0×10(4) plants ha(-1) in HYZ9 have significantly higher yield compared with the density of 27.0×10(4) plants ha(-1) for both varieties. The ideal silique numbers for ZS11 and HYZ9 were ∼0.9×10(4) (n m(-2)) and ∼1×10(4) (n m(-2)), respectively, and ideal primary branches for ZS11 and HYZ9 were ∼250 (n m(-2)) and ∼300 (n m(-2)), respectively. The highest leaf area index (LAI) and silique wall area index (SAI) was ∼5.0 and 7.0, respectively. Moreover, higher leaf net photosynthetic rate (Pn) and water use efficiency (WUE) were observed in the high-yield populations. A significantly higher level of silique wall photosynthesis and rapid dry matter accumulation were supposed to result in the maximum seed yield. Our results suggest that increasing the planting density within certain range is a feasible approach for higher seed yield in winter rapeseed in China.

  4. Equipment evaluation for low density polyethylene encapsulated nitrate salt waste at the Rocky Flats Plant

    International Nuclear Information System (INIS)

    Yamada, W.I.; Faucette, A.M.; Jantzen, R.C.; Logsdon, B.W.; Oldham, J.H.; Saiki, D.M.; Yudnich, R.J.

    1993-01-01

    Mixed wastes at the Rocky Flats Plant (RFP) are subject to regulation by the Resource Conservation and Recovery Act (RCRA). Polymer solidification is being developed as a final treatment technology for several of these mixed wastes, including nitrate salts. Encapsulation nitrate salts with low density polyethylene (LDPE) has been the preliminary focus of the RFP polymer solidification effort. Literature reviews, industry surveys, and lab-scale and pilot-scale tests have been conducted to evaluate several options for encapsulating nitrate salts with LDPE. Most of the effort has focused on identifying compatible drying and extrusion technologies. Other processing options, specifically meltration and non-heated compounding machines, were also investigated. The best approach appears to be pretreatment of the nitrate salt waste brine in either a vertical or horizontal thin film evaporator followed by compounding of the dried waste with LDPE in an intermeshing, co-rotating, twin-screw extruder. Additional pilot-scale tests planned for the fall of 1993 should further support this recommendation. Preliminary evaluation work indicates that meltration is not possible at atmospheric pressure with the LDPE (Chevron PE-1409) provided by RFP. However, meltration should be possible at atmospheric pressure using another LDPE formulation with altered physical and rheological properties: Lower molecular weight and lower viscosity (Epoline C-15). Contract modifications are now in process to allow a follow-on pilot scale demonstration. Questions regarding changed safety and physical properties of the resultant LDPE waste form due to use of the Epoline C-15 will be addressed. No additional work with non-heated mixer compounder machines is planned at this time

  5. MORPHOLOGICAL CHARACTERISTICS AND FORAGE PRODUCTIVITY OF IRRIGATED CACTUS PEAR UNDER DIFFERENT CUTTING INTENSITIES

    Directory of Open Access Journals (Sweden)

    GUILHERME FERREIRA DA COSTA LIMA

    2016-01-01

    Full Text Available This study evaluated the effect of different cutting intensities and years of harvesting on the morphological characteristics and production of fresh (FMP and dry matter (DMP of cactus pear cv. Gigante (Opuntia ficus-indica Mill under conditions of irrigation, high planting density and fertilization, with 12 months of regrowth. The experimental was completely randomized in a factorial design (3 × 2 with 12 replicates. The treatments were three cutting intensities (preserving the mother cladode (PMC, primary cladodes (PPC, or secondary cladodes (PSC, and two years of harvesting. The soil was classified as Cambisol Haplicum and the irrigation water was classified as C4S1 (EC 5.25 dS.m-1 density of 50,000 plants ha-1. The research evaluated plant height, number of cladodes per plant (NCP, length, width, perimeter and thickness of the cladodes, cladode area (CA, cladode area index (CAI, FMP and DMP. There was no significant interaction between treatments (P > 0.05 for the variables plant height, NCP, CAI and FMP. The variables related to cladode morphology showed a significant interaction (P < 0.05. The treatment PSC resulted in a greater DMP (P < 0.05 with a mean of 27.17 Mg ha-1 yr-1, compared to PPC (18.58 Mg ha-1 yr-1 or PMC (11.78 Mg ha-1 yr-1. The treatment PSC promoted greater NCP and forage productivity at harvest and can be considered as a management practice for the sustainability of cactus pear cv. Gigante under irrigation. The more important morphological characteristics were also influenced by the lower cutting intensities.

  6. Coolidge solar powered irrigation pumping project

    Science.gov (United States)

    Larson, D. L.

    1980-01-01

    A 150 kW solar thermal electric power plant which includes over 2100 square meters of parabolic trough type collectors and an organic Rankine cycle turbine engine was constructed on an irrigated farm. The plant is interconnected with the electrical utility grid. Operation is providing an evaluation of equipment performance and operating and maintenance requirements as well as the desirability of an on farm location.

  7. Periphyton density is similar on native and non-native plant species

    NARCIS (Netherlands)

    Grutters, B.M.C.; Gross, Elisabeth M.; van Donk, E.; Bakker, E.S.

    2017-01-01

    Non-native plants increasingly dominate the vegetation in aquatic ecosystems and thrive in eutrophic conditions. In eutrophic conditions, submerged plants risk being overgrown by epiphytic algae; however, if non-native plants are less susceptible to periphyton than natives, this would contribute to

  8. Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

    Science.gov (United States)

    Misra, R. K.; Patel, J. H.; Baxi, V. R.

    2010-05-01

    SummaryGreywater is considered as a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from reuse of greywater which may affect agricultural productivity and environmental sustainability adversely. We conducted a glasshouse experiment to examine variation in growth, water and nutrient use of tomato ( Lycopersicon esculentum Mill. cv. Grosse Lisse) using tap water (TW), laundry greywater (GW) and solutions of low and high concentration of a detergent surfactant (LC and HC, respectively) as irrigation treatments. Each treatment was replicated five times using a randomised block design. Measurements throughout the experiment showed greywater to be significantly more alkaline and saline than the other types of irrigation water. Although all plants received 16 irrigations over a period of 9 weeks until flowering, there were little or no significant effects of irrigation treatments on plant growth. Soil water retention following irrigation reduced significantly when plants were irrigated with GW or surfactant solutions on only three of 12 occasions. On one occasion, water use measured as evapotranspiration (ET) with GW irrigation was similar to TW, but it was significantly higher than the plants receiving HC irrigation. At harvest, various components of plant biomass and leaf area for GW irrigated plants were found to be similar or significantly higher than the TW irrigated plants with a common trend of GW ⩾ TW > LC ⩾ HC. Whole-plant concentration was measured for 12 essential plant nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn, Mo and B) and Na (often considered as a beneficial nutrient). Irrigation treatments affected the concentration of four nutrients (P, Fe, Zn and Na) and uptake of seven nutrients (P, K, Ca, Mg, Na, Fe and B) significantly. Uptake of these seven nutrients by tomato was generally in the order GW ⩾ TW > HC ⩾ LC. GW

  9. Nutrição mineral e extração de nutrientes de planta de milho irrigada com água salina Mineral nutrition and extraction of nutrients by corn plant irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Geocleber G. de Sousa

    2010-11-01

    Full Text Available A utilização de água salina na agricultura irrigada pode causar desequilíbrio nutricional e inibição competitiva na absorção de nutrientes. O objetivo deste trabalho foi avaliar os efeitos da salinidade da água de irrigação sobre o acúmulo, os totais extraídos e a distribuição de nutrientes em plantas de milho. O estudo foi conduzido em condições de campo em um Argissolo Vermelho Amarelo na estação seca, no delineamento em blocos ao acaso, com cinco repetições, de setembro a dezembro de 2007, em Fortaleza, CE. As plantas de milho foram coletadas aos 90 dias após a semeadura e realizadas as seguintes avaliações: teores, extração e distribuição de elementos minerais nas diferentes partes da planta (folha, colmo, grão e sabugo. O aumento da salinidade da água de irrigação aos 90 dias após a semeadura, inibiu o acúmulo de potássio nas folhas e de magnésio e fósforo nos grãos. A extração dos nutrientes e sódio pelas plantas irrigadas com água de salinidade variando de 0,8 a 3,6 dS m-1 obedeceu à seguinte ordem decrescente: K > Mg > Ca > P > Na; no tratamento de maior salinidade (5,0 dS m-1 a sequência de extração foi: K > Ca > Na > P > Mg.The use of saline water in irrigated agriculture can cause nutritional imbalance and competitive inhibition in the absorption of nutrients. The objective of this study was to evaluate the effects of salinity of irrigation water on the accumulation, the total absorption, and the distribution of mineral elements in maize plants. The study was conducted under field conditions in an Yellow Red Argisol in the dry season, in the randomized blocks design with five replicates during September to December 2007 in Fortaleza - CE. The maize plants were collected at 90 days after sowing, and the following assessments were made: content, extraction and distribution of mineral elements in the plant parts (leaf, stem, grain and elderberry. The increase of salinity of irrigation water

  10. Irrigation management of muskmelon with tensiometry

    Directory of Open Access Journals (Sweden)

    Márcio José de Santana

    2017-11-01

    Full Text Available The production and consumption of muskmelon have been increasing (MELO et al., 2014, thus, information on techniques for higher field productions are necessary. The experiment described in the present work was conducted in the IFTM, Uberaba, State of Minas Gerais, Brazil, aiming to evaluate the muskmelon yield under different soil water tensions. A randomized block experimental design was used with five treatments (soil water tensions of 10, 20, 30, 40 and 50 kPa and four replications (plots of two rows of 14 plants. Two harvests were carried out and the fruit yield, stem diameter, number of fruits per plant and efficiency of water use were evaluated. Irrigation was performed with a drip irrigation system and managed with tensiometry. The cultivar Bonus n.2 was used with spacing of 1.0 x 0.6 m. The data of the variables were subjected to the F test and regression test. The treatments showed statistical differences in number of fruits per plant, fruit weight (fruit yield and stem diameter. The highest fruit yield found was 1.36 kg fruit-1 and the highest water use efficiency was 4.08 g mm-1 with irrigation for a soil water tension of 10 kPa. The lowest fruit yield was found with irrigation for a soil water tension of 50 kPa.

  11. Damage of Rhopalosiphum padi (L.) (Hemiptera: Aphididae) on wheat plants related to duration time and density of infestation

    International Nuclear Information System (INIS)

    Roza-Gomes, Margarida F.; Salvadori, Jose R.; Schons, Jurema

    2008-01-01

    Aphids are considered relevant pests on wheat either by direct damage through sap sucking or by indirect damage vectoring BYDV (Barley yellow dwarf virus). Rhopalosiphum padi L. has been observed infesting wheat fields with an increasing frequency. The knowledge and the available technology, besides being more related to other aphids species already recognized as pests, they are insufficient to control the specific c problem of R. padi. Thus, this work evaluated the effects of feeding duration and infestation densities of R. padi on seedlings of wheat cv. EMBRAPA 16. rain yield, yield components and the extent of symptoms were recorded. The experiment was carried out in the fi eld under a completely randomized split-plot experimental design with four replications. The main plot was feeding duration (two and seven days) and the sub-plots were infestation densities (zero, two and 10 aphids per plant). Independent on feeding duration, 10 aphids per plant resulted in significant yield losses, reduction of number of heads and tillers per plant. Canopy dry matter was also reduced. Infestations of two and 10 aphids per plant resulted in continuous yellowing of wheat plants from tillering to the end of flowering stage. When aphids fed for seven days on wheat, more yellowing symptoms were observed at the flower stage in comparison with two days feeding. (author)

  12. Population densities of indigenous Acidobacteria change in the presence of plant growth promoting rhizobacteria (PGPR) in rhizosphere.

    Science.gov (United States)

    Kalam, Sadaf; Das, Subha Narayan; Basu, Anirban; Podile, Appa Rao

    2017-05-01

    Rhizosphere microbial community has diverse metabolic capabilities and plays a crucial role in maintaining plant health. Oligotrophic plant growth promoting rhizobacteria (PGPR), along with difficult-to-culture microbial fractions, might be involved synergistically in microbe-microbe and plant-microbe interactions in the rhizosphere. Among the difficult-to-culture microbial fractions, Acidobacteria constitutes the most dominant phylum thriving in rhizospheric soils. We selected effective PGPR for tomato and black gram and studied their effect on population densities of acidobacterial members. Three facultatively oligotrophic PGPR were identified through 16S rRNA gene sequencing as Sphingobacterium sp. (P3), Variovorax sp. (P4), and Roseomonas sp. (A2); the latter being a new report of PGPR. In presence of selected PGPR strains, the changes in population densities of Acidobacteria were monitored in metagenomic DNA extracted from bulk and rhizospheric soils of tomato and black gram using real time qPCR. A gradual increase in equivalent cell numbers of Acidobacteria members was observed over time along with a simultaneous increase in plant growth promotion by test PGPR. We report characterization of three effective PGPR strains and their effects on indigenous, underexplored difficult-to-culture phylum-Acidobacteria. We suggest that putative interactions between these two bacterial groups thriving in rhizospheric soils could be beneficial for plant growth. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Effects of plant densities on yield, yield components and some morphological characters of two cultivators of oilseed rape (Brassica napus L.)

    DEFF Research Database (Denmark)

    Al-Barzinjy, M.; Stölen, O.; Christiansen, Jørgen Lindskrog

    2003-01-01

    Effects of Plant Densities on Yield, Yield Components and some Morphological Characters of two Cultivators of Oilseed Rape (Brassica napus L.)......Effects of Plant Densities on Yield, Yield Components and some Morphological Characters of two Cultivators of Oilseed Rape (Brassica napus L.)...

  14. Effect of planting density on root lodging resistance and its relationship to nodal root growth characteristics in maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Liu, Shengqun; Song, Fengbin; Liu, Fulai

    2012-01-01

    Increase of planting density has been widely used to increase grain yield in maize. However, it may lead to higher risk of root lodging hence causing significant yield loss of the crop. The objective of this study was to investigate the effect of planting density on maize nodal root growth...

  15. The effect of application of chemical and organic fertilizers on yield and yield components of sesame (Sesamum indicum L. in different plant densities

    Directory of Open Access Journals (Sweden)

    P. Rezvani Moghaddam

    2016-04-01

    Full Text Available In order to understand the effect of plant density and different fertilizers on sesame (Sesamum indicum L. production, an experiment was conducted as a factorial arrangement based on completely randomized block design with three replications. The experimental treatments were fertilizers in four levels (cow manure (30 t.ha-1, municipal compost (30 t.ha-1, chemical fertilizer (250 kg ammonium phosphate + 100 kg urea and control (no-fertilizer and plant density in four levels (20, 30, 40 and 50 plant.m-2. The results showed that all treatments increased the plant height, number of capsule per plant, plant biomass, seed yield, seed weight and number of seed per plant compared to control, significantly. The highest amount of the traits was obtained in manure treatment. The seed yield was increased by increasing plant density, but decreased the plant height, number of capsule per plant, plant biomass, seed yield and weight and number of seed per plant, significantly. 1000-seed weight, harvest index and weight of seed per capsule had no affected by treatments. Our result indicated that the density of 40 plant.m-2 among using manure was the most appropriate of cropping pattern in our experiment.

  16. Plant Density Effect on Grain Number and Weight of Two Winter Wheat Cultivars at Different Spikelet and Grain Positions

    Science.gov (United States)

    Ni, Yingli; Zheng, Mengjing; Yang, Dongqing; Jin, Min; Chen, Jin; Wang, Zhenlin; Yin, Yanping

    2016-01-01

    In winter wheat, grain development is asynchronous. The grain number and grain weight vary significantly at different spikelet and grain positions among wheat cultivars grown at different plant densities. In this study, two winter wheat (Triticum aestivum L.) cultivars, ‘Wennong6’ and ‘Jimai20’, were grown under four different plant densities for two seasons, in order to study the effect of plant density on the grain number and grain weight at different spikelet and grain positions. The results showed that the effects of spikelet and grain positions on grain weight varied with the grain number of spikelets. In both cultivars, the single-grain weight of the basal and middle two-grain spikelets was higher at the 2nd grain position than that at the 1st grain position, while the opposite occurred in the top two-grain spikelets. In the three-grain spikelets, the distribution of the single-grain weight was different between cultivars. In the four-grain spikelets of Wennong6, the single-grain weight was the highest at the 2nd grain position, followed by the 1st, 3rd, and 4th grain positions. Regardless of the spikelet and grain positions, the single-grain weight was the highest at the 1st and 2nd grain positions and the lowest at the 3rd and 4th grain positions. Overall, plant density affected the yield by controlling the seed-setting characteristics of the tiller spike. Therefore, wheat yield can be increased by decreasing the sterile basal and top spikelets and enhancing the grain weight at the 3rd and 4th grain positions, while maintaining it at the 1st and 2nd grain positions on the spikelet. PMID:27171343

  17. Biomass and biomass and biogas yielding potential of sorghum as affected by planting density, sowing time and cultivar

    International Nuclear Information System (INIS)

    Mahmood, A.; Hussain, A.; Shahzad, A. N.; Honermeier, B.

    2015-01-01

    Biogas from biomass is a promising renewable energy source whose importance is increasing in European as well as in other countries. A field experiment at one location (Experimental Station Giessen, Justus Liebig University of Giessen, Germany) over two years was designed to study the effect of altering sowing time (ST), planting density and cultivar on the biomass yield and chemical composition of biomass sorghum, and its potential for methane production. Of the two cultivars tested, cv. Goliath (intraspecific hybrid) was more productive with respect to biomass yield than cv. Bovital (S. bicolor x S. sudanense hybrid). ST also influenced biomass yield and most of the quality parameters measured. Delayed sowing was in general advantageous. The choice of cultivar had a marked effect on biogas and methane yield. The highest biogas and methane yields were produced by late sown cv. Bovital. Sub-optimal planting densities limited biomass accumulation of the crop, however neither the chemical composition nor the methane yield was affected by planting density. (author)

  18. The demography of climate-driven and density-regulated population dynamics in a perennial plant

    DEFF Research Database (Denmark)

    Dahlgren, Johan; Bengstsson, Karin; Ehrlén, Johan

    2016-01-01

    Identifying the internal and external drivers of population dynamics is a key objective in ecology, currently accentuated by the need to forecast the effects of climate change on species distributions and abundances. The interplay between environmental and density effects is one particularly...... important aspect of such forecasts. We examined the simultaneous impact of climate and intraspecific density on vital rates of the dwarf shrub Fumana procumbens over 20 yr, using generalized additive mixed models. We then analyzed effects on population dynamics using integral projection models...... to be driven solely by the environment can overestimate extinction risks if there is density dependence. We conclude that density regulation can dampen effects of climate change on Fumana population size, and discuss the need to quantify density dependence in predictions of population responses...

  19. Using functional-structural plant modeling to explore the response of cotton to mepiquat chloride application and plant population density

    NARCIS (Netherlands)

    Gu, S.; Evers, J.B.; Zhang, L.; Mao, L.; Vos, J.; Li, Z.

    2013-01-01

    The crop growth regulator Mepiquat Chloride (MC) is widely used in cotton production to optimize the canopy structure in order to maximize the yield and fiber quality. Cotton plasticity in relation to MC and other agronomical practice was quantified using a functional-structural plant model of

  20. Drying/rewetting cycles of the soil under alternate partial root-zone drying irrigation reduce carbon and nitrogen retention in the soil-plant systems of potato

    DEFF Research Database (Denmark)

    Sun, Yanqi; Yan, Fei; Liu, Fulai

    2013-01-01

    for five weeks. For each N rate, the PRD and DI plants received a same amount of water, which allowed re-filling one half of the PRD pots close to full water holding capacity. The results showed that plant dry biomass, plant water use, and water use efficiency were increased with increasing N...... retention in the soil–plant systems of potato. Potato plants were grown in 20 L split-root pots with three N-fertilization rates, viz., 1.4 (N1), 2.5 (N2), and 4 (N3) g N pot−1 soil, respectively. At tuber initiation and earlier tuber bulking stages, the plants were subjected to PRD and DI treatment...

  1. Impact of Magnetic Treatment of Irrigation Water on the Growth and Yield of Tomato

    Directory of Open Access Journals (Sweden)

    Kamorudeen Olaniyi YUSUF

    2015-09-01

    Full Text Available This study was carried out to determine whether magnetic treatment of the irrigation water may actually enhance vegetative growth and yield of tomato. Three magnetic flux densities of 124, 319 and 719 G (treatments T1, T2 and T3 were used to treat the water and a control experiment (Tc which was irrigated with non-magnetically treated water was also set up. The magnetic field was produced by an electromagnet that had a variable voltage unit varying the voltage from 4 to 12 V. The tomato were planted in buckets, kept in a transparent garden shed for 130 days and irrigated with magnetically treated water and non-magnetically treated water. A completely randomized design experimental layout was used in this study and each of the three treatments was replicated seven times. The results indicated that tomato crop irrigated with magnetically treated water grew faster than that of the non-magnetically treated water and the stem diameters were bigger than those of control. The heights of tomato plants (T1, T2 T3 and Tc after 47 days were 560.0, 556.4, 588.6 and 469.3 mm respectively. The total yield after 130 days of survey for T1, T2 T3 and Tc were 892.1, 1075.8, 1045.7 and 637.7 g respectively. The percentage increment in yield from the plants treated with magnetically treated water varied from 39.9 to 68.7% compared to the yield from untreated water.

  2. Irrigation water quality as indicator of sustainable rural development

    Directory of Open Access Journals (Sweden)

    Trajković Slaviša

    2004-01-01

    Full Text Available The sustainable rural development more and more depends on the efficient usage of water resources. Most often, at least in one part of the year, the rain is not sufficient for plant growth and rain plant production significantly depends on the yearly precipitation variation. The increase and stability of the agricultural production is possible in the irrigation conditions. The most part (around 70% of the global water resources is used for food production. Irrigation water quality indicator is used to show if the available water resources have the required quality for application in agriculture. Irrigation is characterised by the complex water-plant-soil relationship, and in that eco-system the man as the end user of the irrigated fields occupies a very important place. That explains the difficulties in producing one universal classification of irrigation water quality. The paper analyses numerous water quality classifications from the aspect of the applicability on the quantifying of this indicator. The adopted classification should possess understandable, qualified and internationally comparable indicator. Thus, local classifications (Neigebauer, Miljkovic cannot be used for this indicator. United Nation Food and Agricultural Organization (FAO and US Salinity Laboratory (USSL classifications are used for the evaluation of the irrigation water quality throughout the world. FAO classification gives the complex picture of the usability of the irrigation water from the point of its influence on the soil and the plants. However, the scope of the analyses is not often suited to the needs of that classification, which makes it difficult to apply. The conclusion is that the USSL (US Salinity Laboratory classification is best suited to this range of chemical water analyses. The evaluation of the irrigation water quality indicator in the Juzna Morava river basin, upstream from the Toplica river estuary is given in this paper. Based on the obtained

  3. Weed Control with Cover Crops in Irrigated Potatoes

    Directory of Open Access Journals (Sweden)

    G.H. Mehring

    2016-01-01

    Full Text Available Field experiments at Oakes, ND, USA in 2010 and Carrington, ND, USA in 2011 were conducted to evaluate the potential for cover crops grown in the Northern Great Plains, USA in order to reduce weed emergence and density in irrigated potatoes. Treatments included five cover crop treatments and three cover crop termination treatments. Termination of cover crops was done with glyphosate, disk-till, and roto-till. Cover crop biomass accumulation was greatest for rye/canola and triticale at Oakes, and hairy vetch and hairy vetch/rye at Carrington. Cover crop and termination affected weed control 14, 29, and 51 days after planting (DAP at Oakes. Weed control at Carrington was at least 90% for all cover crop and termination treatments at all three evaluation timings. Marketable yield at Oakes was greater when roto-till was used to terminate the cover crops compared with disk-till or herbicide, which is beneficial for organic systems where herbicides are not used. Marketable yield at Carrington was not affected by cover crop or termination treatments. Results suggest that cover crops can successfully be integrated into irrigated potato production for weed control with yields equal to no cover crop, and with attention to potential mechanical difficulties.

  4. Genetic dissection of maize plant architecture with an ultra-high density bin map based on recombinant inbred lines.

    Science.gov (United States)

    Zhou, Zhiqiang; Zhang, Chaoshu; Zhou, Yu; Hao, Zhuanfang; Wang, Zhenhua; Zeng, Xing; Di, Hong; Li, Mingshun; Zhang, Degui; Yong, Hongjun; Zhang, Shihuang; Weng, Jianfeng; Li, Xinhai

    2016-03-03

    Plant architecture attributes, such as plant height, ear height, and internode number, have played an important role in the historical increases in grain yield, lodging resistance, and biomass in maize (Zea mays L.). Analyzing the genetic basis of variation in plant architecture using high density QTL mapping will be of benefit for the breeding of maize for many traits. However, the low density of molecular markers in existing genetic maps has limited the efficiency and accuracy of QTL mapping. Genotyping by sequencing (GBS) is an improved strategy for addressing a complex genome via next-generation sequencing technology. GBS has been a powerful tool for SNP discovery and high-density genetic map construction. The creation of ultra-high density genetic maps using large populations of advanced recombinant inbred lines (RILs) is an efficient way to identify QTL for complex agronomic traits. A set of 314 RILs derived from inbreds Ye478 and Qi319 were generated and subjected to GBS. A total of 137,699,000 reads with an average of 357,376 reads per individual RIL were generated, which is equivalent to approximately 0.07-fold coverage of the maize B73 RefGen_V3 genome for each individual RIL. A high-density genetic map was constructed using 4183 bin markers (100-Kb intervals with no recombination events). The total genetic distance covered by the linkage map was 1545.65 cM and the average distance between adjacent markers was 0.37 cM with a physical distance of about 0.51 Mb. Our results demonstrated a relatively high degree of collinearity between the genetic map and the B73 reference genome. The quality and accuracy of the bin map for QTL detection was verified by the mapping of a known gene, pericarp color 1 (P1), which controls the color of the cob, with a high LOD value of 80.78 on chromosome 1. Using this high-density bin map, 35 QTL affecting plant architecture, including 14 for plant height, 14 for ear height, and seven for internode number were detected

  5. Effect of nitrogen fertiliser rates and plant density on grain yield of ...

    African Journals Online (AJOL)

    Low soil fertility has constrained maize production in Sidama district in the Southern region of Ethiopia. The effects of four levels of nitrogen fertiliser (0, 46, 92, 138 kg N ha-1) and four plant populations (44000, 53000, 67000 and 89000 plants ha-1) on grain yield of maize were evaluated over four years (1995-98) at Awassa ...

  6. Inhibition of tomato shoot growth by over-irrigation is linked to nitrogen deficiency and ethylene.

    Science.gov (United States)

    Fiebig, Antje; Dodd, Ian C

    2016-01-01

    Although physiological effects of acute flooding have been well studied, chronic effects of suboptimal soil aeration caused by over-irrigation of containerized plants have not, despite its likely commercial significance. By automatically scheduling irrigation according to soil moisture thresholds, effects of over-irrigation on soil properties (oxygen concentration, temperature and moisture), leaf growth, gas exchange, phytohormone [abscisic acid (ABA) and ethylene] relations and nutrient status of tomato (Solanum lycopersicum Mill. cv. Ailsa Craig) were studied. Over-irrigation slowly increased soil moisture and decreased soil oxygen concentration by 4%. Soil temperature was approximately 1°C lower in the over-irrigated substrate. Over-irrigating tomato plants for 2 weeks significantly reduced shoot height (by 25%) and fresh weight and total leaf area (by 60-70%) compared with well-drained plants. Over-irrigation did not alter stomatal conductance, leaf water potential or foliar ABA concentrations, suggesting that growth inhibition was not hydraulically regulated or dependent on stomatal closure or changes in ABA. However, over-irrigation significantly increased foliar ethylene emission. Ethylene seemed to inhibit growth, as the partially ethylene-insensitive genotype Never ripe (Nr) was much less sensitive to over-irrigation than the wild type. Over-irrigation induced significant foliar nitrogen deficiency and daily supplementation of small volumes of 10 mM Ca(NO3 )2 to over-irrigated soil restored foliar nitrogen concentrations, ethylene emission and shoot fresh weight of over-irrigated plants to control levels. Thus reduced nitrogen uptake plays an important role in inhibiting growth of over-irrigated plants, in part by stimulating foliar ethylene emission. © 2015 Scandinavian Plant Physiology Society.

  7. Use of Dehydrated Agar to Estimate Microbial Water Quality for Horticulture Irrigation.

    Science.gov (United States)

    Meador, Dustin P; Fisher, Paul R; Guy, Charles L; Harmon, Philip F; Peres, Natalia A; Teplitski, Max

    2016-07-01

    Petrifilms are dehydrated agar culture plates that have been used to quantify colony forming units (CFU) mL of either aerobic bacteria (Petrifilm-AC) or fungus (Petrifilm-YM), depending on substrate composition. Microbes in irrigation systems can indicate biofilm risk and potential clogging of irrigation emitters. The research objective was to compare counts on Petrifilms versus traditional, hydrated-agar plates using samples collected from recirculated irrigation waters and cultures of isolated known species. The estimated count (in CFU mL) from a recirculated irrigation sample after 7 d of incubation on Petrifilm-YM was only 5.5% of the count quantified using sabouraud dextrose agar (SDA) with chloramphenicol after 14 d. In a separate experiment with a known species, Petrifilm-YM did not successfully culture zoospores of . Isolates of viable zoospores were cultured successfully on potato-dextrose agar (PDA), with comparable counts with a vegetable juice medium supplemented with the antibiotics pimaricin, ampicillin, rifamycin, pentochloronitrobenzene and hymexazol (PARP-H). The quantification of pv. Begoniaceae on Petrifilm-AC was not significantly different ( < 0.05) than on PDA, but was lower than on Reasoner and Goldrich agar (R2A) or with a hemocytometer. The current formulation of Petrifilm-YM is unlikely to be a useful monitoring method for plant pathogens in irrigation water because of the inability to successfully culture oomycetes. However, Petrifilm-AC was an effective method to quantify bacteria and can provide an easy-to-use on-farm tool to monitor biofilm risk and microbial density. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Effects of planting pattern and density on growth indices, yield and yield component of corn (Zea mays in competition with redroot pigweed (Amaranthus retrofelexus(

    Directory of Open Access Journals (Sweden)

    alireza barkhi

    2009-06-01

    Full Text Available An experiment was conducted in 2002-2003 using split-split plot arrangement based on Rondomised Compelete Block Design with three replications at Feiz Abad Agricultural Research Station of Qazvin, in order to study of planting patterns and corn densitis effect in competition with redroot pigweed. Main plots inclouded two planting pattern of corn (P1: single row and P2: double row, sub plots inclouded two corn densities (D1:7 and D2:10 plant/m2 and sub sub plots inclouded 4 weed densities (C1:0, C2:2, C3:6, C4:12 plant/m2. Sampling conducted in 2-weekly intervals and growth indices evaluated. Results indicated that with increasing of weed density CGR, TDW, LAI, number of seeds in row, grain and ear yield decreased but plant height increased. Also LAI, CGR, TDW, number of weed seed and seed,s weight of weed increased. By increasing in corn density LAI, CGR, TDW, ear and grain yield increased, but length and diameter of ear and number of seeds in row decreased. Also LAI and CGR of weed increased, but TDW was decreased. In double row planting pattern just CGR, LAI, TDW of corn were higher significantly than single row planting pattern. But single row planting of weed caused higher LAI, NAR, RGR, CGR and TDW of weed in comparison with double row planting pattern. In 2-way interaction, double row planting pattern and zero densities and 2 weeds/m2 had highest grain yield respectively. There were no significant differences for 3-way interactions but double row planting pattern 10 plant density of corn/m2 zero weed/ m2 had highest grain yield.

  9. Drip irrigation using a PLC based adaptive irrigation system

    OpenAIRE

    Shahidian, S.; Serralheiro, R. P.; Teixeira, J. L.; Santos, F. L.; Oliveira, M. R. G.; Costa, J. L.; Toureiro, C.; Haie, Naim; Machado, R. M.

    2009-01-01

    Most of the water used by man goes to irrigation. A major part of this water is used to irrigate small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. During the growth season crop water needs do not remain constant and varies depending on the canopy, growth stage and climate conditions such as temperature, wind, relative humidity and solar radiation. Thus, it is necessary to find an economic irrigation controller that can adapt the dail...

  10. Pressure and density measurements of selected fluid-bearing zones at the Waste Isolation Pilot Plant (WIPP)

    International Nuclear Information System (INIS)

    Winstanley, D.; Carrasco, R.; Zurkoff, J.

    1986-01-01

    A field effort is presently being conducted at the Waste Isolation Pilot Plant (WIPP) to collect accurate pressure and density information from the Culebra and Magenta dolomite members of the Rustler formation. The spatial variation of fluid density that occurs in these water-bearing units requires the use of numerical models to accurately solve for flow direction and velocity. The groundwater regime is a vital element in possible release scenarios of radionuclide-bearing fluid from the repository. Field tests were conducted on four wells utilizing a testing apparatus composed of two pressure and temperature monitoring systems and a point water sampler. Pressure versus depth plots are linear with a correlation coefficient of 0.999 or greater. Comparison of the calculated density and measured density of water obtained at depth agree within 2 percent of density measurements obtained after continuous pumping of the formation for several days before sampling. The temperature gradients ranged from 0.4 0 to 0.6 0 C per 100 feet. The data presented here are preliminary and serve as developmental information for the detailed operating plan currently under preparation

  11. Impact of shade and cocoa plant densities on soil organic carbon ...

    African Journals Online (AJOL)

    user

    There were no soil organic carbon sequestration in the highest cocoa plant ... It is concluded that cocoa farming could be an effective means to mitigate carbon dioxide ... growth and yield of cocoa at the CRIG substation Bunso (060 13' N,.

  12. [Ecological risks of reclaimed water irrigation: a review].

    Science.gov (United States)

    Chen, Wei-Ping; Zhang, Wei-Ling; Pan, Neng; Jiao, Wen-Tao

    2012-12-01

    Wastewater reclamation and reuse have become an important approach to alleviate the water crisis in China because of its social, economic and ecological benefits. The irrigation on urban green space and farmland is the primary utilization of reclaimed water, which has been practiced world widely. To understand the risk of reclaimed water irrigation, we summarized and reviewed the publications associated with typical pollutants in reclaimed water including salts, nitrogen, heavy metals, emerging pollutants and pathogens, systematically analyzed the ecological risk posed by reclaimed water irrigation regarding plant growth, groundwater quality and public health. Studies showed that salt and salt ions were the major risk sources of reclaimed water irrigation, spreading disease was another potential risk of using reclaimed water, and emerging pollutants was the hot topic in researches of ecological risk. Based on overseas experiences, risk control measures on reclaimed water irrigation in urban green space and farmland were proposed. Five recommendations were given to promote the safe use of reclaimed water irrigation including (1) strengthen long-term in situ monitoring, (2) promote the modeling studies, (3) build up the connections of reclaimed water quality, irrigation management and ecological risk, (4) evaluate the soil bearing capacity of reclaimed water irrigation, (5) and establish risk management system of reclaimed water reuse.

  13. Effects of host plant and larval density on intraspecific competition in larvae of the emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Duan, Jian J; Larson, Kristi; Watt, Tim; Gould, Juli; Lelito, Jonathan P

    2013-12-01

    Competition for food, mates, and space among different individuals of the same insect species can affect density-dependent regulation of insect abundance or population dynamics. The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of North American ash (Fraxinus spp.) trees, with its larvae feeding in serpentine galleries between the interface of sapwood and phloem tissues of ash trees. Using artificial infestation of freshly cut logs of green ash (Fraxinus pennsylvanica Marshall) and tropical ash (Fraxinus uhdei [Wenzig] Lingelsh) with a series of egg densities, we evaluated the mechanism and outcome of intraspecific competition in larvae of A. planipennis in relation to larval density and host plant species. Results from our study showed that as the egg densities on each log (1.5-6.5 cm in diameter and 22-25 cm in length) increased from 200 to 1,600 eggs per square meter of surface area, larval survivorship declined from ≍68 to 10% for the green ash logs, and 86 to 55% for tropical ash logs. Accordingly, larval mortality resulting from cannibalism, starvation, or both, significantly increased as egg density increased, and the biomass of surviving larvae significantly decreased on both ash species. When larval density was adjusted to the same level, however, larval mortality from intraspecific competition was significantly higher and mean biomasses of surviving larvae was significantly lower in green ash than in tropical ash. The role of intraspecific competition of A. planipennis larvae in density-dependent regulation of its natural population dynamics is discussed.

  14. Effect of Varieties and Plant Population Densities on Dry Matter Production, Radiation Interception and Radiation Energy Conversion in Peanut

    Directory of Open Access Journals (Sweden)

    agus suprapto

    2012-05-01

    Full Text Available The solar radiation is one of the major criteria to obtaining advantages on peanuts (Arachishypogaea L.. Although various combinations of crops have been reported, but variety association and plant population densities (PPD during the periodically stage of growth on peanuts have yet to be analyzed. Dry matter production (DM, radiation energy interception, and radiation energy conversions were monitored over the growth period of two varieties of peanut. An experiment was conducted in Jambegede Research Farm, Indonesian Legume and Tuber Crops Research Institute, Malang, East Java, Indonesia, from July until October 2011. The experiment was arranged in a Split Plot Design with three replications. Peanut varieties, as the main plot consisted of two treatments: Kelinci andKancil variety. In addition, five PPD variations as sub plot consisted of 8.1, 11.1, 16.0, 25.0 and 44.4 plant m-2 were arranged in a square spacing. The results showed that DM production from high PPD increased gradually to lower PPD in all varieties. Interception efficiency (IE increased in all varieties from early sowing. A plant population density of 25.0 m-2 and 44.4 plants m-2 intercepted more radiation over 11.1 or 16.0 plants m-2. Conversion efficiency of radiation energy (CE to total dry matter production on Kelinci variety (1.52% indicated a slight higher percentage than on Kancil variety (1.41%. Moreover, the CE and IE values indicated a decrease as the PPD increased on maximum DM.

  15. An assessment of colostomy irrigation.

    Science.gov (United States)

    Laucks, S S; Mazier, W P; Milsom, J W; Buffin, S E; Anderson, J M; Warwick, M K; Surrell, J A

    1988-04-01

    One hundred patients with permanent sigmoid colostomies were surveyed to determine their satisfaction and success with the "irrigation" technique of colostomy management. Most patients who irrigate their colostomies achieve continence. Odors and skin irritation are minimized. The irrigation method is economical, time efficient, and allows a reasonably liberal diet. It avoids bulky appliances and is safe. In appropriately selected patients, the irrigation technique is the method of choice for management of an end-sigmoid colostomy.

  16. Expanding the Annual Irrigation Maps (AIM) Product to the entire High Plains Aquifer (HPA): Addressing the Challenges of Cotton and Deficit-Irrigated Fields

    Science.gov (United States)

    Rapp, J. R.; Deines, J. M.; Kendall, A. D.; Hyndman, D. W.

    2017-12-01

    The High Plains Aquifer (HPA) is the most extensively irrigated aquifer in the continental United States and is the largest major aquifer in North America with an area of 500,000 km2. Increased demand for agricultural products has led to expanded irrigation extent, but brought with it declining groundwater levels that have made irrigation unsustainable in some locations. Understanding these irrigation dynamics and mapping irrigated areas through time are essential for future sustainable agricultural practices and hydrological modeling. Map products using remote sensing have only recently been able to track annual dynamics at relatively high spatial resolution (30 m) for a large portion of the northern HPA. However follow-on efforts to expand these maps to the entire HPA have met with difficulty due to the challenge of distinguishing irrigation in crop types that are commonly deficit- or partially-irrigated. Expanding these maps to the full HPA requires addressing unique features of partially irrigated fields and irrigated cotton, a major water user in the southern HPA. Working in Google Earth Engine, we used all available Landsat imagery to generate annual time series of vegetation indices. We combined this information with climate covariables, planting dates, and crop specific training data to algorithmically separate fully irrigated, partially irrigated, and non-irrigated field locations. The classification scheme was then applied to produce annual maps of irrigation across the entire HPA. The extensive use of ancillary data and the "greenness" time series for the algorithmic classification generally increased accuracy relative to previous efforts. High-accuracy, representative map products of irrigation extent capable of detecting crop type and irrigation intensity within aquifers will be an essential tool to monitor the sustainability of global aquifers and to provide a scientific bases for political and economic decisions affecting those aquifers.

  17. Effect of Irrigation Regimes on Yield of Two Commercial Varieties of Pomegranate in the Climatic Condition in Yazd

    Directory of Open Access Journals (Sweden)

    ali bafkar

    2017-02-01

    Full Text Available Introduction: The maximum water efficiency and water productivity of the agricultural sector is one of the most important and effective ways to deal with the water crisis and mitigate the effects of drought. Therefore, scientific and practical agricultural water productivity in terms of planning and development must be followed. Local or drip irrigation systems supply some of the moist around the roots and the plant uses the moisture in the soil. Irrigation systems and irrigation scheduling affect water uptake by plants. Matrials and Methods: In order to evaluate the effect of irrigation on the yield of 4-year-old pomegranate trees with local irrigation system (Bubbler in sandy loam soil with bulk density 1.15 grams per cubic centimeter a research was performed in Agriculture and Natural Resources Research Center of Yazd province with an altitude of 1230 meters . The region has an arid climate with 51 mm average annual rainfall and average annual temperature of 20 ° C, which is located 10 kilometers from the center of the city of Yazd. This project was designed in a factorial experiment with a randomized complete block with three irrigation regimes I1, I2, I3, including irrigation (FC100%, 25% of deficit irrigation (FC75% and 50 percent deficit irrigation (FC50% on two commercial cultivars of pomegranates, which have been growing at 3 × 4 with three replications. To prevent penetration of water per tree, plots adjacent to each block strip (three meters between rows and between plants within one and a half meters without irrigation tape were used as a guard. Trees around the pool shaped a rectangular building with a flow rate of 96 liters per hour for each tree using Bubbler system. The use of such a system with high flow rate, suitability and cost of such a system in orchards and vineyards, water supply reduces energy consumption in a tree in a short time. To prevent clogging of the filter, disc dropper was used at the beginning of the project

  18. Biological soil attributes in oilseed crops irrigated with oilfield produced water in the semi-arid region

    Directory of Open Access Journals (Sweden)

    Ana Clarice Melo Azevedo de Meneses

    Full Text Available ABSTRACT Wastewater from oil is the main residue of the oil industry. Studies have shown that wastewater, or produced water, can be treated and used as an alternative source for the irrigation of oilseed crops. The aim of this work was to evaluate the effect of treated produced water on the biological properties of soil cultivated with the castor bean cv. BRS Energy and the sunflower cv. BRS 321 respectively, for two and three successive cycles of grain production. The first cycle in the sunflower and castor bean corresponds to the dry season and the second cycle to the rainy season. The third crop cycle in the sunflower relates to the dry season. The research was carried out from August 2012 to October 2013, in the town of Aracati, in the State of Ceará (Brazil, where both crops were submitted to irrigation with filtered produced water (FPW, produced water treated by reverse osmosis (OPW, or groundwater water from the Açu aquifer (ACW, and to no irrigation (RFD. The treatments, with three replications, were evaluated during the periods of pre-cultivation and plant reproduction for soil respiration (Rs, total organic carbon (TOC and the population density of bacteria (Bact and filamentous fungi (Fung in the soil. In the sunflower crop, these soil attributes are sensitive to the irrigation water used. Irrigation of the castor bean affects soil respiration. Under the conditions of this study, irrigation with FPW may be a short-term alternative in the castor bean and sunflower crops.

  19. Germination and initial growth of guava plants irrigated with saline water Germinação de sementes e crescimento inicial da goiabeira irrigada com água salina

    Directory of Open Access Journals (Sweden)

    Lourival F. Cavalcante

    2005-12-01

    Full Text Available The present study was carried in order to evaluate the effect of saline water irrigation with electrical conductivity (ECw of 0.5; 1.5; 3.0; 4.5 and 6.0 dS m-1, on germination and some growth variables during the seedling formation process of four guava cultivars (Psidium guajava L.: Pentecoste, Paluma, Surubim and IPA B-38. Water salinity inhibited the germination process, plant height, stem diameter, leaf area and dry matter production of roots, stems and leaves, independently of cultivar. After germination, the seedlings did not survive due to saline water effects of ECw 4.5 and 6.0 dS m-1. After 180 days of sowing, the seedlings irrigated with ECw more than 1.5 dS m-1 did not present agronomic quality for planting. Dry matter production sequence of different parts of plants was as follows: leaves > roots > stems, without significant differences among cultivars especially when irrigated with saline water of ECw > 3.0 dS m-1.Avaliou-se o efeito da salinidade da água de irrigação, através dos níveis de condutividade elétrica (CEa de 0,5; 1,5; 3,0; 4,5 e 6,0 dS m-1, sobre a germinação de sementes e algumas variáveis de crescimento, durante a formação de mudas de quatro cultivares de goiabeira (Psidium guajava L. Pentecoste, Paluma, Surubim e IPA B-38. A salinidade da água inibiu a germinação, o crescimento em altura, diâmetro do caule, área foliar e fitomassa das raízes, caules e folhas das plantas, independente da cultivar. Após a germinação, as plântulas não sobreviveram aos efeitos salinos das águas de condutividade elétrica CEa 4,5 e 6,0 dS m-1. Ao final do ensaio, 180 dias após a semeadura, não se obtiveram mudas com qualidade agronômica nos tratamentos irrigados com água de salinidade superior a 1,5 dS m-1. A ordem de produção de matéria seca pelos distintos órgãos das plantas, foi: folhas > raízes > caules, mas sem diferir entre cultivares, principalmente quando irrigadas com água de maior salinidade > 3

  20. Condutância estomática em folhas de feijoeiro submetido a diferentes regimes de irrigação Stomatal conductance in leaves of bean plants submitted to different irrigation regimes

    Directory of Open Access Journals (Sweden)

    Auricleia S. Paiva

    2005-04-01

    Full Text Available O controle estomático é importante propriedade fisiológica por meio da qual as plantas limitam a perda de água, ocasionando reduções na condutância estomática e, geralmente, reduzindo as trocas gasosas como forma de resposta das plantas a diversos fatores, incluindo o estresse hídrico. O objetivo deste trabalho foi determinar a condutância estomática em folhas de feijoeiro submetido a diferentes regimes de irrigação. O experimento foi conduzido no Departamento de Engenharia Rural da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal - SP. As irrigações nos tratamentos foram determinadas em função do esgotamento de água no solo: T1 - irrigado quando esse atingiu 40% da capacidade de água disponível (CAD; T2 - quando atingiu 60% da CAD; T3 - quando atingiu 80% da CAD, e T4 - não irrigado (irrigado somente para favorecer a emergência das plântulas. As medições de condutância estomática foram realizadas diariamente no campo, nas duas faces da folha, utilizando-se de um porômetro. Em todos os tratamentos, em diversas medições, foi observada redução da condutância estomática em resposta a baixos valores de potencial mátrico e a altos valores de déficit de pressão de vapor e vice-versa. As folhas das plantas do tratamento T4, que foram submetidas a menor disponibilidade hídrica no solo, apresentaram os menores valores de condutância estomática durante os estádios do florescimento e enchimento de grãos.Stomatal control is an important physiological process for plants to reduce water loss. It causes reduction in stomatal conductance and generally in gas exchanges, as a response of several factors including water stress. The objective of this study was to determine the stomatal conductance of bean leaves submitted to different irrigation regimes. Field experiment was conducted at the São Paulo State University, in Jaboticabal, Brazil. Irrigation of the treatments occurred when available water

  1. [Optimal irrigation index for cotton drip irrigation under film mulching based on the evaporation from pan with constant water level].

    Science.gov (United States)

    Shen, Xiao-Jun; Zhang, Ji-Yang; Sun, Jing-Sheng; Gao, Yang; Li, Ming-Si; Liu, Hao; Yang, Gui-Sen

    2013-11-01

    A field experiment with two irrigation cycles and two irrigating water quotas at squaring stage and blossoming-boll forming stage was conducted in Urumqi of Xinjiang Autonomous Region, Northwest China in 2008-2009, aimed to explore the high-efficient irrigation index of cotton drip irrigation under film mulching. The effects of different water treatments on the seed yield, water consumption, and water use efficiency (WUE) of cotton were analyzed. In all treatments, there was a high correlation between the cotton water use and the evaporation from pan installed above the plant canopy. In high-yield cotton field (including the treatment T4 which had 10 days and 7 days of irrigation cycle with 30.0 mm and 37.5 mm of irrigating water quota at squaring stage and blossoming-boll forming stage, respectively in 2008, and the treatment T1 having 7 days of irrigation cycle with 22.5 mm and 37.5 mm of irrigating water quota at squaring stage and blossoming-boll forming stage, respectively in 2009), the pan-crop coefficient (Kp) at seedling stage, squaring stage, blossoming-boll forming stage, and boll opening stage was 0.29-0.30, 0.52-0.53, 0.74-0.88, and 0.19-0.20, respectively. As compared with the other treatments, T4 had the highest seed cotton yield (5060 kg x hm(-2)) and the highest WUE (1.00 kg x m(-3)) in 2008, whereas T1 had the highest seed cotton yield (4467 kg x hm(-2)) and the highest WUE (0.99 kg x m(-3)) in 2009. The averaged cumulative pan evaporation in 7 days and 10 days at squaring stage was 40-50 mm and 60-70 mm, respectively, and that in 7 days at blossoming-boll forming stage was 40-50 mm. It was suggested that in Xinjiang cotton area, irrigating 45 mm water for seedling emergence, no irrigation both at seedling stage and at boll opening stage, and irrigation was started when the pan evaporation reached 45-65 mm and 45 mm at squaring stage and blossoming-boll stage, respectively, the irrigating water quota could be determined by multiplying cumulative

  2. Tillering dynamics of Tanzania guinea grass under nitrogen levels and plant densities - doi: 10.4025/actascianimsci.v34i4.13382

    Directory of Open Access Journals (Sweden)

    Manoel Eduardo Rozalino Santos

    2012-10-01

    Full Text Available This study evaluated the influence of nitrogen levels (N and plant density (D on the tillering dynamics of Tanzania guinea grass (Panicum maximum Jacq.. Treatments were arranged in a completely randomized block design with 12 treatments and two replicates in a factorial scheme (4 × 3 with four levels of N (0, 80, 160 or 320 kg ha-1 N and three plant densities (9, 25, and 49 plant m-². Higher number of tillers was observed in the treatment with 9 plants m-² and under higher levels of N, especially in the second and third generations. Still, the N influenced quadratically the appearance rate of basal and total tillers, which were also affected by plant density and interaction N × D. However, the appearance rate of aerial tiller was not influenced by factors evaluated. The mortality rate of total tiller was influenced quadratically by the nitrogen levels and plant densities. The mortality rate of basal tiller responded quadratically to plant density, whereas the mortality rate of aerial tiller increased linearly with fertilization. Pastures with low or intermediate densities fertilized with nitrogen, presented a more intense pattern of tiller renewal.

  3. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    International Nuclear Information System (INIS)

    Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

    2016-01-01

    Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  4. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

    2016-07-01

    Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  5. Effects of Cycocel and Nitrogen Application on Yield and Yield Components of Autumn-Grown Oilseed Rape at Different Plant Densities

    Directory of Open Access Journals (Sweden)

    S. Majd

    2013-06-01

    Full Text Available In this research, which was carried out as two experiments (in the field and greenhouse at Research Farm of College of Agriculture, Shiraz University, Shiraz, Iran, in 2009-2010 growing season, the effects of different levels of nitrogen, plant density and cycocel application on yield and yield components of autumn-grown oilseed rape (Talaye cultivar were investigated. The field experiment was designed as split-split plot based on completely randomized blocks design. Treatments included nitrogen level (80, 140, 200 and 260 kg/ha as the main plot, plant density (70 and 90 plants/m2 as sub-plot and cycocel rate (0, 1.4 and 2.8 L/ha as sub- subplot. The greenhouse experiment, which was arranged as a factorial based on complete randomized design, included nitrogen level (0, 50, 100, 150 and 200 kg/ha and cycocel rate (0, 1.4 and 2.8 L/ha. Results showed that the highest seed yield was achieved at 200 kg N/ha, 2.8 L/ha cycocel and plant density of 90 plants/m2 (533.17, 533.96 and 521.6 g/m2, respectively. Application of 2.8 L/ha cycocel was associated with increased number of siliques per plant and final plants dry weight. Increasing plant density from 70 to 90 plants/m2 was associated with decreased number of siliques per plant, plant dry weight and number of seeds per silique. It appears that application of 200 kg N/ha, 2.8 L/ha cycocel and plant density of 90 plants/m2 could be recommended for maximum grain yield of autumn-grown rapeseed cv. Talaye, in agroclimatic conditions similar to this research

  6. The long-term resistance mechanisms, critical irrigation threshold and relief capacity shown by Eugenia myrtifolia plants in response to saline reclaimed water

    DEFF Research Database (Denmark)

    Acosta-Motos, José Ramón; Hernández, José Antonio; Álvarez, Sara

    2017-01-01

    water potential, the relative water content of leaves, leaf stomatal conductance, the leaf photosynthetic rate, water-use efficiency and accumulated evapotranspiration in order to limit water loss; and 4) changes in the antioxidant defence mechanisms. These different responses induced oxidative stress...... to different electric conductivities of the treatments. Based on these premises, we studied the long-term effect of three reclaimed water treatments with different saline concentrations on Eugenia myrtifolia plants. We also looked at the ability of these plants to recover when no drainage was applied. The RW...... with the highest electric conductivity (RW3, EC = 6.96 dS m(-1)) provoked a number of responses to salinity in these plants, including: 1) accumulation and extrusion of phytotoxic ions in roots; 2) a decrease in the shoot/root ratio, leaf area, number of leaves; 3) a decrease in root hydraulic conductivity, leaf...

  7. Growth and yield response to plant density of water leaf ( Talinum ...

    African Journals Online (AJOL)

    The effects of different planting spaces (15cm x 15cm, 20cm x 20cm, 25cm x 25cm and 30cm x 30cm) on the growth and yield of Talinum triangulare (Water leaf) were investigated in two cropping seasons from 2012 to 2013 (rainy and dry seasons) at University of Port Harcourt Teaching and Research farm, Port Harcourt, ...

  8. Trait- and density-mediated indirect interactions initiated by an exotic invasive plant autogenic ecosystem engineer

    Science.gov (United States)

    Dean E. Pearson

    2010-01-01

    Indirect interactions are important for structuring ecological systems. However, research on indirect effects has been heavily biased toward top-down trophic interactions, and less is known about other indirect-interaction pathways. As autogenic ecosystem engineers, plants can serve as initiators of nontrophic indirect interactions that, like top-down pathways, can...

  9. Relationship between Water and Carbon Utilization under Different Straw Mulching and Plant Density of Summer Maize in North China Plain

    Science.gov (United States)

    Liu, Quanru; Du, Shoujian; Yin, Honglian; Wang, Juan

    2018-03-01

    To explore the relationship between water and carbon utilization and key factors to keep high water use efficiency (WUE), a 2-yr experiment was conduct by covering 0 and 0.6 kg m-2 straw to the surface of soil with plant densities of 1.0 × 105, 7.5 × 104, and 5.5 × 104 plants ha-1 in North China Plain during summer maize growing seasons of the 2012 and 2013. Results showed that straw mulching not only increased grain yield (GY), WUE, and carbon efficient ratio (CER) but also inhibited CO2 emission significantly. WUE positively correlated with CER, GY and negative correlated with evapotranspiration (ET) and CO2 emission. CER had the larger direct effect on WUE compared with ET and CO2 emission. The results indicate that straw mulching management in summer maize growing seasons could make sense for inhibiting CO2 emission.

  10. Effect of Superabsorbent Application under Different Irrigation Regimes on Photosynthetic Pigments in Cuminum cyminum and its Relation with Seed and Essential Oil Yield

    Directory of Open Access Journals (Sweden)

    A. Pirzad

    2016-02-01

    Full Text Available Introduction: Cumin, sometimes spelled cummin (Cuminum cyminum L.; Apiaceae, also known as Zeera is native from the East Mediterranean to India. Its seeds are used in the cuisines of many different cultures, and it is also used as a medicinal plant, serving as a digestant, as well as being used to treat anemia and the common cold. Cumin is a drought tolerant plant, has a short growth season of 100 – 120 days, with optimum growth temperature ranges between 25°C and 30 °C. Drought is one of the most important environmental factors that influences seed yield of crop plants in arid and semi-arid regions,through physiological response of plant. To reduce drought stress damages, some synthetic materials like hydroplus superabsorbent polymers, highly hydrophilic due to low cross-links in their structure, can be used to save soil moisture. Thus, superabsorbent polymer may have great potential in restoration and reclamation of soil and storing water available for plant growth and production. Materials and Methods: To evaluate accumulation of photosynthetic pigments and seed yield of cumin, a factorial experiment was conducted based on randomized complete blocks design with three replications at the Research Farm of Urmia University (latitude 37.53° N, 45.08° E, and 1320 m above sea level.- The soil texture of experimental site was clay loam (28% silt, 32% clay, 40% sand with 22.5% field capacity, 1.54 g/cm3 soil density, and pH 7.6. Treatments were four irrigation regimes (irrigation after 50, 100, 150 and 200 mm of evaporation from class A pan and different amounts of superabsorbent polymer (0, 60, 120, 180, 240 and 300 kg/ha. To measure the chlorophyll content (Chlorophyll a, b, and total chlorophyll, 0.25 g of grounded leaves were adjusted to 25 ml by distilled water, and 0.5 ml of this solute was mixed with 4.5 ml acetone 80%. The upper zone of centrifuged solution was taken for spectrophotometery at 645nm and 663 nm wavelengths. To measure the

  11. Influence of greenhouse climate and plant density on external quality of chrysanthemum (Dendranthema grandiflorum (Ramat.)Kitamura) : First steps towards a quality model

    NARCIS (Netherlands)

    Carvalho, S.M.P.; Heuvelink, E.

    2001-01-01

    The effects of greenhouse climate and plant density on external quality of chrysanthemum (Dendranthema grandiflorum syn. Chrysanthemum morifolium) are reviewed. The external quality aspects analysed in this paper are stem morphology (length, diameter and "strength"), leaf morphology (number and

  12. Plant lighting system with five wavelength-band light-emitting diodes providing photon flux density and mixing ratio control

    Directory of Open Access Journals (Sweden)

    Yano Akira

    2012-11-01

    Full Text Available Abstract Background Plant growth and development depend on the availability of light. Lighting systems therefore play crucial roles in plant studies. Recent advancements of light-emitting diode (LED technologies provide abundant opportunities to study various plant light responses. The LED merits include solidity, longevity, small element volume, radiant flux controllability, and monochromaticity. To apply these merits in plant light response studies, a lighting system must provide precisely controlled light spectra that are useful for inducing various plant responses. Results We have developed a plant lighting system that irradiated a 0.18 m2 area with a highly uniform distribution of photon flux density (PFD. The average photosynthetic PFD (PPFD in the irradiated area was 438 micro-mol m–2 s–1 (coefficient of variation 9.6%, which is appropriate for growing leafy vegetables. The irradiated light includes violet, blue, orange-red, red, and far-red wavelength bands created by LEDs of five types. The PFD and mixing ratio of the five wavelength-band lights are controllable using a computer and drive circuits. The phototropic response of oat coleoptiles was investigated to evaluate plant sensitivity to the light control quality of the lighting system. Oat coleoptiles irradiated for 23 h with a uniformly distributed spectral PFD (SPFD of 1 micro-mol m–2 s–1 nm–1 at every peak wavelength (405, 460, 630, 660, and 735 nm grew almost straight upwards. When they were irradiated with an SPFD gradient of blue light (460 nm peak wavelength, the coleoptiles showed a phototropic curvature in the direction of the greater SPFD of blue light. The greater SPFD gradient induced the greater curvature of coleoptiles. The relation between the phototropic curvature (deg and the blue-light SPFD gradient (micro-mol m–2 s–1 nm–1 m–1 was 2 deg per 1 micro-mol m–2 s–1 nm–1 m–1. Conclusions The plant lighting system, with a computer with a

  13. New Approaches to Irrigation Scheduling of Vegetables

    Directory of Open Access Journals (Sweden)

    Michael D. Cahn

    2017-04-01

    Full Text Available Using evapotranspiration (ET data for scheduling irrigations on vegetable farms is challenging due to imprecise crop coefficients, time consuming computations, and the need to simultaneously manage many fields. Meanwhile, the adoption of soil moisture monitoring in vegetables has historically been limited by sensor accuracy and cost, as well as labor required for installation, removal, and collection of readings. With recent improvements in sensor technology, public weather-station networks, satellite and aerial imaging, wireless communications, and cloud computing, many of the difficulties in using ET data and soil moisture sensors for irrigation scheduling of vegetables can now be addressed. Web and smartphone applications have been developed that automate many of the calculations involved in ET-based irrigation scheduling. Soil moisture sensor data can be collected through wireless networks and accessed using web browser or smartphone apps. Energy balance methods of crop ET estimation, such as eddy covariance and Bowen ratio, provide research options for further developing and evaluating crop coefficient guidelines of vegetables, while recent advancements in surface renewal instrumentation have led to a relatively low-cost tool for monitoring crop water requirement in commercial farms. Remote sensing of crops using satellite, manned aircraft, and UAV platforms may also provide useful tools for vegetable growers to evaluate crop development, plant stress, water consumption, and irrigation system performance.

  14. Fate of plant protection products in soilless cultivations after drip irrigation: measured vs. modelled concentrations : Interpretation of the 2014 experiment with the Substance Emission Model

    NARCIS (Netherlands)

    van der Linden AMA; Hoogsteen MJJ; Boesten JJTA; van Os EA; Wipfler EL; MIL; LGW

    2017-01-01

    The Greenhouse Emission Model has recently been adopted as a model package for assessing emissions to and concentrations in groundwater and surface water after use of plant protection products in greenhouse crops. Stakeholders advised that the model be tested against experimental data. In

  15. Density of phonon states in the light-harvesting complex II of green plants

    CERN Document Server

    Pieper, J K; Irrgang, K D; Renger, G

    2002-01-01

    In photosynthetic antenna complexes, the coupling of electronic transitions to low-frequency vibrations of the protein matrix (phonons) plays an essential role in light absorption and ultra-fast excitation energy transfer (EET). The model calculations presented here indicate that inelastic neutron scattering experiments provide invaluable information on the phonon density of states for light-harvesting complex II, which may permit a consistent interpretation of contradictory results from high-resolution optical spectroscopy. (orig.)

  16. Performance of Salix viminalis and Populus nigra x Populus maximowiczii in short rotation intensive culture under high irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Fillion, Maud; Brisson, Jacques [Departement de Sciences biologiques, Universite de Montreal, C.P. 6128, succ. Centre-ville, Montreal, Quebec (Canada); Institut de recherche en biologie vegetale, 4101 Sherbrooke East, Montreal, Quebec (Canada); Teodorescu, Traian I.; Labrecque, Michel [Institut de recherche en biologie vegetale, 4101 Sherbrooke East, Montreal, Quebec (Canada); Sauve, Sebastien [Departement de chimie, Universite de Montreal, C.P. 6128, succursale Centre-ville, Montreal, Quebec (Canada)

    2009-09-15

    On a plantation established in 2004 from stem cuttings at a density of 20,000 trees per hectare, we investigated growth and nutritional plant response to a high hydraulic regime for two species (Salix viminalis and Populus nigra x Populus maximowiczii), using a comparative approach with measurements from irrigated and control plots. The plantation was irrigated from June to September 2005 with about 140 mm per day. The equivalent of 120 Kg NO{sub 3}-N, 40 Kg P{sub 2}O{sub 5}-P and 85 Kg K{sub 2}O-K per hectare per year was applied by means of irrigation with wastewater. No mortality occurred and stem biomass production of both poplar and willow species were not statistically different on irrigated and control areas. However, S. viminalis revealed to be more tolerant to flooded conditions since these corresponded more closely to its nutritional requirements (foliar concentration of 20 mgN g{sup -1}). The capacity of S. viminalis to withstand waterlogged conditions could play an important role in the sustainability of a plantation for the filtration of effluent at low pollutant concentration. (author)

  17. Practical salinity management for leachate irrigation to poplar trees.

    Science.gov (United States)

    Smesrud, Jason K; Duvendack, George D; Obereiner, James M; Jordahl, James L; Madison, Mark F

    2012-01-01

    Landfill leachate can be beneficially reused for irrigation of fiber crops with appropriate attention to nutrient and salinity management. The Riverbend Landfill in Western Oregon has been effectively practicing irrigation of landfill leachate to poplar trees since 1993. Over that time, the site has been adaptively managed to control salinity impacts to the tree crop while beneficially utilizing the applied water and nutrients during each growing season. Representative leachate irrigation water has ranged in concentration of total dissolved solids from 777 to 6,940 mg/L, chloride from 180 to 1,760 mg/L and boron from 3.2 to 7.3 mg/L. Annual leachate irrigation applications have also ranged between 102 and 812 mm/yr. Important conclusions from this site have included: 1) Appropriate tree clone selection and tree stand spacing, thinning, and harvest rotations are critical to maintaining a productive tree stand that is resilient and resistant to salt stress. The most effective combinations have included clones DN-34, OP-367, 184-411, 49-177, and 15-29 planted at spacing of 3.7-m x 1.8-m to 3.7-m x 3.7-m; 2) Leaf tissue boron levels are closely correlated to soil boron levels and can be managed with leaching. When leaf tissue boron levels exceed 200 to 250 mg/kg, signs of salt stress may emerge and should be monitored closely; 3) Salinity from leachate irrigation can be managed to sustain a healthy tree crop by controlling mass loading rates and providing appropriate irrigation blending if necessary. Providing freshwater irrigation following each leachate irrigation and targeting freshwater irrigation as 30 percent of total irrigation water applied has successfully controlled salt impacts to vegetation; and 4) Drip irrigation generally requires more careful attention to long-term soil salinity management than spray irrigation. Moving drip irrigation tubes periodically to prevent the formation of highly saline zones within the soil profile is important. In this paper, a

  18. Visitantes florais de plantas invasoras de áreas com fruteiras irrigadas Floral visitors of weed plants of irrigated orchard areas

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Piedade Kiill

    2000-09-01

    Full Text Available As plantas invasoras afetam a produtividade das fruteiras irrigadas, sendo necessários estudos sobre sua ecologia, principalmente formas de reprodução e associação com insetos. O presente trabalho foi desenvolvido em Petrolina-PE, objetivando classificar os visitantes florais de plantas invasoras em polinizadores e pilhadores, de acordo com o comportamento apresentado. As observações foram feitas de maio a outubro de 1998, em 26 dias não consecutivos, no intervalo das 7h00 às 16h00. As invasoras foram classificadas em nectaríferas e poliníferas, quando visitadas para retirada exclusiva de néctar ou de pólen; e em mistas, quando visitadas para retirada dos dois recursos. Para a análise de freqüência foi adotado um sistema de notas: a- número de visitas >30, b- entre 10 e 30 e c- Weeds can impair yield of irrigated fruit crops, studies about their ecology being needed, especially ways of reproduction and association with insects. This work was carried out in Petrolina, PE, Brazil with the objective of identifying the floral visitors of weeds, and classifying them as pollinators and pollen and/or nectar thieves, according to their behavior. The observations were made between May and October of 1998, in 26 not consecutive days, between 7:00 am and 4:00 pm. The weeds were classified in nectariferous and polliniferous when these were visited exclusively for collection of nectar or pollen, and mixed when these were visited to collect both. A grade system was adopted for the frequency evaluation: a- number of visits >30, b - between 10 to 30, c - <10. Among the 24 weeds observed, 14 were classified as nectariferous, six as polliniferous and four were considered mixed. Among the floral visitors, the following bees were registered (Xylocopa grisescens, X. frontalis, Centris aff. perforator, Ptilotrix aff. plumata, Diadasina riparia, Apis mellifera, Trigona spinipes, Eulaema nigrita, butterflies (Ascia monuste, Papilio thoas brasiliensis

  19. Regulation of Population Densities of Heterodera cajani and Other Plant-Parasitic Nematodes by Crop Rotations on Vertisols, in Semi-Arid Tropical Production Systems in India

    Science.gov (United States)

    Sharma, S. B.; Rego, T. J.; Mohiuddin, M.; Rao, V. N.

    1996-01-01

    The significance of double crop (intercrop and sequential crop), single crop (rainy season crop fallow from June to September), and rotations on densities of Heterodera cajani, Helicotylenchus retusus, and Rotylenchulus reniformis was studied on Vertisol (Typic Pellusterts) between 1987 and 1993. Cowpea (Vigna sinensis), mungbean (Phaseolus aureus), and pigeonpea (Cajanus cajan) greatly increased the population densities of H. cajani and suppressed the population densities of other plant-parasitic nematodes. Mean population densities of H. cajani were about 8 times lower in single crop systems than in double crop systems, with pigeonpea as a component intercrop. Plots planted to sorghum, safflower, and chickpea in the preceding year contained fewer H. cajani eggs and juveniles than did plots previously planted to pigeonpea, cowpea, or mungbean. Continuous cropping of sorghum in the rainy season and safflower in the post-rainy season markedly reduced the population density of H. cajani. Sorghum, safflower, and chickpea favored increased population densities of H. retusus. Adding cowpea to the system resulted in a significant increase in the densities of R. reniformis. Mean densities of total plant-parasitic nematodes were three times greater in double crop systems, with pigeonpea as a component intercrop than in single crop systems with rainy season fallow component. Cropping systems had a regulatory effect on the nematode populations and could be an effective nematode management tactic. Intercropping of sorghum with H. cajani tolerant pigeonpea could be effective in increasing the productivity of traditional production systems in H. cajani infested regions. PMID:19277141

  20. Clay pot irrigation for tomato (Lycopersicon esculentum Mill production in the north east semiarid region of Ethiopia

    Directory of Open Access Journals (Sweden)

    Kebede Woldetsadik

    2011-06-01

    Full Text Available Water shortage is one of the major constraints for production of horticultural crops in arid and semiarid regions. A field experiment was conducted to determine irrigation water and fertilizer use efficiency, growth and yield of tomato under clay pot irrigation at the experimental site of Sekota Dryland Agricultural Research Center, Lalibela, Ethiopia in 2009/10. The experiment comprised of five treatments including furrow irrigated control and clay pot irrigation with different plant population and fertilization methods, which were arranged in Randomized Complete Block Design with three replications. The highest total and marketable fruit yields were obtained from clay pot irrigation combined with application of nitrogen fertilizer with irrigation water irrespective of difference in plant population. The clay pot irrigation had seasonal water use of up to 143.71 mm, which resulted in significantly higher water use efficiency (33.62 kg m-3 as compared to the furrow irrigation, which had a seasonal water use of 485.50 mm, and a water use efficiency of 6.67 kg m-3. Application of nitrogen fertilizer with irrigation water in clay pots improved fertilizer use efficiency of tomato by up to 52% than band application with furrow or clay pot irrigation. Thus, clay pot irrigation with 33,333 plants ha-1 and nitrogen fertilizer application with irrigation water in clay pots was the best method for increasing the yield of tomato while economizing the use of water and nitrogen fertilizer in a semiarid environment.

  1. Evaluation of the toxic effects of four anti-cancer drugs in plant bioassays and its potency for screening in the context of waste water reuse for irrigation.

    Science.gov (United States)

    Lutterbeck, Carlos Alexandre; Kern, Deivid Ismael; Machado, Ênio Leandro; Kümmerer, Klaus

    2015-09-01

    Anti-cancer drugs are compounds that are of high environmental relevance because of their lack of specific mode of action. They can be extremely harmful to living organisms even at low concentrations. The present study evaluated the toxic effects of four frequently used anti-cancer drugs against plant seedlings, namely Cyclophosphamide (CP), Methotrexate (MTX), 5-Fluorouracil (5-FU) and Imatinib (IM). The phytotoxicity experiments were performed with Lactuca sativa seedlings whereas cytotoxicity, genotoxicity and mutagenicity investigations were performed with the well-established Allium cepa assays. MTX was the most phytotoxic compound, followed by 5-FU, CP and IM. Significant differences in the Mitotic Indexes (MI) were observed in three of the studied compounds (MTX, 5-FU and CP), indicating potential cytotoxic activity of these substances. Chromosome aberrations were registered in cells that were exposed to 5-FU, CP and IM. All the four compounds caused the formation of micronucleated cells indicating mutagenic potential. Besides, the assays performed with MTX samples presented a high number of cell apoptosis (cell death). Although it is unlikely that the pharmaceuticals concentrations measured in the environment could cause lethal effects in plants, the obtained results indicate that these compounds may affect the growth and normal development of these plants. So, both tests can constitute important tools for a fast screening of environmental contamination e.g. in the context of the reuse of treated wastewater and biosolids of agricultural purpose. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Effect of different irrigation frequencies on growth and yield of different wheat genotypes in Sindh

    International Nuclear Information System (INIS)

    Khokhar, B.; Hussain, I.

    2010-01-01

    Irrigation at critical growth stages could improve wheat yield significantly. A study was conducted during 2000-2002 to determine effect of different irrigation levels on growth and yield of different wheat genotypes in the province of Sindh. The trial was laid out in split block design at Wheat Research Institute, Sindh, Sakrand, in which four irrigation treatments I3 (irrigation at crown root, booting and soft dough stage), I4 (irrigation at crown root, tillering, booting and soft dough stage), I5 (irrigation at crown root, tillering, booting, anthesis and soft dough stage) and I6 (irrigation at crown root, tillering, booting, anthesis, soft dough and hard dough stage) were in blocks and six wheat genotypes; V-7001, V-7002, V-7004, NARC-9 and CO-9043 and Abadgar-93 were planted. Number of irrigation did not have any significant effect on plant height, whereas plant height was affected significantly in different cultivars. Application of five irrigations at different wheat growth stages resulted in higher spike length, higher number of grains and wheat grain yield. Wheat variety Abadgar-93 and V-7004, had taller plants in comparison with cultivars NARC-9 and V-7004 however, wheat grain yield was not affected significantly among different cultivars. (author)

  3. Research on instability design method without occurring boiling transition for hyper ABWR plants of extended core power density

    International Nuclear Information System (INIS)

    Okamoto, T.; Hotta, A.; Ama, T.

    2008-01-01

    The hyper ABWR (Advanced Boiling Water Reactor) project aims to develop an advanced BWR concept that is competitive in the global market with both highly economic and safety features. Expecting plant construction within the coming ten years, a research program for substantiating the basic design of a high core power density ABWR was conducted. By inheriting the conventional ABWR design, it is possible to reduce construction costs. In order to achieve the rated core power of over 1650MWe which is almost equivalent to that of the EPR (European Pressurized Water Reactor), the core power density of ABWR will be up-rated by at least 25%. Three key subjects linked to this target were recognized. They are, (1) fuel design applicable to the high power density core, (2) improvement of the evaluation method for the coupled neutronic and thermal-hydraulic instability under a wider power-flow operating range, and (3) improvement of the steam separator performance under high quality conditions. In this paper, the second subject has been focused on. In the second subject, the uncertainty approach was introduced in the instability analysis where the best-estimate plant simulator was combined with a direct prediction of boiling transition by the sub-channel code. By employing the CSAU like method, a safety evaluation system that enables to include influences of uncertainties has been developed. Based on the correlation between the time margin for reaching the boiling transition under power oscillations and the decay ratio in the power-flow operation map, an automatic power oscillation suppressing system was designed. The set-point for activating suppression mechanisms (i.e. scram or SRI) could be determined based on this correlation. It was proposed that the present conservative acceptance criterion of the deterministic decay ratio can be replaced with a more rational one of the time margin with including uncertainties. (author)

  4. Portable photovoltaic irrigation pumps

    Energy Technology Data Exchange (ETDEWEB)

    Furber, J. D.

    1980-07-01

    Experiences in developing a solar-powered irrigation pump to meet the needs of poor farmers in developing nations are summarized. The design which evolved is small and portable, employing a high-efficiency electric pump, powered by photovoltaic panels. Particular emphasis is placed on how the system works, and on early field problems experienced with the first prototypes. The resolution of these problems and the performance of actual systems in various countries is presented and user responses are noted.

  5. [Irrigation in colostomies].

    Science.gov (United States)

    Campo, Juana; Lecona, Ana; Caparrós, M Rosario; Barbero, M Antonia; Javier Cerdán, F

    2002-01-01

    The degree of acceptation of irrigation from a colostomy varies ostensibly from some cases to others, therefore, we study what occurs in our medium, separating those patients which have previously undergone other procedures (Group A) from those patients who have been informed and trained about the immediate postoperative period (Group B). 48 patients, 22 or 46% of these patients were considered not apt for irrigation. Of the 26 to whom this procedure was proposed, 14 or 54% accepted. Of these, 5 or 36% abandoned its use while 9 continued its use; this is 64% of those who accepted this procedure, 35% of those to whom it was proposed and 19% of the total study group. 189 patients. This procedure was not recommended to 95 patients, 50%. Of the 94 patients to whom this procedure was proposed, 65 or 69% accepted. Of these, 22 or 34% abandoned its use while 43 continued its use; this is 66% of those; who accepted this procedure, 46% of those to whom it was proposed and 23% of the total study group. In our medium, the practice of irrigation oscillates between 19 and 23% of patients who have undergone a colostomy, without any significant difference referring to the moment when a patient started this procedure. A first report on this study was submitted in the III National Congress for Nursing in Colostomies.

  6. Nitrate leaching beneath a containerized nursery crop receiving trickle or overhead irrigation.

    Science.gov (United States)

    Colangelo, D J; Brand, M H

    2001-01-01

    Container production of nursery crops is intensive and a potential source of nitrogen release to the environment. This study was conducted to determine if trickle irrigation could be used by container nursery producers as an alternative to standard overhead irrigation to reduce nitrogen release into the environment. The effect of overhead irrigation and trickle irrigation on leachate nitrate N concentration, flow-weighted nitrate N concentration, leachate volume, and plant growth was investigated using containerized rhododendron (Rhododendron catawbiense Michx. 'Album') supplied with a controlled-release fertilizer and grown outdoors on top of soil-monolith lysimeters. Leachate was collected over two growing seasons and overwinter periods, and natural precipitation was allowed as a component of the system. Precipitation accounted for 69% of the water entering the overhead-irrigated system and 80% of the water entering the trickle-irrigated system. Leachate from fertilized plants exceeded the USEPA limit of 10 mg L(-1) at several times and reached a maximum of 26 mg L(-1) with trickle irrigation. Average annual loss of nitrate N in leachate for fertilized treatments was 51.8 and 60.5 kg ha(-1) for the overhead and trickle treatments, respectively. Average annual flow-weighted concentration of nitrate N in leachate of fertilized plants was 7.2 mg L(-1) for overhead irrigation and 12.7 mg L(-1) for trickle irrigation. Trickle irrigation did not reduce the amount of nitrate N leached from nursery containers when compared with overhead irrigation because precipitation nullified the potential benefits of reduced leaching fractions and irrigation inputs provided under trickle irrigation.

  7. Estimating irrigation water use in the humid eastern United States

    Science.gov (United States)

    Levin, Sara B.; Zarriello, Phillip J.

    2013-01-01

    Accurate accounting of irrigation water use is an important part of the U.S. Geological Survey National Water-Use Information Program and the WaterSMART initiative to help maintain sustainable water resources in the Nation. Irrigation water use in the humid eastern United States is not well characterized because of inadequate reporting and wide variability associated with climate, soils, crops, and farming practices. To better understand irrigation water use in the eastern United States, two types of predictive models were developed and compared by using metered irrigation water-use data for corn, cotton, peanut, and soybean crops in Georgia and turf farms in Rhode Island. Reliable metered irrigation data were limited to these areas. The first predictive model that was developed uses logistic regression to predict the occurrence of irrigation on the basis of antecedent climate conditions. Logistic regression equations were developed for corn, cotton, peanut, and soybean crops by using weekly irrigation water-use data from 36 metered sites in Georgia in 2009 and 2010 and turf farms in Rhode Island from 2000 to 2004. For the weeks when irrigation was predicted to take place, the irrigation water-use volume was estimated by multiplying the average metered irrigation application rate by the irrigated acreage for a given crop. The second predictive model that was developed is a crop-water-demand model that uses a daily soil water balance to estimate the water needs of a crop on a given day based on climate, soil, and plant properties. Crop-water-demand models were developed independently of reported irrigation water-use practices and relied on knowledge of plant properties that are available in the literature. Both modeling approaches require accurate accounting of irrigated area and crop type to estimate total irrigation water use. Water-use estimates from both modeling methods were compared to the metered irrigation data from Rhode Island and Georgia that were used to

  8. ROOT CANAL IRRIGANTS AND IRRIGATION TECHNIQUES: A REVIEW

    OpenAIRE

    Aniketh; Mohamed; Geeta; Nandakishore; Gourav Kumar; Patrick Timothy; Jayson Mathew; Sahle Abdul

    2015-01-01

    Root canal irrigation is not much emphasised in endodontic therapy. Most articles discussed are on root canal shaping and obturation not much emphasis is given for irrigation. There are many irrigation solutions which are introduced into market. The primary objective of root canal therapy is the ret ention of the pulpless or pulpally involved tooth with its associated periapical tissues in a healthy state. Achievement of this objective requires that the pulpal spaces and con...

  9. Crescimento e índices de troca gasosa em plantas de pepino irrigadas com água enriquecida com CO2 Growth analysis and gaseous exchange in cucumber plants irrigated with carbon dioxide enriched water

    Directory of Open Access Journals (Sweden)

    Kathia A.L. Canizares

    2004-12-01

    physiological indices and gaseous exchange of leaves of Japanese cucumber plants. The experimental design was of randomized blocks, with four and five replications. The treatments consisted of the hybrids Hokuho and Tsuyataro, irrigated with water enriched or not with CO2, 1‰ in the first semester and 0,25‰ in the second. Dry mass weight and leaf area presented an exponential tendency. The beginning of mass production decrease on dry matter, 63 days after transplanting date (DAT, was not possible to be observed. The growth rate and relative growth rate response of hybrid Hokuho differed between treatments, however, for hybrid Tsuyataro the response was similar. The net assimilation rate reached the pending maxim in the phase of vegetative growth and flowering, and was reduced drastically after 20 DAT for hybrid Hokuho, and after the 35 DAT for hybrid Tsuyataro. The leaf area rate from both hybrids decreases lightly during the cultivation, without differences between enriched and non enriched water after 20 DAT. The CO2 assimilation transpiration rate, stomatal conductance and water use efficiency were similar among plants irrigated with enriched and non enriched water during the first semester. Already in the second semester, higher values were observed in plants irrigated with enriched water.

  10. The Study on the Effect of Different Levels of Vermicompost and Plant Density on Oil Content and Components of Evening Primrose (Oenothera biennis L

    Directory of Open Access Journals (Sweden)

    M Azizi

    2014-03-01

    Full Text Available To investigate the effects of different levels of vermicompost and plant density on oil content of evening primrose and its components, an experiment was conducted as a factorial layout based on Randomised Complete Block Design with 12 treatments and 3 replications in experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad during 2008-2009. The treatments were included 4 levels of vermicompost (0, 2, 3 and 5 kg.m-2 and 3 levels of plant density (9, 12 and 20 plant/m-2. Oil extraction was carried out by Soxhelet apparatus and its percentage was determined as weight. Analysis of fatty acids was done by Gas Chromatography device. Density and refractive index of the oil also was evaluated. According to the results, simple effect of vermicompost and plant density was significant only on oil percentage and its refractive index, while the interaction between them was significant on all of the traits. Fatty acids composition of oil in all treatment was the same. The major saturated fatty acid was palmitic acid and linoleic acid was the major unsaturated fatty acid. The amount of γ-linolenic acid was in optimum range (7-8 %. Overall, treatment of 2 kg.m2 vermicompost and plant density of 20 and 9 plant/m-2 was determined as the best treatments by considering the improving of oil production, oil quality and ratio of unsaturated fatty acids to saturated fatty acids, respectively.

  11. Phenotypic Responses of Twenty Diverse Proso Millet (Panicum miliaceum L. Accessions to Irrigation

    Directory of Open Access Journals (Sweden)

    Cedric Habiyaremye

    2017-03-01

    Full Text Available To date, little research has been conducted on the phenotypic responses of proso millet to drought and deficit irrigation treatments in the dryland wheat-based cropping systems of the Palouse bioregion of the U.S. The objectives of this study were to evaluate critical agronomic traits of proso millet, including emergence, plant height, days to heading, days to maturity, and grain yield, with and without supplemental irrigation. Twenty diverse proso millet accessions, originating from Bulgaria, Czechoslovakia, Morocco, the former Soviet Union, Turkey, and the United States, were grown in irrigated and non-irrigated treatments under organic conditions in Pullman, WA, from 2012 to 2014. Irrigation was shown to significantly improve emergence and increase plant height at stem extension and to hasten ripening of all the varieties, whereas heading date was not affected by irrigation in two of the three years tested. Irrigation resulted in higher mean seed yield across all varieties, with ‘GR 665’ and ‘Earlybird’ performing best under irrigation. Seed yield was highest in ‘GR 658’ and ‘Minsum’ in the non-irrigated treatment, suggesting the importance of identification and utilization of varieties adapted to low rainfall conditions. The highest yielding varieties in irrigated systems are unlikely be the highest yielding in dryland systems. Our results suggest that millet has potential as a regionally novel crop for inclusion in traditional dryland cropping rotations in the Palouse ecosystem, thereby contributing to increased cropping system diversity.

  12. Yield response of cotton, maize, soybean, sugar beet, sunflower and wheat to deficit irrigation

    International Nuclear Information System (INIS)

    Kirda, C.; Kanber, R.; Tulucu, K.

    1995-01-01

    Results of several field experiments on deficit irrigation programmes in Turkey are discussed. Deficit irrigation of sugar beet with water stress imposed (i e.,irrigation omitted)during ripening,stage saved nearly 22 % water, yet with no significant yield decrease. An experiment, conducted in Turkey Region, the European part of Turkey,and aimed at studying water production functions of sunflower(i e,yield vs water consumption), revealed that water stress imposed at either head forming or seed filling stags influence yield the least , and 40 % savings of irrigation water supply , compared with traditional practices in the region, can be achieved without significant yield reduction. Water stress imposed at vegetative and flowering stages of maize hindered the yield most significantly. The results showed that deficit irrigation can be a feasible option under limited supply of irrigation if stress occurs during yield formation stage. A four year field experiments aiming at developing deficit irrigation strategies for soybean showed that soybean was at the most sensitive to water stress during flowering and pod filling stages, and irrigation during these stages would ensure high yields. Results of experiments on cotton showed that irrigations omitted during yield formation stage did not significantly hinder the yield. Similarly wheat give good yield response if irrigated at booting,heading and milking stages, depending on w heather conditions. In areas where rainfall at planting is limited, supplementary irrigation during this period can ensure good establishment of wheat crop. 1 tab; 9 figs; 59 refs (Author)

  13. Gain-P: A new strategy to increase furrow irrigation efficiency

    International Nuclear Information System (INIS)

    Schmitz, G.H.; Wohling, T.; Paly, M. D.; Schutze, N.

    2007-01-01

    The new methodology GAIN-P combines Genetic Algorithms, Artificial Intelligence techniques and rigorous Process modeling for substantially improving irrigation efficiency. The new strategy simultaneously identifies optimal values of both scheduling and irrigation parameters for an entire growing season and can be applied to irrigation systems with adequate or deficit water supply. In this contribution, GAIN-P is applied to furrow irrigation tackling the more difficult subject of the more effective deficit irrigation. A physically -based hydrodynamic irrigation model is iteratively coupled with a 2D subsurface flow model for generating a database containing all realistically feasible scenarios of water application in furrow irrigation. It is used for training a problem-adapted artificial neural network based on self-organized maps, which in turn portrays the inverse solution of the hydrodynamic furrow irrigation model and thus enormously speeds up the overall performance of the complete optimization tool. Global optimization with genetic algorithm finds the schedule with maximum crop yield for the given water volume. The impact of different irrigation schedules on crop yield is calculated by the coupled furrow irrigation model which also simulates soil evaporation, precipitation and root water uptake by the plants over the whole growing seasons, as well as crop growth and yield. First results with the new optimization strategy show that GAIN-P has a high potential to increase irrigation efficiency. (author)

  14. Effect of Irrigation Intervals on Some Morphophysiological Traits of Basil (Ocimum basilicum L. Ecotypes

    Directory of Open Access Journals (Sweden)

    M Goldani

    2012-10-01

    Full Text Available In order to determine the effect of different irrigation intervals on some morphophysiological traits of basil (Ocimum basilicum L., an experiment was conducted as factorial based on randomized complete block design with three replications under greenhouse conditions during 2010. Treatments included five irrigation intervals with 4, 8, 12, 16 and 20 days intervals and two ecotypes of basil (green and purple. The results showed that by increasing irrigation interval plant height, spike number, spike weight and shoot dry weight between irrigation intervals decreased. Purple basil was more tolerant than basil green ecotype to drought stress. Interaction between irrigation intervals and ecotypes showed that the best treatment related to four days irrigation interval and purple basil ecotype. The effect of irrigation intervals on root area, root diameter mean, total length, root volume and dry weight of root was significant. In all irrigation intervals, purple basil had better performance compared to green ecotype. The results showed that by increasing in irrigation interval decreased root surface area, but increased total root length. It was concluded that increasing irrigation interval up to 12 days decreased shoot and root surface areas. Increasing irrigation interval decreased chlorophyll- a, b and increased prolin amino acid content of basil leaf.

  15. Improving efficiencies of irrigation and nitrogen uptake in wheat

    International Nuclear Information System (INIS)

    Bazza, M.

    2000-01-01

    Three years of field studies and lysimeter experiments on irrigated wheat had the objective of finding ways of managing irrigation and N fertilization to minimize losses and reduce contamination of groundwater. Applied N had significant positive effects on crop-water consumptive use. The highest N losses occurred during early growth. Irrigation had little effect on N loss when it was practiced efficiently. Under the prevailing conditions, it is recommended that no N be applied to wheat at planting, in order to limit N losses by leaching caused by the high precipitation that usually occurs during early development when crop-N requirements are small. No more than 120 kg N ha -1 should be applied in total to minimize groundwater pollution and maximize N-uptake efficiency and economic returns. Also, for economic and environmental reasons, irrigation should be limited to 80% of the total requirement and to depths of 40 to 60 mm. (author)

  16. Integrating Water Supply Constraints into Irrigated Agricultural Simulations of California

    Science.gov (United States)

    Winter, Jonathan M.; Young, Charles A.; Mehta, Vishal K.; Ruane, Alex C.; Azarderakhsh, Marzieh; Davitt, Aaron; McDonald, Kyle; Haden, Van R.; Rosenzweig, Cynthia E.

    2017-01-01

    Simulations of irrigated croplands generally lack key interactions between water demand from plants and water supply from irrigation systems. We coupled the Water Evaluation and Planning system (WEAP) and Decision Support System for Agrotechnology Transfer (DSSAT) to link regional water supplies and management with field-level water demand and crop growth. WEAP-DSSAT was deployed and evaluated over Yolo County in California for corn, rice, and wheat. WEAP-DSSAT is able to reproduce the results of DSSAT under well-watered conditions and reasonably simulate observed mean yields, but has difficulty capturing yield interannual variability. Constraining irrigation supply to surface water alone reduces yields for all three crops during the 1987-1992 drought. Corn yields are reduced proportionally with water allocation, rice yield reductions are more binary based on sufficient water for flooding, and wheat yields are least sensitive to irrigation constraints as winter wheat is grown during the wet season.

  17. Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

    NARCIS (Netherlands)

    Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

    2014-01-01

    The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

  18. A Review of Environmental Contamination and Health Risk Assessment of Wastewater Use for Crop Irrigation with a Focus on Low and High-Income Countries.

    Science.gov (United States)

    Khalid, Sana; Shahid, Muhammad; Bibi, Irshad; Sarwar, Tania; Shah, Ali Haidar; Niazi, Nabeel Khan

    2018-05-01

    Population densities and freshwater resources are not evenly distributed worldwide. This has forced farmers to use wastewater for the irrigation of food crops. This practice presents both positive and negative effects with respect to agricultural use, as well as in the context of environmental contamination and toxicology. Although wastewater is an important source of essential nutrients for plants, many environmental, sanitary, and health risks are also associated with the use of wastewater for crop irrigation due to the presence of toxic contaminants and microbes. This review highlights the harmful and beneficial impacts of wastewater irrigation on the physical, biological, and chemical properties of soil (pH, cations and anions, organic matter, microbial activity). We delineate the potentially toxic element (PTEs) build up in the soil and, as such, their transfer into plants and humans. The possible human health risks associated with the use of untreated wastewater for crop irrigation are also predicted and discussed. We compare the current condition of wastewater reuse in agriculture and the associated environmental and health issues between developing and developed countries. In addition, some integrated sustainable solutions and future perspectives are also proposed, keeping in view the regional and global context, as well as the grounded reality of wastewater use for crop production, sanitary and planning issues, remedial techniques, awareness among civil society, and the role of the government and the relevant stakeholders.

  19. Effects of nitrogen application and plant densities on flower yield, essential oils, and radiation use efficiency of Marigold (Calendula officinalis L.)

    International Nuclear Information System (INIS)

    Ameri, A.A.; Nasiri Mahalati, M.

    2010-01-01

    Efficient use of radiation for medicinal plants production, might increase flower yield, essential oils and extract yield .A split plot design.was used in a two years (2005 and 2006) field study in Torogh region(36,10° N,59.33° E and 1300 m altitude) of Mashhad, Iran, to observe the effects of different nitrogen application and plants densities on flower dry matter production, essential oils, and radiation use efficiency in a multi-harvested Marigold (Calendula officinalis). The levels of nitrogen fertilizer were 0, 50, 100 and 150 kg ha-1 and levels of density were 20, 40, 60 and 80 plant m-2. The combined analysis results revealed significant effects of nitrogen and density levels on flower dry matter production, essential oils, and radiation use efficiency of Marigold. The highest dry flower production obtained by 150 kg ha-1 N and 80 plant m-2 plant population (102.86 g m-2). The higher flower dry matter production caused more essential oils and extract production in high nitrogen and density levels. The amount of essential oils and extract per 100g flower dry matter decreased during the flower harvesting period. The higher amount of essential oil and extract obtained at early flowering season. The essential oil and extract ranged from 0.22 to 0.12 (ml. per 100g flower dry matter) and 2.74 to 2.13 (g per 100g flower dry matter) respectively. Increase of both nitrogen and density caused higher radiation use efficiency. The most radiation use efficiency obtained at 150 kg ha-1 nitrogen and 80 Plant m-2desity treatments. In 150 kg ha-1 nitrogen treatment, increase of density levels from 20 plant m-2 to 80 Plant m-2 caused increase in radiation use efficiency from 1.41 g MJ-1 to 1.44 g MJ-1 respectively

  20. Produtividade e qualidade da flor-de-seda em diferentes densidades e sistemas de plantio Productivity and quality of rooster tree in different planting densities and planting systems

    Directory of Open Access Journals (Sweden)

    Maria Verônica Meira de Andrade

    2008-01-01

    Full Text Available Avaliou-se o efeito de dois sistemas de plantio (sem camalhão e com camalhão e de três espaçamentos (1,0 × 1,5 m; 1,5 × 2,0 m; e 2,0 × 2,0 m sobre a qualidade e a produtividade de flor-de-seda aos 60 dias de rebrotação. Utilizou-se o delineamento experimental com blocos casualizados em esquema fatorial 2 × 3 (dois sistemas de manejo do solo e três densidades de plantio com cinco repetições, em parcelas subdivididas no espaço e no tempo. Plantas escolhidas aleatoriamente foram cortadas, separadas por tratamento e analisadas quanto aos teores de matéria seca (MS, matéria orgânica (MO, cinzas, extrato etéreo (EE, proteína bruta (PB, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, celulose, hemicelulose, lignina, carboidratos não-fibrosos (CNF e carboidratos totais (CT e quanto à produtividade (kg MS/ha. Os sistemas de manejo do solo e as densidades de plantio não influenciaram a composição em MO, cinzas, FDN, EE, lignina, celulose, CNF e CT. As densidades de plantio influenciaram o teor de hemicelulose e FDA. O sistema de manejo do solo com camalhão teve efeito linear decrescente sobre o teor de PB. A maior produtividade de MS (699,72 kg/ha da flor-de-seda foi verificada no sistema de plantio mais adensado (1,0 m × 1,5 m e correspondeu a 6.666 plantas/ha.The effect of two soil handling systems was evaluated (without furrow and with furrow, three spacing (1.0 m × 1.5 m; 1.5 m × 2.0 m and 2.0 m × 2.0 m on the quality and the productivity of rooster tree 60 days after cut. It was used a split-plot (space and time factorial arrangement in a randomized block design. Factors were two soil handling systems and three planting densities (2 × 3 with five replications per treatment. Plants chosen randomly were cut, separated in accordance with treatments and analyed the contents of dry matter (DM, organic matter (OM, mineral matter (MM, ether extract (EE, crude protein (CP, neutral detergent fiber (NDF, acid

  1. Irrigation water management: Basic principles and applications

    OpenAIRE

    Ella, Victor B.

    2007-01-01

    This presentation defines the term, irrigation, as well as explains the common methods of irrigation in attempt to define the fundamental principles needed to wisely design an irrigation system. It outlines a typical drip irrigation set-up, and discusses management of an irrigation system, including water volume application suggestions. LTRA-5 (Agroforestry and Sustainable Vegetable Production)

  2. Agriculture Irrigation and Water Use

    OpenAIRE

    Bajwa, Rajinder S.; Crosswhite, William M.; Hostetler, John E.; Wright, Olivia W.; United States Department of Agriculture, Economic Research Service

    1992-01-01

    The 17 Western States, plus Arkansas, Florida, and Louisiana, account for 91 percent of all U.S. irrigated acreage, with the Western States alone contributing over 85 percent. This report integrates data on the distribution, characteristics, uses, and management of water resources from a wide variety of data sources. The report includes charts and tables on water use in irrigation; farm data comparing selected characteristics of irrigated and nonirrigated farms; and data on water applicatio...

  3. Increased malaria transmission around irrigation schemes in Ethiopia and the potential of canal water management for malaria vector control.

    Science.gov (United States)

    Kibret, Solomon; Wilson, G Glenn; Tekie, Habte; Petros, Beyene

    2014-09-13

    Irrigation schemes have been blamed for the increase in malaria in many parts of sub-Saharan Africa. However, proper water management could help mitigate malaria around irrigation schemes in this region. This study investigates the link between irrigation and malaria in Central Ethiopia. Larval and adult mosquitoes were collected fortnightly between November 2009 and October 2010 from two irrigated and two non-irrigated (control) villages in the Ziway area, Central Ethiopia. Daily canal water releases were recorded during the study period and bi-weekly correlation analysis was done to determine relationships between canal water releases and larval/adult vector densities. Blood meal sources (bovine vs human) and malaria sporozoite infection were tested using enzyme-linked immunosorbent assay (ELISA). Monthly malaria data were also collected from central health centre of the study villages. Monthly malaria incidence was over six-fold higher in the irrigated villages than the non-irrigated villages. The number of anopheline breeding habitats was 3.6 times higher in the irrigated villages than the non-irrigated villages and the most common Anopheles mosquito breeding habitats were waterlogged field puddles, leakage pools from irrigation canals and poorly functioning irrigation canals. Larval and adult anopheline densities were seven- and nine-fold higher in the irrigated villages than in the non-irrigated villages, respectively, during the study period. Anopheles arabiensis was the predominant species in the study area. Plasmodium falciparum sporozoite rates of An. arabiensis and Anopheles pharoensis were significantly higher in the irrigated villages than the non-irrigated villages. The annual entomological inoculation rate (EIR) calculated for the irrigated and non-irrigated villages were 34.8 and 0.25 P. falciparum infective bites per person per year, respectively. A strong positive correlation was found between bi-weekly anopheline larval density and canal water

  4. Soil capacitance sensors and stem dendrometers. Useful tools for irrigation scheduling of commercial orchards?

    Energy Technology Data Exchange (ETDEWEB)

    Bonet, L.; Ferrer, P.; Castel, J. R.; Intrigliolo, D. S.

    2010-07-01

    Irrigation scheduling is often performed based on a soil water balance, where orchard evapotranspiration is estimated using the reference evapotranspiration (ETo) times the crop coefficient (Kc). This procedure, despite being widely spread, has some uncertainties. Because of this, plant and soil water status monitoring could be alternatively or complementarity used to schedule irrigation. The usefulness of capacitance probes was evaluated during several seasons in large irrigation districts where irrigation practices were changed over years from the ETo * Kc model to the analysis of soil water status trend. This area corresponds to drip irrigated orchards planted with citrus, peach, nectarine and persimmon. Around 25% less irrigation was applied with no substantial yield penalty when the information provided by capacitance probes was correctly applied for irrigation management. On the other hand, the usefulness of stem dendrometers for continuously monitoring plant water status was evaluated in a young plum experimental orchard. Over two years, irrigation was scheduled using exclusively trunk shrinkage via the signal intensity approach by means of a baseline equation previously obtained in the orchard. Results showed that it was not always possible to schedule irrigation based on the trunk shrinkage signal intensity due to the temporal changes in the reference values that occurred as trees aged. Overall, results obtained are discussed in terms of the possible extrapolation at field level of both capacitance probes and stem dendrometers. Advantages and drawbacks of each technique are analyzed and discussed. (Author) 34 refs.

  5. Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

    Science.gov (United States)

    Zhang, Yifei; Kang, Jian

    2017-11-01

    The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity

  6. Irrigation management of sigmoid colostomy.

    Science.gov (United States)

    Jao, S W; Beart, R W; Wendorf, L J; Ilstrup, D M

    1985-08-01

    Questionnaires were sent to 270 patients who had undergone abdominoperineal resection and sigmoid colostomy at the Mayo Clinic, Rochester, Minn, during the ten years from 1972 to 1982; 223 patients returned their questionnaires with evaluable data. Sixty percent of the patients were continent with irrigation, and 22% were incontinent with irrigation. Eighteen percent had discontinued irrigation for various reasons. The proportion continent was higher in women, younger patients, and previously constipated patients. A poorly constructed colostomy may cause acute angle, parastoma hernia, stomal prolapse, or stenosis and thus be the cause of failure of irrigation.

  7. Effect of rooting depth, plant density and planting date on maize (Zea Mays L.) yield and water use efficiency in semi-arid Zimbabwe: Modelling with AquaCrop

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.

    2014-01-01

    Under low and poorly distributed rainfall higher food production can be achieved by increasing crop water use efficiency (WUE) through optimum soil fertility management and selection of deep-rooting cultivars, appropriate plant density and planting dates. We explored AquaCrop's applicability in

  8. Soil Compressibility under Irrigated Perennial and Annual Crops in a Semi-Arid Environment

    Directory of Open Access Journals (Sweden)

    Rafaela Watanabe

    Full Text Available ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2 and 15 (B15 years cultivation, pasture (P, and a corn and beans succession (MB, as well as the reference areas for soil quality and corresponding natural vegetation (NVB2, NVB15, NVP and NVMB. Samples were collected at layers of 0.00-0.10 and 0.20-0.30 m; and for B2 and B15, samples were collected in the row and inter-row spaces. The following properties were determined: degree of compactness (DC, preconsolidation pressure (σp, compression index (Cc, maximum density (ρmax, critical water content (WCcrit, total organic carbon (TOC and carbon of light organic matter (Clom. Mean values were compared by the t-test at 5, 10, 15 and 20 % probability. An increase was seen in DC at a layer of 0.20-0.30 m in MB (p<0.15, showing the deleterious effects of preparing the soil by ploughing and chiselling, together with the cumulative traffic of heavy machinery. The TOC had a greater influence on ρmax than the stocks of Clom. Irrigation caused a reduction in Cc, and there was no effect on σp at field capacity. The planting rows showed different behaviour for Cc, ρmax, and WCcrit,, and in general the physical properties displayed better conditions than the inter-row spaces. Values for σp and Cc showed that agricultural soils display greater load-bearing capacity and are less susceptible to compaction in relation to soils under natural vegetation.

  9. Review. Deficit irrigation in fruit trees and vines in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Sanchez, M. C.; Domingo, R.; Castel, J. R.

    2010-07-01

    Water has become the most precious of natural resources in many areas of Spain and, since agriculture is the major consumer of water, improvements in water use efficiency are increasingly sought. Regulated deficit irrigation (RDI) is an irrigation strategy based on applying only a fraction of the plant water requirements during certain periods of plant development. The paper reviews the available information on RDI strategies, in woody tree crops and vines based on studies by Spanish research groups. Both the promising results obtained and the drawbacks are covered. (Author) 130 refs.

  10. Remote sensing technologies applied to the irrigation water management on a golf course

    Science.gov (United States)

    Pedras, Celestina; Lança, Rui; Martins, Fernando; Soares, Cristina; Guerrero, Carlos; Paixão, Helena

    2015-04-01

    An adequate irrigation water management in a golf course is a complex task that depends upon climate (multiple microclimates) and land cover (where crops differ in morphology, physiology, plant density, sensitivity to water stress, etc.). These factors change both in time and space on a landscape. A direct measurement provides localized values of the evapotranspiration and climate conditions. Therefore this is not a practical or economical methodology for large-scale use due to spatial and temporal variability of vegetation, soils, and irrigation management strategies. Remote sensing technology combines large scale with ground measurement of vegetation indexes. These indexes are mathematical combinations of different spectral bands mostly in the visible and near infrared regions of the electromagnetic spectrum. They represent the measures of vegetation activity that vary not only with the seasonal variability of green foliage, but also across space, thus they are suitable for detecting spatial landscape variability. The spectral vegetation indexes may enhance irrigation management through the information contained in spectral reflectance data. This study was carried out on the 18th fairway of the Royal Golf Course, Vale do Lobo, Portugal, and it aims to establish the relationship between direct measurements and vegetation indexes. For that it is required (1) to characterize the soil and climatic conditions, (2) to assessment of the irrigation system, (3) to estimate the evapotranspiration (4) and to calculate the vegetation indices. The vegetation indices were determined with basis on spectral bands red, green and blue, RGB, and near Infrared, NIR, obtained from the analysis of images acquired from a unpiloted aerial vehicle, UAV, platform. The measurements of reference evapotranspiration (ETo) were obtained from two meteorological stations located in the study area. The landscape evapotranspiration, ETL, was determined in the fairway with multiple microclimates

  11. A comparative study of wireless and wired sensors networks for deficit irrigation management

    Science.gov (United States)

    Torres Sánchez, Roque; Domingo Miguel, Rafael; Valles, Fulgencio Soto; Perez-Pastor, Alejandro; Lopez Riquelme, Juan Antonio; Blanco Montoya, Victor

    2016-04-01

    In recent years, the including of sensors in the context of agricultural water management, has received an increasing interest for the establishment of irrigation strategies, such as regulated deficit irrigation (RDI). These strategies allow a significant improvement of crop water productivity (marketable yield / water applied), especially in woody orchards. The application of these deficit irrigation strategies, requires the monitoring of variables related to the orchard, with the purpose of achieving an efficiently irrigation management, since it is necessary to know the soil and plant water status to achieve the level of water deficit desired in each phenological stage. These parameters involve the measurements of soil and plant parameters, by using appropriate instrumentation devices. Traditional centralized instrumentation systems include soil matric potential, water content and LVDT sensors which information is stored by dataloggers with a wired connection to the sensors. Nowadays, these wired systems are being replaced by wireless ones due, mainly, to cost savings in wiring and labor. These technologies (WSNs) allow monitoring a wide variety of parameters in orchards with high density of sensors using discrete and autonomous nodes in the trees or soil places where it is necessary, without using wires. In this paper we present a trial in a cherry crop orchard, with different irrigation strategies where both a wireless and a wired system have been deployed with the aim of obtaining the best criteria on how to select the most suitable technology in future agronomic monitoring systems. The first stage of this study includes the deploying of nodes, wires, dataloggers and the installation of the sensors (same for both, wired and wireless systems). This stage was done during the first 15 weeks of the trial. Specifically, 40 MPS6 soil matric potential, 20 Enviroscan water content and 40 (LVDT and band) dendometers were installed in order to cover the experimental

  12. Optimization of irrigation water in stone fruit and table grapes

    Science.gov (United States)

    de la Rosa, Jose Mª; Castillo, Cristina; Temnani, Abdel; Pérez-Pastor, Alejandro

    2017-04-01

    In water scarcity areas, it must be highlighted that the maximum productions of the crops do not necessarily imply maximum profitability. Therefore, during the last years a special interest in the development of deficit irrigation strategies based on significant reductions of the seasonal ET without affecting production or quality has been observed. The strategies of regulated deficit irrigation (RDI) are based on the reduction of water supply during non critical periods, the covering of water needs during critical periods and maximizing, at the same time, the production by unit of applied water. The main objective of this experiment was to implement, demonstrate and disseminate a sustainable irrigation strategy based on deficit irrigation to promote its large scale acceptance and use in woody crops in Mediterranean agroecosystems, characterized by water scarcity, without affecting the quality standards demanded by exportation markets. Five demonstration plots were established in representative crops of the irrigating community of Campotejar (Murcia, Spain): i) Peach trees, cv. catherina in the "Periquitos" farm; ii) Apricot trees, cv. "Red Carlet" in "La Hoya del Fenazar" farm; iii) Nectarine trees, cv. Viowhite in "Agrícola Don Fernando" farm; iv) Table grape, cv "Crimson Seedless" in "La Hornera" farm; and v) Paraguayan cv. carioca in "The Hornera" farm. In each demonstration plot, at least two irrigation treatments were established: i) Control (CTL), irrigated to ensure non-limiting water conditions (120% of crop evapotranspiration) and ii) Regulated deficit irrigation (RDI) irrigated as CTL during critical periods and decreasing irrigation in non-critical periods. The plant water status indicators evaluated were midday stem water potential and Trunk Diameter Fluctuation derived indices: maximum daily shrinkage (MDS) and trunk daily growth rate (TGR); vegetative growth of the different crops from trunk diameter and pruning dry weight, fruit growth and fruit

  13. Irrigation ponds: Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

    Institute of Scientific and Technical Information of China (English)

    DONG Bin; MAO Zhi; BROWN Larry; CHEN XiuHong; PENG LiYuan; WANG JianZhang

    2009-01-01

    Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and un-recycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China.With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious.Traditional ir-rigation and drainage systems only focus on issues concerning water quantity, i.e.the capacity of irri-gation in drought and drainage in waterlogging period, yet have no requirement on water quality im-provement, how to clean the water quality of farmland drainage through remodeling the existing irriga-tion and drainage systems has a very important realistic meaning.Pond is an important irrigation facil-ity in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use.Such water storage features of pond provide the possibility and potential capacity for drainage water treat-ment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system.To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site.The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water.Other issues, e.g.how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

  14. Irrigation ponds:Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

    Institute of Scientific and Technical Information of China (English)

    BROWN; Larry

    2009-01-01

    Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and unrecycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China. With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious. Traditional irrigation and drainage systems only focus on issues concerning water quantity, i.e. the capacity of irrigation in drought and drainage in waterlogging period, yet have no requirement on water quality improvement. how to clean the water quality of farmland drainage through remodeling the existing irrigation and drainage systems has a very important realistic meaning. Pond is an important irrigation facility in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use. Such water storage features of pond provide the possibility and potential capacity for drainage water treatment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system. To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site. The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water. Other issues, e.g. how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

  15. Assessment of Irrigation Water Quality and Suitability for Irrigation in ...

    African Journals Online (AJOL)

    A number of factors like geology, soil, effluents, sewage disposal and other environmental conditions in which the water stays or moves and interacts are among the factors that affect the quality of irrigation water. This study was conducted to determine the quality and suitability of different water sources for irrigation purpose ...

  16. Effect of irrigation on heavy metals content of wastewater irrigated ...

    African Journals Online (AJOL)

    There is an urgent need to educate farmers on the dangers of the presence of heavy metals in soils as well as the quality of irrigation water especially if it comes from tanning industries for increased crop production. Accordingly, soil and irrigation wastewater study was conducted to assess the concentrations of heavy ...

  17. Fusing probability density function into Dempster-Shafer theory of evidence for the evaluation of water treatment plant.

    Science.gov (United States)

    Chowdhury, Shakhawat

    2013-05-01

    The evaluation of the status of a municipal drinking water treatment plant (WTP) is important. The evaluation depends on several factors, including, human health risks from disinfection by-products (R), disinfection performance (D), and cost (C) of water production and distribution. The Dempster-Shafer theory (DST) of evidence can combine the individual status with respect to R, D, and C to generate a new indicator, from which the overall status of a WTP can be evaluated. In the DST, the ranges of different factors affecting the overall status are divided into several segments. The basic probability assignments (BPA) for each segment of these factors are provided by multiple experts, which are then combined to obtain the overall status. In assigning the BPA, the experts use their individual judgments, which can impart subjective biases in the overall evaluation. In this research, an approach has been introduced to avoid the assignment of subjective BPA. The factors contributing to the overall status were characterized using the probability density functions (PDF). The cumulative probabilities for different segments of these factors were determined from the cumulative density function, which were then assigned as the BPA for these factors. A case study is presented to demonstrate the application of PDF in DST to evaluate a WTP, leading to the selection of the required level of upgradation for the WTP.

  18. Ring Irrigation System (RIS design through customer preference representation

    Directory of Open Access Journals (Sweden)

    Ridwan Infandra I.Z.

    2018-01-01

    Full Text Available In agricultural field, irrigation is one of the most interesting considerations affecting the rate of plant growth and development. Micro-irrigation as the dripping or sprinkle method is one of the irrigation types that applies the small amount of water for fulfilling the humidity requirement. The most important factors affecting the demand of water for plants are soil conditions and effect of climatic factors. With less human labour required, to improve the irrigation method from the recent days, analyzing water used or water permeation automatically through the soil moisture has been raised as the interesting topic. Proposed in this research is the ring irrigation system (RIS which is introduced as an alternative channel for emitters that drip water directly onto the soil at the plant’s root zone where the soil conditions before and after watering can be quickly detected by the sensors. This RIS can be used for the potted plant, green house, or other small farm fields. Product design and development (PDD is applied in this research for assisting the designer to understand and create the RIS prototype properly according to the customer’s requirements where the suggested functions obtained will be added and tested.

  19. Kalanchoe crop development under different levels of irrigation

    Directory of Open Access Journals (Sweden)

    Fátima Cibele Soares

    Full Text Available ABSTRACT Despite its importance in the floriculture sector, irrigation management of kalanchoe is characterized by empiricism, being necessary further studies on the use of water by this crop. Thus, the objective of this study is to analyze the several effects of irrigation levels on the growth of kalanchoe crop conducted in greenhouse in the municipality of Alegrete, state of Rio Grande do Sul. The experiment was conducted in a 7 x 15 m protected environment. The experimental design was completely randomized, with four treatments (irrigation levels corresponding to 40, 60, 80 and 100% of the pot water retention capacity - PC and four repetitions, totaling sixteen plots. The crop cycle was 224 days after transplanting and the applied average depths were: 451.82; 367.38; 282.94; 198.51 mm for treatments: 100; 80; 60 and 40% of PC, respectively. Canopy area and number of leaves per plant were evaluated over the crop cycle. In the end of the cycle, the canopy diameter, number of inflorescences per plant and the number of flowers per plant were evaluated. No significant differences were found only to the canopy area, by the F test. Irrigation water depths between 40 and 70% of the pot capacity were more appropriate for the crop growth in the study region. The cultivar presented the best development at irrigation levels below the maximum vessel water retention capacity, that is, it is resistant to drought.

  20. Deficit irrigation strategies

    DEFF Research Database (Denmark)

    Stikic, Radmilla; Savíc, Sladjana; Jovanovic, Zorica

    2010-01-01

    Book Description: Horticulture is the industry and science of plant cultivation, including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding...... grafting techniques at the seedling stage to overcome soil-borne diseases, the application of biotechnology tools in the conservation of critically endangered plant species, salinity tolerance of ornamental horticultural species, and others....

  1. Web/smart phone based control and feedback systems for irrigation systems

    Science.gov (United States)

    The role of the internet and mobile devices in the control and feedback of irrigation systems is reviewed. This role is placed in the larger context of four distinct components required for irrigation management, including 1. the control panel; 2. remote control; 3. soil, plant, and weather (SPW) se...

  2. Comparison of corn, grain sorghum, soybean, and sunflower under limited irrigation.

    Science.gov (United States)

    Corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] constitute a large share of the annual total irrigated planted area in the central Great Plains. This study aimed to determine the effect of limited irrigation on grain yield, water use, and profitability of corn and soybean in comparison with ...

  3. Size asymmetry in intraspecific competition and the density-dependence of inbreeding depression in a natural plant population: a case study in cassava (Manihot esculenta Crantz, Euphorbiaceae).

    Science.gov (United States)

    Pujol, B; McKey, D

    2006-01-01

    The effects of competition on the genetic composition of natural populations are not well understood. We combined demography and molecular genetics to study how intraspecific competition affects microevolution in cohorts of volunteer plants of cassava (Manihot esculenta) originating from seeds in slash-and-burn fields of Palikur Amerindians in French Guiana. In this clonally propagated crop, genotypic diversity is enhanced by the incorporation of volunteer