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Sample records for weed kochia scoparia

  1. Mechanism of sulfonylurea herbicide resistance in the broadleaf weed, Kochia scoparia

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    Saari, L.L.; Cotterman, J.C.; Primiani, M.M. (E.I. duPont de Nemours Co., Inc., Wilmington, DE (USA))

    1990-05-01

    Selection of kochia (Kochia scoparia) biotypes resistant to the sulfonylurea herbicide chlorsulfuron has occurred through the continued use of this herbicide in monoculture cereal-growing areas in the United States. The apparent sulfonylurea resistance observed in kochia was confirmed in greenhouse tests. Fresh and dry weight accumulation in the resistance kochia was 2- to >350-fold higher in the presence of four sulfonylurea herbicides as compared to the susceptible biotype. Acetolactate synthase (ALS) activity isolated from sulfonylurea-resistant kochia was less sensitive to inhibition by three classes of ALS-inhibiting herbicides, sulfonylureas, imidazolinones, and sulfonanilides. The decrease in ALS sensitivity to inhibition (as measured by the ratio of resistant I{sub 50} to susceptible I{sub 50}) was 5- to 28-fold, 2- to 6-fold, and 20-fold for sulfonylurea herbicides, imidazolinone herbicides, and a sulfonanilide herbicide, respectively. No differences were observed in the ALS-specific activities or the rates of ({sup 14}C)chlorsulfuron uptake, translocation, and metabolism between susceptible and resistant kochia biotypes. The K{sub m} values for pyruvate using ALS from susceptible and resistant kochia were 2.13 and 1.74 mM, respectively. Based on these results, the mechanism of sulfonylurea resistance in this kochia biotype is due solely to a less sulfonylurea-sensitive ALS enzyme.

  2. Fitness Outcomes Related to Glyphosate Resistance in Kochia (Kochia scoparia: What Life History Stage to Examine?

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    Omobolanle Adewale Osipitan

    2017-06-01

    Full Text Available A fast-spreading weed, kochia (Kochia scoparia, has developed resistance to the widely-used herbicide, glyphosate. Understanding the relationship between the occurrence of glyphosate resistance caused by multiple EPSPS gene copies and kochia fitness may suggest a more effective way of controlling kochia. A study was conducted to assess fitness cost of glyphosate resistance compared to susceptibility in kochia populations at different life history stages, that is rate of seed germination, increase in plant height, days to flowering, biomass accumulation at maturity, and fecundity. Six kochia populations from Scott, Finney, Thomas, Phillips, Wallace, and Wichita counties in western Kansas were characterized for resistance to field-use rate of glyphosate and with an in vivo shikimate accumulation assay. Seed germination was determined in growth chambers at three constant temperatures (5, 10, and 15 C while vegetative growth and fecundity responses were evaluated in a field study using a target-neighborhood competition design in 2014 and 2015. One target plant from each of the six kochia populations was surrounded by neighboring kochia densities equivalent to 10 (low, 35 (moderate, or 70 (high kochia plants m−2. In 2015, neighboring corn densities equivalent to 10 and 35 plants m−2 were also evaluated. Treatments were arranged in a randomized complete block design with at least 7 replications. Three kochia populations were classified as glyphosate-resistant (GR [Scott (SC-R, Finney (FN-R, and Thomas (TH-R] and three populations were classified as glyphosate-susceptible (GS [Phillips (PH-S, Wallace (WA-S and Wichita (WI-S]. Of the life history stages measured, fitness differences between the GR and GS kochia populations were consistently found in their germination characteristics. The GR kochia showed reduced seed longevity, slower germination rate, and less total germination than the GS kochia. In the field, increases in plant height, biomass

  3. Influence of soil properties and soil moisture on the efficacy of indaziflam and flumioxazin on Kochia scoparia L.

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    Sebastian, Derek J; Nissen, Scott J; Westra, Phil; Shaner, Dale L; Butters, Greg

    2017-02-01

    Kochia (Kochia scoparia L.) is a highly competitive, non-native weed found throughout the western United States. Flumioxazin and indaziflam are two broad-spectrum pre-emergence herbicides that can control kochia in a variety of crop and non-crop situations; however, under dry conditions, these herbicides sometimes fail to control this important weed. There is very little information describing the effect of soil properties and soil moisture on the efficacy of these herbicides. Soil organic matter (SOM) explained the highest proportion of variability in predicting the herbicide dose required for 80% kochia growth reduction (GR80 ) for flumioxazin and indaziflam (R2 = 0.72 and 0.79 respectively). SOM had a greater impact on flumioxazin phytotoxicity compared to indaziflam. Flumioxazin and indaziflam kochia phytotoxicity was greatly reduced at soil water potentials below -200 kPa. Kochia can germinate at soil moisture potentials below the moisture required for flumioxazin and indaziflam activation, which means that kochia control is greatly influenced by the complex interaction between soil physical properties and soil moisture. This research can be used to gain a better understanding of how and why some weeds, like kochia, are so difficult to manage even with herbicides that normally provide excellent control. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. Effect of Hexaconazole and Penconazole on Kochia (Kochia scoparia Freezing Tolerance

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    A. Kamandy

    2016-07-01

    Full Text Available Introduction Cold and freezing are the most important limiting factors on development of sensitive plants. When the ambient temperature deviates from optimal, physiological, and biochemical, metabolic and molecular changes will occur within plants. This is an effort of plants to maximize growth and developmental processes and to maintain cellular homeostasis during such adverse conditions. At the extremes of the natural temperature range of plant, the degree of physiological, cellular, metabolic and molecular dysfunction becomes so severe that it leads to death. Triazoles are the most potent groups of growth retardants with multiple effects. Plant growing with paclobutrazol generally has little effect on rates of net photosynthetic rate. However, because the compound reduces leaf area, net photosynthesis on a per plant basis is probably reduced. They have exhibited growth regulating, fungicidal, herbicidal, apicidal and antibacterial activities. More recently, it was found that triazole compounds are able to increase tolerance of plants to cold and freezing stress. Kochia (Kochia scoparia (L. Schrad., an out crossing species whose pollen move between plants in windy areas, has recently been considered as a forage or fodder crop in marginal lands. Steppuhn and Wall (1993 claimed that Kochia offers great potential as a crop that can be grown on saline soils, yielding fodder in quantities approaching that produced by alfalfa (Medicago sativa L.. Shamsutdinov et al. (1996 also reported more than 15 Mg ha-1 dry-matter production for Kochia under saline conditions and concluded that it is a good candidate for forage hay. Thus, the aim of the present study was to determine whether the triazole compounds could increase tolerance of kochia against freezing stress. Materials and Methods An experiment was carried out with hexaconazole and penconazole in 0, 10 and 20 mg.L-1 and freezing temperatures 0, -2, -4, -6 and -8 degree centigrade in factorial based

  5. A psbA mutation in Kochia scoparia (L) Schrad from railroad rights-of-way with resistance to diuron, tebuthiuron and metribuzin.

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    Mengistu, Lemma W; Christoffers, Michael J; Lym, Rodney G

    2005-11-01

    Kochia [Kochia scoparia (L) Schrad] has become resistant to many herbicides used in cropland and railroad rights-of-way in North Dakota and Minnesota. Kochia scoparia plants that had survived annual treatments with diuron and tebuthiuron were sampled along railroad rights-of-way in North Dakota and Minnesota. The samples were screened in the greenhouse for resistance to diuron, tebuthiuron, metribuzin and bromoxynil from 0.5x to 32x the recommended use rates. A resistant K scoparia accession (MN-3R) was confirmed with resistance up to 16-fold higher than recommended use rates for tebuthiuron and diuron and up to 4-fold higher for metribuzin. However, the resistant K scoparia accession was susceptible to bromoxynil even at 50% of the recommended use rate. The herbicide binding region of the psbA gene fragment of eight resistant (R) and seven susceptible (S) K scoparia accessions was PCR-amplified and sequenced for detection of mutations. The psbA gene of four R K scoparia accessions was mutated at residue 219 with substitution of isoleucine for valine (GenBank accession number AY251265). The seven S K scoparia accession sequences were wild-type at this residue (GenBank accession number AY251266). The other four R accessions sequences showed a previously known triazine R mutation with substitution of glycine for serine at residue 264. All 15 K scoparia accessions were wild-type at all other psbA residues within the region analyzed. Resistance to diuron, tebuthiuron and metribuzin among the railroad rights-of-way K scoparia is probably due to the mutation at residue 219 of the psbA gene in some plants, but due to the previously reported Ser(264)Gly substitution in other plants. Target-site resistance associated with a change of valine to isoleucine at residue 219 of the psbA target-site in weeds has previously been reported for Poa annua L selected in diuron-treated grass seed fields, and for Amaranthus powelli S Wats selected in linuron-treated carrot fields. This is

  6. 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.

  7. Growth and Reproduction of Glyphosate-Resistant and Susceptible Populations of Kochia scoparia

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    Kumar, Vipan; Jha, Prashant

    2015-01-01

    Evolution of glyphosate-resistant kochia is a threat to no-till wheat-fallow and glyphosate-resistant (GR) cropping systems of the US Great Plains. The EPSPS (5-enol-pyruvylshikimate-3-phosphate synthase) gene amplification confers glyphosate resistance in the tested Kochia scoparia (L.) Schrad populations from Montana. Experiments were conducted in spring to fall 2014 (run 1) and summer 2014 to spring 2015 (run 2) to investigate the growth and reproductive traits of the GR vs. glyphosate-susceptible (SUS) populations of K. scoparia and to determine the relationship of EPSPS gene amplification with the level of glyphosate resistance. GR K. scoparia inbred lines (CHES01 and JOP01) exhibited 2 to 14 relative copies of the EPSPS gene compared with the SUS inbred line with only one copy. In the absence of glyphosate, no differences in growth and reproductive parameters were evident between the tested GR and SUS inbred lines, across an intraspecific competition gradient (1 to 170 plants m-2). GR K. scoparia plants with 2 to 4 copies of the EPSPS gene survived the field-use rate (870 g ha-1) of glyphosate, but failed to survive the 4,350 g ha-1 rate of glyphosate (five-times the field-use rate). In contrast, GR plants with 5 to 14 EPSPS gene copies survived the 4,350 g ha-1 of glyphosate. The results from this research indicate that GR K. scoparia with 5 or more EPSPS gene copies will most likely persist in field populations, irrespective of glyphosate selection pressure. PMID:26580558

  8. Tandem Amplification of a Chromosomal Segment Harboring 5-Enolpyruvylshikimate-3-Phosphate Synthase Locus Confers Glyphosate Resistance in Kochia scoparia1[W][OPEN

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    Jugulam, Mithila; Niehues, Kindsey; Godar, Amar S.; Koo, Dal-Hoe; Danilova, Tatiana; Friebe, Bernd; Sehgal, Sunish; Varanasi, Vijay K.; Wiersma, Andrew; Westra, Philip; Stahlman, Phillip W.; Gill, Bikram S.

    2014-01-01

    Recent rapid evolution and spread of resistance to the most extensively used herbicide, glyphosate, is a major threat to global crop production. Genetic mechanisms by which weeds evolve resistance to herbicides largely determine the level of resistance and the rate of evolution of resistance. In a previous study, we determined that glyphosate resistance in Kochia scoparia is due to the amplification of the 5-Enolpyruvylshikimate-3-Phosphate Synthase (EPSPS) gene, the enzyme target of glyphosate. Here, we investigated the genomic organization of the amplified EPSPS copies using fluorescence in situ hybridization (FISH) and extended DNA fiber (Fiber FISH) on K. scoparia chromosomes. In both glyphosate-resistant K. scoparia populations tested (GR1 and GR2), FISH results displayed a single and prominent hybridization site of the EPSPS gene localized on the distal end of one pair of homologous metaphase chromosomes compared with a faint hybridization site in glyphosate-susceptible samples (GS1 and GS2). Fiber FISH displayed 10 copies of the EPSPS gene (approximately 5 kb) arranged in tandem configuration approximately 40 to 70 kb apart, with one copy in an inverted orientation in GR2. In agreement with FISH results, segregation of EPSPS copies followed single-locus inheritance in GR1 population. This is the first report of tandem target gene amplification conferring field-evolved herbicide resistance in weed populations. PMID:25037215

  9. Evaluation of base, optimum and ceiling temperature for (Kochia scoparia L. Schard with application of Five-Parameters-Beta Model

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    S. Sabouri Rad

    2016-05-01

    Full Text Available Kochia (Kochia scoparia L. Schard is an annual, halophyte and drought resistant plant, that it can be irrigated with saline water and a valuable source for forage under drought and saline ecosystems. In order to evaluate germination characteristics of kochia, an experiment was conducted at Physiology laboratory of Ferdowsi University of Mashhad, Iran, during 2009. This experiment was conducted in a completely randomized design with four replications. Germination was evaluated at 5, 10, 15, 20, 25, 30, 35 and 40°C under dark germinator with 50-60 percentage relative humidity. The results showed that the highest germination percentage was obtained at 20-30°C and the lowest obtained at 40°C. The longest and the shortest period to 20 and 50 germination percentage were recorded to 5-10°C and 20-30°C, respectively. The longest and the shortest period to 80 percentage germination were belonging to 15 and 30°C, respectively. Based on Five Parameters Beta model, base, optimum and ceiling temperatures for kochia estimated 3.4, 25 and 43.3°C, respectively. However, seed of this plant is able to germinate in wide temperature range.

  10. [Preparation of water in oil type cream with high content of water containing Kochia scoparia fruit and Cnidium monnieri fruit].

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    Kohri, Naonori; Yamashita, Miki; Kanazawa, Tsutomu; Kodera, Hajime

    2011-01-01

    Kikisui is a herbal lotion containing Kochia scoparia Fruit and Cnidium monnieri Fruit that is clinically used as an antipruritic for itchy dry skin. However, this formulation is unsuitable for inducing a prolonged effect. Here, we attempted to change the formulation from a lotion to a cream. The cream we chose was a water-in-oil (W/O) type emulsion for enhancing skin compatibility. In addition, the high water content imparts a sensation of coolness. However, it is difficult to prepare a stable W/O type cream with high water content using a mechanical mixing method. Instead, we prepared the W/O type emulsion using liquid crystals. Water containing cocamidopropyl betaine was added to a dispersed phase comprising an oil phase of oleic acid and liquid paraffin that was constantly stirred. Addition of an aqueous solution containing Kochia scoparia Fruit and Cnidium monnieri Fruit decreased the stability of the cream. However, addition of glycerin as a humectant, and ethyl p-hydroxybenzoate/n-butyl p-hydroxybenzoate as preservatives enhanced the stability of the cream. The stability of the emulsion was correlated with the apparent viscosity of the cream. The final W/O type cream had a water content of 83% and was stable for more than 6 months at 4°C. Furthermore, ostol, which is one of the main biologically active herbal compounds, was also stable for more than 6 months.

  11. Evaluation of Nitrogen and Phosphorous Levels on Forage Yield and Characteristics of Kochia scoparia in Irrigating with Two Saline Waters

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    S Khaninejad

    2013-10-01

    Full Text Available Kochia scoparia is a salt resistant plant that can be used in producing forage in the areas with salt water and soil resources. One of the problems which produce the forage plants in these areas decreases the function and quality of the forage in irrigation condition with salt water. Therefore, using the chemical fertilizers can be considered as a useful solution. This study was conducted to evaluate the effects of various levels of phosphorus and nitrogen fertilizer in irrigating condition with saline water on forage yield and characteristics of Kochia by applying split plot experiments based on Randomized Complete Block design with three replications. The main plots consisted two levels of salinity of irrigating water, 5.2 and 16.5 dS/m, and the subplot consisted of factorial of three nitrogen levels in the form of urea (0, 100, 200 kg/h and three phosphorus levels in the form of Triple Super Phosphate (0, 75, 150 kg/h. Results showed that salinity had no significant effect on height, stem diameter and dry matter percentage. But, nitrogen application leads to increase in height, lateral shoots and forage yield compared with control. Phosphorous had significant effect of dry forage yield. The interactions of salt with nitrogen and phosphorus showed that the fertilizers can partially reduce the negative effects of salt stress on Kochia and improve the forage characteristics and biomass production.

  12. Evaluation of Quantitative and Qualitative Characteristic of Forage Kochia (Kochia scoparia in Different Salinity Levels and Time

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    J Nabati

    2015-04-01

    Full Text Available Increase salinity in soil and water resourses in agricultural lands has created major challenges in crops production. Kochia can grow under saline conditions and used as fodder in dry and saline areas. Therefore, three experiments was conducted in complete randomize design with four replication, to study effects of different levels of salinity (0, 10, 20, 30, 40, 50 and 60 dS m-1 at different growth stages (planting and early seedling and salinity appllication intervally. Results of applying saline water at the beginning of growth showed that kochia seedling was able to survive up to 30 dS m-1 sodium chloride. The results showed that increasing salinity at planting and early seedling satge reduced plant height, branches number, shoot fresh and dry weight, and increased digestible dry matter, digestive value, and crude protein yield. On the other hand with increasing salinity digestibility of dry matter, organic matter digestibility, crude protein and ash percentage were increased. Total phenol was not significantly affected by salinity in all treatments. Application of salinity intermittently at early seedling except of digestive value and ash percentage had no significant affect on other treats. Generally, results showed that the kochia seedlings are sensitive to salinity higher than 30 dS m-1 and also kochia be able to keep biomass production with salinity appllication intervally.

  13. Evaluation of Some Physiological Characteristics and Antioxidants Activity in Kochia (Kochia scoparia) in Different of Salinity Levels and Growth Stages

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    j nabati; m kafi; A Nezami; P Rezvani Moghaddam; A Masoumi; M Zare Mehrgerdi

    2014-01-01

    Soil salinity threat for agricultural ecosystems in many parts of Iran, and negatively affects crop production. In order to examine salinity tolerance of Kochia a series of experiments were conducted in CRD with four replications, seven levels of salinity (0, 10, 20, 30, 40, 50 and 60 dS.m-1), two growth stages (planting and early seedling) and interval irrigation. Result showed that decrease of root dry weight, root volume, membrane stability index were more increased at planting than early ...

  14. Evaluation of Quantitative and Qualitative Characteristic of Forage Kochia (Kochia scoparia) in Different Salinity Levels and Time

    OpenAIRE

    J Nabati; M Kafi; A. Nezami; P Rezvani Moghaddam; A Masoumi; M Zare Mehrgerdi

    2015-01-01

    Increase salinity in soil and water resourses in agricultural lands has created major challenges in crops production. Kochia can grow under saline conditions and used as fodder in dry and saline areas. Therefore, three experiments was conducted in complete randomize design with four replication, to study effects of different levels of salinity (0, 10, 20, 30, 40, 50 and 60 dS m-1) at different growth stages (planting and early seedling) and salinity appllication intervally. Results of applyin...

  15. Chemical Composition, in vitro Digestibility and Fermentative Gas Production of Kochia scoparia Irrigated by Water Containing Different Level of Salinity

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    reza valizadeh

    2016-11-01

    Full Text Available Introduction Shortage of feedstuff is one of the important problems of animal nutrition in Iran. Salinity is a global problem worldwide in particular in arid and semi-arid zones such as Iran. Salinity is an important factor in the growth of plants. Its initial effect to plants is through its effect in the availability of water to plants. Halophytes have good ability to draw water from soils of low water potential due to their ability to maintain a salt balance comparable to the salt in the soil they are growing. Lands in high irrigation districts are susceptible to soil salinization. Soil salinization is the primary cause of productivity decline in highly developed and irrigated land schemes While the increase in soil and water salinity in many agricultural areas of the world has created major challenges in the production of food crops, it has also presented some new prospects for livestock agriculture. There are plants that grow under saline conditions, and historically, they have been opportunistically used as fodder for grazing livestock or as components of mixed rations to replace roughage. Using of seawater for irrigation of this plant because of shortage of sweet water and for higher production of these plants was necessary for feedstuff. The aim of this study was evaluation of Chemical composition, In vitro digestibility and gas production of Kochia scoparia under six level of salinity including 10, 20, 30, 40, 50, 60 ds/m. Materials and Methods The Kochia scoparia was irrigated by normal tap water (the control and water containing 6 levels of salinity including 10, 20, 30, 40, 50, 60 deci Siemens per meter (ds/m. The salinity was applied gradually in accordance with the plant growth advancement (2 ds/m increment per each irrigation period. Oven dried (65◦C for 48 h chopped samples were ground to pass through a 1-mm screen. The samples were analyzed according to the standard procedures for chemical composition (AOAC 2000, Van-Soest et

  16. Evaluation of Some Physiological Characteristics and Antioxidants Activity in Kochia (Kochia scoparia in Different of Salinity Levels and Growth Stages

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    j nabati

    2014-07-01

    Full Text Available Soil salinity threat for agricultural ecosystems in many parts of Iran, and negatively affects crop production. In order to examine salinity tolerance of Kochia a series of experiments were conducted in CRD with four replications, seven levels of salinity (0, 10, 20, 30, 40, 50 and 60 dS.m-1, two growth stages (planting and early seedling and interval irrigation. Result showed that decrease of root dry weight, root volume, membrane stability index were more increased at planting than early seedling stages. Relative water content was increased with increasing salinity levels in all experiments except at interval irrigation. Proline and osmotic potential increased with increasing salinity levels. Catalase, glutathione reductase, DPPH - radical scavenging activities and total phenol were higher with more increased at planting than early seedling. Sodium concentration and sodium to potassium ratio in shoot and root increased with increasing salinity levels. Generally, despite application of high levels of salinity stress kochia was able to survive and tolerate these levels of salinity.

  17. A Mixture of Extracts of Kochia scoparia and Rosa multiflora with PPAR α/γ Dual Agonistic Effects Prevents Photoaging in Hairless Mice

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    Hyerin Jeon

    2016-11-01

    Full Text Available Activation of peroxisome proliferator-activated receptors (PPAR α/γ is known to inhibit the increases in matrix metalloproteinase (MMP and reactive oxygen species (ROS induced by ultraviolet light (UV. Extracts of natural herbs, such as Kochia scoparia and Rosa multiflora, have a PPAR α/γ dual agonistic effect. Therefore, we investigated whether and how they have an antiaging effect on photoaging skin. Eighteen-week-old hairless mice were irradiated with UVA 14 J/cm2 and UVB 40 mJ/cm2 three times a week for 8 weeks. A mixture of extracts of Kochia scoparia and Rosa multiflora (KR was topically applied on the dorsal skin of photoaging mice twice a day for 8 weeks. Tesaglitazar, a known PPAR α/γ agonist, and vehicle (propylene glycol:ethanol = 7:3, v/v were applied as positive and negative controls, respectively. Dermal effects (including dermal thickness, collagen density, dermal expression of procollagen 1 and collagenase 13 and epidermal effects (including skin barrier function, epidermal proliferation, epidermal differentiation, and epidermal cytokines were measured and compared. In photoaging murine skin, KR resulted in a significant recovery of dermal thickness as well as dermal fibroblasts, although it did not change dermal collagen density. KR increased the expression of dermal transforming growth factor (TGF-β. The dermal effects of KR were explained by an increase in procollagen 1 expression, induced by TGF-β, and a decrease in MMP-13 expression. KR did not affect basal transepidermal water loss (TEWL or stratum corneum (SC integrity, but did decrease SC hydration. It also did not affect epidermal proliferation or epidermal differentiation. KR decreased the expression of epidermal interleukin (IL-1α. Collectively, KR showed possible utility as a therapeutic agent for photoaging skin, with few epidermal side effects such as epidermal hyperplasia or poor differentiation.

  18. Effect of Drought Stress on Leaf Water Status, Electrolyte Leakage, Photosynthesis Parameters and Chlorophyll Fluorescence of Two Kochia Ecotypes (Kochia scoparia Irrigated With Saline Water

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    A Masoumi

    2012-12-01

    Full Text Available Rainfall deficiency and the development of salinity in Iran are the most important factors for using new salt and drought-resistant plants instead of conventional crops. Kochia species have recently attracted the attention of researchers as a forage and fodder crop in marginal lands worldwide due to its drought and salt tolerant characteristics. This field experiment was performed at the Salinity Research Station of Ferdowsi University of Mashhad, Iran, in a split plot based on randomized complete block design with three replications in 2008. Drought stress, including four levels (control, no irrigation in vegetative stage, no irrigation at reproductive stage and no irrigation at maturity stage for four weeks, and two Kochia ecotypes (Birjand and Borujerd were allocated as main and sub plots, respectively. Relative water content, electrolyte leakage, photosynthesis parameters and chlorophyll fluorescence were assayed every two week from late vegetative stage. Results showed that drought stress decreased significantly measured parameters in plants under stress, in all stages. Plants completely recovered after eliminating stress and rewatering and recovered plants did not show significant difference with control. Electrolyte leaking and chlorophyll fluorescence showed the lowest change among the measured parameters. It can emphasize that resistant to stress conditions in this plant and cell wall is not damaged at this level of stress situation. Birjand ecotype from the arid region, revealed a better response than Borujerd ecotype to drought stress. Probably it returns to initial adaptation of Birjand. In general this plant can recover after severe drought stress well. It is possible to introduce this plant as a new fodder in arid and saline conditions.

  19. Effect of Nitrogen and Triple Super Phosphate Levels on Physiological Characteristics of Kochia scoparia in Salinity Stress

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    saeed khaninejad

    2014-09-01

    Full Text Available Decreasing yield and forage quality in saline water irrigating conditions, is one of the problems of forage production. Therefore, using the chemical fertilizers can be considered as a useful solution. This study was conducted to assess the effects of different levels of phosphorus and nitrogen fertilizers with saline water on physiological characteristics of Kochia, through a split plot factorial experiments with three replications .The main experimental units consisted of the levels of salinity of irrigating water, 5.2 and 16.5 dS m-1, and the subsidiary experimental units consisted of three nitrogen levels in form of 46%N (0, 100, 200 kg ha-1 and three phosphorus levels in form of triple super phosphate (0, 75, 150 kg ha-1, arranged in factorial form in experimental units. Results showed that the effect of salinity on studied physiological properties was not significant. Green area index (GAI and membrane stability index (MSI were significantly increased with using nitrogen fertilizers on 5.2 dS/m salinity level to control group ,while phosphorus did not affect on them. In all properties, fertilizers application on 16.5 dS/m salinity level not only had no considerable effect on stress tolerance, but also increased the harmful effects of salinity. GAI had a high correlation (0.71 with dry forage yield related to the studied factors. Generally, 75 kg Triple Super Phosphate fertilizer from 100 kg Urea improved studied physiological properties without side effects.

  20. COMPOSICIÓN QUÍMICA, DEGRADACIÓN IN SITU E IN VITRO DE Kochia scoparia CON RELACIÓN A LA FECHA DE SIEMBRA Y EDAD DE CORTE

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    Manuel Gonzalez Ronquillo

    2011-05-01

    La Kochia scoparia es una fuente alternativa de proteína de calidad media para la alimentación en rumiantes; por lo anterior, es importante conocer su composición química, así como su degradación y fermentación en el rumen, ya que esta puede variar en función de la fecha de establecimiento y la edad al corte. Para ello se evaluó la composición química. La evaluación de la degradación se realizo mediante el uso de la técnica de producción de gas in vitro y la degradación ruminal in sacco. La Kochia scoparia se cultivo en tres fechas (F de siembra (F1, 07/12/2001; F2, 06/01/2002; y F3, 05/02/2002 y se realizó el corte a dos edades distintas (78 y 119 días postsiembra, C1 y C2, respectivamente. El contenido de MO (g 100g de MS fue superior (P≤0.05 para F1 (90.8 con respecto a F2 y F3 (89.1, y el contenido de PC cambio entre fechas de corte, (P≤0.05 F3 > F2 > F1 (16.4, 15.3, 13.3 %, respectivamente. La producción de gas in vitro (mL gas g-1 de MS no fue diferente (P≥0.05 entre fechas de siembra (185 pero sí para cortes (P≤0.05, siendo C1 > C2 (199.6 vs 171.7; en la degradación in vitro de la materia seca, no se observó diferencias (P≥0.05 entre fechas (53.11 mg 100 mg de MS pero C1 fue superior (P≤0.05 a C2 (59.3 vs 46.9 mg 100 mg de MS. La degradación de la proteína fue estimada mediante la incubación ruminal in situ (PDR, g 100g de MS, siendo superior (p≤0.05 F2 (71.8 con respecto a F1 y F3 (62.9 y 59.3 y C1 > C2 (P≤0.05 (67.6 vs 61.8. Por su contenido de PC, la Kochia scoparia se sugiere como una fuente alternativa de proteína de calidad media para los rumiantes, por tener una degradación en rumen superior al 60 %, la cual está influenciada por el estado de madurez de la planta y su fecha de establecimiento.  Â

  1. Optical Sensing of Weed Infestations at Harvest.

    Science.gov (United States)

    Barroso, Judit; McCallum, John; Long, Dan

    2017-10-19

    Kochia ( Kochia scoparia L.), Russian thistle ( Salsola tragus L.), and prickly lettuce ( Lactuca serriola L.) are economically important weeds infesting dryland wheat ( Triticum aestivum L.) production systems in the western United States. Those weeds produce most of their seeds post-harvest. The objectives of this study were to determine the ability of an optical sensor, installed for on-the-go measurement of grain protein concentration, to detect the presence of green plant matter in flowing grain and assess the potential usefulness of this information for mapping weeds at harvest. Spectra of the grain stream were recorded continuously at a rate of 0.33 Hz during harvest of two spring wheat fields of 1.9 and 5.4 ha. All readings were georeferenced using a Global Positioning System (GPS) receiver with 1 m positional accuracy. Chlorophyll of green plant matter was detectable in the red (638-710 nm) waveband. Maps of the chlorophyll signal from both fields showed an overall agreement of 78.1% with reference maps, one constructed prior to harvest and the other at harvest time, both based on visual evaluations of the three green weed species conducted by experts. Information on weed distributions at harvest may be useful for controlling post-harvest using variable rate technology for herbicide applications.

  2. Effect of Kochia (Kochia indica Plant Density on Yield and Some Physiological Characteristics of Sorghum under Salinity Stress

    Directory of Open Access Journals (Sweden)

    GH. Ranjbar

    2016-02-01

    Full Text Available This study was carried out in two years, 2012 and 2013, to determine the effects of salinity and different kochia plant densities on yield and some physiological characteristics of sorghum (cv. Sepideh at Salinity Research Center, National Salinity Research Center, Yazd, Iran. Treatments consisted of water salinity levels: 2 (control, 6, 10, and 14 dS m-1 of NaCl as main plots and different kochia (K. indica densities: 0 (weed free sorghum, D0, 80 (D1, 60 (D2, and 40 (D3 cm between kochia plants on the sorghum row as sub plots. Results showed that at each salinity level, increase in kochia plant density was accompanied by reduction in sorghum dry matter, leaf area index and crop growth rate. Decreases in dry matter and leaf area index of sorghum due to kochia were more pronounced when grown at salinities of up to 6 dS m-1. Chlorophyll content index at 6, 10 and 14 dS m-1 were 23, 32 and 40% lower than the non-saline control. Increase in irrigation water salinity was accompanied by increase in canopy temperature. Canopy temperature of plants subjected to 14 dS m-1 of salt was higher than the non–stressed control by 13.6%. The weed free sorghum treatment had the highest canopy temperature. Therefore, it is necessary to control both salinity and Kochia indica to avoid meaningful decreases in sorghum yield.

  3. Forage kochia: Friend or foe

    Science.gov (United States)

    Blair L. Waldron; R. Deane Harrison; N. Jerry Chatterton; Burke W. Davenport

    2001-01-01

    Perennial forage kochia (Kochia prostrata) is a halfshrub valuable for reclamation, fire breaks, and livestock and wildlife forage on semiarid and saline rangelands. Interest is mounting about this species, but some are concerned that it will become an invader of perennial communities. Only one cultivar (Immigrant) has been released in the United States. Eighty-one...

  4. Effects of Two Halophytic Plants (Kochia and Atriplex on Digestibility, Fermentation and Protein Synthesis by Ruminal Microbes Maintained in Continuous Culture

    Directory of Open Access Journals (Sweden)

    A. Riasi

    2012-05-01

    Full Text Available Eight continuous culture fermenters were used in a completely randomized design to evaluate various nutritional values of Kochia (Kochia scoparia compared with Atriplex (Atriplex dimorphostegia. Dried and pelleted samples (leaves and stems provided substrate for metabolism by ruminal microbes maintained in a continuous culture fermentation system. Results indicated that there were no differences (p>0.05 in dry matter (DM and crude protein (CP digestibility between the two halophytic plants. Atriplex had higher (p0.05 between the two halophytic plants in molar proportion of acetate and propionate, but the concentration of butyrate and valerate in Kochia were about two fold of Atriplex (p<0.05. When Kochia provided substrate to the microbes, protein synthesis was higher (p<0.05 compared with feeding Atriplex (5.96 vs. 4.85 g N/kg of OM truly digested. It was concluded that Kochia scoparia and Atriplex dimorphostegia had similar digestibility of DM and CP. It appears that these halophytic plants may not have enough digestible energy for high producing ruminants.

  5. Environ: E00364 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00364 Kochia scoparia fruit Crude drug Kochia scoparia [TAX:83154] Amaranthaceae (...amaranth family) Kochia scoparia fruit (dried) Crude drugs [BR:br08305] Dicot plants: others Amaranthaceae (amaranth family) E00364 Kochia fruit ...

  6. The genus Kochia (Chenopodiaceae) in North America

    Science.gov (United States)

    Ge-Lin Chu; Stewart Sanderson

    2008-01-01

    The genus Kochia and Bassia with which it has been combined, of Chenopodiaceae tribe Camphorosmeae, were at one time considered to include plants native to Eurasia, Australia, and North America, and included species of both C3 and C4 photosynthetic types. This aggregate has been reduced in size by removal of a large group of C3 Australian genera and species. Because of...

  7. Artemisia scoparia – A new source of artemisinin

    Directory of Open Access Journals (Sweden)

    Aditi Singh

    2010-03-01

    Full Text Available Artemisinin is considered as the most active and potent antimalarial drug. Till date Artemisia annua Linn. plant is the only source for its production The present investigation was carried out with an objective to search a new plant for artemisinin. An attempt was made on a perennial faintly odoratus herb, Artemisia scoparia Waldst et Kit. to find out an alternative of A. annua for the production of artemisinin. The yield of artemisinin was higher in aerial plant parts (0.015% in comparison to callus culture (0.001%. The present study concluded that Artemisia scoparia contains an antimalarial drug artemisinin.

  8. Artemisia scoparia – A new source of artemisinin

    Directory of Open Access Journals (Sweden)

    Aditi Singh

    2010-06-01

    Full Text Available Artemisinin is considered as the most active and potent antimalarial drug. Till date Artemisia annua Linn. plant is the only source for its production The present investigation was carried out with an objective to search a new plant for artemisinin. An attempt was made on a perennial faintly odoratus herb, Artemisia scoparia Waldst et Kit. to find out an alternative of A. annua for the production of artemisinin. The yield of artemisinin was higher in aerial plant parts (0.015% in comparison to callus culture (0.001%. The present study concluded that Artemisia scoparia contains an antimalarial drug artemisinin.

  9. hispidulin and other constituents of scoparia dulcis linn

    African Journals Online (AJOL)

    Administrator

    Chemical and Pharmaceutical Bulletin, 35: 3963-3966. Hayashi T., Kawasaki M., Miwa Y., Taga T. and Morita N. (1990). “Antiviral agent of plant origin. III. Scopadulin, a novel tetra- cyclic diterpene from Scoparia dulcis L”. Chemical and Pharmaceutical Bulletin, 38. (4): 945-947. Hayashi T., Kishi M., Kawasaki M., Arisawa.

  10. Page 1 Chemical Examination of Artemisia scoparia Waldst, and Kit ...

    Indian Academy of Sciences (India)

    Chemical Examination of Artemisia scoparia Waldst, and Kit, 155. Scoparin is insoluble in concentrated hydrochloric acid either in the cold or in the hot. When treated with aqueous or alcoholic caustic potash, it dissolves with an intense yellow coloration, which is characteristic of many unsaturated lactones. It does not give ...

  11. Scoparia dulcis reduces the severity of Trypanosoma bruceiinduced ...

    African Journals Online (AJOL)

    We investigated the effect of oral administration of the herb, Scoparia dulcis, on Trypanosoma bruceiinduced changes in plasma lipid profile in rabbits over a period of twenty eight days. Results obtained show that infection with T. brucei resulted in significant increases in plasma total cholesterol, trriacylglycerol, and low ...

  12. Agronomic Weeds.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University examines agronomic weed problems and control. Contents include a listing of the characteristics of weeds, a section on herbicides, and a section on the important weeds of agronomic crops in Pennsylvania. The herbicide section discusses systemic herbicides, contact…

  13. 'Snowstorm' a new forage kochia cultivar with improved stature, productivity, and nutritional content for enhanced fall and winter grazing

    Science.gov (United States)

    'Snowstorm' forage kochia (Bassia prostrata [L.] A.J. Scott) (synonym=Kochia prostrata [L.] Schrad.) (Reg. No. CV-_____, PI _____) was released on March 22, 2012, by the USDA-ARS and the Utah Agricultural Experiment Station. Snowstorm was evaluated as OTVSEL and Otavny-select, and was developed as ...

  14. Essential oil of Artemisia scoparia inhibits plant growth by generating reactive oxygen species and causing oxidative damage.

    Science.gov (United States)

    Singh, Harminder Pal; Kaur, Shalinder; Mittal, Sunil; Batish, Daizy Rani; Kohli, Ravinder Kumar

    2009-02-01

    We investigated the chemical composition and phytotoxicity of the essential oil extracted from leaves of Artemisia scoparia Waldst. et Kit. (red stem wormwood, Asteraceae). GC/GC-MS analyses revealed 33 chemical constituents representing 99.83% of the oil. The oil, in general, was rich in monoterpenes that constitute 71.6%, with beta-myrcene (29.27%) as the major constituent followed by (+)-limonene (13.3%), (Z)-beta-ocimene (13.37%), and gamma-terpinene (9.51%). The oil and beta-myrcene were evaluated in a dose-response bioassay under laboratory conditions for phytotoxicity against three weeds-Avena fatua, Cyperus rotundus, and Phalaris minor. A significant reduction in germination, seedling growth, and dry matter accumulation was observed in the test weeds. At the lowest treatment of 0.07 mg/ml Artemisia oil, germination was reduced by 39%, 19%, and 10.6% in C. rotundus, P. minor, and A. fatua, respectively. However, the inhibitory effect of beta-myrcene was less. In general, a dose-dependent effect was observed and the growth declined with increasing concentration. Among the three weeds, the inhibitory effect was greatest on C. rotundus, so it was selected for further studies. We explored the explanation for observed growth inhibition in terms of reactive oxygen species (ROS: lipid peroxidation, membrane integrity, and amounts of conjugated dienes and hydrogen peroxide)-induced oxidative stress. Exposure of C. rotundus to Artemisia oil or beta-myrcene enhanced solute leakage, indicating membrane disintegration. There were increased levels of malondialdehyde and hydrogen peroxide, indicating lipid peroxidation and induction of oxidative stress. We conclude that Artemisia oil inhibits plant root growth through generation of ROS-induced oxidative damage.

  15. Biological recovery the steppe of Hammada scoparia after enclosure in the region of Naama (Algeria

    Directory of Open Access Journals (Sweden)

    Boucherit Hafidha

    2017-03-01

    Full Text Available This work was being carried out in the steppe of remth (Hammada scoparia in Oranian part of the Saharan Atlas (Tiout - south of Naama. The H. scoparia of Saharan group occupies the foothills south of the Saharan Atlas and glazes and hamadas of the northern part of the Sahara where it seems to find its optimum development. The objective of the study is the floristic and ecological characterisation of the steppe vegetation groups of H. scoparia after 4 years of enclosure grazing (Eg. For the past three decades, steppe of H. scoparia were completely overwhelmed, both in their structure and their operation by increasing the herd and the continued use of natural pastures using animal load significantly higher than the production potential of course, which is reflected by the reduction of their capacity for natural regeneration.

  16. Robotic weeding and automated weed measurements

    DEFF Research Database (Denmark)

    Christensen, S.; Søgaard, H.T.; Jørgensen, R.N.

    2003-01-01

    The goal of decreasing herbicide usage has so far focused on reducing the herbicide dosage or replacing chemical weed control by hoeing and harrowing. The conventional weed control strategy is to apply the same dose of herbicide or the same intensity of hoeing and harrowing in the whole field...... the state-of-the-art of automated weed measurement methods and the research projects concerning autonomous platform and information system for crop and weed monitoring and robotic weeding....

  17. ECOLOGICAL WEED MANAGEMENT

    OpenAIRE

    Radicetti, Emanuele

    2012-01-01

    Nowadays there is much concern over environmental and human health impacts on weed management practices which has led agricultural producers and scientists in many countries to seek innovative strategies for weed control. As weed management systems are being developed, ecological knowledge will become more and more important and the complexity of weed management must be considered. Therefore understanding weed-crop ecology will lead to more effective weed prevention, management, and control t...

  18. Evaluation of antimalarial, free-radical-scavenging and insecticidal activities of Artemisia scoparia and A. Spicigera, Asteraceae

    Directory of Open Access Journals (Sweden)

    Fariba H. Afshar

    2011-12-01

    Full Text Available Artemisia species (Asteraceae, widespread throughout the world, are a group of important medicinal plants. The extracts of two medicinal plants of this genus, Artemisia scoparia Waldst. & Kit. and A. spicigera C. Koch, were evaluated for potential antimalarial, free-radical-scavenging and insecticidal properties, using the heme biocrystallisation and inhibition assay, the DPPH assay and the contact toxicity bioassay using the pest Tribolium castaneum, respectively. The methanol extracts of both species showed strong free-radical-scavenging activity and the RC50 values were 0.0317 and 0.0458 mg/mL, respectively, for A. scoparia and A. spicigera. The dichloromethane extracts of both species displayed a moderate level of potential antimalarial activity providing IC50 at 0.778 and 0.999 mg/mL for A. scoparia and A. spicigera, respectively. Both species of Artemisia showed insecticidal properties. However, A. spicigera was more effective than A. scoparia.

  19. Ecologically sustainable weed management

    DEFF Research Database (Denmark)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne

    2016-01-01

    , and greater weed impacts due to changes in climate and land use. Broad-scale use of new approaches is needed if weed management is to be successful in the coming era. We examine three approaches likely to prove useful for addressing current and future challenges from weeds: diversifying weed management......Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade...... strategies with multiple complementary tactics, developing crop genotypes for enhanced weed suppression, and tailoring management strategies to better accommodate variability in weed spatial distributions. In all three cases, proof-of-concept has long been demonstrated and considerable scientific innovations...

  20. Crop–weed competition

    DEFF Research Database (Denmark)

    Gallandt, Eric R.; Weiner, Jacob

    2015-01-01

    Competition from weeds is the most important of all biological factors that reduce agricultural crop yield. This occurs primarily because weeds use resources that would otherwise be available to the crop. The magnitude of yield loss is affected by numerous agronomic and environmental factors, most...... importantly, weed density and time of emergence relative to the crop. Practices that (1) reduce the density of weeds, (2) maximise occupation of space or uptake of resources by the crop or (3) establish an early-season size advantage of the crop over the weeds will minimise the competitive effects of weeds...... on crops. Longer term management of crop–weed competition can be achieved through crop rotations, specifically crop sequences that reduce the weed seed bank, and therefore seedling density, and prevent proliferation of perennial weeds. Key ConceptsKey Concepts * Plant growth requires sunlight, water...

  1. Evaluation of anti-nociceptive, anti-inflammatory and antipyretic activities of Artemisia scoparia hydromethanolic extract.

    Science.gov (United States)

    Habib, Muheet; Waheed, Ishrat

    2013-01-09

    Artemisia scoparia (redstem wormwood) locally known as jhahoo or jaukay, is traditionally used in pain, inflammation and febrile conditions. So far, little or no scientific work has been reported to validate its folk uses in the alleviation of pain, fever and inflammation. The present study was designed to explore the analgesic, anti-inflammatory and antipyretic effects of the Artemisia scoparia hydromethanolic extract (ASHME), and to validate its traditional use in Asia. This study made use of thermal (hot plate induced) and chemical (acetic acid induced) nociception models in mice. In addition, the mechanism of antinociception in hot plate test was further evaluated in the presence of caffeine (10mg/kg), naloxone (2mg/kg) and monosodium glutamate (1g/kg). While carrageenan induced rat paw edema and yeast induced mouse pyrexia models were used to test the anti-inflammatory and antipyretic activities. Administration of single intraperitoneal doses (400mg/kg and 800 mg/kg) of ASHME significantly reduced the carrageenan induced paw edema in rats (P400mg/kg). These findings suggest that the Artemisia scoparia hydromethanolic extract of ASHME possesses anti-nociceptive, anti-inflammatory and antipyretic potentials, which support its use, for the said conditions, in traditional medicine and should be further exploited for its use in clinical medicine. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Alteration in Memory and Electroencephalogram Waves with Sub-acute Noise Stress in Albino Rats and Safeguarded by Scoparia dulcis.

    Science.gov (United States)

    Loganathan, Sundareswaran; Rathinasamy, Sheeladevi

    2016-01-01

    Noise stress has different effects on memory and novelty and the link between them with an electroencephalogram (EEG) has not yet been reported. To find the effect of sub-acute noise stress on the memory and novelty along with EEG and neurotransmitter changes. Eight-arm maze (EAM) and Y-maze to analyze the memory and novelty by novel object test. Four groups of rats were used: Control, control treated with Scoparia dulcis extract, noise exposed, and noise exposed which received Scoparia extract. The results showed no marked difference observed between control and control treated with Scoparia extract on EAM, Y-maze, novel object test, and EEG in both prefrontal and occipital region, however, noise stress exposed rats showed significant increase in the reference memory and working memory error in EAM and latency delay, triad errors in Y-maze, and prefrontal and occipital EEG frequency rate with the corresponding increase in plasma corticosterone and epinephrine, and significant reduction in the novelty test, and significant reduction in the novelty test, amplitude of prefrontal, occipital EEG, and acetylcholine. These noise stress induced changes in EAM, Y-maze, novel object test, and neurotransmitters were significantly prevented when treated with Scoparia extract and these changes may be due to the normalizing action of Scoparia extract on the brain, which altered due to noise stress. Noise stress exposure causes EEG, behavior, and neurotransmitter alteration in the frontoparietal and occipital regions mainly involved in planning and recognition memoryOnly the noise stress exposed animals showed the significant alteration in the EEG, behavior, and neurotransmittersHowever, these noise stress induced changes in EEG behavior and neurotransmitters were significantly prevented when treated with Scoparia extractThese changes may be due to the normalizing action of Scoparia dulcis (adoptogen) on the brain which altered by noise stress. Abbreviations used: EEG

  3. Modelling weed emergence patterns

    NARCIS (Netherlands)

    Vleeshouwers, L.M.

    1997-01-01

    Anticipating weed pressure may be important in selecting and timing weed control measures in order to optimize their effectiveness, and thus reduce herbicide use. Therefore, a predictive model of the time of emergence and the numbers of seedling emerging (the weed emergence pattern) after

  4. Ecologically sustainable weed management

    NARCIS (Netherlands)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne; Childs, Dylan; Christensen, Svend; Cousens, Roger; Eizenberg, Hanan; Heijting, Sanne; Loddo, Donato; Merotto, Aldo; Renton, Michael; Riemens, Marleen

    2016-01-01

    Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade, and

  5. Horny Goat Weed

    Science.gov (United States)

    Horny goat weed is an herb. The leaves are used to make medicine. As many as 15 horny goat weed species are known as “yin yang huo” in Chinese medicine. Horny goat weed is used for weak back and knees, joint ...

  6. Weed exterminator and method of exterminating weed

    NARCIS (Netherlands)

    Van der Tempel, J.

    2010-01-01

    The invention relates to a method of exterminating weed, which method comprises the steps of: providing an extermination chamber (14, 14a, 14b, 14c) having at least one open side (14d), placing the open side (14d) over weed to be exterminated; substantially closing off the edge of the open side of

  7. Weed exterminator and method of exterminating weed

    OpenAIRE

    Van der Tempel, J.

    2010-01-01

    The invention relates to a method of exterminating weed, which method comprises the steps of: providing an extermination chamber (14, 14a, 14b, 14c) having at least one open side (14d), placing the open side (14d) over weed to be exterminated; substantially closing off the edge of the open side of the extermination chamber (14, 14a, 14b) and the ground or soil in which the weed is present; providing a refrigerant in the extermination chamber (14, 14a, 14b, 14c); keeping the extermination cham...

  8. Herbicide Resistant Weed Management

    Science.gov (United States)

    Metribuzin and rimsulfuron are the only two herbicides registered for postemergence broadleaf weed control in potatoes, and represent the two classes of herbicides, triazines and ALS inhibitors, with the most reported cases of resistant weeds world wide. Other postemergence grass herbicides belongin...

  9. Effect of Plowing Frequency and Weeding Methods on Weeds and ...

    African Journals Online (AJOL)

    The effect of repeated tillage and weed control methods on weed infestation and ... Grain yield reduction in zero-till and three times plowing was 59 and 21%, ... Twice weeding reduced weed population by 28% and increased wheat grain yield ...

  10. Weed ecology and population dynamics

    Science.gov (United States)

    A global rise in herbicide resistant weed genotypes, coupled with a growing demand for food produced with minimal external synthetic inputs, is driving producer interest in reducing reliance on herbicides for weed management. An improved understanding of weed ecology can support the design of weed s...

  11. Three new anti-HBV active constituents from the traditional Chinese herb of Yin-Chen (Artemisia scoparia).

    Science.gov (United States)

    Geng, Chang-An; Huang, Xiao-Yan; Chen, Xing-Long; Ma, Yun-Bao; Rong, Guang-Qing; Zhao, Yong; Zhang, Xue-Mei; Chen, Ji-Jun

    2015-12-24

    Yin-Chen is a famous traditional Chinese medicine (TCM) in China for the treatment of acute and chronic hepatitis. Two species, namely Artemisia scoparia and Artemisia capillaris, are documented in Chinese Pharmacopoeia as the authentic resources for Yin-Chen. Previous investigation has proved that chlorogenic acid analogs and phenolic acids are two main types of the anti-HBV active constituents of A. capillaris. However, there is no investigation concerned with the anti-HBV components of A. scoparia. The aim of the present study is to recognize the new anti-HBV constituents of A. scoparia by detailed LCMS analyses. LCMS and bioassay-guided fractionation on the active part of A. scoparia led to the isolation of three new compounds. Their structures were determined by detailed spectroscopic analyses. Anti-HBV assay involving inhibition on HBsAg and HBeAg secretions and HBV DNA replication were performed in virto on HepG 2.2.15 cell line. The 90% ethanol extract of A. scoparia was revealed with anti-HBV activity for the first time, which was further separated into several fractions by column chromatography. Fr. D-4 was revealed with the highest anti-HBV activity, from which three new compounds including one unusual 4-pyridone glucoside (1) and two polyacetylene glucosides (2-3) were isolated under the guidance of LCMS analyses. Compounds 1-3 exhibited activity against the secretions of HBsAg and HBeAg, and HBV DNA replication. In particular, compounds 2 and 3 inhibited HBV DNA replication with IC50 values of 0.07 ± 0.04 and 0.012 ± 0.05 mM, with SI values of 23.6 and 17.1, respectively. Based on the MS/MS experiment, the fragmentation pathways of 1 in both positive and negative modes, and 2 and 3 in negative mode were proposed. The ion pairs of 388-208 (positive) and 432-206 (negative) for 1, 503-341 (negative) for 2, and 503-203 (negative) for 3, could be recognized as their respective diagnostic ions. The first time investigation on the anti-HBV constituents of A

  12. Transdisciplinary weed research: new leverage on challenging weed problems?

    Science.gov (United States)

    Transdisciplinary Weed Research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social aspec...

  13. Transdisciplinary weed research: new leverage on challenging weed problems?

    NARCIS (Netherlands)

    Jordan, N.; Schut, M.; Graham, S.; Barney, J.N.; Childs, D.Z.; Christensen, S.B.; Cousens, R.D.; Davis, A.S.; Eizenberg, H.; Ervin, D.E.; Fernandez-Quintanilla, C.; Harrison, L.J.; Harsch, M.A.; Heijting, S.; Liebman, M.; Loddo, D.; Mirsky, S.B.; Riemens, M.; Neve, P.; Peltzer, D.A.; Renton, M.; Williams, M.; Recasens, J.; Sønderskov, M.

    2016-01-01

    Transdisciplinary weed research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social

  14. Effect of plant spacing and weeding frequency on weed infestation ...

    African Journals Online (AJOL)

    Common bean is an important food and cash crop in eastern Ethiopia. However, its yield is constrained by weeds. Therefore, this study was conducted in 2012 main cropping season at Haramaya and Hirna research fields, eastern Ethiopia, to determine the effect of plant spacing and weeding frequency on weeds, yield ...

  15. Weeds and Wildlife: Perceptions and Practices of Weed Managers

    Directory of Open Access Journals (Sweden)

    Emma H Carlos

    2014-01-01

    Full Text Available Negative impacts of invasive plants or weeds on biodiversity have been well established yet their role in providing key habitats and resources for wildlife has been little understood. Weed removal thus has the potential to adversely affect wildlife but whether this is considered during weed management is poorly known. To determine the extent of this knowledge, we examined the perceptions of weed managers regarding wildlife and weed management in Victoria, Australia. We surveyed 81 weed managers of varying levels of experience from different types of organisations, including state and local government, community groups and private companies. We found 90% of managers had observed wildlife-weed interactions and that most (70% adjusted management programmes to accommodate wildlife. Despite this, few (19% had adopted the recommended practice of combining gradual weed removal with re-vegetation. While management programmes included monitoring of native vegetation, consideration of wildlife monitoring in weed management was rare. This highlights the need for management to better understand and respond to wildlife-weed relationships. If the improvement of wildlife habitat is included in the objectives of weed programmes, as it should be, then wildlife should also be incorporated in project monitoring. This would lead to a greater understanding of the role weeds and their management have in each situation and, ultimately, more informed decision making.

  16. Anti-anxiety activity of hydro alcoholic extract of Scoparia dulcis Linn. assessed using different experimental anxiety models In rodents

    Directory of Open Access Journals (Sweden)

    Arasan Elayaraja

    2015-03-01

    Full Text Available Scoparia dulcis belonging to the family Scrophulariaceae is an valuable medicinal herb, had showed antiviral, antimalarial, anticancer and antidiabetic activities. The present study was aimed to investigate the anti-anxiety activity of crude ethanolic extract of S.dulcis L by various behavioural models. Preliminary phytochemical investigation revealed the presence of  phenols and flavonoids. The extract at 100mg/kg and 200mg/kg was evaluated for anti anxiety activity by  Open-field test [OFT], Elevated plus-maze test [EPM], Elevated Zero-maze test [EZM],, Social interaction test [SI] And  Novelty induced suppressed feeling latency test [FL]   and the results of behavioral tests indicated the dose dependent anti-anxiety activity of  Scoparia dulcis which is comparable to standard. It was concluded that crude ethanolic extract showed anti anxiety activity.Further studies are needed to identify the anxiolytic mechanism(s and the phytochemicals responsible for the observed anxiolytic effect  of the hydroalcoholic extract of Scoparia dulcis. 

  17. Grass and weed killer poisoning

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002838.htm Grass and weed killer poisoning To use the sharing features on this page, please enable JavaScript. Many weed killers contain dangerous chemicals that are harmful if ...

  18. Proficiencies of Artemisia scoparia against CCl4 induced DNA damages and renal toxicity in rat.

    Science.gov (United States)

    Sajid, Moniba; Khan, Muhammad Rashid; Shah, Naseer Ali; Ullah, Shafi; Younis, Tahira; Majid, Muhammad; Ahmad, Bushra; Nigussie, Dereje

    2016-05-27

    Artemisia scoparia is traditionally used in the local system of medicine in kidney disorders. This study aimed at scrutinizing the nephroprotective prospective of A. scoparia methanol extract against carbon tetrachloride (CCl4) provoked DNA damages and oxidative stress in kidneys of rat. Dried aerial parts of A. scoparia were powdered and extracted with methanol to obtain the viscous material (ASM). Sprague Dawley male rats (42) were grouped (7) having 6 rats in each. Group I remained untreated and Group II treated intraperitoneally (i.p) with DMSO + olive oil (1 ml/kg body weight (bw). Rats of Group III - VI were treated with CCl4 (1 ml/kg bw; i.p 30 % v/v in olive oil). Animals of Group IV were co-administered with 100 mg/kg bw of silymarin whereas rats of Group V and VI with 150 mg/kg bw and 300 mg/kg bw of ASM at an interval of 48 h for four weeks. Animals of Group VII were administered with ASM (300 mg/kg bw) alone. DNA damages were investigated with comet assay in renal tissues while the oxidative injuries were estimated in serum and renal tissues. Co-administration of ASM to rats significantly reduced the DNA damages at 300 mg/kg dose as indicated in comet length (40.80 ± 2.60 μm), head length (34.70 ± 2.21 μm), tail length (7.43 ± 1.24 μm) and DNA content in head (88.03 ± 2.27 %) to that of CCl4 for comet length (63.16 ± 2.11 μm), head length (23.29 ± 1.50 μm), tail length (39.21 ± 2.81 μm) and DNA content of head (74.81 ± 2.18 %) in renal cell's nuclei. Increased level of urea, creatinine, bilirubin, blood urea nitrogen whereas decreased concentration of proteins in serum of CCl4 treated animals were restored towards the normal level with co-administration of ASM. CCl4 injection in rats decreased the activity level of CAT, POD, SOD, GST and γ-GT and GSH contents while elevated levels of TBARS, H2O2 and nitrite contents were observed in renal tissues. A noteworthy retrieval of all these

  19. Artemisia scoparia Enhances Adipocyte Development and Endocrine Function In Vitro and Enhances Insulin Action In Vivo

    Science.gov (United States)

    Richard, Allison J.; Fuller, Scott; Fedorcenco, Veaceslav; Beyl, Robbie; Burris, Thomas P.; Mynatt, Randall; Ribnicky, David M.; Stephens, Jacqueline M.

    2014-01-01

    Background Failure of adipocytes to expand during periods of energy excess can result in undesirable metabolic consequences such as ectopic fat accumulation and insulin resistance. Blinded screening studies have indicated that Artemisia scoparia (SCO) extracts can enhance adipocyte differentiation and lipid accumulation in cultured adipocytes. The present study tested the hypothesis that SCO treatment modulates fat cell development and function in vitro and insulin sensitivity in adipose tissue in vivo. Methods In vitro experiments utilized a Gal4-PPARγ ligand binding domain (LBD) fusion protein-luciferase reporter assay to examine PPARγ activation. To investigate the ability of SCO to modulate adipogenesis and mature fat cell function in 3T3-L1 cells, neutral lipid accumulation, gene expression, and protein secretion were measured by Oil Red O staining, qRT-PCR, and immunoblotting, respectively. For the in vivo experiments, diet-induced obese (DIO) C57BL/6J mice were fed a high-fat diet (HFD) or HFD containing 1% w/w SCO for four weeks. Body weight and composition, food intake, and fasting glucose and insulin levels were measured. Phospho-activation and expression of insulin-sensitizing proteins in epididymal adipose tissue (eWAT) were measured by immunoblotting. Results Ethanolic extracts of A. scoparia significantly activated the PPARγ LBD and enhanced lipid accumulation in differentiating 3T3-L1 cells. SCO increased the transcription of several PPARγ target genes in differentiating 3T3-L1 cells and rescued the negative effects of tumor necrosis factor α on production and secretion of adiponectin and monocyte chemoattractant protein-1 in fully differentiated fat cells. DIO mice treated with SCO had elevated adiponectin levels and increased phosphorylation of AMPKα in eWAT when compared to control mice. In SCO-treated mice, these changes were also associated with decreased fasting insulin and glucose levels. Conclusion SCO has metabolically beneficial

  20. Biotechnology in weed control

    Science.gov (United States)

    Biotechnology can be used to enhance the management of weeds in several ways. Crops have been made resistant to herbicides by inserting transgenes that impart herbicide resistance into the plant genome. Glyphosate and glufosinate-resistant crops are commercialized in North America and crops made res...

  1. Robotic weed monitoring

    DEFF Research Database (Denmark)

    Bochtis, Dionysis; Sørensen, Claus Aage Grøn; Jørgensen, R N

    2011-01-01

    -farm operating console, the mobile robotic unit, and a field server for generating and storingmaps. The hypothesis is that it is possible to automate the planning and execution of theoperation of monitoring of the in-field weed density and species distribution. The developedplanning system includes the automatic...

  2. Weed Identification and Control in Vegetable Crops.

    Science.gov (United States)

    Ferretti, Peter A., Comp.

    This agriculture extension service publication from Pennsylvania State University examines weed control and identification in vegetable crops. Contents include: (1) Types of weeds; (2) Reducing losses caused by weeds, general control methods and home garden weed control; (3) How herbicides are used; (4) Specific weeds in vegetable plantings; and…

  3. INTEGRATED WEED CONTROL IN MAIZE.

    Science.gov (United States)

    Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

    2015-01-01

    Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach.

  4. WeedML: a Tool for Collaborative Weed Demographic Modeling

    OpenAIRE

    Holst, Niels

    2010-01-01

    WeedML is a proposed standard to formulate models of weed demography, or maybe even complex models in general, that are both transparent and straightforward to re-use as building blocks for new models. The paper describes the design and thoughts behind WeedML which relies on XML and object-oriented systems development. Proof-of-concept software is provided as open-source C++ code and executables that can be downloaded freely.

  5. of different weed control methods on weed infestation, growth and ...

    African Journals Online (AJOL)

    thinkexploitsint'l

    Poor soybean yield in farmers' plots is attributable to weed-crop competition and low soil fertility. (Sodangi et al. ... The Kwara State government is determined to modernize agriculture and make farming more attractive through ..... integrated with hand weeding recorded far superior yields of soybean seed. Also, a number of.

  6. The Effects of Different Weed Control Methods on Weed Infestation ...

    African Journals Online (AJOL)

    A field experiment was conducted during the 2012 and 2013 rainy season at the Kwara State University Teaching and Research Farm located in Malete. The aim was to determine the effect(s) of different weed control methods on Weed infestation, growth and yield of soybeans (variety TGX 1448 – 2E). The experiment ...

  7. A Method of Hepatocyte Extraction Conjugated with HPLC is Established for Screening Potential Active Components in Chinese Medicines—Probing Herba Artemisiae Scopariae as an Exemplifying Approach

    Directory of Open Access Journals (Sweden)

    Hong-Wei Fan

    2012-02-01

    Full Text Available In order to establish an effective and quick method for screening potential bioactive compounds in Traditional Chinese Medicines (TCMs, hepatocytes were employed for extracting either bifendate, a clinical medicine for liver diseases, or chemicals in Herba Artemisiae Scopariae (A. Scopariae, a commonly used traditional Chinese medicine for remedying liver diseases such as hepatitis induced by viruses, chemicals or alcohol. After hepatocyte extraction the compounds were analyzed by HPLC, therefore this method was referrred to as hepatocyte extraction conjugated with HPLC (HE-HPLC. In the first part of this study, HE-HPLC showed that bifendate was extracted by hepatocytes and detected by HPLC-DAD which indicated the feasibility of this method. Then in the second part of the study, the potential active components in the A. scopariae extract were studied using HE-HPLC. Six chemicals in the A. scopariae extract, which could bind to hepatocytes in vitro, were detected by HPLC-DAD and three were identified as 7-hydroxy-coumarin (7-OH-C, capillartemisin A and 7-methoxy-coumarin, respectively. In vitro assays showed that 7-OH-C protected HL-7702 hepatocytes from H2O2 injury. The results indicated that these compounds could be extracted by hepatocytes, could be detected by HPLC and more importantly were bioactive. It is suggested that HE-HPLC is a useful method for screening potent active components in Chinese medicines used to treat liver diseases.

  8. Weed Identification Field Training Demonstrations.

    Science.gov (United States)

    Murdock, Edward C.; And Others

    1986-01-01

    Reviews efforts undertaken in weed identification field training sessions for agriprofessionals in South Carolina. Data over a four year period (1980-1983) revealed that participants showed significant improvement in their ability to identify weeds. Reaffirms the value of the field demonstration technique. (ML)

  9. Interference of allelopathic wheat with different weeds.

    Science.gov (United States)

    Zhang, Song-Zhu; Li, Yong-Hua; Kong, Chui-Hua; Xu, Xiao-Hua

    2016-01-01

    Interference of allelopathic wheat with weeds involves a broad spectrum of species either independently or synergistically with competitive factors. This study examined the interference of allelopathic wheat with 38 weeds in relation to the production of allelochemical 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) in wheat with and without root-root interactions. There were substantial differences in weed biomass and DIMBOA concentration in wheat-weed coexisting systems. Among 38 weeds, nine weeds were inhibited significantly by allelopathic wheat but the other 29 weeds were not. DIMBOA levels in wheat varied greatly with weed species. There was no significant relationship between DIMBOA levels and weed suppression effects. Root segregation led to great changes in weed inhibition and DIMBOA level. Compared with root contact, the inhibition of eight weeds was lowered significantly, while significantly increased inhibition occurred in 11 weeds with an increased DIMBOA concentration under root segregation. Furthermore, the production of DIMBOA in wheat was induced by the root exudates from weeds. Interference of allelopathic wheat with weeds not only is determined by the specificity of the weeds but also depends on root-root interactions. In particular, allelopathic wheat may detect certain weeds through the root exudates and respond by increasing the allelochemical, resulting in weed identity recognition. © 2015 Society of Chemical Industry.

  10. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  11. 7 CFR 201.15 - Weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation or...

  12. 75 FR 68945 - Update of Noxious Weed Regulations

    Science.gov (United States)

    2010-11-10

    ..., carnation weed. Geraldton carnation-weed, leiteira. Inula britannica British elecampane British elecampane..., fingergrass),'' ``Euphorbia terracina Linnaeus (false caper, Geraldton carnation weed)'', ``Inula britannica...

  13. Weed clearance in Hudiara Nallah by chemical weed control

    Energy Technology Data Exchange (ETDEWEB)

    Dhillon, G.S

    1981-11-15

    Hudiara Nallah is a flood stream in West Punjab. It has a length of about 45km and breadth of nearly 25 metres. About 20 subsidiary drains join with the Nallah. These drains have a length of about 270km. The Nallah has a discharge capacity of 1248 cusecs. Most of the subsidiary drains start from ponds which are generally infected with Eichhornia plants. These plants enter into the subsidiary drains and finally into Hudiara Nallah. The plants float freely on the surface of water and multiply at a high rate. One plant of the weed propagates to 24 plants in a period of one month. The plants thus cover the whole drain in a few months. The weed also originates from seeds. Their heavy growth forms a mat-like surface. The weeds also choke bridges and sometimes cause damage to their structures. These obstruct the flow of water and decrease the carrying capacity of the drain. Their infestation thus causes floods and the very purpose of the drains gets lost. Thus the Nallah is heavily infested with Eichhornia crassipes (water hyacinth weed). Due to its fast propagation and heavy infestation it was not possible to clear the weed manually. The problem was, therefore, referred to the Chemistry Division of the Irrigation and Power Research Institute, Amritsar, by the Drainage Circle of the Irrigation Department in June 1978 when weed propagation was in full swing. A chemical treatment method of eradication was attempted.

  14. Energy options in weed control

    Energy Technology Data Exchange (ETDEWEB)

    Rao, A.R.; Bhan, V.M.

    1985-08-01

    Taking into account the energy costs of weedicide production, formulation, transportation and the fixed energy inputs through equipment on farms in Haryana and the man-days needed for weed control, the energy inputs in weed control by manual or chemical methods have been evaluated. Use of 2,4-D accounts for about 84 Mcal/ha of wheat or rice. Methabenzthiazuron as an alternative would account for the consumption of 248 Mcal/ha. Manual weeding in wheat accounts for 46 Mcal/ha and in a crop of rice for 54 Mcal/ha. Weed control, by whatever method, accounts for 0.5-2.7% of the energy inputs needed to raise a crop of wheat or rice in Haryana and is not a significant energy user.

  15. Brassicas limited in weed control

    OpenAIRE

    Kristiansen, P

    2006-01-01

    This article discusses the limitations of using brassica cover crops for weed control. A brief overview of the role of cover crops is provided, followed by a short review of research looking at brassica cover crops.

  16. WEED INFESTATION IN DIFFERENT FARMING SYSTEMS

    Directory of Open Access Journals (Sweden)

    MAGDALENA LACKO-BARTOŠOVÁ

    2002-05-01

    Full Text Available The aim of this work was to investigate the influence of ecological and conventional farming systems on weed seedbank and actual weed infestation of winter wheat at agricultural farms Sebechleby, Plavé Vozokany and Dačov Lom. Significant differences between systems were determined only at the co-operative Sebechleby where the higher weed seedbank was in ecological system. Higher number of determined weed species in weed seedstock was in ecological system at Plavé Vozokany and Sebechleby. Dominant weed species in both systems were Chenopodium album L. and Amaranthus retroflexus L.. Higher degree of actual weed infestation was determined in ecological system. Characteristics of systems was the occurrence of perennial species Cirsium arvense and non detection of Amaranthus retroflexus L., weed that had very high weed seedbank in soil.

  17. Site-specific weed control technologies

    DEFF Research Database (Denmark)

    Christensen, Svend; Søgaard, Henning Tangen; Kudsk, Per

    2009-01-01

    Site-specific weed control technologies are defined as machinery or equipment embedded with technologies that detect weeds growing in a crop and, taking into account predefined factors such as economics, takes action to maximise the chances of successfully controlling them. In the article, we...... describe the basic parts of site specific weed control technologies, comprising of weed sensing systems, weed management models and precision weed control implements. A review of state-of-the-art technologies shows that several weed sensing systems and precision implements have been developed over the last...... two decades, though barriers prevent their breakthrough. Most important among these is the lack of a truly robust weed recognition method, owing to mutual shading among plants and limitations in the capacity of highly accurate spraying and weeding apparatuses.   Another barrier is the lack...

  18. Can global weed assemblages be used to predict future weeds?

    Directory of Open Access Journals (Sweden)

    Louise Morin

    Full Text Available Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems.

  19. Sheldon-Hart - High Desert Weed Management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — (1)Treat 500 acres of previously mapped invasive weeds on Hart Mountain; followup monitoring and spot treatment where needed, (2)treat 110 acres of invasive weeds...

  20. Little Pend Oreille - Weeding for Wildlife

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project builds on previous funding to work with volunteers to manage weeds. Our hope is train volunteers in the use of GPS units, map the extent of specific weed...

  1. Quantitative Estimate of Weeds of Sugarcane ( Saccharum ...

    African Journals Online (AJOL)

    A quantitative method was employed for the enumeration of weeds. Quadrats were laid along transects and individual weed species in each quadrat was identified and counted. Simpson's diversity index, Sorensen similarity index and relative abundance were used to determine the weed community structure. A total of 51 ...

  2. Managing weeds with a population dynamics approach

    Science.gov (United States)

    No-till cropping systems are increasing land productivity. A critical aspect of no-till is controlling weeds. Herbicides are a crucial tool for weed management, but weed resistance is decreasing control efficacy and increasing input costs. Scientists and producers are seeking a broader perspectiv...

  3. Prospects for site specific weed management

    DEFF Research Database (Denmark)

    Christensen, Svend; Rasmussen, Jesper; Pedersen, Søren Marcus

    2014-01-01

    Research on Site Specific Weed Management (SSWM) started in the late 80's. Since that moment, considerable research has been conducted on different aspects of SSWM, from fundamental studies on the spatial ecology of weeds to the applied development and testing of new technologies for weed detection...

  4. What's a Weed? Knowledge, Attitude and Behaviour of Park Visitors about Weeds.

    Directory of Open Access Journals (Sweden)

    Michael Ansong

    Full Text Available Weeds are a major threat to biodiversity globally degrading natural areas of high conservation value. But what are our attitudes about weeds and their management including weeds in national parks? Do we know what a weed is? Do we consider weeds a problem? Do we support their management? Are we unintentionally spreading weeds in parks? To answer these questions, we surveyed visitors entering a large popular national park near the city of Brisbane, Australia. Park visitors were knowledgeable about weeds; with >75% correctly defining weeds as 'plants that grow where they are not wanted'. About 10% of the visitors, however, provided their own sophisticated definitions. This capacity to define weeds did not vary with people's age, sex or level of education. We constructed a scale measuring visitors' overall concern about weeds in parks using the responses to ten Likert scale statements. Over 85% of visitors were concerned about weeds with older visitors, hikers, and those who could correctly define weeds more concerned than their counterparts. The majority think visitors unintentionally introduce seeds into parks, with many (63% having found seeds on their own clothing. However, over a third disposed of these seeds in ways that could facilitate weed spread. Therefore, although most visitors were knowledgeable and concerned about weeds, and support their control, there is a clear need for more effective communication regarding the risk of visitors unintentionally dispersing weed seeds in parks.

  5. What’s a Weed? Knowledge, Attitude and Behaviour of Park Visitors about Weeds

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2015-01-01

    Weeds are a major threat to biodiversity globally degrading natural areas of high conservation value. But what are our attitudes about weeds and their management including weeds in national parks? Do we know what a weed is? Do we consider weeds a problem? Do we support their management? Are we unintentionally spreading weeds in parks? To answer these questions, we surveyed visitors entering a large popular national park near the city of Brisbane, Australia. Park visitors were knowledgeable about weeds; with >75% correctly defining weeds as ‘plants that grow where they are not wanted’. About 10% of the visitors, however, provided their own sophisticated definitions. This capacity to define weeds did not vary with people’s age, sex or level of education. We constructed a scale measuring visitors’ overall concern about weeds in parks using the responses to ten Likert scale statements. Over 85% of visitors were concerned about weeds with older visitors, hikers, and those who could correctly define weeds more concerned than their counterparts. The majority think visitors unintentionally introduce seeds into parks, with many (63%) having found seeds on their own clothing. However, over a third disposed of these seeds in ways that could facilitate weed spread. Therefore, although most visitors were knowledgeable and concerned about weeds, and support their control, there is a clear need for more effective communication regarding the risk of visitors unintentionally dispersing weed seeds in parks. PMID:26252004

  6. Weed suppression ability of spring barley varieties

    DEFF Research Database (Denmark)

    Christensen, Svend

    1995-01-01

    Three years of experiments with spring barley showed significant differences in weed suppression ability among varieties. Weed dry matter in the most suppressive variety, Ida, was 48% lower than the mean weed dry matter of all varieties, whereas it was 31% higher in the least suppressive variety......, Grit. Ranking varietal responses to weed competition in terms of grain yield loss corresponded well to ranking weed dry matter produced in crop weed mixtures. There was no correspondence between the varietal grain yields in pure stands and their competitiveness, suggesting that breeding to optimize...... interception model was developed to describe the light interception profiles of the varieties. A study of the estimated parameters showed significant correlation between weed dry matter, rate of canopy height development and the light interception profile. However, when estimates were standardized to eliminate...

  7. Weed Recognition Framework for Robotic Precision Farming

    DEFF Research Database (Denmark)

    Kounalakis, Tsampikos; Triantafyllidis, Georgios; Nalpantidis, Lazaros

    2016-01-01

    In this paper, we introduce a novel framework which applies known image features combined with advanced linear image representations for weed recognition. Our proposed weed recognition framework, is based on state-of-the-the art object/image categorization methods exploiting enhanced performance...... using advanced encoding and machine learning algorithms. The resulting system can be applied in a variety of environments, plantation or weed types. This results in a novel and generic weed control approach, that in our knowledge is unique among weed recognition methods and systems. For the experimental...... evaluation of our system, we introduce a challenging image dataset for weed recognition. We experimentally show that the proposed system achieves significant performance improvements in weed recognition in comparison with other known methods....

  8. [Effect of artenisiae scopariae and poriae powder on calpain-2 expression in liver tissue from rats with obstructive jaundice].

    Science.gov (United States)

    Cui, Yubao

    2015-05-01

    To explore the eff ect of artenisiae scopariae and poriae powder (ASPD) on calpain-2 expression in liver tissue from rats with obstructive jaundice. The rat model of obstructive jaundice was established. SD rats was divided into the control group, the obstructive jaundice group, the obstructive jaundice model plus ASPD group, the obstructive jaundice model plus saline group. Th e serum levels of TBIL, ALT, AST and other biochemical indexes were detected. The pathological changes of liver tissue were evaluated by HE staining. The calpain-2 mRNA and protein expression in liver was measured by Real-time PCR and immunohistochemistry or Western blot, respectively. The calpain-2 mRNA and protein expression levels were significantly up-regulated in live tissues from the rats with obstructive jaundice in a time-dependent manner. The ASPD could inhibit the calpain-2 expression in rats with obstructive jaundice concomitant with the decreased liver damage and the improved liver function, suggesting that calpain-2 was involved in endoplasmic reticulum stress-mediated cellular apoptosis and the occurrence of obstructive jaundice. ASPD could be used for patients with obstructive jaundice to promote the recovery of liver function after operation and to reduce the incidence of complications, which provide a theoretical basis for the reasonable application of traditional Chinese medicine in the peroperative period.

  9. Weed Mapping with Co-Kriging Using Soil Properties

    DEFF Research Database (Denmark)

    Heisel, Torben; Ersbøll, Annette Kjær; Andreasen, Christian

    1999-01-01

    Our aim is to build reliable weed maps to control weeds in patches. Weed sampling is time consuming but there are some shortcuts. If an intensively sampled variable (e.g. soil property) can be used to improve estimation of a sparsely sampled variable (e.g. weed distribution), one can reduce weed...

  10. Weeds and their control in cassava | Melifonwu | African Crop ...

    African Journals Online (AJOL)

    Root yields from farmers' fields are generally low, partly due to effects of weed competition. Hoe-weeding is the common practice among cassava farmers. The frequency and timing of weeding depend on such factors as climate, cultural practices, crop growth, soil fertility and weed species. Some common noxious weeds of ...

  11. Overview of glyphosate-resistant weeds worldwide.

    Science.gov (United States)

    Heap, Ian; Duke, Stephen O

    2017-10-10

    Glyphosate is the most widely used and successful herbicide discovered to date, but its utility is now threatened by the occurrence of several glyphosate-resistant weed species. Glyphosate resistance first appeared in Lolium rigidum in an apple orchard in Australia in 1996, ironically the year that the first glyphosate-resistant crop (soybean) was introduced in the USA. Thirty-eight weed species have now evolved resistance to glyphosate, distributed across 37 countries and in 34 different crops and six non-crop situations. Although glyphosate-resistant weeds have been identified in orchards, vineyards, plantations, cereals, fallow and non-crop situations, it is the glyphosate-resistant weeds in glyphosate-resistant crop systems that dominate the area infested and growing economic impact. Glyphosate-resistant weeds present the greatest threat to sustained weed control in major agronomic crops because this herbicide is used to control weeds with resistance to herbicides with other sites of action, and no new herbicide sites of action have been introduced for over 30 years. Industry has responded by developing herbicide resistance traits in major crops that allow existing herbicides to be used in a new way. However, over reliance on these traits will result in multiple-resistance in weeds. Weed control in major crops is at a precarious point, where we must maintain the utility of the herbicides we have until we can transition to new weed management technologies. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. The future for weed control and technology.

    Science.gov (United States)

    Shaner, Dale L; Beckie, Hugh J

    2014-09-01

    This review is both a retrospective (what have we missed?) and prospective (where are we going?) examination of weed control and technology, particularly as it applies to herbicide-resistant weed management (RWM). Major obstacles to RWM are discussed, including lack of diversity in weed management, unwillingness of many weed researchers to conduct real integrated weed management research or growers to accept recommendations, influence or role of agrichemical marketing and governmental policy and lack of multidisciplinary research. We then look ahead to new technologies that are needed for future weed control in general and RWM in particular, in areas such as non-chemical and chemical weed management, novel herbicides, site-specific weed management, drones for monitoring large areas, wider application of 'omics' and simulation model development. Finally, we discuss implementation strategies for integrated weed management to achieve RWM, development of RWM for developing countries, a new classification of herbicides based on mode of metabolism to facilitate greater stewardship and greater global exchange of information to focus efforts on areas that maximize progress in weed control and RWM. There is little doubt that new or emerging technologies will provide novel tools for RMW in the future, but will they arrive in time? © 2013 Her Majesty the Queen in Right of Canada Pest Management Science © 2013 Society of Chemical Industry.

  13. [Pseudomonas genus bacteria on weeds].

    Science.gov (United States)

    Gvozdiak, R I; Iakovleva, L M; Pasichnik, L A; Shcherbina, T N; Ogorodnik, L E

    2005-01-01

    It has been shown in the work that the weeds (couch-grass and ryegrass) may be affected by bacterial diseases in natural conditions, Pseudomonas genus bacteria being their agents. The isolated bacteria are highly-aggressive in respect of the host-plant and a wide range of cultivated plants: wheat, rye, oats, barley, apple-tree and pear-tree. In contrast to highly aggressive bacteria isolated from the affected weeds, bacteria-epi phytes isolated from formally healthy plants (common amaranth, orache, flat-leaved spurge, field sow thistle, matricary, common coltsfoot, narrow-leaved vetch) and identified as P. syringae pv. coronafaciens, were characterized by weak aggression. A wide range of ecological niches of bacteria evidently promote their revival and distribution everywhere in nature.

  14. Epianthropochory in Mexican weed communities.

    Science.gov (United States)

    Vibrans, H

    1999-04-01

    The diaspores of the 50 most important maize field weed species (agrestals) in a traditional maize-growing area of south-central Mexico (region of Puebla and Tlaxcala) were analyzed for morphological adaptations to long-distance dispersal. Adaptations to wind-dispersal were absent and to endozoochory were minimal. Most species had no visible adaptations and are presumably transported with mud. However, about one-quarter of the taxa, particularly the tall and dominant ones, relied at least partially on burrs with hooks or awns. The possible vectors for these exo- or epizoochorous species are discussed: the most likely regular dispersers are humans (epianthropochory). Interviews with farmers confirm this conclusion. Using humans as vectors allows the plant to transport relatively large seeds to favorable habitats (directed dispersal). The importance of this relatively rare dispersal adaptation in Mexican maize field weeds leads to questions on the origin and evolution of these agrestals.

  15. Parasitic fungi on selected invasive weeds

    OpenAIRE

    Forejtová, Zuzana

    2010-01-01

    Parasitic fungi on selected invasive weeds Zuzana Forejtová Abstract This thesis deals with the invasive plant species problems and their pathogens in the Czech Republic. Special attention is given to weed species colonizing the agroecosystems. The modes and consequences of plant invasions are presented in theoretical part. Practical part includes a list and descriptions of found parasitic fungal pathogens colonizing selected invasive weeds. Moreover, this thesis can be used for educational p...

  16. Precise tillage systems for enhanced non-chemical weed management

    NARCIS (Netherlands)

    Kurstjens, D.A.G.

    2007-01-01

    Soil and residue manipulation can assist weed management by killing weeds mechanically, interfering in weed lifecycles, facilitating operations and enhancing crop establishment and growth. Current tillage systems often compromise these functions, resulting in heavy reliance on herbicides,

  17. Effect of stale seedbed preparations and subsequent weed control in lettuce (cv. Iceboll) on weed densities

    NARCIS (Netherlands)

    Riemens, M.M.; Weide, van der R.Y.; Bleeker, P.O.; Lotz, L.A.P.

    2007-01-01

    The effects of stale seedbed preparations and several weed control methods on the emergence of weeds in lettuce were studied. The specific goal was to evaluate the use of a stale seedbed in combination with chemical or mechanical weed control methods in the field. Depending on location and year,

  18. Effect of Weed Management on Weeds and Grain Yield of Haricot ...

    African Journals Online (AJOL)

    weed management. Therefore, the objective of this study was to determine the effect of weed management, variety and their interaction on weeds and grain yield .... Datura stramonium L. Solanaceae. Moonflower. Annual. 3.0. Galinsoga parviflora Cav. Asteraceae. Gellant Solder. Annual. 28.0. Argemone ochroleuca Sweet.

  19. Effect of weed management on weeds and grain yield of haricot bean

    African Journals Online (AJOL)

    Weeds are one of the major constraints limiting haricot bean productivity and production. Field experiments were conducted on the effect of weed managements on weeds and grain yield of haricot bean (Phaseolus Vulgaris L.) at Melkassa Agricultural Research Center from 2011 - 2013. The objective was to determine the ...

  20. Linking Farmer Weed Management Behavior with Weed Pressure: More than Just Technology

    NARCIS (Netherlands)

    Riemens, M.M.; Groeneveld, R.M.W.; Kropff, M.J.; Lotz, L.A.P.; Renes, R.J.; Sukkel, W.; Weide, van der R.Y.

    2010-01-01

    Most studies on weed population dynamics in farming systems have focused on the effects of different weed control strategies. Those studies usually assume that farmers, operating within a particular system, have a uniform management style. However, it is likely that weed management decision making

  1. Weeds of onion fields and effects of some herbicides on weeds in ...

    African Journals Online (AJOL)

    Weeds are one of the most important problems in onion (Allium cepa L.) production areas, since onion plants are poor competitors. This study was conducted in order to identify the weed species in onion fields in Cukurova Region, establish the effects of some herbicides on weeds and the yield of onion in reducing the ...

  2. A STUDY ON WEED CONTROL IN SOYBEAN

    Directory of Open Access Journals (Sweden)

    S. TJITROSEMITO

    1991-01-01

    Full Text Available Two field experiments on weed control in soybeans were carried out at BIOTROP, Bogor, Indonesia from February to June, 1989. The critical period for weed control was found to be between 20 - 40 days after planting of soybean (c. v. Wilis grown at a planting distance of 40 x 10 cm. It did not coincide with the fastest growth in terms of trifoliate leaf number. Further studies were suggested to understand the physiological growth of soybean related to weed control. Pendimethalin at 660- 1320 g a.e./ha applied one day after sowing did not cause any phytotoxic effect to soybean and had good weed control performance.

  3. Nutrient absorbtion of weeds in maize.

    Science.gov (United States)

    Lehoczky, E; Kismányoky, A; Nagy, P; Németh, T

    2008-01-01

    Our study was carried out in Hungary at Keszthely, in 2007. The effect of different cultivation methods: no-till drill, disk tillage, conventional tillage (ploughing) and five increasing N doses were studied on the weediness. The bi-factorial trial was arranged in split plot design with four replications. Crop rotation: winter wheat-winter wheat-maize-maize. The seeding of maize was 23rd of April in 2007. The weed survey was made with Balázs-Ujvárosi coenological method on the 17th of May. In the experiment were found 21 weed species. We collected all plants of every weed species by plots. The sample area was 1 m2. Furthermore five maize plants per plot were sampled on the 22nd of May. Maize was at 3-4 leaves stage. For reason of competition studies no herbicides were applied on sampling sites. The aerial parts of weeds and maize plants were collected, and the fresh and dry matter weight was measured. We analyzed in detail, the occurrence of weed species, and the biomass production of weeds in comparison with maize. The effect of different cultivation methods markedly demonstrated the weed cover, the number of perennial and annual weeds and the number of occurring weed species.

  4. Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent

    Science.gov (United States)

    González, Eduardo; Sher, Anna A.; Anderson, Robert M.; Bay, Robin F.; Bean, Daniel W.; Bissonnete, Gabriel J.; Cooper, David J.; Dohrenwend, Kara; Eichhorst, Kim D.; El Waer, Hisham; Kennard, Deborah K.; Harms-Weissinger, Rebecca; Henry, Annie L.; Makarick, Lori J.; Ostoja, Steven M.; Reynolds, Lindsay V.; Robinson, W. Wright; Shafroth, Patrick B.; Tabacchi, Erich

    2017-01-01

    Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2) which species that were secondary invaders persisted over time. In a collaborative study by 16 research institutions, we monitored plant species composition following control of non-native Tamarix trees along southwestern U.S. rivers using defoliation by an introduced biocontrol beetle, and three physical removal methods: mechanical using saws, heavy machinery, and burning in 244 treated and 79 untreated sites across six U.S. states. Physical removal favored secondary invasions immediately after Tamarix removal (0–3 yrs.), while in the biocontrol treatment, secondary invasions manifested later (> 5 yrs.). Within this general trend, the response of weeds to control was idiosyncratic; dependent on treatment type and invader. Two annual tumbleweeds that only reproduce by seed (Bassia scoparia and Salsola tragus) peaked immediately after physical Tamarix removal and persisted over time, even after herbicide application. Acroptilon repens, a perennial forb that vigorously reproduces by rhizomes, and Bromus tectorum, a very frequent annual grass before removal that only reproduces by seed, were most successful at biocontrol sites, and progressively spread as the canopy layer opened. These results demonstrate that strategies to control Tamarix affect secondary invasions differently among species and that time since disturbance is an important, generally overlooked, factor affecting response.

  5. The effect of sowing strategy, row distance and mechanical weed control on weeds and yield in organic winter wheat

    OpenAIRE

    Rasmussen, Ilse A.

    2002-01-01

    A series of field experiments were carried out in winter wheat grown under organic conditions in Denmark on fields with different weed pressure. The treatments were sowing strategy (normal sowing time, late sowing and false seedbed), row distance (12 cm and 24 cm row distance) and weed control method (untreated, mechanical weed control (weed harrowing at 12 cm supplemented with row hoeing at 24 cm), and herbicide weed control). Weed biomass was largest at the normal sowing time and was reduce...

  6. Weeds in a Changing Climate: Vulnerabilities, Consequences, and Implications for Future Weed Management.

    Science.gov (United States)

    Ramesh, Kulasekaran; Matloob, Amar; Aslam, Farhena; Florentine, Singarayer K; Chauhan, Bhagirath S

    2017-01-01

    Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C3 and C4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C4 plants. Although CO2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the crop-weed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an integral

  7. Effects of Planting Date, Time and Methods of Weed Control on Weed Density and Biomass in Cumin Fields

    Directory of Open Access Journals (Sweden)

    R. Ghorbani

    2011-01-01

    Full Text Available Abstract Two field experiments were carried out in order to evaluate the effect of planting date, method and date of weed control on weed density and biomass in the experimental research field, Faculty of Agriculture, Ferdowsi University of Mashhad, during 2006 and 2007. Treatments included planting date (30 December, 20 January and 30 February, weeding date (first true leaf, start of branching and beginning of flowering stages and weed control methods (hand weeding, fire treatment and control. The results showed that there were significant differences in the number of weeds between different sowing dates, weeding dates and control methods. The highest mean density and biomass of weeds were obtained on the planting date, 30 February, and when weed was controlled at the first leaf appearance stage with fire treatment. The most appropriate time for weed control was at the beginning of cumin flowering. Fire treatment reduced weed growth in the first half of growing season. However, hand weeding significantly reduced weed density and biomass in the second half of cumin growing season. The first planting date caused the lowest mean weed biomass and the highest cumin yield compared to later planting dates. Hand weeding treatment contained lower mean weed density and biomass compared to fire treatment, however, cumin yield was lower in hand weeding plots than fire treatment. Keywords: Cultural control, Cuminum cyminum, Fire, Hand weeding, Control time

  8. WEED SURVEYING OF PHACELIA (PHACELIA TANACETIFOLIA L.) AND EVALUATING THE EFFICIENCY OF THE WEED CONTROL.

    Science.gov (United States)

    Horváth, E; Szabó, R

    2014-01-01

    The experiment was set up in an area of 9 ha that was split into 4 plots: in plot 1 the row spacing was 12 cm and the seeding rate was 10 kg; in plot 2 the row spacing was 24 cm and the seeding rate was 10 kg; in plot 3 the row spacing was 24 cm and the seeding rate was 8 kg; in plot 4 the row spacing was 12 cm and the seeding rate was 8 kg. After the weed surveying, the total weed coverage was established as follows: in plot 1 the total weed coverage was 11.34%, in plot 2 it was 12.3%, in plot 3 it was 18%, and in plot 4 the total weed coverage was 15%. Based on the weed survey, on the test area the following dicotyledon weeds belonging to the T4 Raunkiaer plant life-form category occupied the highest percentage: heal-all, black-bindweed, goosefoot. The proportion of the perennial dicotyledons: field bindweed (G3), tuberous pea (G1), white campion (H3) was negligible. In all four cases the weed control was executed using the same herbicide in the same doses and with regard to the weed species it showed the same level of efficiency. The smaller row spacing and higher seeding rate has a beneficial effect on the weed suppressing capacity of the crop, the crop's weed suppressing capacity is better and the development of the weeds becomes worse.

  9. 7 CFR 201.50 - Weed seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seed. 201.50 Section 201.50 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or...

  10. Weed management strategies for castor bean crops

    Directory of Open Access Journals (Sweden)

    Augusto Guerreiro Fontoura Costa

    2014-04-01

    Full Text Available Castor bean crops are agriculturally relevant due to the quality and versatility of their oil, both for the chemical industry and for biodiesel production. Proper weed management is important for both the cultivation and the yield of castor bean crops; therefore, the intention of the present work is to review pertinent information regarding weed management, including the studies regarding weed interference periods, chemical controls for use in different crop production systems and herbicide selectivity, for castor bean crops. Weed science research for castor bean crops is scarce. One of the main weed management challenges for castor bean crops is the absence of herbicides registered with the Ministry of Agriculture, Livestock and Food Supply (MALFS. Research for viable herbicides for weed control in castor bean crops should be directed by research and/or rural extension institutions, associations and farmers cooperatives, as well as by manufactures, for the registration of these selective herbicides, which would be primarily used to control eudicotyledons in castor bean crops. New studies involving the integration of weed control methods in castor bean also may increase the efficiency of weed management, for both small farmers using traditional crop methods in the Brazilian Northeast region, as well as for areas with the potential for large scale production, using conservation tillage systems, such as the no-tillage crop production system.

  11. Parthenium Weed ( Parthenium hysterophorus L.) Research in ...

    African Journals Online (AJOL)

    The highly competitive, adaptable and allergenic weed Parthenium hysterophorus (Compositae) is an invasive annual weed believed to be introduced to Ethiopia in 1970s. Field surveys, plant biodiversity impacts, and analysis of secondary plant compounds in P. hysterophorus and its possible impact on human health ...

  12. An autonomous weeding robot for organic farming

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2006-01-01

    The objective of this research is the replacement of hand weeding in organic farming by a device working autonomously at ¯eld level. The autonomous weeding robot was designed using a structured design approach, giving a good overview of the total design. A vehicle was developed with a diesel engine,

  13. Molecular biology approaches to weed management

    Science.gov (United States)

    Global climate change appears to be favorable for invasive weed development and spread because invasive species in general are proficient at succeeding in new environments. To worsen matters, herbicide-resistant weeds have become a severe threat in modern agricultural systems due to the extensive us...

  14. Rice Production under Different Weed Management Technologies ...

    African Journals Online (AJOL)

    USER

    This study investigated the adoption and profitability of weed management technologies for rice production, namely; oxidiaxon, pendimethalin, hoe weeding and farmers' practice which comprised recycling of paddy previous harvest as seeds, use of hoe for land preparation, fertilizer broadcasting and use of family labour, ...

  15. MYCOPOPULATION OF WEEDS IN ARABLE CROPS

    Directory of Open Access Journals (Sweden)

    Karolina Vrandečić

    2004-06-01

    Full Text Available A large number of weeds are alternative hosts to numerous pathogenic agents of fungus diseases to arable crops and they represent inoculum source to cultivated plants. The aim of our investigation was to determine weed mycopopulation, to establish pathogenicity of some fungi to cultivated plants as well as to choose potential parasites for biological control of weeds. During a two year investigation of weed mycopopulation obtained from root crops at five localities in East Slavonia and Baranya 32 fungus species were established at 25 weeds that were characterized by disease symptoms. Seven fungi species were determined on roots of 18 weeds, although there were no obvious disease symptoms. Obligated parasites along with 21 determined fungi are of Oomycetes, Plectomycetes and Hemibasidiomycetes genus. Facultative parasites from 18 determined fungus species are of Discomycetes, Pyrenomycetes, Coelomycetes and Hyphomycetes genus. Isolates of Sclerotinia sclerotiorum were tested for their pathogenicity to soybean. The results showed that there were no significant differences in pathogenicity of isolates in artificial conditions in laboratory. In natural conditions isolates from soybean were more pathogenic to soybean than the isolates from weeds. Experiments done with sunflower showed that the isolates from weeds were more pathogenic than isolates from sunflower. The isolates of Phomopsis/Diaporthe complex affected the length of germ, the length of necrosis and seed disease differently. Results showed that the isolates from weeds of Phomopsis species are pathogenic to soybean representing an important source of inoculum to soybean. Isolates of Fusarium species isolated from weeds were pathogenic for popcorn seedlings. Artificial infection of Abutilon theophrasti by Colletotrichum coccodes showed that foliar mass wilted earlier and whole plants died. For the first time in Croatia the presence of 14 fungus species was determined on 27 new hosts.

  16. Effect of Cultural Practices in Night on Weed Density and Weed Dry Matter

    Directory of Open Access Journals (Sweden)

    M.H Rashed Mohasel

    2011-01-01

    Full Text Available Abstract In order to evaluate the response of weed seeds to light, two experiments, at two different locations were conducted at Ferdowsi university of Mashhad in 2009. At the first experiment, field was ploughed in day and night. Weed density was evaluated 70 d after plough, with 1×1 quadrate. At the second experiment, at night treatment, ploughing, potato planting and weeding with cultivator were done at night. Weed sampling was done twice at 43 and 130 days after planting with 1×1 quadrate and weeds were identified and counted. Result showed pigweed (Amaranthus retroflexus L., sowthistle (Sonchus oleraceus L., crabgrass (Digitaria sanguinalis (L. scop, jimsonweed (Datura stramonium L. and mallow (Hibiscus trionum L. did not observed at night plough, in contrast, night plough has no significance influence on common lambsquarters (Chenopodium album L., and black nightshade (Solanum nigrum L.. Only common lambsquarters had similar appearance in two treatments, indicating insusceptibility of this weed to time of plough. Interestingly, at the second experiment, result was very similar. Potato yield was higher at night treatment, but not significant. This research showed that some cultural practice like plough, planting and weeding with cultivator in night can reduce weed density and weed dry matter. Keywords: Germination, Time of plough, Sustainable weeds management, Light

  17. Adapting weed management in rice to changing climates

    NARCIS (Netherlands)

    Rodenburg, J.; Meinke, H.B.

    2011-01-01

    This paper provides some of the scientific background on how projected environmental conditions could affect weeds and weed management in rice in Africa. Elevated CO2 levels may have positive effects on rice competitiveness with C4 weeds, but these are generally outnumbered by C3 species in weed

  18. 220 213 Effects of Weeds on the Profitabili

    African Journals Online (AJOL)

    2008-12-02

    Dec 2, 2008 ... This signifies that lack of weeding decreased farm profit more than the cost of weeding. Hence, the contribution of weeding cost to farm revenue is more important than its opportunity cost. However, the production of both crops will be more profitable if the cost weeding is reduced or saved since it cannot be.

  19. A rotational framework to reduce weed density in organic systems

    Science.gov (United States)

    Weeds are a major obstacle to successful crop production in organic farming. Producers may be able to reduce inputs for weed management by designing rotations to disrupt population dynamics of weeds. Population-based management in conventional farming has reduced herbicide use 50% because weed den...

  20. Competitive influence of Eleusine indica and other weeds on the ...

    African Journals Online (AJOL)

    (Received 13 December, 2000; accepted 5 February, 2002) ABSTRACT Delayed weed removal is the primary cause of maize yield loss in smallholder agriculture. The slog for weed management could probably be reduced if the initial weed control removal is restricted to the in-row weeds, followed soon after by elimation of ...

  1. Influence of cowpea and melon populations on weed infestation and ...

    African Journals Online (AJOL)

    Small farmers in the humid regions of tropical Africa spend 30–42% of their total farm labour input in controlling weeds. Chemical weed control is normally recommended but high cost of herbicides and environmental pollution are specific problems with chemical weed control. A three year bio-weed control system with three ...

  2. Seeding method and rate influence on weed suppression in aerobic ...

    African Journals Online (AJOL)

    High weed pressure is amongst the major constraints to the extensive adoption of aerobic rice system as a water-wise technique. Towards developing a sustainable weed management strategy, seeding method and rate may substantially contribute to weed suppression and reduce herbicide use and weeding cost. A trough ...

  3. Weed Garden: An Effective Tool for Extension Education

    Science.gov (United States)

    Beck, Leslie; Patton, Aaron J.

    2015-01-01

    A weed garden was constructed to quantify and improve identification skills among clientele. The garden was planted with over 100 weed species based on surveys on problematic weeds. The weed garden proved useful for introducing additional hands-on learning activities into traditional lecture-based seminars. Through seminar and field day attendee…

  4. Acetolactate synthase inhibiting herbicides bind to the regulatory site.

    Science.gov (United States)

    Subramanian, M V; Loney-Gallant, V; Dias, J M; Mireles, L C

    1991-05-01

    Acetolactate synthase from spontaneous mutants of tobacco (Nicotiana tabacum; KS-43 and SK-53) and cotton (Gossypium hirsutum; PS-3, PSH-91, and DO-2) selected in tissue culture for resistance to a triazolopyrimidine sulfonanilide showed varying degrees of insensitivity to feedback inhibitor(s) valine and/or leucine. A similar feature was evident in the enzyme isolated from chlorsulfuron-resistant weed biotypes, Kochia scoparia and Stellaria media. Dual inhibition analyses of triazolopyrimidine sulfonanilide, thifensulfuron, and imazethapyr versus feedback inhibitor leucine revealed that the three herbicides were competitive with the amino acid for binding to acetolactate synthase from wild-type cotton cultures. Acetolactate synthase inhibiting herbicides may bind to the regulatory site on the enzyme.

  5. Soil solarization for weed control in carrot

    Directory of Open Access Journals (Sweden)

    MARENCO RICARDO ANTONIO

    2000-01-01

    Full Text Available Soil solarization is a technique used for weed and plant disease control in regions with high levels of solar radiation. The effect of solarization (0, 3, 6, and 9 weeks upon weed populations, carrot (Daucus carota L. cv. Brasília yield and nematode infestation in carrot roots was studied in São Luís (2º35' S; 44º10' W, MA, Brazil, using transparent polyethylene films (100 and 150 mm of thickness. The maximum temperature at 5 cm of depth was about 10ºC warmer in solarized soil than in control plots. In the study 20 weed types were recorded. Solarization reduced weed biomass and density in about 50% of weed species, including Cyperus spp., Chamaecrista nictans var. paraguariensis (Chod & Hassl. Irwin & Barneby, Marsypianthes chamaedrys (Vahl O. Kuntze, Mitracarpus sp., Mollugo verticillata L., Sebastiania corniculata M. Arg., and Spigelia anthelmia L. Approximately 40% of species in the weed flora were not affected by soil mulching. Furthermore, seed germination of Commelina benghalensis L. was increased by soil solarization. Marketable yield of carrots was greater in solarized soil than in the unsolarized one. It was concluded that solarization for nine weeks increases carrot yield and is effective for controlling more than half of the weed species recorded. Mulching was not effective for controlling root-knot nematodes in carrot.

  6. Weed seeds on clothing: a global review.

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2014-11-01

    Weeds are a major threat to biodiversity including in areas of high conservation value. Unfortunately, people may be unintentionally introducing and dispersing weed seeds on their clothing when they visit these areas. To inform the management of these areas, we conducted a systematic quantitative literature review to determine the diversity and characteristics of species with seeds that can attach and be dispersed from clothing. Across 21 studies identified from systematic literature searches on this topic, seeds from 449 species have been recorded on clothing, more than double the diversity found in a previous review. Nearly all of them, 391 species, are listed weeds in one or more countries, with 58 classified as internationally-recognised environmental weeds. When our database was compared with weed lists from different countries and continents we found that clothing can carry the seeds of important regional weeds. A total of 287 of the species are listed as aliens in one or more countries in Europe, 156 are invasive species/noxious weeds in North America, 211 are naturalized alien plants in Australia, 97 are alien species in India, 33 are invasive species in China and 5 are declared weeds/invaders in South Africa. Seeds on the clothing of hikers can be carried to an average distance of 13 km, and where people travel in cars, trains, planes and boats, the seeds on their clothing can be carried much further. Factors that affect this type of seed dispersal include the type of clothing, the type of material the clothing is made from, the number and location of the seeds on plants, and seed traits such as adhesive and attachment structures. With increasing use of protected areas by tourists, including in remote regions, popular protected areas may be at great risk of biological invasions by weeds with seeds carried on clothing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. مطالعه ارزش غذایی علوفه گیاه شورزیست کوشیا (Kochia scoparia در شرایط تنش شوری

    Directory of Open Access Journals (Sweden)

    جعفر نباتی

    2014-03-01

    Full Text Available تولید علوفه باکیفیت از گیاهان شورزیست‌ از اهداف اصلی زراعت در بوم­زیست‌های تحت تنش شوری می‌باشد. کوشیا گیاهی شورزیست‌ است که ظرفیت مناسبی برای تولید علوفه دارد. هدف از این آزمایش بررسی کیفیت و کمیت علوفه کوشیا و برخی مواد ضد تغذیه‌ای علوفه تولیدی تحت شرایط آبیاری با آب شور بود. این آزمایش با استفاده از سه توده کوشیا (بیرجند، بروجرد و سبزوار و سه سطح شوری (5/2، 10/5 و 23/1 دسی زیمنس بر متر به صورت آزمایش کرت‌های خرد شده در قالب طرح بلوک‌های کامل تصادفی در سه تکرار اجرا شد. نتایج نشان داد که قابلیت هضم ماده خشک برگ و کل اندام هوایی تحت تأثیر شوری قرار نگرفت، اما قابلیت هضم ماده خشک ساقه در تنش شدید شوری افزایش پیدا کرد. قابلیت هضم ماده آلی برگ، ساقه و کل اندام هوایی در تیمار 5/10 دسی زیمنس بر متر بیشتر از سایر تیمارها بود. افزایش شدت تنش شوری موجب کاهش درصد پروتئین کل اندام هوایی شد ولی بین توده‌های کوشیا اختلافی مشاهده نشد. افزایش میزان شوری موجب کاهش درصد الیاف نامحلول در شوینده خنثی (NDF و الیاف نامحلول در شوینده اسیدی (ADF کل اندام هوایی شد. بین توده‌ها، توده سبزوار از نظر درصدNDF کل اندام هوایی بیشترین مقدار را دارا بود، اما از نظر درصدADF  کل اندام هوایی اختلافی بین توده‌ها مشاهده نشد. میزان فنل و تانن با افزایش شدت تنش شوری روند افزایشی نشان دادند با این وجود اختلاف معنی‌داری بین سطوح مختلف شوری مشاهده نشد. در میان توده‌های کوشیا نیز توده سبزوار بیشترین میزان فنل کل و تانن را در اندام‌های هوایی خود تولید کرد. در مجموع کیفیت علوفه کوشیا در ابتدای مراحل گل‌دهی قابل مقایسه با سایر گیاهان علوفه‌ای رایج می‌باشد و تا 23/1 دسی زیمنس بر متر اختلافی از نظر کیفیت علوفه در توده‌های مورد مطالعه وجود نداشت.

  8. Contrasting weed species composition in perennial alfalfas and six annual crops: implications for integrated weed management

    OpenAIRE

    Meiss, Helmut; Médiène, Safia; Waldhardt, Rainer; Caneill, Jacques; Munier-Jolain, Nathalie

    2010-01-01

    International audience; Weed communities are most strongly affected by the characteristics and management of the current crop. Crop rotation may thus be used to prevent the repeated selection of particular weed species. While weed communities are frequently compared among annual crops, little is known about the differences between annual and perennial crops that may be included in the rotations. Moreover, nearly all existing studies (17 articles reviewed) are based on local field experiments ...

  9. Weeds in Organic Fertility-Building Leys: Aspects of Species Richness and Weed Management

    Directory of Open Access Journals (Sweden)

    Thomas F. Döring

    2017-02-01

    Full Text Available Legume-based leys (perennial sod crops are an important component of fertility management in organic rotations in many parts of Europe. Despite their importance, however, relatively little is known about how these leys affect weed communities or how the specific composition of leys may contribute to weed management. To determine whether the choice of plant species in the ley affects weeds, we conducted replicated field trials at six locations in the UK over 24 months, measuring weed cover and biomass in plots sown with monocultures of 12 legume and 4 grass species, and in plots sown with a mixture of 10 legume species and 4 grass species. Additionally, we monitored weed communities in leys on 21 organic farms across the UK either sown with a mixture of the project species or the farmers’ own species mix. In total, 63 weed species were found on the farms, with the annuals Stellaria media, Sonchus arvensis, and Veronica persica being the most frequent species in the first year after establishment of the ley, while Stellaria media and the two perennials Ranunculus repens and Taraxacum officinale dominated the weed spectrum in the second year. Our study shows that organic leys constitute an important element of farm biodiversity. In both replicated and on-farm trials, weed cover and species richness were significantly lower in the second year than in the first, owing to lower presence of annual weeds in year two. In monocultures, meadow pea (Lathyrus pratensis was a poor competitor against weeds, and a significant increase in the proportion of weed biomass was observed over time, due to poor recovery of meadow pea after mowing. For red clover (Trifolium pratense, we observed the lowest proportion of weed biomass in total biomass among the tested legume species. Crop biomass and weed biomass were negatively correlated across species. Residuals from the linear regression between crop biomass and weed biomass indicated that at similar levels of crop

  10. In vivo immunoprotective role of Indigofera tinctoria and Scoparia dulcis aqueous extracts against chronic noise stress induced immune abnormalities in Wistar albino rats

    Directory of Open Access Journals (Sweden)

    Boothapandi Madakkannu

    Full Text Available Indigofera tinctoria and Scoparia dulcis are being widely used in Indian folk medicine for the treatment of various disorders. Environmental noise pollution is thought to be an important factor for many health problems and it causes immune abnormalities. In the present study immune-regulating potential of I. tinctoria and S. dulcis aqueous extracts on innate and adaptive immune system of wistar albino rats was evaluated during normal and chronic noise induced stress conditions. The results demonstrated that both I. tinctoria and S. dulcis aqueous extracts (200 mg/kg b.w showed immunostimulant effect on both innate and adaptive immune response of wistar albino rat compared to control group under normal condition. The noise stress (100 dB for 1 h, 20 days induced animals showed suppressive effects on immune response by decreasing macrophage phagocytosis, antibody secretion by spleen cells, humoral immune response, proliferation of lymphocytes, cytotoxicity, TNF α expression, granzyme B and perforin expression in splenic NK cells. Similarly, noise stress also caused DNA damage in tissues. However, the suppressed effects induced by noise stress on rat immune system were significantly prevented by oral administration of both I. tinctoria and S. dulcis aqueous extracts. Considering all these results it is suggested that the selected medicinal plant’s aqueous extracts have the potential to prevent the effects of noise stress induced rat immune system and explore a strong immunostimulant potential applicable to clinical practices. Keywords: Indigofera tinctoria, Scoparia dulcis, Chronic noise stress, Immunomodulatory, Innate immunity, Adaptive immunity

  11. Alien species in the Finnish weed flora

    Directory of Open Access Journals (Sweden)

    T. HYVÖNEN

    2008-12-01

    Full Text Available The present study aimed at assessing the invasion of alien weed species in Finland based on a review of their occurrence in the Finnish weed flora. The evaluation was conducted for the three phases of the invasion process, i.e. introduction, naturalization and invasion. The literature review revealed that 815 alien weed species occur in Finland of which 314 are regarded as naturalized. Based on their occurrence in different climate zones, the risk of naturalization of new harmful alien weed species was deemed low for those species not currently found in Finland, but higher for species occurring as casual aliens in Finland. In the latter group, 10 species of concern were detected. Exploration of the distribution patterns of naturalized species within Finland revealed species occupancy to be dependent on the residence time of the species. Established neophytes can be expected to extend their ranges and to increase occupation of agricultural habitats in the future.;

  12. Weed Resistance to Synthetic Auxin Herbicides.

    Science.gov (United States)

    Busi, Roberto; Goggin, Danica E; Heap, Ian; Horak, Michael J; Jugulam, Mithila; Masters, Robert A; Napier, Richard; Riar, Dilpreet S; Satchivi, Norbert M; Torra, Joel; Westra, Phillip; Wright, Terry R

    2017-12-13

    Herbicides classified as synthetic auxins have been most commonly used to control broadleaf weeds in a variety of crops and in non-cropland areas since the first synthetic auxin herbicide (SAH), 2,4-D, was introduced to the market in the mid-1940s. The incidence of weed species resistant to SAHs is relatively low considering their long-term global application with 29 broadleaf weed species confirmed resistant to date. An understanding of the context and mechanisms of SAH resistance evolution can inform management practices to sustain the longevity and utility of this important class of herbicides. A symposium was convened during the 2nd Global Herbicide Resistance Challenge (May 2017 in Denver, CO, USA) to provide an overview of the current state of knowledge of SAH resistance mechanisms including case studies of weed species resistant to SAHs and perspectives on mitigating resistance development in SAH-tolerant crops. This article is protected by copyright. All rights reserved.

  13. Teenagers with Jimson weed (Datura stramonium) poisoning.

    Science.gov (United States)

    Spina, Sean P; Taddei, Anthony

    2007-11-01

    We report 2 cases of teenagers who were poisoned with Jimson weed (Datura stramonium) and presented to the emergency department with a severe acute anticholinergic toxidrome after ingestion of several hundred seeds. The patients presented with visual hallucinations, disorientation, incomprehensible and nonsensical speech, and dilated sluggish pupils. Both patients required restraints for combativeness until adequate sedation with lorazepam and haloperidol was achieved. Jimson weed is found in southern Canada and the United States and can cause acute anticholinergic poisoning and death in humans and animals. The treatment of choice for anticholinergic poisoning is mainly supportive care and gastrointestinal decontamination with activated charcoal. Jimson weed intoxication should be considered in cases of patients presenting with unexplained peripheral and central anticholinergic symptoms including delirium, agitation and seizures, especially among younger patients and partygoers. It is important that health care professionals recognize that Jimson weed is a toxic, indigenous, "wild" growing plant, subject to misuse and potentially serious intoxication requiring hospitalization.

  14. WHITE BLISTER SPECIES (Albuginaceae ON WEEDS

    Directory of Open Access Journals (Sweden)

    Karolina Vrandečić

    2011-06-01

    Full Text Available The obligate fungi inside the family Albuginaceae are widespread world wide and cause white rust or white blister disease. Mycopopulation of weeds has been researched within the project „The role of weeds in epidemiology of row-crop diseases“. The aim of this research was to identify white blister species occurring on weeds in Eastern Croatia. Weed plants with disease symptoms characteristic for white blister species have been collected since 2001 on location Slavonia and Baranja country. Determination of white blister species was based on morphological characters of pathogen and the host. Wilsoniana bliti was determined on Amaranthus retroflexus and Amaranthus hybridus leaves. Capsella bursa pastoris is a host for Albugo candida. Ambrosia artemisiifolia is a host for Pustula sp. and Cirsium arvense was found to be host for Pustula spinulosa. Wilsoniana portulaceae was determined on Portulaca oleracea.

  15. Selectivity of weed harrowing in lupin

    OpenAIRE

    Jensen, Rikke K.; Rasmussen, Jesper; Melander, Bo

    2004-01-01

    Three field experiments were conducted in lupin in 1997, 1998 and 1999 to study two aspects of selectivity of post-emergence weed harrowing; the ability of the crop to resist soil covering (the initial damage effect), and the ability of the crop to tolerate soil covering (the recovery effect). Each year soil covering curves and crop tolerance curves were established in three early growth stages of lupin. Soil covering curves connected weed control and crop soil cover in weedy plots, and crop ...

  16. Crop diversity prevents serious weed problems

    DEFF Research Database (Denmark)

    Melander, Bo

    2016-01-01

    Weed management in organic crop production could benefit from more diversification of today’s cropping systems. However, the potential of diversification needs better documentation and solid suggestions for employment in practise must be identified.......Weed management in organic crop production could benefit from more diversification of today’s cropping systems. However, the potential of diversification needs better documentation and solid suggestions for employment in practise must be identified....

  17. Effect of different integrated weed management methods on weed density and yield of sugar beet crop

    Directory of Open Access Journals (Sweden)

    alireza koochaki

    2009-06-01

    Full Text Available In order to compare different weed management methods in sugar beet, two experiments were conducted at mashhad for two years in 2005-2006 and 2006-2007. Each experiment designed as a Complete Randomized Block with three replication. The treatments include: Metamitron(Goltix plus Phenmedipham (Betanal (Gol+Bet, Goltix plus Cultivation (Gol+Cu, Disk plus Betanal (Di+Bet, Disk plus Cultivation(Di+Cu, Cover Crop plus Betanal (Co+Bet, Cover Crop plus Cultivation (Co+Cu, Weeding (W and Betanal plus Weeding (Bet+W. Samplings were taken at three stages early season, after imposing the treatments and late season. Results showed that at early season in two experiments, density of weeds was lower in cover crop and disk treatment compared with other treats and the second sampling in first experiment, weeding and disk plus cultivation of treatments with 21.5 and 26.6 respectively plants per m2 and in second experiment year, weeding and application betanal plus weeding treatments, with 14 and 17.8 respectively plant in m2 showed the lowest. In the second experiment year, minimum and maximum sugar beet yield were obtained with cover crop plus betanal and weeding with 43 and 104 ton per hectare respectively. The lowest yield was obtained in check plots with 3.5ton per hectare. Maximum sugar contain (19.35% was obtained in betanal herbicide plus cultivation treatment and minimum (14.88% was obtained with hand weeding treatment. However maximum sugar beet yield was obtained with betanal plus weeding (17.85 ton per hectare and the minimum with cover crop plus betanal (7.5 ton per hectare. Key words: integrated weed management, cover crop, herbicide, cultivation, sugar beet.

  18. Weed detection using unmanned aircraft vehicles

    Directory of Open Access Journals (Sweden)

    Pflanz, Michael

    2014-03-01

    Full Text Available In contrast to agricultural remote sensing technologies, which are based on images from satellites or manned aircrafts, photogrammetry at low altitude from unmanned aircraft vehicles lead to higher spatial resolution, real-time processing and lower costs. Moreover multicopter aircrafts are suitable vehicles to perform precise path or stationary flights. In terms of vegetation photogrammetry this minimises motion blur and provide better image overlapping for stitching and mapping procedures. Through improved image analyses and through the recent increase in the availability of powerful batteries, microcontrollers and multispectral cameras, it can be expected in future that spatial mapping of weeds from low altitudes will be promoted. A small unmanned aircraft vehicle with a modified RGB camera was tested taking images from agricultural fields. A microcopter with six rotors was applied. The hexacopter in particular is GPS controlled and operates within predefined areas at given altitudes (from 5 to 10 m. Different scenarios of photogrammetrically weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. First experiences with microcopter showed a high potential for site-specific weed control. Images analyses with regards to recognition of weed patches can be used to adapt herbicide applications to varying weed occurrence across a field.

  19. WEED MANAGEMENT AND CONTROL IN POTATOES

    Directory of Open Access Journals (Sweden)

    Marcelo Cleón de Castro Silva

    2011-07-01

    Full Text Available This review shows instructions to potatoes' farmer about behavior of the weeds and how to manage them so as to minimize loss of productivity through the use of control strategies for potato crop. The prevention consists in adoption of practices that prevents entry of unwanted species of weeds in the planting site. The control reduces the infestation of these species, but this practice does not eradicate them completely. However, it needs to control the weeds before the area preparation for planting the tubers until complete closure of the soil by shoots of potatoes during the critical period. After covering the soil, the potato crop does not suffer negative interference caused by weeds. The cultural practices include a good plane for harvest, plant crop rotation, the planting of appropriate plants for covering the soil, the ideal space to the planting and the correct time to potato planting. The control must be efficient to reduce the number of weeds in the area to avoid economic losses to farmers. It is necessary to establish weed management strategies in order to maintain sustainable farming systems, preserving the environment and quality of life of the farmer.

  20. Weed flora of South Africa 1: major groupings

    Directory of Open Access Journals (Sweden)

    M. J. Wells

    1983-12-01

    Full Text Available Whilst attention has been focussed on combating priority weeds we have neglected to obtain an overall picture of our weed flora. To rectify the position a National Weed List has been compiled, the weeds have been classified and an analysis made of the weed flora. Aspects covered in this paper are: major taxa, exotic and indigenous species and kinds of weeds. The presence of imbalances or power shifts between indigenous taxa is indicated by the fact that most weeds are supplied by a few families, and that Monocotyledon species are twice as likely to be weeds as are Dicotyledon species. The preponderance of Monocotyledon weeds is explained by re-invasion of cultivated and abandoned fields in grassland areas rather than by a shift towards Monocotyledon species in the veld. Exotic weeds contribute to imbalances via their greater versatility as well as by re-inforcing some taxa or kind of weed groupings at the expense of others. There is a power shift towards exotic Gymnosperms. Apart from flora weeds, exotics provide most agrestals, lawn weeds and weeds of planted pastures, and nearly as many ruderals as the indigenous species.

  1. On weed competition and population dynamics : considerations for crop rotations & organic farming

    NARCIS (Netherlands)

    Mertens, S.K.

    2002-01-01

    Key words: organic farming, weeds, weed management, weed ecology, weed diversity, matrix population model, elasticity analysis, neighbourhood model, survey, crop row spacing, mechanical hoe, harrow, Polygonum convolvulus ,

  2. Combining a weed traits database with a population dynamics model predicts shifts in weed communities.

    Science.gov (United States)

    Storkey, J; Holst, N; Bøjer, O Q; Bigongiali, F; Bocci, G; Colbach, N; Dorner, Z; Riemens, M M; Sartorato, I; Sønderskov, M; Verschwele, A

    2015-04-01

    A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed, populated and analysed, initially using data for 19 common European weeds, to begin to consolidate trait data in a single repository. The initial choice of traits was driven by the requirements of empirical models of weed population dynamics to identify correlations between traits and model parameters. These relationships were used to build a generic model, operating at the level of functional traits, to simulate the impact of increasing herbicide and fertiliser use on virtual weeds along gradients of seed weight and maximum height. The model generated 'fitness contours' (defined as population growth rates) within this trait space in different scenarios, onto which two sets of weed species, defined as common or declining in the UK, were mapped. The effect of increasing inputs on the weed flora was successfully simulated; 77% of common species were predicted to have stable or increasing populations under high fertiliser and herbicide use, in contrast with only 29% of the species that have declined. Future development of the WTDB will aim to increase the number of species covered, incorporate a wider range of traits and analyse intraspecific variability under contrasting management and environments.

  3. Level of threshold weed density does not affect the long-term frequency of weed control.

    NARCIS (Netherlands)

    Wallinga, J.; Oijen, van M.

    1997-01-01

    Weed control thresholds are often presented as a means to reduce unnecessary control measures, thereby increasing the effectiveness of weed management. While the threshold is a useful tool for cost-effective application of control on a single-year base, its role over the longer term is more

  4. Species and dynamics of floating weed seeds in paddy field

    OpenAIRE

    Ranling Zuo; Sheng Qiang

    2008-01-01

    In order to explore effective methods for weed control in paddy fields, we investigated the dynamics of weed seeds in Nanjing from June to November of 2005. A total of 24 weed species representing 15families were found before seedling transplanting and at late growth stage of rice, while during irrigation stage, 26 species of 17 families were identified from floating weed seeds. The two stages shared 18 weed species, accounting for 56.25% of the total weeds. Most of them belonged to Gramineae...

  5. A New Hoe Blade for Inter-Row Weeding

    DEFF Research Database (Denmark)

    Green, O.; Znova, L.; Melander, Bo

    2016-01-01

    . The aim is mainly to improve weeding effectiveness against tall-growing and tap-rooted weed species. The ‘Ducksfoot’ hoe blade is commonly used for traditional inter-row weeding in row crops such as sugar beets and maize. This blade usually provides satisfactory weed control, if soils are not too wet...... and weeds are relatively small. The term ‘Ducksfoot’ covers a range of hoe blade configurations where all have some resemblance with the shape of a ducks foot. However, the ‘Ducksfoot’ blade is not an optimal solution for weed control in narrow inter-row spaces. Several disadvantages have been encountered...

  6. Developments in physical weed control in Northwest Europe

    Directory of Open Access Journals (Sweden)

    Riemens, Marieen

    2016-02-01

    Full Text Available In North West Europe there is an increasing need for advanced weed control methods. This paper gives an overview of the developments in physical weed control methods. Current innovations in interrow weeding focus on systems that take over the steering function of the driver in order to make them more precise and reduce crop losses. The latest developments in intrarow weeding techniques involve technologies that automatically detect and classify crop and weed plants and use this information to guide a weeding device. Several commercially available examples are presented.

  7. Combining a weed traits database with a population dynamics model predicts shifts in weed communities

    DEFF Research Database (Denmark)

    Storkey, Jonathan; Holst, Niels; Bøjer, Ole Mission

    2015-01-01

    , populated and analysed, initially using data for 19 common European weeds, to begin to consolidate trait data in a single repository. The initial choice of traits was driven by the requirements of empirical models of weed population dynamics to identify correlations between traits and model parameters....... These relationships were used to build a generic model, operating at the level of functional traits, to simulate the impact of increasing herbicide and fertiliser use on virtual weeds along gradients of seed weight and maximum height. The model generated ‘fitness contours’ (defined as population growth rates) within...... this trait space in different scenarios, onto which two sets of weed species, defined as common or declining in the UK, were mapped. The effect of increasing inputs on the weed flora was successfully simulated; 77% of common species were predicted to have stable or increasing populations under high...

  8. Ecological Intensification Through Pesticide Reduction: Weed Control, Weed Biodiversity and Sustainability in Arable Farming.

    Science.gov (United States)

    Petit, Sandrine; Munier-Jolain, Nicolas; Bretagnolle, Vincent; Bockstaller, Christian; Gaba, Sabrina; Cordeau, Stéphane; Lechenet, Martin; Mézière, Delphine; Colbach, Nathalie

    2015-11-01

    Amongst the biodiversity components of agriculture, weeds are an interesting model for exploring management options relying on the principle of ecological intensification in arable farming. Weeds can cause severe crop yield losses, contribute to farmland functional biodiversity and are strongly associated with the generic issue of pesticide use. In this paper, we address the impacts of herbicide reduction following a causal framework starting with herbicide reduction and triggering changes in (i) the management options required to control weeds, (ii) the weed communities and functions they provide and (iii) the overall performance and sustainability of the implemented land management options. The three components of this framework were analysed in a multidisciplinary project that was conducted on 55 experimental and farmer's fields that included conventional, integrated and organic cropping systems. Our results indicate that the reduction of herbicide use is not antagonistic with crop production, provided that alternative practices are put into place. Herbicide reduction and associated land management modified the composition of in-field weed communities and thus the functions of weeds related to biodiversity and production. Through a long-term simulation of weed communities based on alternative (?) cropping systems, some specific management pathways were identified that delivered high biodiversity gains and limited the negative impacts of weeds on crop production. Finally, the multi-criteria assessment of the environmental, economic and societal sustainability of the 55 systems suggests that integrated weed management systems fared better than their conventional and organic counterparts. These outcomes suggest that sustainable management could possibly be achieved through changes in weed management, along a pathway starting with herbicide reduction.

  9. Ecological Intensification Through Pesticide Reduction: Weed Control, Weed Biodiversity and Sustainability in Arable Farming

    Science.gov (United States)

    Petit, Sandrine; Munier-Jolain, Nicolas; Bretagnolle, Vincent; Bockstaller, Christian; Gaba, Sabrina; Cordeau, Stéphane; Lechenet, Martin; Mézière, Delphine; Colbach, Nathalie

    2015-11-01

    Amongst the biodiversity components of agriculture, weeds are an interesting model for exploring management options relying on the principle of ecological intensification in arable farming. Weeds can cause severe crop yield losses, contribute to farmland functional biodiversity and are strongly associated with the generic issue of pesticide use. In this paper, we address the impacts of herbicide reduction following a causal framework starting with herbicide reduction and triggering changes in (i) the management options required to control weeds, (ii) the weed communities and functions they provide and (iii) the overall performance and sustainability of the implemented land management options. The three components of this framework were analysed in a multidisciplinary project that was conducted on 55 experimental and farmer's fields that included conventional, integrated and organic cropping systems. Our results indicate that the reduction of herbicide use is not antagonistic with crop production, provided that alternative practices are put into place. Herbicide reduction and associated land management modified the composition of in-field weed communities and thus the functions of weeds related to biodiversity and production. Through a long-term simulation of weed communities based on alternative (?) cropping systems, some specific management pathways were identified that delivered high biodiversity gains and limited the negative impacts of weeds on crop production. Finally, the multi-criteria assessment of the environmental, economic and societal sustainability of the 55 systems suggests that integrated weed management systems fared better than their conventional and organic counterparts. These outcomes suggest that sustainable management could possibly be achieved through changes in weed management, along a pathway starting with herbicide reduction.

  10. Seasonal scouting of weeds in a sugarbeet field in Mashhad

    Directory of Open Access Journals (Sweden)

    azita ashrafi

    2009-06-01

    Full Text Available Weed scouting is an important part of integrated weed management system. In order to evaluate weed emergence pattern and management efficiency on weed populations, a 2 ha sugarbeet field in Mashhad was selected and evaluated during 2002 growing season. Weeds were identified and counted at 441 points at the intersection of a 7m by 7m grid within 0.15 m2 quadrates. The evaluations were done 3 times [pre management (1 and post management (2]. Geostatistical techniques (kriging were used to analyze the spatial structure of weeds and dynamics of weed patches. 34 weed species were observed across the field. Wide ranges of weeds were observed during growing season including, winter annual (e. g. Sinapis arvensis and Fumaria officinalis, summer annual (e. g. Echinochloa crus-galli, biennial (Dacus caraota and perennal (e. g. Convolvulus arvensis. Solanum nigrum, Chenopodium album, Amaranthus spp., Convolvulus arvensis, Polygonum aviculare and Echinochloa crus-galli were the common weeds over growing season. In early growing season, Solanum nigrum with 404.71 seedlings per m2 was present in all samples constituted 81.32% of weed community, but in 2nd and 3rd sampling time, Convolvulus arvensis was the dominant species with 33.29% and 29.26% of weed community. Relative density percentage of perennial and grassy weeds (generally C4 species was increased over the season but the relative density percentage of broadleaf annual weeds was decreased. Main locations of weed emergence were persisted as elliptical patches east ward and west ward of field over the season. The results of this study indicated that scouting and understanding of weed emergence behavior could be used to design effective strategies of weed management.

  11. Weed management in Solanaceae crops in Portugal.

    Science.gov (United States)

    Afonso, M Júlia

    2008-01-01

    Portugal has very good climatic-edafic conditions for Solanaceae crops, regarding to either yield quality or quantity. Tomato (Lycopersicon esculentum Miller.), potato (Solanum tuberosum L.) and pepper (Capsicum annuum L.) are the most social-economically important Solanaceae and aubergine (Solanum melongena L.) area of cultivation is increasing. Tomato is cultivated for fresh consumption and, primarily, for industrial processing. Is one of the most profitable vegetable crop and the main vegetable for industry. Potato is the annual vegetable crop with the largest cultivated area. Pepper is one of the main crops for vegetable frozen industry. Tomato, pepper and aubergine are cultivated in the field (outdoor) in Spring-Summer season. In greenhouses, they're also grown during other months and, at the southmost region (Algarve), during the whole year. Potato is cultivated almost the whole year through. Weed management is essential to achieve yield rentability and, for crops growing in the field, herbicides play an important role, due to their efficacy or inherent limitations of other control measures. This paper presents the state of art, in Portugal, regarding to some cultural and social-economical aspects of these crops (e.g., cultivated areas, productions, main producer regions), main weeds, weed control methods and, in particular, registered herbicides, with indication of their usage conditions (application timings and spectrum of weeds controlled) according to the principles of Good Plant Protection Practice and Integrated Weed Management.

  12. Characterization of weed flora in rubber trees plantations of Bongo ...

    African Journals Online (AJOL)

    SARAH

    2013-10-31

    Oct 31, 2013 ... Rubiaceae, Apocynaceae, Poaceae, Cyperaceae, Euphorbiaceae, Moraceae, Amaranthaceae,. Mimosaceae, Fabaceae, Cucurbitaceae and Commelinaceae. Weeds' mapping was established and illustrated by 4 main weed groups in relation with the stage of rubber trees development. For the plantations.

  13. An Ultrasonic System for Weed Detection in Cereal Crops

    Directory of Open Access Journals (Sweden)

    Dionisio Andújar

    2012-12-01

    Full Text Available Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group

  14. An ultrasonic system for weed detection in cereal crops.

    Science.gov (United States)

    Andújar, Dionisio; Weis, Martin; Gerhards, Roland

    2012-12-13

    Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were

  15. 7 CFR 201.16 - Noxious-weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds. 201.16 Section 201.16 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.16 Noxious-weed seeds. (a) Except for those kinds of noxious-weed seeds shown in paragraph (b) of this section, the names of the kinds of noxious-weed seeds and the...

  16. Checklist for the crop weeds of Paraguay.

    Science.gov (United States)

    De Egea, Juana; Mereles, Fátima; Peña-Chocarro, María Del Carmen; Céspedes, Gloria

    2016-01-01

    Paraguay, a country whose economy is based mainly on agriculture and livestock for export, has experienced a major expansion in mechanized crops during the last few decades. Despite being heavily dependent on agriculture, Paraguay has very limited research on crop weeds, in spite of these having a high economic impact on production. This work aims to update and enhance the knowledgebase on the most common weeds affecting productive fields throughout the different ecoregions of Paraguay. We present here the first checklist of crop weeds for the country, which includes a total of 256 taxa (189 species, 10 subspecies, 54 varieties and 3 forms), with the most species-rich families being Poaceae and Asteraceae followed by Malvaceae, Amaranthaceae, Fabaceae and Solanaceae. The list includes three new records for the country. Synonyms, distribution details within Paraguay, habit and a voucher specimen are provided for each taxon.

  17. Checklist for the crop weeds of Paraguay

    Directory of Open Access Journals (Sweden)

    Juana De Egea

    2016-10-01

    Full Text Available Paraguay, a country whose economy is based mainly on agriculture and livestock for export, has experienced a major expansion in mechanized crops during the last few decades. Despite being heavily dependent on agriculture, Paraguay has very limited research on crop weeds, in spite of these having a high economic impact on production. This work aims to update and enhance the knowledgebase on the most common weeds affecting productive fields throughout the different ecoregions of Paraguay. We present here the first checklist of crop weeds for the country, which includes a total of 256 taxa (189 species, 10 subspecies, 54 varieties and 3 forms, with the most species-rich families being Poaceae and Asteraceae followed by Malvaceae, Amaranthaceae, Fabaceae and Solanaceae. The list includes three new records for the country. Synonyms, distribution details within Paraguay, habit and a voucher specimen are provided for each taxon.

  18. Assessment of the impact of some common weed management ...

    African Journals Online (AJOL)

    A 5X5 Latin Square experiment was conducted in a farmer's field in the Ga East Municipality of the Greater Accra Region to evaluate the efficacies of different weed management systems and their effect on pineapple production. The different weed management systems evaluated were T1 - weedy check, T2- manual weed ...

  19. Effect of the Critical Period of Weed Interference on Optimum ...

    African Journals Online (AJOL)

    A field study was carried out at the National Root Crop Research Institute experimental farm to determine the critical period of weed interference and magnitude of yield loss caused by weed on turmeric in 2008 and 2009 cropping season. Turmeric was subjected to 13 weeding regimes using randomized complete block ...

  20. Image-based thresholds for weeds in maize fields

    DEFF Research Database (Denmark)

    Asif, Ali; Streibig, Jens Carl; Christensen, Svend

    2015-01-01

    in some parts of the field and if late germinating weeds do not affect yield, it may not be necessary the spray such places from an economic point of view. Consequently, it makes sense to develop weed control thresholds for patch spraying, based on weed cover early in the growing season. In Danish maize...

  1. Evaluation of Botanical Herbicides against Common Weed Species ...

    African Journals Online (AJOL)

    growth weed species in coffee farm. The future research should give emphasis to develop. IPM of coffee weeds with integrating biocontrol approaches such as bioherbicides as the proven finding of this investigation. Introduction. Weed control is one of the most difficult problems in organic farming where synthetic herbicides ...

  2. Weed supression by smother crops and selective herbicides

    Directory of Open Access Journals (Sweden)

    Severino Francisco José

    2004-01-01

    Full Text Available Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.

  3. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the

  4. Pest Control in Corn and Soybeans: Weeds - Insects - Diseases.

    Science.gov (United States)

    Doersch, R. E.; And Others

    This document gives the characteristics and application rates for herbicides used to control annual weeds in corn, annual and perennial broadleaf weeds in corn, quackgrass and yellow nutsedge in corn, and annual weeds in soybeans. It also gives insecticide use information for corn and soybeans. A brief discussion of disease control in corn and…

  5. Critical period of weed control In cumin (Cuminum cyminum

    Directory of Open Access Journals (Sweden)

    azade hoseyni

    2009-06-01

    Full Text Available In order to evaluate the critical period of weed control in Cumin, an experiment with Complete Randomized Block Design and three replications was conducted in experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, During 2004-2005 growing season. Treatments included different combinations of weed free and weed infested periods (20, 30, 40 and 80 days after germination plus weedy check and weed free check. Critical period weed control was evaluated with Gompertz and Logestic functions. Traits measured were yield and yield components, harvest index of cumin and also number and weight of weed species. Results showed the critical period was between 24-38 days after germination. With increasing interfereing period at early or late growth stages of cumin, the economic yield was reduced. By extending weeding periods at early stage of growth or during the growth period, dry weight of weeds were reduced, while extending weeding period at the end of growth stage and also weed free during growth period, early or late stages of growth had no significant effects on yield components except on number of umbels per plant. Harvest index was positively affected by early weeding. It appears that early weeding was somehow more effective on yield components for cumin.

  6. Descriptive and mechanistic models of crop–weed competition

    NARCIS (Netherlands)

    Bastiaans, L.; Storkey, J.

    2017-01-01

    Crop-weed competitive relations are an important element of agroecosystems. Quantifying and understanding them helps to design appropriate weed management at operational, tactical and strategic level. This chapter presents and discusses simple descriptive and more mechanistic models for crop-weed

  7. Influence of Land use Intensity and Weed Management Practice on ...

    African Journals Online (AJOL)

    The effects of land use intensity and weed management practice on weed seedling emergence, growth and characterization of weed species were examined at Ilorin, in the southern Guinea savanna of Nigeria. The study was conducted on three pieces of land with known cropping history, laid out as randomized complete ...

  8. Competition of rapeseed ( Brassica napus L.) cultivars with weeds ...

    African Journals Online (AJOL)

    One of the agronomic methods in weeds management is to recognize cultivars possessing high competitive ability with weeds and to recognize the effective characters in order to breed competitive cultivars in weeds sustainable management. Cultivar identification and discrimination has become an important issue in ...

  9. A century of progress in weed control in hardwood seedbeds

    Science.gov (United States)

    David B. South

    2009-01-01

    Weeds have existed in nurseries since before the time Bartram grew hardwoods during the 18th century. Hand weeding was the primary method of weed control during the first part of the 20th century. From 1931 to 1970, advances in chemistry increased the use of herbicides, and advances in engineering increased the reliance on machines for cultivation. Many managers now...

  10. 7 CFR 201.52 - Noxious-weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The determination of the number of seeds, bulblets, or tubers of individual noxious weeds present per unit weight...

  11. Evaluation of UAV imagery for mapping Silybum marianum weed patches

    Science.gov (United States)

    The invasive weed, milk thistle (Silybum marianum), has the tendency to grow in patches. In order to perform site-specific weed management, determining the spatial distribution of weeds is important for its eradication. Remote sensing has been used to perform species discrimination, and it offers pr...

  12. 7 CFR 361.6 - Noxious weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Noxious weed seeds. 361.6 Section 361.6 Agriculture..., DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.6 Noxious weed... considered noxious weed seeds. (1) Seeds with no tolerances applicable to their introduction: Aeginetia spp...

  13. Conservation implications of weed management of lake reservoirs ...

    African Journals Online (AJOL)

    Management of weeds around lake reservoirs is often implemented to reduce any possibility of siltation. However, machineries used in weed management have resulted in habitat degradation and geometrical multiplication of weeds by chopping rhizomes and scattering seeds. In general, the removal offers some feedbacks ...

  14. Response of okra ( Abelmoschus esculentus (L.) Moench) to weed ...

    African Journals Online (AJOL)

    Three mulch types–plastic mulch, grass mulch (Panicum maximum) and wood shavings (of Tectonia grandis)– were compared with hand weeding and no weeding control in a randomized complete block experiment with three replications. Growth and yield characteristics of okra were assessed together with weed control ...

  15. Focus on ecological weed management : what is hindering adoption?

    NARCIS (Netherlands)

    Bastiaans, L.; Paolini, R.; Baumann, D.T.

    2008-01-01

    Despite increased concerns regarding the heavy reliance of many cropping systems on chemical weed control, adoption of ecological weed management practices is only steadily progressing. For this reason, this paper reflects on both the possibilities and limitations of cultural weed control practices.

  16. Water-soluble carbohydrates of root components and activity rhythms at vegetative growth stage of Artemisia scoparia in northeastern grassland of China.

    Science.gov (United States)

    Wang, Shiyu; Yang, Yunfei; Zhi, Heng

    2017-01-01

    The root system of perennials is composed of the roots of different growth years. The nutrient storage capacities and activities of roots are an important basis for judging root components and plant senescence. In this research, changes in the contents of water-soluble carbohydrate (WSC) were used as indicators of the nutrient storage and activity of roots of different life years. From the early resprouting stage to the rapid growth stage, Artemisia scoparia L. plants of 1-3 age classes were sampled and measured once every 18 days. The nutrient storage capacities and activity rhythms of plant root components of the three age classes were analysed quantitatively. Among the A. scoparia population in northeast China, the nutrient storage capacities of 1a/2a plant root collars and 2-year old roots were generally large, whereas those of 3a plant root collars and 3-year old roots were significantly reduced. As for changes in the WSC content in the root system at the 18 day resprouting stage, the decline rates in the root collars of the 1a and 2a plants were 102 and 109 times those of the 3a plants, respectively. The decline rate in the 2-year old roots of the 1a plants was 1.8 times that of the 2a plants and 29.6 times that of the 3a plants. When nutrients were most active, all root components of the 1a plants entered into the resprouting stage, but the 2/3-year old roots of the 2a plants lagged behind. All the root components of the 3a plants generally lagged. At the vegetative growth stage, the WSC contents in all root components of the 1a plants declined logarithmically. For the 3a plants, the content in the root collars decreased linearly with that in the 3-year old roots. The older root components (3-year old roots) of the 2a plants and all root components of the 3a plants exhibited signs of aging.

  17. Virus infection of a weed increases vector attraction to and vector fitness on the weed

    Science.gov (United States)

    Chen, Gong; Pan, Huipeng; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Fang, Yong; Shi, Xiaobin; Zhang, Youjun

    2013-01-01

    Weeds are important in the ecology of field crops, and when crops are harvested, weeds often become the main hosts for plant viruses and their insect vectors. Few studies, however, have examined the relationships between plant viruses, vectors, and weeds. Here, we investigated how infection of the weed Datura stramonium L. by tomato yellow leaf curl virus (TYLCV) affects the host preference and performance of the TYLCV vector, Bemisia tabaci (Gennadius) Q. The results of a choice experiment indicated that B. tabaci Q preferentially settled and oviposited on TYLCV-infected plants rather than on healthy plants. In addition, B. tabaci Q performed better on TYLCV-infected plants than on healthy plants. These results demonstrate that TYLCV is indirectly mutualistic to B. tabaci Q. The mutually beneficial interaction between TYLCV and B. tabaci Q may help explain the concurrent outbreaks of TYLCV and B. tabaci Q in China. PMID:23872717

  18. Weeds of onion fields and effects of some herbicides on weeds in ...

    African Journals Online (AJOL)

    Jane

    2010-10-18

    Oct 18, 2010 ... Weed-free plots gave the highest yield (16.2a kg/m2) and were followed by oxadiazon. (11.9b kg/m2), oxyfluorfen .... onion plots of 2 x 3 m2 were separated by one meter buffer area. The onion seeds of “Aki” .... During experiments, weed numbers were counted as one m2 permanent quadrates per plot.

  19. Weed seed germination in winter cereals under contrasting tillage systems

    DEFF Research Database (Denmark)

    Scherner, Ananda

    2015-01-01

    Grass weeds and Gallium aparine are major weed problems in North European arable cropping systems with high proportions of winter crops, especially winter wheat (Clarke et al., 2000; Melander et al., 2008). Problems are accentuated where inverting tillage is omitted, as weed seeds tend to accumul......Grass weeds and Gallium aparine are major weed problems in North European arable cropping systems with high proportions of winter crops, especially winter wheat (Clarke et al., 2000; Melander et al., 2008). Problems are accentuated where inverting tillage is omitted, as weed seeds tend...... to reduce weed numbers and soil seedbank. However, in recent years Integrated Weed Management (IWM) principles have acquired a stronger place in agriculture (Ghersa et al., 2000; Bastiaans et al., 2008). IWM systems aim at manipulating soil tillage, crop rotation and cover cropping to minimize the impact...... of weeds. An important component in IWM is to understand and ultimately predict weed emergence patterns in relation to the cropping system and the tillage method applied. A better understanding of the cumulative emergence patterns of weed species in winter crops under different tillage regimes will help...

  20. Weed hosts of cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Vennila, S; Prasad, Y G; Prabhakar, M; Agarwal, Meenu; Sreedevi, G; Bambawale, O M

    2013-03-01

    The exotic cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) invaded India during 2006, and caused widespread infestation across all nine cotton growing states. P. solenopsis also infested weeds that aided its faster spread and increased severity across cotton fields. Two year survey carried out to document host plants of P. solenopsis between 2008 and 2010 revealed 27, 83, 59 and 108 weeds belonging to 8, 18, 10 and 32 families serving as alternate hosts at North, Central, South and All India cotton growing zones, respectively. Plant species of four families viz., Asteraceae, Amaranthaceae, Malvaceae and Lamiaceae constituted almost 50% of the weed hosts. While 39 weed species supported P. solenopsis multiplication during the cotton season, 37 were hosts during off season. Higher number of weeds as off season hosts (17) outnumbering cotton season (13) at Central over other zones indicated the strong carryover of the pest aided by weeds between two cotton seasons. Six, two and seven weed hosts had the extreme severity of Grade 4 during cotton, off and cotton + off seasons, respectively. Higher number of weed hosts of P. solenopsis were located at roadside: South (12) > Central (8) > North (3) zones. Commonality of weed hosts was higher between C+S zones, while no weed host was common between N+S zones. Paper furnishes the wide range of weed hosts of P. solenopsis, discusses their significance, and formulated general and specific cultural management strategies for nationwide implementation to prevent its outbreaks.

  1. Weeds optimally grow in peat swamp after burning

    Directory of Open Access Journals (Sweden)

    P.D. Susanti

    2014-07-01

    Full Text Available After clearing land by burning the peat, then the weeds and undergrowth will flourish. Even sometimes, the weeds are eventually burned again. Weed is known as a destroyer plant that has to be controlled. Through proper treatment, the existing weeds in peatlands can be potentiallly exploited. The purpose of this study was to determine the calorific value of briquettes as one of peatland weeds utilization. The results showed that the calorific value ranged from 2,492 cal/g to 5,230 cal/g. The lowest calorific value was on ‘teki kecil’ grass (Scirpus grossus Lf, while the highest calorific value was observed for ‘bantalaki grass’ (Hymenachne amplexicaulis Nees. The high calorific value of the peat weeds are potential for biomass briquettes raw materials. The utilization and use of peat weed briquettes as a raw materials expected can reduce land degradation due to peat swamp burning

  2. Team-up Crop Diversification and Weed Management: PRODIVA

    DEFF Research Database (Denmark)

    Gerowitt, B.; Melander, B.; Krawczyk, R.

    2015-01-01

    The research-network PRODIVA focuses on a better utilization of crop diversification for weed management in North European arable cropping systems. The goal is to maintain diverse arable weed vegetation that is manageable in the long-term and could fulfil other necessary systemfunctions including...... in organic agriculture. Regional fields will be surveyed for weeds to safeguard the relevance of the experimental research. Current cropping practices and their influence on weed pressure and weed diversity will be identified. The project will involve relevant stakeholders from the participating countries...... the results. Neither are crop diversification methods restricted to Organic Farming, nor can IWM (Integrated Weed Management) be successfully implemented without respecting the role of weeds in agro-ecosystems. The project “PRODIVA - Crop diversification and weeds“ is supported within the ERA-net CORE Organic...

  3. Weed Control Trials in Cottonwood Plantations

    Science.gov (United States)

    R. M. Krinard

    1964-01-01

    Weed control in the first year is essential for establishing a cottonwood plantation, for the young trees can neither survive nor grow well if they must compete with other plants. Once the light and moisture conditions are established in its favor, cottonwood becomes the fastest growing tree in the South.

  4. Weed Control in Black Walnut Plantations

    Science.gov (United States)

    Calvin F. Bey; Robert D. Williams

    1976-01-01

    Weeds must be controlled for at least 3 years to successfully establish walnut plantations. Whether by cultivating or applying chemicals, a strip or spot 4 feet wide is sufficient the first 2 years, followed by a 6-foot spot or strip for the third and fourth years.

  5. Natural Compounds for Pest and Weed Control

    Science.gov (United States)

    The control of insect pests and invasive weeds has become more species-selective because of activity-guided isolation, structure elucidation, and total synthesis of naturally produced substances with important biological activities. Examples of isolated compounds include insect pheromones, antifeed...

  6. Bioactive compounds for pest and weed control

    Science.gov (United States)

    The control of insect pests and invasive weeds has become more species-selective because of activity-guided isolation, structure elucidation, and total synthesis of naturally produced substances with important biological activities. Examples of isolated compounds include insect pheromones, antifeed...

  7. Parthenium weed ( Parthenium hysterophorus L.) research in ...

    African Journals Online (AJOL)

    Parthenium is an exotic invasive weed that now occurs widely in Ethiopia. Surveys to determine the presence and distribution of pathogens associated with parthenium and further evaluation of the pathogens found as potential biocontrol agents were carried out in Ethiopia since 1998. Several fungal isolates of the genus ...

  8. Weed Dynamics and Management in Wheat

    DEFF Research Database (Denmark)

    Jabran, Khawar; Mahmood, Khalid; Melander, Bo

    2017-01-01

    Wheat is among the most important cereal and food crops of world and is grown in almost all parts of the world. It is a staple for a large part of the world population. Any decline in wheat yield by biotic or abiotic factors may affect global food security adversely. Weeds are the most damaging...

  9. Parthenium Weed (Parthenium hysterophorus L.) Research in

    African Journals Online (AJOL)

    attacking the weed and determination of their origin in the introduced range is important before introduction of biocontrol agents from abroad. Therefore, the objectives of biocontrol studies carried out were: 1) to collect and identify pathogens associated with Parthenium seed, leaf and other plant parts from different locations; ...

  10. Mycorrhizal fungi suppress aggressive Agricultural weeds.

    NARCIS (Netherlands)

    Rinaudo, V.; Barberi, P.; Giovannetti, M.; van der Heijden, M.G.A.

    2010-01-01

    Plant growth responses to arbuscular mycorrhizal fungi (AMF) are highly variable, ranging from mutualism in a wide range of plants, to antagonism in some non-mycorrhizal plant species and plants characteristic of disturbed environments. Many agricultural weeds are non mycorrhizal or originate from

  11. Bio-gas production from alligator weeds

    Science.gov (United States)

    Latif, A.

    1976-01-01

    Laboratory experiments were conducted to study the effect of temperature, sample preparation, reducing agents, light intensity and pH of the media, on bio-gas and methane production from the microbial anaerobic decomposition of alligator weeds (Alternanthera philoxeroides. Efforts were also made for the isolation and characterization of the methanogenic bacteria.

  12. INFLUENCE OF WEED CONTROL METHODS, POULTRY MANURE ...

    African Journals Online (AJOL)

    User

    INFLUENCE OF WEED CONTROL METHODS, POULTRY MANURE AND PLANTING. PATTERN ON GROWTH AND YIELD ATTRIBUTES OF MAIZE (Zea mays L.) IN THE. NORTHERN GUINEA SAVANNAH ZONE OF NIGERIA. Bature, M.S.,1 Ishaya, D.B.,2 2Mahadi, M.A2, Sharifai, A.I2; Muhammed, A.A2; Hassan, A. H1;.

  13. Weed Science and Technology. MP-17.

    Science.gov (United States)

    Alley, Harold P.; Lee, Gary A.

    This document is one in a series distributed by the Agricultural Extension Service of the University of Wyoming-Laramie. It presents the principles and methods of weed control especially as it relates to the use of herbicides. The factors influencing the effectiveness of both foliar-applied and soil-applied herbicides are discussed. A listing of…

  14. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean.

    Science.gov (United States)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    2015-07-01

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without weeds. Weed species and the methods to maintain weed-free controls varied between years to mitigate treatment effects, and to allow detection of general soybean weed responses. Soybean plants were not visibly nutrient- or water-stressed. We identified 55 consistently downregulated genes in weedy plots. Many of the downregulated genes were heat shock genes. Fourteen genes were consistently upregulated. Several transcription factors including a PHYTOCHROME INTERACTING FACTOR 3-like gene (PIF3) were included among the upregulated genes. Gene set enrichment analysis indicated roles for increased oxidative stress and jasmonic acid signaling responses during weed stress. The relationship of this weed-induced PIF3 gene to genes involved in shade avoidance responses in Arabidopsis provide evidence that this gene may be important in the response of soybean to weeds. These results suggest that the weed-induced PIF3 gene will be a target for manipulating weed tolerance in soybean. No claim to original US government works New Phytologist © 2015 New Phytologist Trust.

  15. Determining treatment frequency for controlling weeds on traffic islands using chemical and non-chemical weed control

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Larsen, S.U.; Andreasen, Christian

    2013-01-01

    /flame, hot water or left untreated. The treatments were carried out at regular, predetermined intervals throughout the growing season in 2004, whereas in 2005 and 2006 how many treatments that were required to keep weed cover below a predetermined acceptance level of 2% were investigated. Percentage weed...... of treatments per year were required: glyphosate 2.5, hot water 3, flames 5, hot air/flames 5.5 and steam 5.5 treatments. The results demonstrate that the weed control should be adjusted to the prescribed quality for the traffic islands by regularly assessing the need for weed control. They also show......Many public authorities rely on the use of non-chemical weed control methods, due to stringent restrictions on herbicide use in urban areas. However, these methods usually require more repeated treatments than chemical weed management, resulting in increased costs of weed management. In order...

  16. Image analysis as a non-destructive method to assess regrowth of weeds after repeated flame weeding

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2013-01-01

    , and therefore it may influence the long-term effect of repeated treatments. Visual assessment of weed cover or image analysis do not affect the remaining parts of the weed plants after treatment, but the methods may have other disadvantages. In order to evaluate and compare three methods we measured changes...... treatment frequency (2, 4, 6, 8 and 10 yearly treatments). Image analysis and visual assessment of images were easy methods to measure vegetation cover. The experiments showed that increasing dosages and frequent treatments resulted in increasing reduction of plant weight and vegetation cover. However......Efficient non-chemical weed control like flame weeding often requires repeated treatments. In weed control experiments the effect of each treatment may be estimated by removing and weighing the remaining weed biomass after the treatment, but the method influences the weed plants ability to regrow...

  17. Weed Biomass and Weed Species Diversity of Juvenile Citrus Trees Intercrop with some Arable Crops

    Directory of Open Access Journals (Sweden)

    Patience Mojibade OLORUNMAIYE

    2012-02-01

    Full Text Available A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34% in all the plots except in citrus/maize plot (0.78% at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m-2 respectively than in citrus/groundnut plot (143.00 m-2. Similarly, significantly lower grass weed densities were produced in citrus/Mucuna and citrus/sweet potato (0.33 m-2 each plots than the control plot (11.33 m-2. Whereas citrus/corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m-2 than citrus/Mucuna plot (126.47 g m-2 at 3WAP, citrus/large green plot (16.15 g m-2 and citrus/groundnut plot (123.25 g m-2 followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m-2 in all the plots compared with control plot.

  18. Effect of Different Methods of Chemical Weed Control Irrigation Regimes on Weed Biomass and Safflower Yield

    Directory of Open Access Journals (Sweden)

    M. Matinfar

    2011-06-01

    Full Text Available In order to investigate the effects of different weed control methods and moisture regimes on safflower (Carthamus tinctorius, a field split plot experiment based on randomized complete block design with 4 replications was conducted in Takestan Iran, during growing seasons of 2007-8. Three irrigations regimes (normal irrigation, restricted irrigation at stem elongation and restricted irrigation at  flowering stage were assigned to the main plots and nine chemical weed control method (complete hand weeding, treflan with 2 L/ha as pre plant herbicide, sonalan with 3 L/ha ad pre plant herbicide, estomp with 3 L/ha as pre plant herbicide, gallant super with 0/75 L/ha as post emergence herbicide, treflan with 2 L/ha as pre plant herbicide+ gallant super with 0/75 L/ha as post emergence herbicide, sonalan with 3 L/ha as pre plant herbicide + gallant super with 0/75 L/ha as post emergence herbicide estomp with 3 L/ha as pre plant herbicide + gallant super with 0/75 L/ha as post emergence herbicide and without hand weeding to sub- plots. At the end of growing period traits like number of head   per plant, number of seed per head, 1000 grain weight, percent of seed oil, yield of seed oil and grain yield were measured. Results indicated that treflan + gallant super treatment in restricted irrigation at stem elongation stage had the lowest dry weight of weeds. In this study maximum grain yield (2927 Kg/ha was achieved from hand weeding + usual irrigation treatments. In general treflan + gallant super treatment was the most effective treatment on safflower yield and weed control.

  19. The benefits of using quantile regression for analysing the effect of weeds on organic winter wheat

    NARCIS (Netherlands)

    Casagrande, M.; Makowski, D.; Jeuffroy, M.H.; Valantin-Morison, M.; David, C.

    2010-01-01

    P>In organic farming, weeds are one of the threats that limit crop yield. An early prediction of weed effect on yield loss and the size of late weed populations could help farmers and advisors to improve weed management. Numerous studies predicting the effect of weeds on yield have already been

  20. A Non-Chemical System for Online Weed Control

    Science.gov (United States)

    Rueda-Ayala, Victor; Peteinatos, Gerassimos; Gerhards, Roland; Andújar, Dionisio

    2015-01-01

    Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%–91%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide. PMID:25831085

  1. A non-chemical system for online weed control.

    Science.gov (United States)

    Rueda-Ayala, Victor; Peteinatos, Gerassimos; Gerhards, Roland; Andújar, Dionisio

    2015-03-30

    Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%-91%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide.

  2. Weed control in energy forest production. Ograesbekaempning vid energiskogsodling

    Energy Technology Data Exchange (ETDEWEB)

    Danfors, B.

    1985-01-01

    The aim of the work was to collect, analyse and present experiences from mechanical and chemical weed control. The drainage status of the soil have to be good if mechanical control shall be used. Chemical weed control with soil-active herbicides requires less herbicide on mineral soils than on organic soils. Weed control must be started the year before planting the cuttings. The energy forestry plantation should be planted with the greatest possible precision to enable weed control between the rows. If weed control is neglected the energy forestry plantation will be unsuccessful. In all such plantations an intensive supervision of the weeds is required for the 2 first years. When the plantation has become established, the weed will have difficulties in competing with the energy plants. Seed-propagated weeds can be controlled if the entire area is sprayed with a soil-active herbicide immediately after the planting of the cuttings. Soils with different organic contents require different doses of herbicide. At present, research is being concentrated on preparing recommendations on doses for different soils. If the spraying with soil-active herbicides is unsuccessful there must be alternative forms of weed control. Weed control in growing stands protect the plants. After harvest the competitive conditions change radically for the weeds. There may now be justification in applying an early spraying before new shoots have developed. Granulated soil-active herbicides may be an alternative. Under favourable conditions the energy plantations is capable of growing faster than the weeds without the help of herbicides or mechanical weed control. Recommendations for the use of herbicides have been prepared for different situations. (BoK).

  3. Water management as a key component of integrated weed management

    Directory of Open Access Journals (Sweden)

    Giuseppe Zanin

    2011-02-01

    Full Text Available Water management within the cropping system is a key factor for an integrated weed management. Soil moisture affects seed persistence and seed dormancy, thus influencing their germination, the establishment of seedlings as well as the competition at adult stage and the number, vitality and dormancy of the new seeds produced by the weeds. The interactions among water availability and competition are very complex and still not fully understood. A research effort in this sector should the be very relevant for the development of new approaches of weed management, such as “Ecological weed management”, aiming to reduce weed density and competitiveness and, in the medium term, to prevent undesired modifications of the weed flora.

  4. Weed Identification Using An Automated Active Shape Matching (AASM) Technique

    DEFF Research Database (Denmark)

    Swain, K C; Nørremark, Michael; Jørgensen, R N

    2011-01-01

    Weed identification and control is a challenge for intercultural operations in agriculture. As an alternative to chemical pest control, a smart weed identification technique followed by mechanical weed control system could be developed. The proposed smart identification technique works on the con......Weed identification and control is a challenge for intercultural operations in agriculture. As an alternative to chemical pest control, a smart weed identification technique followed by mechanical weed control system could be developed. The proposed smart identification technique works......-leaf growth stage model for Solanum nigrum L. (nightshade) is generated from 32 segmented training images in Matlab software environment. Using the AASM algorithm, the leaf model was aligned and placed at the centre of the target plant and a model deformation process carried out. The parameters used...

  5. Drought Tolerance and Perennial Weed Management

    OpenAIRE

    Nkurunziza, Libère; Andreasen, Christian; Liu, Fulai; Streibig, Jens Carl

    2011-01-01

    The aim of this study was to investigate the effect of controlled soil water deficits on sprouting and shoot growth of Canada thistle, coltsfoots and quackgrass. A gradient of soil water contents was created by establishing different densities of barley. The plants were harvested 14 days after watering was stopped. On Canada thistle and coltsfoots, relative water content (RWC) in leaves was measured prior to harvest and biomass of all weed shoots were recorded at harvest. In terms of shoot bi...

  6. Saccharum munja Roxb, an underexploited weed

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, P.; Gujral, G.S.; Madan, M.

    1984-01-01

    Utilisation of the biomass potential of hardy weeds is important, especially for the Third World countries. The present review analyses the possible use of Saccharum munja Roxb., a perennial tropical grass. The plant is capable of stabilising land, can be added to animal feed or from the raw material for manufacture of a variety of handicrafts and furniture. Additional uses like paper making, chemical extraction and carbon production are also considered. 50 references.

  7. Digital image analysis offers new possibilities in weed harrowing research

    OpenAIRE

    Rasmussen, Jesper; Nørremark, Michael

    2006-01-01

    Two field experiments were carried out in winter wheat to determine the optimal intensity and timing of weed harrowing. Each experiment was designed to create a series of intensities by increasing the number of passes at varying growth stages. Visual assessments and digital image processing were used to assess crop soil cover associated with weed harrowing. The study showed that winter wheat responded differently to weed harrowing at different growth stages. In autumn, the crop was severely d...

  8. Crop rotation and its ability to suppress perennial weeds

    OpenAIRE

    Askegaard, Margrethe

    2016-01-01

    The appropriate combination of crops and green manures prevents spread of perennial weeds and increases crop yields and quality. Weed-suppressing crop rotations are absolutely essential for sustainable organic arable farming. Practical recommendation Basic rules • Implement green manures, such as clover or lucerne, in at least 20 % of the rotation. • Do not grow more than 50 % of cereals with low weed competitiveness in the rotation. Do not cultivate such crops for more than 2 con...

  9. Critical Period of Weed Control in Aerobic Rice

    Science.gov (United States)

    Anwar, M. P.; Juraimi, A. S.; Samedani, B.; Puteh, A.; Man, A.

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7–49 days after seeding in off-season and 7–53 days in main season to achieve 95% of weed-free yield, and 23–40 days in off-season and 21–43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21–43 days for better yield and higher economic return. PMID:22778701

  10. Weeds in spring cereal fields in Finland - a third survey

    Directory of Open Access Journals (Sweden)

    J. SALONEN

    2008-12-01

    Full Text Available A survey of weeds in spring cereal fields was conducted in 16 regions of southern and central Finland in 1997-1999. Data were collected from conventional and organic farms, both of which applied their normal cropping practices. A total of 690 fields were investigated by counting and weighing the weed species from ten sample quadrats 0.1 m2 in size in late July - early August. Altogether 160 weed species were found, of which 134 were broad-leaved and 26 grass species. The total number of weed species ranged from 41 to 84 between regions. In organically farmed fields, the average species number was 24 and in conventionally farmed fields 16. The most frequent weed species were Viola arvensis 84%, Stellaria media 76% and Galeopsis spp. 70%. Only 18 species exceeded the frequency level of 33%. The average density of weeds was 136 m-2 (median= 91 in sprayed conventional fields, 420 m-2 (374 in unsprayed conventional fields and 469 m-2 (395 in organic fields. The average air-dry above-ground biomass of weeds was 163 kg ha-1 (median=63, 605 kg ha-1 (413 and 678 kg ha-1 (567, respectively. Weed biomass accounted for 3% of the total biomass of the crop stand in sprayed conventional fields and for 17% in organic fields. Elymus repens, the most frequent grass species, produced the highest proportion of weed biomass.

  11. Chemical and mechanical weed control in soybean (Glycine max

    Directory of Open Access Journals (Sweden)

    Weber, Jonas Felix

    2016-02-01

    Full Text Available In this study we investigated the possibility of chemical and mechanical weed control strategies in soybean. Soybean field experiments were carried out in 2013 and 2014 in Southern Germany. Five treatments including common herbicide mixtures and four mechanical weed control treatments, implementing a harrow and a hoe, were tested at different locations. In the herbicide experiments two treatments were applied by PRE emergence herbicides (metribuzin, clomazone, dimethenamid and metribuzin, flufenacet, clomazone and another two treatments were sprayed with a combination of PRE + POST emergence herbicides (metribuzin, flufenacet, thifensulfuron and pendimethalin, thifensulfuron, bentazone, cycloxydim. Furthermore, a POST herbicide treatment was implemented (thifensulfuron, bentazone, thifensulfuron and fluazifop-P-butyl. In the mechanical weed control experiments, treatments were: three times hoeing, PRE emergence harrowing plus three times hoeing, hoeing and harrowing in rotation or three times harrowing. In both experiments an untreated control was included. A 90% weed control efficacy and 23% yield increase was observed in the POST herbicide treatment. PRE + POST treatments resulted in 92% to 99% weed control efficiency and 15% yield increase compared to the untreated control. In the mechanical weed control experiments the combination of PRE emergence harrowing and POST emergence hoeing resulted in 82% weed control efficiency and 34% higher yield compared to the untreated control. Less weed control efficiency (72% was observed in the harrow treatment, leading to 20% higher yield compared to the control. The suitability of both strategies for implementation in “Integrated Weed Management” has been investigated.

  12. Problems and achievements of cotton (Gossypium Hirsutum L. weeds control

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2017-09-01

    Full Text Available Abstract. Weed control in the cultivation of cotton is critical to the yield and quality of production. The influence of economically important weeds was studied. Chemical control is the most effective method of weed control in cotton but much of the information on it relates to primary weed infestation. Problems with primary weed infestation in cotton have been solved to a significant extent. The question of secondary weed infestation with annual and perennial graminaceous weeds during the period of cotton vegetation is also determined largely by the use of antigraminaceous herbicides. The data related to herbicides to effectively control secondary germinated broadleaf weeds in conventional technology for cotton growing are quite scarce, even globally. We are still seeking effective herbicides for control of these weeds in cotton crops. Studies on their influence on the sowing characteristics of cotton seed and the quality of cotton fiber are still insufficient. In the scientific literature there is not enough information on these questions. The combinations of herbicides, as well as their tank mixtures with fertilizers or plant growth regulators are more efficient than autonomous application. Often during their combined application higher synergistic effect on yield is produced. There is information about cotton cultivars resistant to glyphosate. These cultivars are GMO and they are banned within the European Union, including Bulgaria.

  13. Integrated Weed Management Strategies for Control of Hydrilla

    National Research Council Canada - National Science Library

    Nelson, Linda S; Shearer, Judy F

    2009-01-01

    ...), and the fungal pathogen Mycoleptodiscus terrestris (Gerd.) Ostazeski, applied alone and in combination with one another, as an integrated weed management strategy against the nuisance aquatic plant, hydrilla...

  14. Critical period of weed control in aerobic rice.

    Science.gov (United States)

    Anwar, M P; Juraimi, A S; Samedani, B; Puteh, A; Man, A

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7-49 days after seeding in off-season and 7-53 days in main season to achieve 95% of weed-free yield, and 23-40 days in off-season and 21-43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21-43 days for better yield and higher economic return.

  15. Estimating Time of Weed Emergence in Cucumber (Cucumis sativus L.

    Directory of Open Access Journals (Sweden)

    Nihat Tursun

    2015-02-01

    Full Text Available Modelling is carried out for eleven major weeds in cucumber to develop estimated models for weed emergence time. Weed species were grouped according to their emergence patterns. Amaranthus retroflexus, Chenopodium album, Heliotropium europaeum, Polygonum aviculare and Solanum nigrum were early emerging, Convolvulus arvensis, Cyperus rotundus, Cynodon dactylon, Portulaca oleracea and Sorghum halepense were season long emerging Tribulus terrestris was the late emerging weed species. Different non-linear growth curves (Chapman-Richard, Weibull, logistic, Gompertz and cubic spline fitted to the data of cumulative percent emergence for the different species and years. Cubic spline seemed the best model for many species.

  16. Herbicide-resistant weed management: focus on glyphosate.

    Science.gov (United States)

    Beckie, Hugh J

    2011-09-01

    This review focuses on proactive and reactive management of glyphosate-resistant (GR) weeds. Glyphosate resistance in weeds has evolved under recurrent glyphosate usage, with little or no diversity in weed management practices. The main herbicide strategy for proactively or reactively managing GR weeds is to supplement glyphosate with herbicides of alternative modes of action and with soil-residual activity. These herbicides can be applied in sequences or mixtures. Proactive or reactive GR weed management can be aided by crop cultivars with alternative single or stacked herbicide-resistance traits, which will become increasingly available to growers in the future. Many growers with GR weeds continue to use glyphosate because of its economical broad-spectrum weed control. Government farm policies, pesticide regulatory policies and industry actions should encourage growers to adopt a more proactive approach to GR weed management by providing the best information and training on management practices, information on the benefits of proactive management and voluntary incentives, as appropriate. Results from recent surveys in the United States indicate that such a change in grower attitudes may be occurring because of enhanced awareness of the benefits of proactive management and the relative cost of the reactive management of GR weeds. Copyright © 2011 Society of Chemical Industry.

  17. Weed-cover versus weed-removal management in olive orchards: influence on the carbon balance at the ecosystem scale

    Science.gov (United States)

    Chamizo, Sonia; Serrano-Ortiz, Penélope; Vicente-Vicente, José Luis; Sánchez-Cañete, Enrique P.; López-Ballesteros, Ana; Kowalski, Andrew S.

    2016-04-01

    Agriculture plays an important role in the C budget at the global scale. Traditional practices based on soil tillage and applying herbicides to remove weeds have caused damage to soils and led to important losses of soil organic C and increased CO2 emissions to the atmosphere. Changing trends from traditional agriculture to conservation agriculture practices may have an important role in both C and water budgets and the transformation of agriculture from C source to C sink. The objective of this study was to analyse the effect of two treatments, weed removal by herbicides versus weed cover conservation, on the C balance in an irrigated olive orchard in SE Spain. Measurements of CO2 exchange were made from October 2014 to September 2015 using two eddy covariance towers, one for each olive crop treatment. Results show that CO2 fluxes at the ecosystem scale were similar in the two treatments during initial conditions, prior to weed growth in the soils without herbicide application (October). During the first week, daily net ecosystem exchange (NEE) was close to zero in both treatments, with values ranging from 1.06 to -0.41 g C m-2 in the weed cover treatment, and from 0.76 to -0.69 g C m-2 in the weed removal treatment. As weed growth increased, higher net CO2 assimilation was found in the treatment with weed cover. In both treatments, maximum net CO2 assimilation was found in March, with a monthly NEE of -72 and -28 g C m-2 in the treatment with and without weed cover, respectively. In May, after the weeds were cut and left on the soil, a strong increase was observed in NEE in the treatment with weed cover due to decreased CO2 assimilation and increased respiration compared to the treatment without weed cover. Therefore, soil chamber measurements showed average respiration rates of 2.57 and 1.57 μmol m-2 s-2 in the weed cover and weed removal treatment, respectively. Finally, the highest monthly NEE was registered during July, with both treatments showing a similar

  18. Chemical and Mechanical Control of Soybean (Glycin max L. Weeds

    Directory of Open Access Journals (Sweden)

    Ebrahim Gholamalipour Alamdari

    2016-10-01

    Full Text Available To evaluate effects of the various concentrations of two herbicides of the trifluralin and Imazethapyr and weeding on weeds control, yield and yield components of soybean (Glycin max L., an experiment was carried out based on randomized complete block design with three replications at the Agriculture Land of Ghravolhaji Village in Kallale district of Golestan province in 2014. Treatments consisted of planting soybean under weeding, without weeding and application of trifluralin and Imazethapyr as 100% trifluralin, 75% trifluralin + 25% Imazethapyr, 50% trifluralin + 50% Imazethapyr, 25% trifluralin + 75% Imazethapyr, 100% pursuit, 100% Imazethapyr + 25% trifluralin, 25% Imazethapyr + 100% trifluralin, 100% Imazethapyr + 50% trifluralin and 50% Imazethapyr + 100% trifluralin. density of each weed, their total density and inhibition percentage were measured. Results showed that the effect of chemical weed control on all traits measured, except seed number per pot, 1000 seed weight, content of chlorophyll a and total chlorophyll, were significant. The highest leaf area, plant height, number of pods per plant, aerial plant dry weight, seed number per plant and seed weight per plant were observed in the treatment of the 100% Imazethapyr (238.67 cm2, weeding (57.69 cm, both treatments of weeding (33.10 and 25% Imazethapyr +100% trifluralin (28.3, both treatment of weeding (163.92 g and 100%  Imazethapyr (163.70 g, weeding (67.10 seed per plant, both treatment of weeding and 100%  Imazethapyr + 50% trifluralin (10.27 seed per plant respectively. The highest seed yield was obtained from weeding treatment (2383 kg/h. Based on the results, the highest content of protein and chlorophyll b in soybean were obtained from weeding treatment. The highest inhibition percentage of weeds was found in the additional treatment of 50% Imazethapyr + 100% trifluralin (75.19 and 100% Imazethapyr + 25% trifluralin (72.86. The lowest and highest total phenols content and

  19. Weed control of growing stands of energy forests

    Energy Technology Data Exchange (ETDEWEB)

    Noren, O.; Danfors, B.; Stambeck, A.

    1983-01-01

    Investigations that would lead to the selection of suitable methods of weed control in growing stands of energy forests were started. Different methods of accomplishing the weed control measures, i.e., both mechanical and chemical methods must be available. The mechanical measures can be done either with powered or nonpowered tillage implements. The chemical weed control will require special techniques and equipment. As regards mechanical weed control, a tool-bar was built upon which different tillage units could be attached. Weed control with non-powered tillage implements gives best results on mineral soils. On orgnogenic soils the degree of humification and the number of weeds are decisive for the result. The tool-bar was also used to test ground-driven discs, diameter 520 mm. These work well under most conditions and can also be used on organogenic soils with abundant growth of weeds. The placement of the implement, preferably in two parts, one in front and one at the rear of the tractor permits greater precision to be achieved when driving at the same time as the implement can be slightly more roomy. On organogenic soils a rotary cultivator often gives good results in weed control. Where the weed growth was too dense leaves and stems became entwined around the axles. On low-humified soils residues of roots and stumps caused problems. The bulletin discusses weed-wiper technique as well as spraying, and different technical solutions are proposed. In order to achieve effective mechanical or chemical weed control it is necessary to place high demands on the precision in the planting of the cuttings. Another requirement that arises in different situations is the accessibility. Machinery and vehicles must be designed so that they can be fitted with suitable wheel equipment or tracks that provide better carying capacity. Long-term soil compaction can also be reduced if the wheel equipment is suitably designed.

  20. Effect of weed control treatments and cutting frequency on weed dry ...

    African Journals Online (AJOL)

    Two experiments were conducted during the rainy seasons of 2012 and 2013 at the Teaching and Research Farm of the Department of Crop Science, University of Nigeria, Nsukka, to evaluate the growth and leaf yield of Telfairia occidentials Hook F. as influenced by weed control treatments and cutting frequencies.

  1. Biodiversity of segetal weed community in continuous potato cultivated with metribuzin-based weed control

    Directory of Open Access Journals (Sweden)

    Pawlonka Zbigniew

    2015-01-01

    Full Text Available The objective of the work reported here was to determine the relationship between herbicide rate and the biodiversity of weed communities in potato cultivated in continuous cropping. A seven-year field experiment was conducted to examine the effect of 4 metribuzin rates and an uncontrol on weed infestation in successive years of continuous potato cultivation. The following indices were calculated: the Shannon-Wiener and Simpson’s indices of species diversity and the Simpson’s index of domination. A total of 33 species were recorded in the experimental plots. Echinochoa crus-galli was the dominant species. The most abundant segetal communities were observed in untreated plots. An application of the herbicide reduced the biodiversity of the agrophytocenosis. Cultivation in continuous cropping increased the species number of the weed community in potato. The herbicide and cultivation in continuous cropping did not significantly affect the biodiversity indices but their values, to a great extent, confirmed the trends revealed by the analysis of weed infestation

  2. Farmers deserve credit for contributing to the weed surveys

    OpenAIRE

    Salonen, Jukka; Hofmeijer, Merel A.J.; Zarina, Livija; Krawczyk, Roman; Verwijst, Theo; Melander, Bo

    2018-01-01

    Weed surveys were carried out in the PRODIVA project during 2015-2016 with a smooth collaboration with farmers. More than 200 fields were surveyed in six countries around the Baltic Sea. In addition to the weed observations in spring cereal fields we collected information about the farming practices in organic cropping.

  3. Research on weed species for phytoremediation of boron polluted soil

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... This research was aimed to investigate the application of weed species for phytoremediation of soil polluted with boron. A greenhouse experiment was conducted to study the effect of increasing boron. (B) application on the growth and B uptake of common weed species, Sorghum halepense L. Pers.,.

  4. Evaluation of Botanical Herbicides against Common Weed Species ...

    African Journals Online (AJOL)

    Evaluation of botanical herbicides against common weed species of coffee. [2] herbicides were varied among plant extracts as well as with application frequency. Essential oils extracted from E. citrodora and C. winterianus caused significantly the highest percentage growth retardation of weeds as compared to untreated ...

  5. Weed occurrence on pavements in five North European towns

    NARCIS (Netherlands)

    Melander, B.; Holst, N.; Grundy, A.; Kempenaar, C.; Riemens, M.M.; Verschwele, A.; Hansson, D.

    2009-01-01

    Weeds on pavements in urban areas are unwanted mainly because they cause an untidy appearance or sometimes structural damage. Glyphosate has been the principal weed control method for years, but policies in several European towns have changed to lower dependence on herbicides. Instead, less

  6. Effects of different crop associations and fertilizer types on weed ...

    African Journals Online (AJOL)

    Experiments were conducted at the Teaching and Research Farm of the University of Ibadan in 1998/1999 and 1999/2000 cropping seasons to determine the effects of different crop associations and fertilizer types on the weed biomass. The results showed that crop associations did not significantly affect weed density and ...

  7. Domestic geese: biological weed control in an agricultural setting.

    Science.gov (United States)

    Tricia L. Wurtz

    1995-01-01

    Vertebrate herbivores can be effective agents of biological weed control in certain applications. I compared the use of domestic geese for weed control in an agricultural field with the herbicide hexazinone and with hand control. Newly planted spruce seedlings acted as a prototype crop that would be unpalatable to the geese. Trampling by geese led to as much as 47%...

  8. Impact of natural weed infestation on the performance of selected ...

    African Journals Online (AJOL)

    W.D.Clayton, Panicum maximum Jacq, Imperata cylindrica L., Panicum repens L., Cynodon dactylon L. and Cyperus rotundus L. were the major weed problems of sugarcane in Ilorin. The monthly hoe weeded treatment had significantly higher tiller count which translated to higher cane yield (22.61 to 72.54 t/ha) than other ...

  9. Effect of Cropping Practices on Weed Species Composition in a ...

    African Journals Online (AJOL)

    It was shown that although the groundnut crop had more than a dozen week species, the most dominant species were Commelina benghalensis, Rhynchelytrum repens, Eleucine Indica, Bidens pilosa, Acanthospermum hispidus. Although the effect of the hoe-weeding regimes on the subsequent weed flore were subtle, it is ...

  10. Effect of different weed management techniques on growth ...

    African Journals Online (AJOL)

    The weed management techniques included slashing at 8-weekly intervals, mulching alone, glyphosate + slashing, glyphosate + mulching, glyphosate alone and a weed-free control. Glyphosate + mulching proved to have the greatest positive influence on plant height, plant girth, leaf area and number of leaves throughout ...

  11. Efficacy of various herbicides against weeds in wheat ( Triticum ...

    African Journals Online (AJOL)

    Weeds are one of the most important factors that impose a great threat to the crop yield. In order to alleviate the weeds infestation in wheat (Triticum aestivum L.), the efficacy of various pre and post-emergence herbicides were tested during Rabi 2009 to 2010 at the Agronomic Research Area, University of Agriculture, ...

  12. UAV low-altitude remote sensing for precision weed management

    Science.gov (United States)

    Precision weed management, an application of precision agriculture, accounts for within-field variability of weed infestation and herbicide damage. Unmanned aerial vehicles (UAVs) provide a unique platform for remote sensing of field crops. They are more efficient and flexible than manned agricultur...

  13. Weed management in banana production: The use of Nelsonia ...

    African Journals Online (AJOL)

    EJIRO

    The effects of this Acanthaceae on banana yield parameters, snails' population and weed species ... The coffee farmers manage the growth of these plants and use them as green fertilizers and for weed suppression. Rye (Secale cereale L.) is an excellent example of a ..... also found in pot experiments in Australia, that.

  14. Big Data for weed control and crop protection

    NARCIS (Netherlands)

    Evert, van F.K.; Fountas, S.; Jakovetic, D.; Crnojevic, V.; Travlos, I.; Kempenaar, C.

    2017-01-01

    Farmers have access to many data-intensive technologies to help them monitor and control weeds and pests. Data collection, data modelling and analysis, and data sharing have become core challenges in weed control and crop protection. We review the challenges and opportunities of Big Data in

  15. Role of herbicide-resistant crops in integrated weed management

    Science.gov (United States)

    Chemical weed control began with the use of 2,4-D in the mid-1940s. Since then, a wide array of herbicides has been commercialized and that has greatly contributed to increased crop yields. With the introduction of several new, more specific and more effective herbicides, the cost of weed control wi...

  16. How to Identify and Control Water Weeds and Algae.

    Science.gov (United States)

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  17. Evaluation of Different Weed Control Techniques in Soyabean ...

    African Journals Online (AJOL)

    Ten weed control treatments consisting of wheel type weeder [3 and 6 weeks after planting (wap)]; hoe weeding (3 and 6 wap); Pre-emergence application of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] + prometryn [N, N'-bis (1-methylethyl)-6-(methylthio)-1,3,5-triazine-2 ...

  18. Weed biocontrol in the EU: from serendipity to strategy

    Science.gov (United States)

    Biological control of weeds is a globally-recognized approach to the management of the worst invasive plants in the world. Unfortunately, accidental introduction of agents account for most weed biocontrol in the EU, but do include a number of current or emerging successes. From the redistribution of...

  19. Weed science research and funding: a call to action

    Science.gov (United States)

    Weed science has contributed much to agriculture, forestry and natural resource management over its history. However, if it is to remain relevant as a scientific discipline, it is long past time for weed scientists to take a step outside the “herbicide efficacy box” and address system-level issues i...

  20. An Autonomous Robotic System for Mapping Weeds in Fields

    DEFF Research Database (Denmark)

    Hansen, Karl Damkjær; Garcia Ruiz, Francisco Jose; Kazmi, Wajahat

    2013-01-01

    The ASETA project develops theory and methods for robotic agricultural systems. In ASETA, unmanned aircraft and unmanned ground vehicles are used to automate the task of identifying and removing weeds in sugar beet fields. The framework for a working automatic robotic weeding system is presented...

  1. Effect of weed management methods and nitrogen fertilizer rates on ...

    African Journals Online (AJOL)

    Inefficient weed management practices and the use of inappropriate nitrogen fertilizer rates are the major causes of low yield of wheat in Ethiopia. Therefore, field experiments were conducted at Bobicho and Faate in southern Ethiopia to determine the effect of weed management practices and N fertilizer rates on grain yield ...

  2. Effect of fertilizer in controlling weeds under intercropping of pearl ...

    African Journals Online (AJOL)

    Jane

    2011-07-25

    Jul 25, 2011 ... Carr et al. (1995) and Bulson et al. (1997) found a greater weed biomass in sole cropped legumes than in ... advantage, while there is a yield disadvantage from intercropping if. LERT is less than one (LERT < 1) (Raji, ... petition and consequently, increased weeds biomass. (Liebman and Robichaux, 1990).

  3. Exploring cost-effective maize integrated weed management ...

    African Journals Online (AJOL)

    ACSS

    Several production constraints have led to low yields (< 2.5 t ha-1) in maize (Zea mays L.) in. Uganda, among which are weeds. This study investigated the most cost-effective integrated weed management (IWM) approach in maize in eastern Uganda. An experiment was conducted at. Ikulwe station, Mayuge in 2011 and ...

  4. Systematic design of an autonomous platform for robotic weeding

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2010-01-01

    The systematic design of an autonomous platform for robotic weeding research in arable farming is described. The long term objective of the project is the replacement of hand weeding in organic farming by a device working autonomously at field level. The distinguishing feature of the described

  5. Effects of Nitrogen, Potassium and Weed Interference on Yield of ...

    African Journals Online (AJOL)

    Parameters studied included bulb weight (g), bulb diameter (cm) and bulb heights (cm). The result indicated significant (P<0.05) effect of potassium, nitrogen and weed interference on the yield of onion. Highest bulb yield was obtained with 250 kg/ha potassium, 150 kg/ha nitrogen and the 4 WAT weeding regime. No bulbs ...

  6. Effects of weed management on the prevalence of pink pineapple ...

    African Journals Online (AJOL)

    An on-farm experiment was conducted in August 2010 to evaluate the efficacy of various weed management methods used in pineapple cultivation in Ghana in limiting the prevalence of the pineapple mealybugs and their tending ants. The experiment was a 5X5 Latin Square design with 5 replications. The weed ...

  7. Effect Of Weed On Oil Palm Inflorenscence Production: Implication ...

    African Journals Online (AJOL)

    Weed consistently depressed the performance of oil palm and this depressive effect was attributed to aggressive growth resources, smothering of the oil palm and preventing the palm from proper ventilation and solar radiation. Weed interference on inflorescence production of oil palm was assessed with the view of ...

  8. Effects of varying weeds substrates on vermicomposting and ...

    African Journals Online (AJOL)

    Suitability of some grasses, weeds and poultry droppings, either sole or in combination for vermicomposting as well as the effect of vermicompost on soil properties, growth and nodulation of cowpea were assessed. The results indicated that poultry droppings, sole grass or weed substrates were not suitable for ...

  9. Characterization of weed flora in rubber trees plantations of Bongo ...

    African Journals Online (AJOL)

    Objectives: the main objective of this study is to characterize the weed floristic diversity of the Bongo rubber trees plantation and to provide a map for sustainable weed management. Methodology and results: a floristic survey of the Para rubber plantations of Bongo (Southeast Côte d'Ivoire) was conducted in 2007 and early ...

  10. Critical Period for Weed Removal in Garden Egg (Solanum Incanum ...

    African Journals Online (AJOL)

    Field experiments were conducted at the Teaching and Research Farm, Adeyemi College of Education, Ondo during the 2004 and 2005 cropping seasons to determine the extent of yield loss due to weed infestation and the critical time for weed removal in garden egg (Solanum incanum). The experiment which was ...

  11. Developing selection protocols for weed competitiveness in aerobic rice

    NARCIS (Netherlands)

    Zhao, D.L.; Atlin, G.N.; Bastiaans, L.; Spiertz, J.H.J.

    2006-01-01

    Aerobic rice production systems, wherein rice is dry-sown in non-puddled soil and grown as an upland crop, offer large water savings but are subject to severe weed infestation. Weed-competitive cultivars will be critical to the adoption of aerobic rice production by farmers. Breeding

  12. Weed management in banana production: The use of Nelsonia ...

    African Journals Online (AJOL)

    During a survey of weeds in the Tiko banana plantations, the plant Nelsonia canescens (Lam.) Spreng was found to have invaded large areas of the plantation with no visible adverse effects on the banana crop. The effects of this Acanthaceae on banana yield parameters, snails' population and weed species diversity and ...

  13. Economic assessment of tillage systems and weed control methods ...

    African Journals Online (AJOL)

    This study was conducted to appraise the economics of different land preparation systems and weed management options in maize cultivation in three ecological zones (Ikenne, Ibadan and Ilorin) of southwestern Nigeria. Four tillage systems as main treatments and six weed control methods as sub-treatments were ...

  14. WEED FLORA OF CASSAVA IN WEST NILE ZONES OF UGANDA ...

    African Journals Online (AJOL)

    ACSS

    Information on weeds of cassava (Manihot esculenta Crantz) in eastern Africa is limited. The objective of this study was to establish the status of weed flora in selected cassava growing regions of Uganda. This study was conducted in 2013 at Abi Zonal Agricultural Research and Development Institute; (AbiZARDI) in Arua, ...

  15. Managing invasive plants in natural areas: Moving beyond weed control

    Science.gov (United States)

    Dean Pearson; Yvette Ortega

    2009-01-01

    Exotic invasive plants present one of the greatest challenges to natural resource management. These weeds can alter entire communities and ecosystems, substantially degrading important ecosystem services such as forage for wild and domestic herbivores, water and soil quality, recreational values, and wildlife habitat. Traditionally, weed management in natural areas has...

  16. Field Applications of Automated Weed control: Northwest Europe

    NARCIS (Netherlands)

    Hofstee, J.W.; Nieuwenhuizen, A.T.

    2014-01-01


    In Northwest Europe there is high need for advanced weed control methods. The use of crop protection chemicals has become stricter, and integrated pest management is required by regulations from the European Union. This need has resulted in the development of several advanced weed control

  17. Weed Suppression by Seven Clover Species

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Shirley M.; King, Jane R.; Izaurralde, R Cesar C.; O' Donovan, John T.

    2001-01-01

    Used as cover crops, clover species may differ in their ability to suppress weed growth. Field trials were conducted in Alberta, Canada to measure the growth of brown mustard [Brassica juncea (L.) Czern.], in mowed and nonmowed production, as influenced by alsike (Trifolium hybridum L.), balansa [T. michelianum Savi var. balansae (Boiss.) Azn.], berseem (T. alexandrinum L.), crimson [T. incarnatum (Boiss.) Azn.], berseem (T. alexandrinum L.), crimson (T. incarnatum L.), Persian (T. resupinatum L.), red (T. pratense L.), and white Dutch (T. repens L.) clover and fall rye (Secale cereale L.). In 1997, clovers reduced mustard biomass in nonmowed treatments by 29% on a high- fertility soil (Typic Cryoboroll) at Edmonton and by 57% on a low- fertility soil (Typic Cryoboralf) at Breton. At Edmonton, nonmowed mustard biomass was reduced by alsike and berseem clover in 1996 and by alsike, balansa, berseem, and crimson clover in 1997. At Breton, all seven clover species suppressed weed biomass. A negative correlation was noted among clover and mustard biomass at Edmonton but not at Breton. The effects of mowing varied with location, timing, and species. Mowing was beneficial to crop/weed proportion at Edmonton but not at Breton. Mowing at early flowering of mustard large-seeded legumes and sweetclover (Melilotus offici) produced greater benefit than mowing at late flowering. With early mowing, all clover species suppressed mustard growth at Edmonton. Clovers reduced mustard regrowth (g plant21 ) and the number of mustard plants producing regrowth. The characteristics of berseem clover (upright growth, long stems, high biomass, and late flowering) would support its use as a cover crop or forage in north-central Alberta.

  18. Restoring interventions: eco-sustainable weed control

    Directory of Open Access Journals (Sweden)

    Facciotto G

    2006-01-01

    Full Text Available The creation and enlargement of ecological networks is paramount to conserve plant biodiversity, to offer refuge to the local fauna and to improve the environment in general. Such networks intend to conserve areas of great natural value, to restore degraded areas and to link them physically through the creation of ecological corridors. The work described was carried out in order to improve and enlarge an ecological corridor within the experimental farm “Mezzi” of CRA-ISP at Casale Monferrato (AL - Italy. One of its bigger problems, weed control, was solved by increasing the planting density, by sowing herbaceous crops and mulching with woody chips.

  19. Allelopatic potential of weeds under the minimalization of soil treatment

    Directory of Open Access Journals (Sweden)

    Mikhail A. Mazirov

    2014-01-01

    Full Text Available The content of water-dispersible phenol substances in rhizosphere both of annual and perennial species of weeds (Cirsium arvense, Sonchus arvensis increases under soil treatment minimalization. The higher content of phenol substances of researched weeds is defined in rhizosphere of Common Couch (Agropyrum repens. The absence of intensive anthropogenic treatment of plowing layer which accumulates the significant mass of weed’s roots in the cause of much more higher allelopathic potential of some species’ of weeds. The high level of saturation by weeds in agrophytocoenosis under non-tillage soil treatment is defines the competitiveness between certain sepsis’ of weeds, especially, at the beginning of the vegetation. In this case, increasing the secretion of phenol substances is one of the physiological screenings of such competitiveness.

  20. The Effect of Laser Treatment as a Weed Control Method

    DEFF Research Database (Denmark)

    Mathiassen, Solvejg K; Bak, Thomas; Christensen, Svend

    2006-01-01

    A laser beam directed towards weeds can be an efficient weed control method as an alternative to herbicides. Lasers may deliver high-density energy to selected plant material, raising the temperature of the water in the plant cells and thereby stop or delay the growth. A commercial use of lasers ...... (exposure time and spot size of the laser beam). The experiment also showed a significant difference between two wavelengths. In order to improve the performance and to validate the efficacy on a broader spectrum of weed species, further research and development is needed.......A laser beam directed towards weeds can be an efficient weed control method as an alternative to herbicides. Lasers may deliver high-density energy to selected plant material, raising the temperature of the water in the plant cells and thereby stop or delay the growth. A commercial use of lasers...

  1. Applying a weed risk assessment approach to GM crops.

    Science.gov (United States)

    Keese, Paul K; Robold, Andrea V; Myers, Ruth C; Weisman, Sarah; Smith, Joe

    2014-12-01

    Current approaches to environmental risk assessment of genetically modified (GM) plants are modelled on chemical risk assessment methods, which have a strong focus on toxicity. There are additional types of harms posed by plants that have been extensively studied by weed scientists and incorporated into weed risk assessment methods. Weed risk assessment uses robust, validated methods that are widely applied to regulatory decision-making about potentially problematic plants. They are designed to encompass a broad variety of plant forms and traits in different environments, and can provide reliable conclusions even with limited data. The knowledge and experience that underpin weed risk assessment can be harnessed for environmental risk assessment of GM plants. A case study illustrates the application of the Australian post-border weed risk assessment approach to a representative GM plant. This approach is a valuable tool to identify potential risks from GM plants.

  2. RoboWeedSupport - Detection of weed locations in leaf occluded cereal crops using a fully convolutional neural network

    DEFF Research Database (Denmark)

    Dyrmann, Mads; Jørgensen, Rasmus Nyholm; Midtiby, Henrik Skov

    2017-01-01

    This pap er presents a metho d for au tomating weed detectio n in colour images despite heavy lea f occlusion. A fully convolu tio n al neural network is used to detect the weed s. The netwo rk is trained and validated on a tot al of more than 17,000 ann otations of w eeds in images from wint er w...

  3. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean

    NARCIS (Netherlands)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald|info:eu-repo/dai/nl/254842836; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without

  4. Benefits of Precision Farming Technologies for Mechanical Weed Control in Soybean and Sugar Beet—Comparison of Precision Hoeing with Conventional Mechanical Weed Control

    Directory of Open Access Journals (Sweden)

    Christoph Kunz

    2015-04-01

    Full Text Available Weed infestations and associated yield losses require effective weed control measures in soybean and sugar beet. Besides chemical weed control, mechanical weeding plays an important role in integrated weed management systems. Field experiments were conducted at three locations for soybean in 2013 and 2014 and at four locations for sugar beet in 2014 to investigate if automatic steering technologies for inter-row weed hoeing using a camera or RTK-GNSS increase weed control efficacy, efficiency and crop yield. Treatments using precision farming technologies were compared with conventional weed control strategies. Weed densities in the experiments ranged from 15 to 154 plants m−2 with Chenopodium album, Polygonum convolvulus, Polygonum aviculare, Matricaria chamomilla and Lamium purpureum being the most abundant species. Weed hoeing using automatic steering technologies reduced weed densities in soybean by 89% and in sugar beet by 87% compared to 85% weed control efficacy in soybean and sugar beet with conventional weeding systems. Speed of weed hoeing could be increased from 4 km h−1 with conventional hoes to 7 and 10 km·h−1, when automatic steering systems were used. Precision hoeing technologies increased soybean yield by 23% and sugar beet yield by 37%. After conventional hoeing and harrowing, soybean yields were increased by 28% and sugar beet yield by 26%.

  5. Use of weeds as traditional vegetables in Shurugwi District, Zimbabwe.

    Science.gov (United States)

    Maroyi, Alfred

    2013-08-20

    Most agricultural weeds are usually regarded as undesirable and targeted for eradication. However, weeds are useful to human beings as food and traditional medicines. Few studies have been done to document the uses of weeds as traditional vegetables. This study was therefore, done to document indigenous knowledge related to the diversity and use of agricultural weeds as traditional vegetables in Shurugwi District, Zimbabwe, emphasizing their role in food security and livelihoods of the local people. Semi-structured interviews, observation and guided field walks with 147 participants were employed between December 2011 and January 2012 to obtain ethnobotanical data on the use of edible weeds as traditional vegetables. Based on ethnobotanical information provided by the participants, botanical specimens were collected, numbered, pressed and dried for identification. A total of 21 edible weeds belonging to 11 families and 15 genera, mostly from Amaranthaceae (19%), Asteraceae and Tiliaceae (14.3%), Capparaceae, Cucurbitaceae and Solanaceae (9.5% each) were identified. Of the documented edible weeds, 52.4% are indigenous while 47.6% are exotic to Zimbabwe; either semi-cultivated or growing naturally as agricultural weeds in farmlands, fallow land and home gardens. Among the main uses of edible weeds were leafy vegetables (81%), followed by edible fruits (19%), edible corms (9.5%), edible flowers and seeds (4.8% each). The most important edible weeds were Cleome gynandra, cited by 93.9% of the participants, Cucumis metuliferus (90.5%), Cucumis anguria (87.8%), Corchorus tridens (50.3%) and Amaranthus hybridus (39.5%). All edible weeds were available during rainy and harvest period with Cleome gynandra, Corchorus tridens, Cucumis anguria, Cucumis metuliferus and Moringa oleifera also available during the dry season, enabling households to obtain food outputs in different times of the year. The importance of edible weeds for local livelihoods was ubiquitously perceived

  6. Use of weeds as traditional vegetables in Shurugwi District, Zimbabwe

    Science.gov (United States)

    2013-01-01

    Background Most agricultural weeds are usually regarded as undesirable and targeted for eradication. However, weeds are useful to human beings as food and traditional medicines. Few studies have been done to document the uses of weeds as traditional vegetables. This study was therefore, done to document indigenous knowledge related to the diversity and use of agricultural weeds as traditional vegetables in Shurugwi District, Zimbabwe, emphasizing their role in food security and livelihoods of the local people. Materials and methods Semi-structured interviews, observation and guided field walks with 147 participants were employed between December 2011 and January 2012 to obtain ethnobotanical data on the use of edible weeds as traditional vegetables. Based on ethnobotanical information provided by the participants, botanical specimens were collected, numbered, pressed and dried for identification. Results A total of 21 edible weeds belonging to 11 families and 15 genera, mostly from Amaranthaceae (19%), Asteraceae and Tiliaceae (14.3%), Capparaceae, Cucurbitaceae and Solanaceae (9.5% each) were identified. Of the documented edible weeds, 52.4% are indigenous while 47.6% are exotic to Zimbabwe; either semi-cultivated or growing naturally as agricultural weeds in farmlands, fallow land and home gardens. Among the main uses of edible weeds were leafy vegetables (81%), followed by edible fruits (19%), edible corms (9.5%), edible flowers and seeds (4.8% each). The most important edible weeds were Cleome gynandra, cited by 93.9% of the participants, Cucumis metuliferus (90.5%), Cucumis anguria (87.8%), Corchorus tridens (50.3%) and Amaranthus hybridus (39.5%). All edible weeds were available during rainy and harvest period with Cleome gynandra, Corchorus tridens, Cucumis anguria, Cucumis metuliferus and Moringa oleifera also available during the dry season, enabling households to obtain food outputs in different times of the year. The importance of edible weeds for local

  7. Determination of critical period for weed control in the second crop ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... Weeds are a major constraint in corn production. Understanding the critical period for weed control. (CPWC) can be a tool for effective weed control and reducing the impacts of weeds. Three experiments were conducted to determine CPWC in the second corn crop from 1996 to 1998. The critical period for.

  8. Biological control of weeds in European crops: recent achievements and future work

    NARCIS (Netherlands)

    Müllerer-Schärer, H.; Greaves, M.P.

    2000-01-01

    Approaches to the biological control of weeds in arable crops and integration of biological weed control with other methods of weed management are broadly discussed. Various types of integrative approaches to biological control of weeds in crops have been studied within the framework of a concerted

  9. Weed Interference Effects on Leaves, Internode and Harvest Index of Dry Bean (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Hossein GHAMARI

    2015-03-01

    Full Text Available The development of appropriate weed management strategies and efficient use of herbicides relies upon understanding weed-crop interactions. A field study was carried out to assess the effect of weed interference on leaves, internode and harvest index of dry bean (Phaseolus vulgaris L.. The experiment was established under a randomized complete block design with two types of weed interference treatments: plots with weeds and plots without weeds at different time intervals (0, 10, 20, 30, 40 and 50 days after crop emergence. The sigmoid Boltzmann model was used to quantify the crop traits as influenced by weed interference. Prolonged delays in weed removal reduced gradually the number of leaves of the crop. Weed interference decreased dry weight of leaves as well, so that the lowest value of it (33.49 g plant-1 was observed in full season during weed-infested treatment. Infestation of weeds affected the length of the crop internodes. While the weed interference duration increased, the length of the internodes decreased. Harvest index was also sensitive to weed competition. As the crop was kept weed-infested from the emergence for increasing periods of time, harvest index decreased to a value of 28.01%. A significant negative correlation between total biomass of weeds and dry bean traits (number of leaves, leaves dry weight, internode length and harvest index was observed. Therefore, weeds are able to adversely affect dry bean growth through constraining environmental resources and impairing leaves as the photosynthetic areas.

  10. Effect of tillage on the efficacy of CGA362622 on weed control in maize

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... time and resources managing weeds. Tillage alone or in combination with good cropping methods is ... help in managing herbicide resistance weeds and may also increase weed density as well as reduce crop yield .... This change in weed compo- sition agrees with Richley et al. (1977) indicating shift.

  11. Dynamics of weed populations : spatial pattern formation and implications for control

    NARCIS (Netherlands)

    Wallinga, J.

    1998-01-01

    Modelling studies were carried out to analyse spatio-temporal dynamics of annual weed populations and to identify the key factors that determine the long-term herbicide use of weed control programmes. Three different weed control programmes were studied.

    In the first weed

  12. Integrating management techniques to restore sites invaded by mile-a-minute weed, Persicaria perfoliata

    Science.gov (United States)

    Ellen C. Lake; Judith Hough-Goldstein; Vincent. D' Amico

    2014-01-01

    Efforts to suppress an invasive weed are often undertaken with the goal of facilitating the recovery of a diverse native plant community. In some cases, however, reduction in the abundance of the target weed results in an increase in other exotic weeds. Mile-a-minute weed (Persicaria perfoliata (L.) H. Gross (Polygonaceae)) is an annual vine from...

  13. 76 FR 39811 - International Center for Technology Assessment and the Center for Food Safety; Noxious Weed...

    Science.gov (United States)

    2011-07-07

    ... Assessment and the Center for Food Safety; Noxious Weed Status of Kentucky Bluegrass Genetically Engineered... engineered for tolerance to the herbicide glyphosate should not be listed as a Federal noxious weed and... noxious weeds. Our decision is based on our analysis of available scientific data, our weed risk...

  14. Yield loss prediction models based on early estimation of weed pressure

    DEFF Research Database (Denmark)

    Asif, Ali; Streibig, Jens Carl; Andreasen, Christian

    2013-01-01

    been proposed to predict yield loss, relative to yield in weed free environment from early measurements of weed infestation. The models are integrated in some weed management advisory systems. Generally, the recommendations from the advisory systems are applied to the whole field, but weed control...... thresholds are more relevant for site-specific weed management, because weeds are unevenly distributed in fields. Precision of prediction of yield loss is influenced by various factors such as locations, yield potential at the site, variation in competitive ability of mix stands of weed species and emergence...

  15. Preliminary studies on chemical weed control in eucalyptus (hybrid) nursery

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N.S.; Desappa; Singh, C.D.

    1985-12-01

    Weeds adversely affect the germination and growth of seedlings in the Eucalyptus hybrid nursery beds. Manual weeding which is generally followed is time consuming, difficult and less effective. In order to overcome this problem a study was undertaken for effective control of weeds in Eucalyptus hybrid nursery by means of preemergence weedicides viz. Baseline (profluralin), Pendimethaline (Stemp 30 EC), Ronster (Oxadiazen) and Simazine. They were applied to nursery beds as pre-emergence spray, at 1.5, 1.5, 0.5 and 1 kg/ha respectively. Basalin was most effective in controlling both dicot and monocot weeks followed by pendimethaline and Ronster. Simazine was lethal to both Eucalyptus and weed seed germination. Seedling of Eucalyptus in Basalin treated plots were more in number (153/sq ft.), taller (24 cm) and healthier compared to other weedicide treatments. Maximum number of dicot and monocot weeds were found in control plot, consequently, seedling growth was very much suppressed. The studies indicated that preemergence chemical weedicides could be effectively used to control nursery weeds and that Basalin weedicide is more effective in controlling both dicot and monocot weeds and appear to be a suitable chemical weedicide for Eucalyptus hybrid nurseries. 8 references, 3 tables.

  16. Wallowa Canyonlands Weed Partnership : Completion Report November 19, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Mark C.; Ketchum, Sarah

    2008-12-30

    Noxious weeds threaten fish and wildlife habitat by contributing to increased sedimentation rates, diminishing riparian structure and function, and reducing forage quality and quantity. Wallowa Resources Wallowa Canyonlands Partnership (WCP) protects the unique ecological and economic values of the Hells Canyon grasslands along lower Joseph Creek, the lower Grande Ronde and Imnaha Rivers from invasion and degradation by noxious weeds using Integrated Weed Management techniques. Objectives of this grant were to inventory and map high priority weeds, coordinate treatment of those weeds, release and monitor bio-control agents, educate the public as to the dangers of noxious weeds and how to deal with them, and restore lands to productive plant communities after treatment. With collaborative help from partners, WCP inventoried {approx} 215,000 upland acres and 52.2 miles of riparian habitat, released bio-controls at 23 sites, and educated the public through posters, weed profiles, newspaper articles, and radio advertisements. Additionally, WCP used other sources of funding to finance the treatment of 1,802 acres during the course of this grant.

  17. Allelobiosis in the interference of allelopathic wheat with weeds.

    Science.gov (United States)

    Li, Yong-Hua; Xia, Zhi-Chao; Kong, Chui-Hua

    2016-11-01

    Plants may chemically affect the performance of neighbouring plants through allelopathy, allelobiosis or both. In spite of increasing knowledge about allelobiosis, defined as the signalling interactions mediated by non-toxic chemicals involved in plant-plant interactions, the phenomenon has received relatively little attention in the scientific literature. This study examined the role of allelobiosis in the interference of allelopathic wheat with weeds. Allelopathic wheat inhibited the growth of five weed species tested, and the allelochemical (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) production of wheat was elicited in the presence of these weeds, even with root segregation. The inhibition and allelochemical levels varied greatly with the mixed species density. Increased inhibition and allelochemical levels occurred at low and medium densities but declined at high densities. All the root exudates and their components of jasmonic acid and salicylic acid from five weeds stimulated allelochemical production. Furthermore, jasmonic acid and salicylic acid were found in plants, root exudates and rhizosphere soils, regardless of weed species, indicating their participation in the signalling interactions defined as allelobiosis. Through root-secreted chemical signals, allelopathic wheat can detect competing weeds and respond by increased allelochemical levels to inhibit them, providing an advantage for its own growth. Allelopathy and allelobiosis are two probably inseparable processes that occur together in wheat-weed chemical interactions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Capabilities of unmanned aircraft vehicles for low altitude weed detection

    Science.gov (United States)

    Pflanz, Michael; Nordmeyer, Henning

    2014-05-01

    Sustainable crop production and food security require a consumer and environmental safe plant protection. It is recently known, that precise weed monitoring approaches could help apply pesticides corresponding to field variability. In this regard the site-specific weed management may contribute to an application of herbicides with higher ecologically aware and economical savings. First attempts of precision agriculture date back to the 1980's. Since that time, remote sensing from satellites or manned aircrafts have been investigated and used in agricultural practice, but are currently inadequate for the separation of weeds in an early growth stage from cultivated plants. In contrast, low-cost image capturing at low altitude from unmanned aircraft vehicles (UAV) provides higher spatial resolution and almost real-time processing. Particularly, rotary-wing aircrafts are suitable for precise path or stationary flight. This minimises motion blur and provides better image overlapping for stitching and mapping procedures. Through improved image analyses and the recent increase in the availability of microcontrollers and powerful batteries for UAVs, it can be expected that the spatial mapping of weeds will be enhanced in the future. A six rotors microcopter was equipped with a modified RGB camera taking images from agricultural fields. The hexacopter operates within predefined pathways at adjusted altitudes (from 5 to 10 m) by using GPS navigation. Different scenarios of optical weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. Our experiences showed high capabilities for site-specific weed control. Image analyses with regard to recognition of weed patches can be used to adapt herbicide application to varying weed occurrence across a field.

  19. Biodegradable agrochemicals from Thai tropical weeds

    Energy Technology Data Exchange (ETDEWEB)

    Kokpol, U.; Veerachato, G.; Tippyang, S.; Chavasiri, W.

    1999-12-16

    In the search for biodegradable agrochemical substances from Thai tropical weeds, alcoholic extract of 8 species of Thai tropical weeds were bioassayed on biological activity (plant seedling inhibition, piscicidal, antifeedant and antimicrobial). According to preliminary bioassay results, two of the most active plants have been chosen for further study. The whole plant of Trianthema portulacastrum was extracted with dichloromethane and methanol. The extracts were fractionated by column chromatography, which led to the isolation of seven substances. By mean of physical properties, chemical reactions and spectroscopic data, seven isolated substances were characterized as a mixture of straight long chain esters (1), a mixture of straight long chain alcohols (C{sub 30}-C{sub 33}) (2), a mixture of stigmasterol and {beta}-sitosterol (3), 6,8-dimethey 1-5-,7-dihydroxychromone (4), a novel flavone compound (6,8-dimethey 1-2',5-dihydroxy-7-methoxyflavone (5)), a mixture of stigmasteryl-3-O-{beta}-glucopyranoside and {beta}-sitostery 1-3-O-{beta}-glucopyranoside (6) and an oxalate salt (7). Only the oxalate salt shows 100% inhibition on Chinese cabbage seed at dose 0.01 g/1.5 g of cellulose. The other Thai tropical weed sphaeranthus africanus Linn. yielded eleven substances upon extraction with hexane, chloroform, ethyl acetate and butanol, respectively. They were a mixture of long chain hydrocarbons (C{sub 23}, C{sub 25}, C{sub 30}, C{sub 33}) (8), a mixture of long chain esters (9), a mixture of long chain alcohols (C{sub 23}, C{sub 25}, C{sub 27}, C{sub 30}, C{sub 33}) (10), friedelan-3{beta}-ol (11), a mixture of long chain alcohols (C{sub 26}, C{sub 27}, C{sub 29}, C{sub 30}, C{sub 33}) (12), stigmasterol (13), a mixture of long chain acids(C{sub 19}-C{sub 25}) (14), stigmasteryl-3-O-{beta}-D-glucopyranoside (15), chrysopleno-D (16), chrysopleno-C (17) and quercetagetin-3,7-dimethyl ether (18). The structures of these isolated compounds were established on the

  20. Growing oganic cereals in Northern Ireland - disease and weed problems

    OpenAIRE

    MERCER, P.C.

    2006-01-01

    The small organic arable sector in N. Ireland could be expanded to provide winter feed for cattle. Spring barley or wheat are likely to be the most suitable crops as they are reported to have fewer weed and disease problems than winter cereals. Trials from 2003 –05 on weed control showed no consistent effect of cultivar, although higher seed rates reduced weed biomass and tended to increase yield, albeit marginally. Trials on disease control showed no synergistic effects of two- or three-way ...

  1. A weed suppressive index for spring barley (Hordeum vulgare) varieties

    DEFF Research Database (Denmark)

    Hansen, P K; Kristensen, K; Willas, J

    2008-01-01

    A screening programme for crop variety competitiveness would ideally be based on only a few, non-destructive measurements of key growth traits. In this study we measured the weed suppressive ability of 79 varieties of spring barley in two ways: (i) directly, by weed coverage assessments under weedy...... successfully developed a method for indexing the weed suppressive ability of spring barley varieties. The suppressive index ranged from 12% in Lux and 55% in Modena in proportion to the 90% quantile coverage of all varieties. The index was validated against independent data from two locations in 2005 with 14...

  2. Microbial weeds in hypersaline habitats: the enigma of the weed-like Haloferax mediterranei

    Science.gov (United States)

    Oren, Aharon; Hallsworth, John E.

    2014-10-01

    Heterotrophic prokaryotic communities that inhabit saltern crystallizer ponds are typically dominated by two species, the archaeon Haloquadratum walsbyi and the bacterium Salinibacter ruber, regardless of location. These organisms behave as 'microbial weeds' as defined by Cray et al. (Microb Biotechnol6: 453–492, 2013) that possess the biological traits required to dominate the microbiology of these open habitats. Here, we discuss the enigma of the less abundant Haloferax mediterranei, an archaeon that grows faster than any other, comparable extreme halophile. It has a wide window for salt tolerance, can grow on simple as well as on complex substrates and degrade polymeric substances, has different modes of anaerobic growth, can accumulate storage polymers, produces gas vesicles, and excretes halocins capable of killing other Archaea. Therefore, Hfx. mediterranei is apparently more qualified as a 'microbial weed' than Haloquadratum and Salinibacter. However, the former differs because it produces carotenoid pigments only in the lower salinity range and lacks energy-generating retinal-based, light-driven ion pumps such as bacteriorhodopsin and halorhodopsin. We discuss these observations in relation to microbial weed biology in, and the open-habitat ecology of, hypersaline systems.

  3. Control of aquatic weeds through pollutant reduction and weed utilization: a weed management approach in the lower Kafue River of Zambia

    Science.gov (United States)

    Sinkala, Thomson; Mwase, Enala T.; Mwala, Mick

    The aquatic weed situation in the Kafue River in Zambia continues to be a major challenge to the sustainable utilization of the water resources of the river. The general methods for managing the weeds, especially the water hyacinth, include use of bio-agents, chemicals, mechanical and physical approaches. These have had very little impact. This paper reports on a project that is investigating weed management strategies which involve use of cleaner production (CP) approach and the utilization of the weed for economic purposes. In addition, the ecological implications of these methods are being assessed. Effluent assessments indicated that apart from nitrates and phosphates, other effluent parameters met the Environmental Council of Zambia standards. Results further show that all the 24 areas surveyed for CP have uncontrolled socio-economic activities which generate both point and non-point sources of pollution that enter the water bodies. To minimize pollution, efforts include devising policy and technical strategies with the involvement of the affected riparian community. Production of mushroom by the communities using the water hyacinth substrate has been demonstrated. Up to 2.1 kg of mushroom was harvested from a single flush over a period of 4-5 weeks. Vegetables grown on soils treated with water hyacinth manure performed better than those grown using commercial fertiliser. The economics of the production are however, yet to be confirmed. If weed usage is proven economically and ecologically viable, the riverine community is envisaged to play a big role in aquatic weed management. High numbers of invertebrates known to be sensitive to pollution have been recorded in the weed-infested Kafue River implying that the water is of ;good; quality for these aquatic invertebrates. This observed quality of water may be due to water hyacinth playing a role by sieving pollutants from the river.

  4. Fungal Phytotoxins in Sustainable Weed Management.

    Science.gov (United States)

    Vurro, Maurizio; Boari, Angela; Casella, Francesca; Zonno, Maria Chiara

    2017-04-26

    Fungal phytotoxins are natural secondary metabolites produced by plant pathogenic fungi during host-pathogen interactions. They have received considerable particular attention for elucidating disease etiology, and consequently to design strategies for disease control. Due to wide differences in their chemical structures, these toxic metabolites have different ecological and environmental roles and mechanisms of action. This review aims at summarizing the studies on the possible use of thesemetabolites as tools in biological and integrated weed management, e.g. as: novel and environmentally friendly herbicideslead for novel compounds; sources of novel mechanisms of action. Moreover, the limiting factors for utilizing those metabolites in practice will also be briefly discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Cutting weeds with a CO2 laser

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Christensen, S.

    2001-01-01

    Stems of Chenopodium album. and Sinapis arvensis. and leaves of Lolium perenne. were cut with a CO2 laser or with a pair of scissors. Treatments were carried out on greenhouse-grown pot plants at three different growth stages and at two heights. Plant dry matter was measured 2 to 5 weeks after...... treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose-response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO2 laser than C. album....... When stems were cut below the meristems, 0.9 and 2.3 J mm(-1) of CO2 laser energy dose was sufficient to reduce by 90% the biomass of C. album and S. arvensis respectively. Regrowth appeared when dicotyledonous plant stems were cut above meristems, indicating that it is important to cut close...

  6. Can tithonia diversifolia (Hemsl). A. Gray, a pantropic invasive weed ...

    African Journals Online (AJOL)

    A. Gray, a pantropic invasive weed species, cleanup spent lubricating oil polluted soils? ... Global Journal of Environmental Sciences ... Two pot trials were conducted in the crop garden of the Department of Crop Protection and Environmental ...

  7. 97 BIODIVERSITY AND IMPORTANCE OF FLOATING WEEDS OF ...

    African Journals Online (AJOL)

    AJTCAM

    , Pakistan. Introduction. Aquatic weeds are those unabated plants which grow and complete their life cycle in water and cause harm to aquatic environment directly and to related eco-environment relatively. Water is one of the most important ...

  8. Effect of organic mulch materials on maize performance and weed ...

    African Journals Online (AJOL)

    Effect of organic mulch materials on maize performance and weed growth in the derived savanna of south eastern Nigeria. ... Nigeria Agricultural Journal ... The experiment was conducted at the Research and Teaching Farm of the Federal ...

  9. Weed Control Sprayers: Calibration and Maintenance. Special Circular 81.

    Science.gov (United States)

    Myers, Arthur L.

    This manual covers aspects of calibration and maintenance of weed control sprayers including variables affecting application rate, the pre-calibration check, calculations, band spraying, nozzle tip selection, agitation, and cleaning. (BB)

  10. Weed management practices in natural ecosystems: a critical overview

    Directory of Open Access Journals (Sweden)

    C.F. Reinhardt

    2000-07-01

    Full Text Available Increasing public pressure against the use of pesticides and other agricultural inputs has placed increased emphasis on the development of ecologically based pest management. One distinct reaction of the Weed Science discipline has been the swing away from herbicide research to increased research on the basic biology and ecology of weeds in hopes of reduced reliance on "technological crutches" such as herbicides and other practices that are potentially harmful to the environment. Biological control is the long-standing alternative to the use of herbicides and interest in the former practice has been boosted by the realization that the use of herbicides may lead to the development of herbicide resistance in weed populations, and that herbicide residues occur in surface and groundwater. Supporters of herbicide use would point out that biological control is generally not effective in crop production systems, and is basically slow-acting. Debates between protagonists for the exclusive use of one or the other weed management practice tend to obscure the benefits that integration of different techniques are likely to have. For natural ecosystems it is proposed that integration of the more subtle practice of biological control with the use of herbicides, which relatively quickly overwhelm a biological system with mortality, is likely to be the most effective weed management tool. Different weed management practices that could be considered in natural ecosystems are discussed in terms of three key performance rating criteria, viz. activity, selec- tivity and persistence In this concise review, general discussion is focussed on the fundamentals of weed management practices, with the view to promote concept-based approaches that are critical for the development of effective weed management strate- gies.

  11. Evaluation of Basta ( glufosinate ammonium ) for weed control in ...

    African Journals Online (AJOL)

    Basta at the rate of 0.6 - 1.0 kg a.i./ha effectively controlled most of the weeds found in coffee growing areas of Ghana, over much longer periods than the use of paraquat at the rate of 0.3 - 0.6 kg a.i./ha. However both herbicides could not effectively suppress perennial weeds such as Imperata cylindrica, Panicum maximum, ...

  12. A Case Study of Allelopathic Effect on Weeds in Wheat

    Directory of Open Access Journals (Sweden)

    Slaveya T. Petrova

    2015-06-01

    Full Text Available Most powerful and effective method of weed control is by chemical substances called herbicides. In recent years, they were published quite data on different side effects of herbicides on humans, animals, crops and the environment as a whole. Therefore, the increased interest for biological weed control lately is reasonable, since its improvement and expansion will contribute to limiting excessive use of herbicides, respectively their harmful effects and will support the successful implementation of complex weed control. The purpose of this study was to investigate the effect of selected plant species, containing allelopathic active substances, on germination, growth and biomass of some widespread weeds in wheat. Experiments were carried out at laboratory conditions using seeds of wheat (Triticum aestivum L., sort Sadovo 1 and most common weeds therein: Johnson grass (Sorghum halepense (L Pers, white pigweed (Chenopodium album L., twitch (Cynodon dactylon L. and curly dock (Rumex crispus L.. Allelopathic substances were extracted with distilled water from flowers of lavender (Lavandula angustifolia Mill., leaves of basil (Ocimum basilicum L., leaves of spearmint (Mentha longifolia (L Huds., and leaves of peppermint (Mentha piperita L.. Of the tested active allelopathic plants, the most negative impact on germination of all weeds seeds (including wheat, as well as on the development of plants exhibited the water extract of lavender. Lavender and basil had a stronger negative effect on white pigweed and twitch compared with both mint species. A significant inhibitory effect of spearmint even at low concentrations was recorded on the germination of all weed species tested while the wheat was slightly affected, which manifests this plant as a potential effective species in strategies for weed control management.

  13. Effectiveness of the Primextra Gold in controlling weeds of ...

    African Journals Online (AJOL)

    The efficacy of Primextra Gold herbicide in controlling weeds in cucumber was evaluated in this research. The experiment was laid out in a randomized complete block design with four replications. Seven weed control treatments – 0.0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5 kg a.i/pot – were applied pre-emergent for this study.

  14. FruitGrowth - Gasburning in Orchards - Environment friendly weed control

    DEFF Research Database (Denmark)

    Bertelsen, Keld Kjærhus; Duzel, Jasmin; Nielsen, Søren Hundevadt

    Gas burning makes treatment of weed organic. The new ENVO-DAN burner saves 40% gas and treats ½ meter in width. It can be mounted on a standard lawn tractor, orchard tractor or a mobile robot.......Gas burning makes treatment of weed organic. The new ENVO-DAN burner saves 40% gas and treats ½ meter in width. It can be mounted on a standard lawn tractor, orchard tractor or a mobile robot....

  15. Evaluation of Antibacterial Properties, Acute Toxicity and Immuno ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Methanolic extract of the plant was assessed for antibacterial activity against ... Scoparia dulcis (sweet broom weed or licorice weed) ... Determination of Minimum Inhibitory Concentration (M.I.C.): M.I.C. was .... Resarch Journal of Biological Sciences. ... Phytochemical analysis and Antimicrobial activity of Scoparia dulcis and ...

  16. Robust Crop and Weed Segmentation under Uncontrolled Outdoor Illumination

    Directory of Open Access Journals (Sweden)

    Hong Y. Jeon

    2011-06-01

    Full Text Available An image processing algorithm for detecting individual weeds was developed and evaluated. Weed detection processes included were normalized excessive green conversion, statistical threshold value estimation, adaptive image segmentation, median filter, morphological feature calculation and Artificial Neural Network (ANN. The developed algorithm was validated for its ability to identify and detect weeds and crop plants under uncontrolled outdoor illuminations. A machine vision implementing field robot captured field images under outdoor illuminations and the image processing algorithm automatically processed them without manual adjustment. The errors of the algorithm, when processing 666 field images, ranged from 2.1 to 2.9%. The ANN correctly detected 72.6% of crop plants from the identified plants, and considered the rest as weeds. However, the ANN identification rates for crop plants were improved up to 95.1% by addressing the error sources in the algorithm. The developed weed detection and image processing algorithm provides a novel method to identify plants against soil background under the uncontrolled outdoor illuminations, and to differentiate weeds from crop plants. Thus, the proposed new machine vision and processing algorithm may be useful for outdoor applications including plant specific direct applications (PSDA.

  17. Analysis of weed flora in conventional and organic potato production

    Directory of Open Access Journals (Sweden)

    Nikolić, Lj.

    2013-12-01

    Full Text Available Composition of weed flora is highly dynamic and depends upon great number of factors, of which cultural practices that are applied by humans in certain crops are the most important. One of the most frequently grown plants in the world and in our country is potato (Solanum tuberosum L., Solanaceae, due to its high biological and nutritive value. Therefore, in the paper was presented taxonomic analysis of weed flora in potato grown conventionally and according to the principles of organic agricultural production, with the intention to point out to eventual differences between present weeds. Of the total number of identified species, from phylum Equisetophyta and class Equisetopsida, in organic potato crop, was determined only one, Equisetum arvense. Of remaining 38 weeds from phylum Magnoliophyta., classified into two classes, Magnoliopsida and Liliopsida. On both of potato growing systems, 39 weed species were found, classified into 16 families and 32 genus. Of the total number, 31 species was identified in conventional potato crop, and only 23 species in potato crop grown according to organic principles, which is for about quarter less. Biological spectrum of weed flora in both potato growing systems is pronouncedly of terrophytic – geophytic type. In the spectrum of area types were recorded differences, i.e. in the conventional potato crop represented are only widely distributed species, while in the organic crop, beside species of wide distribution are also present elements of Pontic group.

  18. The critical period of weed control in corn Zea mays at Mashhad, Iran

    Directory of Open Access Journals (Sweden)

    majid abaspoor

    2009-06-01

    Full Text Available In order to determine the critical period of weed control in corn, an experiment was conducted at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad in year 2000. The experiment consisted of two discrete periods, a weed-free and a weed infested period. The weed-free period consisted of removing all weeds till 4th (19 days after planting, 7th (34 days after planting, 11th (48 days after planting, 13th (52 days after planting, and 17th (59 days after planting, leaf growth stages and weed free check for growing season (123 days after planting, and the critical time of weed infested consisted of removing all weeds from fourth (19 days after planting, 7th (34 days after planting, 11th (48 days after planting, 13th (52 days after planting, and 17th (59 days after planting, leaf growth stages and weedy infested check for growing season. All treatments were compared in a randomized complete block design with four replications. The results showed that by prolonging weed-infested period, dry matter and leaf surface area of weeds per square meter were increased, but by increasing weed-infested period, weed density was decreased. The lowest weed density (23 weed plants per m2 was shown at infested all period of corn growing season. By passing the growing season, C4 weed species such as red root pigweed and barnyard grass were dominant compared with C3 weed species. At weed infested all period of corn growing season, red root pigweed had the highest dry matter (93% of all weeds dry matter and leaf surface area (86% of all weeds leaf surface compared with other weed species. At the first treatment of critical weed-free (19 days after planting the regrowth of weeds were substantial which resulted in decreasing growth of corn. Grain yield of corn were significantly higher at 52, 59 and 123 days after planting in weed free treatments compared with 48, 52, 59 and 123 days after planting in weed infested treatments. However, there were no

  19. Weed management in short rotation poplar and herbaceous perennial crops grown for biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Buhler, D.D. [USDA-Agricultural Research Service National Soil Tilth Lab., Ames, IA (United States); Netzer, D.A.; Riemenschneider, D.E. [USDA-Forest Service, Forestry Sciences Lab., Rhinelander, WI (United States); Hartzler, R.G. [Iowa State Univ., Ames, IA (United States). Dept. of Agrimony

    1998-12-31

    Weed management is a key element of any crop production system. Weeds are a particular problem in the production of short rotation woody and perennial herbaceous biomass crops due to the shortage of registered herbicides and integrated weed management systems. Herbicides will be an important component of weed management of biomass crops. However, producers should take a broader view of weeds and incorporate all available weed management tactics in these production systems. In both short rotation poplar and herbaceous perennial crops, weed control during the establishment period is most critical. New plantings of these species grow very slowly and do not compete well with weeds until a canopy develops. Effective weed control can double the growth of short rotation poplar crops and affect the variability of the resulting stand. In crops like switchgrass, uncontrolled weeds during establishment can result in stand failure. Cultural practices such as site preparation, using weed-free seed, fallowing, selecting the proper planting dates, companion crops and controlling weeds in previous crops must be combined with herbicides to develop integrated management systems. Weeds may also cause problems in established stands through competition with the biomass crop and by contaminating the product. Effective and economical weed management systems will be essential for the development of short rotation woody and herbaceous perennial biomass crop production systems. (Author)

  20. Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.).

    Science.gov (United States)

    Hosseini, Seyed Z; Firouzi, Saeed; Aminpanah, Hashem; Sadeghnejhad, Hamid R

    2016-03-01

    Field experiment was conducted at Agricultural and Natural Resources Research Center of Golestan Province, Iran, to determine the effects of tillage system and weed management regime on yield and weed populations in soybean ( Glycin max L.). The experimental design was a split plot where the whole plot portion was a randomized complete block with three replicates. Main plots were tillage system: 1- No-till row crop seeding, 2- No-till seed drilling, 3- Tillage with disc harrow and drill planting, 4- Tillage with chisel packer and drill planting. The subplots were weed management regimes: 1-Weed control with herbicide application, 2- Hand weeding, 3- Herbicide application plus hand weeding, and 4- Non-weeding. Results indicated that the main effects of tillage system and weed management regime were significant for seed yield, pod number per plant, seed number per pod, weed density and biomass, while their interaction were significant only for weed density, weed biomass, and seed number per pod. The highest grain yields (3838 kg ha-1) were recorded for No-till row crop seeding. The highest seed yield (3877 kg ha-1) also was recorded for weed control with herbicide and hand weeding treatment, followed by hand weeding (3379 kg ha-1).

  1. [Spatial and temporal dynamics of the weed community in the Zoysia matrella lawn].

    Science.gov (United States)

    Liu, Jia-Qi; Li, You-Han; Zeng, Ying; Xie, Xin-Ming

    2014-02-01

    The heterogeneity of species composition is one of the main attributes in weed community dynamics. Based on species frequency and power law, this paper studied the variations of weed community species composition and spatial heterogeneity in a Zoysia matrella lawn in Guangzhou at different time. The results showed that there were 43 weed species belonging to 19 families in the Z. matrella lawn from 2007 to 2009, in which Gramineae, Compositae, Cyperaceae and Rubiaceae had a comparative advantage. Perennial weeds accounted for the largest proportion of weeds and increased gradually in the three years. Weed communities distributed in higher heterogeneity than in a random model. Dominant weeds varied with season and displayed regularity in the order of 'dicotyledon-monocotyledon-dicotyledon weeds' and 'perennial-annual-perennial weeds'. The spatial heterogeneity of weed community in Z. matrella lawn was higher in summer than in winter. The diversity and evenness of weed community were higher in summer and autumn than in winter and spring. The number of weed species with high heterogeneity in summer was higher than in the other seasons. The spatial heterogeneity and diversity of weed community had no significant change in the three years, while the evenness of weed community had the tendency to decline gradually.

  2. The biology of habitat dominance; can microbes behave as weeds?

    Science.gov (United States)

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-01-01

    Summary Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These ‘microbial weeds’ are able to dominate the communities that develop in fertile but uncolonized – or at least partially vacant – habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi

  3. Tillage and residue burning affects weed populations and seed banks.

    Science.gov (United States)

    Narwal, S; Sindel, B M; Jessop, R S

    2006-01-01

    An integrated weed management approach requires alternative management practices to herbicide use such as tillage, crop rotations and cultural controls to reduce soil weed seed banks. The objective of this study was to examine the value of different tillage practices and stubble burning to exhaust the seed bank of common weeds from the northern grain region of Australia. Five tillage and burning treatments were incorporated in a field experiment, at Armidale (30 degrees 30'S, 151 degrees 40'E), New South Wales, Australia in July 2004 in a randomized block design replicated four times. The trial was continued and treatments repeated in July 2005 with all the mature plants from the first year being allowed to shed seed in their respective treatment plots. The treatments were (i) no tillage (NT), (ii) chisel ploughing (CP), (iii) mould board ploughing (MBP), (iv) wheat straw burning with no tillage (SBNT) and (v) wheat straw burning with chisel ploughing (SBC). Soil samples were collected before applying treatments and before the weeds flowered to establish the seed bank status of the various weeds in the soil. Wheat was sown after the tillage treatments. Burning treatments were only initiated in the second year, one month prior to tillage treatments. The major weeds present in the seed bank before initiating the trial were Polygonum aviculare, Sonchus oleraceus and Avena fatua. Tillage promoted the germination of other weeds like Hibiscus trionum, Medicago sativa, Vicia sp. and Phalaris paradoxa later in the season in 2004 and Convolvulus erubescens emerged as a new weed in 2005. The MBP treatment in 2004 reduced the weed biomass to a significantly lower level of 55 g/m2 than the other treatments of CP (118 g/m2) and NT plots (196 g/m2) (P < 0.05). However, in 2005 SBC and MBP treatments were similar in reducing the weed biomass. In 2004, the grain yield trend of wheat was significantly different between CP and NT, and MBP and NT (P < 0.05) with maximum yield of 5898

  4. Automated weed detection in the field - possibilities and limits

    Directory of Open Access Journals (Sweden)

    Pflanz, Michael

    2016-02-01

    Full Text Available Unmanned Aerial Vehicles (UAV have become omnipresent and adequate tools to generate high-resolution spatial data of agricultural cropland. Their implementation into remote sensing approaches of weeds provides suitable applications for a site-specific herbicide management. In general, an increasingly use of innovative technologies gradually leads from agricultural research into the practical application. This requires an evaluation of possibilities and limits of UAV-based remote sensing procedures. While spectrals from UAVs are being used already for mapping needs of nutrient or water, the image supported weed detection is much more complex and at the moment not relevant in practice. In this regard, there is a lack of weed and crop differentiation through spectral analyses and object-based approaches separate different plants not species-specific or are not adapted to morphologic changes of the growth. Moreover, there is a need for alternative positioning techniques without GPS, as it is required for a precise optical imaging analysis at low altitudes. To evaluate the possibilities and limitations of automated weed identification regarding the optical and sampling requirements, flights were carried out with a hexacopter at an altitude of 5 m over agricultural crop land with variable weed patches. The altitude was controlled by the GPS-autopilot. Images were captured at geo-referenced points and the number of different weed species was simultaneously determined by manually counting. The required optical resolution on the ground was estimated by comparing the number of weeds between image analysis on the PC and with the field rating data.

  5. Allelopathic assessment of selected common weeds in Malaysia

    Science.gov (United States)

    Nurul Ain, M. B.; Nornasuha, Y.; Ismail, B. S.

    2016-11-01

    A laboratory study was conducted to evaluate the allelopathic potential of eight common weed species in Malaysia, namely, Ageratum conyzoides, Tridax procumbens, Cyperus iria, Fimbristylis miliacea, Eleusine indica, Imperata cylindrica, Lygodium flexuosum and Nephrolepis biserrata of different morphological characteristics (broadleaves, sedges, grasses and ferns). The allelopathic study of these weeds was carried out by testing the leaf litter leachate through the Sandwich method and the volatile compounds of these weeds through the Dish pack method with three replicates for each donor species. The results obtained from both methods were statistically analyzed and the means had converted to percentage growth inhibition to determine the inhibition pattern on the radicle and hypocotyl growth of lettuce seedlings. Among the eight weed species tested, Ageratum conyzoides showed the strongest growth inhibition on lettuce radicle elongation (86%) in the sandwich bioassay compared to the control, followed by Tridax procumbens (71%), which both species being broadleaves weeds. In the dish pack bioassay Lygodium flexuosum (fern) demonstrated maximum inhibition on the growth the radicle and hypocotyl for each different distance from the source well. On the other hand, two weed species exhibited enhanced on the growth radicle and hypocotyl when compared to that of the control in dish pack bioassay. Nephrolepis biserrata and Fimbristylis miliacea were the species that showed the highest growth stimulatory effect. The results presented can be utilized as benchmark information for further research on the elucidation of leachates and volatile chemicals involved in allelopathy in nature. The information can also be helpful in the development of new bioactive chemicals from natural products in weed control strategies.

  6. Emerging Challenges and Opportunities for Education and Research in Weed Science.

    Science.gov (United States)

    Chauhan, Bhagirath S; Matloob, Amar; Mahajan, Gulshan; Aslam, Farhena; Florentine, Singarayer K; Jha, Prashant

    2017-01-01

    In modern agriculture, with more emphasis on high input systems, weed problems are likely to increase and become more complex. With heightened awareness of adverse effects of herbicide residues on human health and environment and the evolution of herbicide-resistant weed biotypes, a significant focus within weed science has now shifted to the development of eco-friendly technologies with reduced reliance on herbicides. Further, with the large-scale adoption of herbicide-resistant crops, and uncertain climatic optima under climate change, the problems for weed science have become multi-faceted. To handle these complex weed problems, a holistic line of action with multi-disciplinary approaches is required, including adjustments to technology, management practices, and legislation. Improved knowledge of weed ecology, biology, genetics, and molecular biology is essential for developing sustainable weed control practices. Additionally, judicious use of advanced technologies, such as site-specific weed management systems and decision support modeling, will play a significant role in reducing costs associated with weed control. Further, effective linkages between farmers and weed researchers will be necessary to facilitate the adoption of technological developments. To meet these challenges, priorities in research need to be determined and the education system for weed science needs to be reoriented. In respect of the latter imperative, closer collaboration between weed scientists and other disciplines can help in defining and solving the complex weed management challenges of the 21st century. This consensus will provide more versatile and diverse approaches to innovative teaching and training practices, which will be needed to prepare future weed science graduates who are capable of handling the anticipated challenges of weed science facing in contemporary agriculture. To build this capacity, mobilizing additional funding for both weed research and weed management

  7. Emerging Challenges and Opportunities for Education and Research in Weed Science

    Directory of Open Access Journals (Sweden)

    Bhagirath S. Chauhan

    2017-09-01

    Full Text Available In modern agriculture, with more emphasis on high input systems, weed problems are likely to increase and become more complex. With heightened awareness of adverse effects of herbicide residues on human health and environment and the evolution of herbicide-resistant weed biotypes, a significant focus within weed science has now shifted to the development of eco-friendly technologies with reduced reliance on herbicides. Further, with the large-scale adoption of herbicide-resistant crops, and uncertain climatic optima under climate change, the problems for weed science have become multi-faceted. To handle these complex weed problems, a holistic line of action with multi-disciplinary approaches is required, including adjustments to technology, management practices, and legislation. Improved knowledge of weed ecology, biology, genetics, and molecular biology is essential for developing sustainable weed control practices. Additionally, judicious use of advanced technologies, such as site-specific weed management systems and decision support modeling, will play a significant role in reducing costs associated with weed control. Further, effective linkages between farmers and weed researchers will be necessary to facilitate the adoption of technological developments. To meet these challenges, priorities in research need to be determined and the education system for weed science needs to be reoriented. In respect of the latter imperative, closer collaboration between weed scientists and other disciplines can help in defining and solving the complex weed management challenges of the 21st century. This consensus will provide more versatile and diverse approaches to innovative teaching and training practices, which will be needed to prepare future weed science graduates who are capable of handling the anticipated challenges of weed science facing in contemporary agriculture. To build this capacity, mobilizing additional funding for both weed research and

  8. Weed Diversity Affects Soybean and Maize Yield in a Long Term Experiment in Michigan, USA.

    Science.gov (United States)

    Ferrero, Rosana; Lima, Mauricio; Davis, Adam S; Gonzalez-Andujar, Jose L

    2017-01-01

    Managing production environments in ways that promote weed community diversity may enhance both crop production and the development of a more sustainable agriculture. This study analyzed data of productivity of maize (corn) and soybean in plots in the Main Cropping System Experiment (MCSE) at the W. K. Kellogg Biological Station Long-Term Ecological Research (KBS-LTER) in Michigan, USA, from 1996 to 2011. We used models derived from population ecology to explore how weed diversity, temperature, and precipitation interact with crop yields. Using three types of models that considered internal and external (climate and weeds) factors, with additive or non-linear variants, we found that changes in weed diversity were associated with changes in rates of crop yield increase over time for both maize and soybeans. The intrinsic capacity for soybean yield increase in response to the environment was greater under more diverse weed communities. Soybean production risks were greatest in the least weed diverse systems, in which each weed species lost was associated with progressively greater crop yield losses. Managing for weed community diversity, while suppressing dominant, highly competitive weeds, may be a helpful strategy for supporting long term increases in soybean productivity. In maize, there was a negative and non-additive response of yields to the interaction between weed diversity and minimum air temperatures. When cold temperatures constrained potential maize productivity through limited resources, negative interactions with weed diversity became more pronounced. We suggest that: (1) maize was less competitive in cold years allowing higher weed diversity and the dominance of some weed species; or (2) that cold years resulted in increased weed richness and prevalence of competitive weeds, thus reducing crop yields. Therefore, we propose to control dominant weed species especially in the years of low yield and extreme minimum temperatures to improve maize yields

  9. Early hominids may have been weed species.

    Science.gov (United States)

    Meindl, Richard S; Chaney, Morgan E; Lovejoy, C Owen

    2018-01-22

    Panid, gorillid, and hominid social structures appear to have diverged as dramatically as did their locomotor patterns as they emerged from a late Miocene last common ancestor (LCA). Despite their elimination of the sectorial canine complex and adoption of bipedality with its attendant removal of their ready access to the arboreal canopy, Australopithecus was able to easily invade novel habitats after florescence from its likely ancestral genus, Ardipithecus sp. Other hominoids, unable to sustain sufficient population growth, began an inexorable decline, culminating in their restriction to modern refugia. Success similar to that of earliest hominids also characterizes several species of macaques, often termed "weed species." We here review their most salient demographic features and find that a key element is irregularly elevated female survival. It is reasonable to conclude that a similar feature characterized early hominids, most likely made possible by the adoption of social monogamy. Reduced female mortality is a more probable key to early hominid success than a reduction in birth space, which would have been physiologically more difficult.

  10. Weed suppression by green manure in an agroecological system

    Directory of Open Access Journals (Sweden)

    Katia Maria Garicoix Recalde

    2015-12-01

    Full Text Available ABSTRACT Green manure promotes efficient suppression of weeds, but green manure species can exhibit distinct behaviors, depending on the environmental conditions. This study aimed to evaluate the potential of soil mulching and weed suppression by spring/summer green manure species grown in the spring/summer season, at different growth stages and after management (cut, for 90 days during the cassava crop cycle. The study was carried out in the 2010/2011 season, in a system managed under agroecological principles. The treatments consisted of different green manure species and arrangements: Crotalaria juncea, Cajanus cajan, Canavalia brasiliensis, Canavalia ensiformis, Pennisetum americanum, Crotalaria juncea and Pennisetum americanum intercropped; Mucuna aterrima, Sorghum bicolor, a mixture of all the green manures in study and a control plot under fallow. The experiment was arranged in a randomized block design with four replications. The evaluations of the soil cover either by the green manures or weeds were performed at 45, 90 and 105 days after the emergence of the green manures. The cassava crop was planted under reduced tillage system at 11 days after the cut of the green manures. The percentage of soil covered by weeds and the dry matter produced were evaluated at 30, 60 and 90 days after planting. The results showed that the green manures had a suppressive effect on weeds during their life cycle, as well as during the first months after its management (cut, composing the mulch.

  11. New possibilities for weed control in conventional soybeans

    Directory of Open Access Journals (Sweden)

    Petersen, Jan

    2014-02-01

    Full Text Available In field trials in was investigated, if the use of the in Germany new active ingredient imazamox enlarge the possibilities of post emergence weed control in soybeans. Furthermore new herbicide strategies were tested on efficacy and selectivity in soybeans. The use of imazamox was very selective and showed a relative broad spectrum of controlled weed species. However, efficacy of imazamox must be supported by a pre-emergence treatment and in most cases by a tank mix partner. For example cleavers (Galium aparine can not be controlled by imazamox. Tankmixtures of imazamox and bentazon indicated an antagonism. Efficacy to some weed species was reduced compared to solo application. The low dose concept – three applications of low doses at cotyledon stage of weeds led to some success. However, these strategies must be further investigated, before they can be recommended to commercial farming practice. All herbicide strategies tested showed some surviving weed species. This indicates that choice of herbicides, dose rates and application strategies must be done very careful and site specific.

  12. Cruciferous weeds in oil seed rape – appearance and control

    Directory of Open Access Journals (Sweden)

    Klingenhagen, Günter

    2014-02-01

    Full Text Available Different cruciferous weeds were drilled in autumn 2011 and 2012 in a field near Münster. Beside common species like hedge mustard (Sisymbrium officinale Scop., shepherd`s purse (Capsella bursa-pastoris, pennycress (Thlaspiarvense, tall hedge mustard (Sisymbrium loeselii and flixweed (Descurainia sophia, we tried to establish weeds that are not common on arable land in Germany until now. These were: Yellow rocket (Barbarea vulgaris, hoary cress (Lepidium draba and Turkish rocket (Bunias orientalis. In autumn 2011 emergence of the sown weeds was poor. In the second year of experiment we got good emergence of the named weeds excluding hoary cress (Lepidium draba. In autumn 2011 and 2012 different herbicidecombinations were applied across the stripes. The best results were achieved with Colzor Trio (clomazone + dimethachlor + napropamid which was applied in pre-emergence state, a spray sequence Butisan Gold (metazachlor + quinmerac + dimethenamid-P applied in pre-emergence followed by Salsa (ethametsulfuronmethyl + Trend (adjuvant in post-emergence and Clearfield-Vantiga (metazachlor + quinmerac + imazamox + Dash (adjuvant, also applied in post-emergence state of the weeds.

  13. The weeding handbook a shelf-by-shelf guide

    CERN Document Server

    Vnuk, Rebecca

    2015-01-01

    "No! We can't rid of that!" Vnuk, author of the popular "Weeding Tips" column on Booklist Online, is here to show you that yes, you can. A library is an ever-changing organism; when done the right way, weeding helps a library thrive by focusing its resources on those parts of the collection that are the most useful to its users. Her handbook takes the guesswork out of this delicate but necessary process, giving public and school library staff the knowledge and the confidence to effectively weed any collection, of any size. Going through the proverbial stacks shelf by shelf, Vnuk: Explains why weeding is important for a healthy library, demonstrating that a vibrant collection leads to robust circulation, which in turn affects library budgets Walks readers through a library's shelves by Dewey area, with recommended weeding criteria and call-outs in each area for the different considerations of large collections and smaller collections Features a chapter addressing reference, media, magazines and newspapers, e-b...

  14. Microwave Technologies as Part of an Integrated Weed Management Strategy: A Review

    Directory of Open Access Journals (Sweden)

    Graham Brodie

    2012-01-01

    Full Text Available Interest in controlling weed plants using radio frequency or microwave energy has been growing in recent years because of the growing concerns about herbicide resistance and chemical residues in the environment. This paper reviews the prospects of using microwave energy to manage weeds. Microwave energy effectively kills weed plants and their seeds; however, most studies have focused on applying the microwave energy over a sizable area, which requires about ten times the energy that is embodied in conventional chemical treatments to achieve effective weed control. A closer analysis of the microwave heating phenomenon suggests that thermal runaway can reduce microwave weed treatment time by at least one order of magnitude. If thermal runaway can be induced in weed plants, the energy costs associated with microwave weed management would be comparable with chemical weed control.

  15. Composición química de los aceites esenciales de las hojas de Helicteres guazumifolia (Sterculiaceae, Piper tuberculatum (Piperaceae, Scoparia dulcis (Arecaceae y Solanum subinerme (Solanaceae, recolectadas en Sucre, Venezuela

    Directory of Open Access Journals (Sweden)

    Gabriel Ordaz

    2011-06-01

    Full Text Available Los aceites esenciales son biosintetizados por plantas aromáticas y pueden obtenerse de cualquier órgano de la misma, tienen gran aplicación en la industria farmacéutica, sanitaria, cosmética, agrícola y de alimentos. Los aceites esenciales de las hojas de las plantas Helicteres guazumifolia, Piper tuberculatum, Scoparia dulcis y Solanum subinerme fueron obtenidos mediante hidrodestilación con rendimientos de 0.004, 0.032, 0.016 y 0.005%, respectivamente. La CG/EM permitió identificar la mayoría de los constituyentes de estos aceites esenciales (88.00, 89.80, 87.50 y 89.47%, respectivamente, encontrándose en mayor proporción metabolitos no volátiles de estructura no terpenoidal en H. guazumifolia (30.28%, sesquiterpenoides oxigenados en P. tuberculatum (52.19%, sesquiterpenos en S. dulcis (26.09% y derivados oxigenados de diterpenos en S. subinerme (39.67%. Los constituyentes mayoritarios fueron el diisobutilftalato (13.11% en H. guazumifolia, (--espatulenol (11.37% en P. tuberculatum y el trans-fitol (8.29 y 36.00% para S. dulcis y S. subinerme, respectivamente. El diisooctilftalato fue el constituyente común en los aceites esenciales de todas las especies y los compuestos volátiles trans-pinano, L-linalool, β-ionona, isofitol, neofitadieno, trans-fitol, dibutilftalato y hexadecanoato de metilo, fueron detectados en tres de estas esencias. Esto sugiere que dichas plantas pueden requerir metabolitos secundarios similares para su interacción ecológica, posiblemente debido a factores ambientales comunes.Chemical composition of essential oils from leaves of Helicteres guazumifolia (Sterculiaceae, Piper tuberculatum (Piperaceae, Scoparia dulcis (Arecaceae and Solanum subinerme (Solanaceae from Sucre, Venezuela. Essential oils, biosynthesized and accumulated in aromatic plants, have a wide range of applications in the pharmaceutical health, cosmetics, food and agricultural industry. This study aimed to analyze the secondary

  16. Possibilities and limitations of weed management in fruit crops of the temperate climate zone

    OpenAIRE

    Lisek Jerzy

    2014-01-01

    This manuscript contains information on the species composition of weed communities in orchards in Poland and other countries of the temperate climate zone. The manuscript deals with the influence of weeds on crops and the interaction between the weeds and other living organisms. The main methods of weed regulation are described. Characteristics of the particular crops – fruit trees and small fruits – and solutions that are either objects of study or have already been introduced into...

  17. Smoking the Other: marijuana and counterhegemony in Weeds.

    Science.gov (United States)

    Lavoie, Dusty

    2011-01-01

    Subverting suburban modernity, the SHOWTIME television series Weeds invites its audiences to situate their opinions about marijuana amid spheres of bourgeois soccer-moms, class politics, turf wars, raw economics, violent milieux, and multiculti heterogeneity. I argue that Weeds encourages us to "smoke the Other"; that is, to hesitantly accept difference, in line with many drug circles' etiquette. The phrase "smoking the Other" is a critical alteration of bell hooks' (1992, Black looks: Race and representation. Boston: South End Press) conception of whites' ethnic "devouring" as "eating the Other," a rather rigid schematic itself problematized by Weeds' transgressive self-conscious playfulness with stereotyped ethnicities, loopy plotlines, and counterhegemonic dialogue. Cultural/political implications follow. Copyright © 2011 Informa Healthcare USA, Inc.

  18. Alternative surfacing materials for weed control at BC Hydro substations

    Energy Technology Data Exchange (ETDEWEB)

    Wells, T.C.; Shrimpton, G.M.

    1997-04-01

    A two year study was conducted by BC Hydro in which a variety of surfacing materials were tested for their suitability for use in substations. Ideally, surfacing materials should have the following characteristics: high electrical resistivity in both dry and wet conditions, resistance to invasion by weeds, good driveability, good drainage, non-flammable, reasonably priced, no dust to foul conductors, and be aesthetically pleasing. Trials at Vernon Koksilah, and Ingledow substations were conducted to test the materials. A qualitative estimate of the amount of weed control provided by each material was recorded. The trials were meant to provide operational recommendations and screening information to allow for future testing of promising materials or combination of materials. Results showed that no single material meets all the desired criteria. The surfaces that best combined good weed control, electrical resistance and surface stability was a 15 cm deep layer of crushed gravel, especially if underlain by a layer of geotextile. 4 refs., 3 tabs., 1 fig.

  19. Weed seed predation in organic and conventional fields

    DEFF Research Database (Denmark)

    Navntoft, S; Wratten, S D; Kristensen, K

    2009-01-01

    % in conventional fields although variation was high. Significantly different removal rates between the two field types were found only 9 m from the field edge with approximately four times higher losses of fathen seeds in organic fields. There was also a strong tendency towards higher seed losses at organic field......Enhanced biological control of weed seeds may improve sustainability of agricultural production. Biological control due to seed predation may be higher in organic fields because organic production generally supports more seed predators. To investigate such a difference, weed seed predation...... was studied in autumn in eight organic and eight conventional mixed cropping fields in New Zealand. Predation rates were estimated by observing removal rates of seeds of the annual weeds fathen or common lambsquarter (Chenopodium album) and Persian speedwell (Veronica persica). The seed losses were recorded...

  20. Weed control through crop rotation and alternative management practices

    Directory of Open Access Journals (Sweden)

    Böhm, Herwart

    2014-02-01

    Full Text Available Economic as well as agricultural and socio-political changes have an impact on crop management and thus also on crop rotation design and the related effects on the weed flora. Likewise other changes in cultivation such as reduced tillage practices, earlier sowing date, etc. cause an increase in weed infestation resp. an increased use of herbicides and if so contribute to herbicide resistance. The positive effects of crop rotation, but also of alternative management practices such as choice of varieties, catch crops, mixed cropping, green chop, and the share of predators, as well as methods of direct non-chemical weed control are presented and discussed for both, conventional and organic farming. If alternative management methods should be more practiced, especially trade-offs need to be broken, or incentives be offered.

  1. On the development, environmental effects and human dimension of weed management strategies

    NARCIS (Netherlands)

    Riemens, M.M.

    2009-01-01

    On the development, environmental effects and human dimension of weed management strategies. On farm weed management is influenced by many factors. These factors comprise the development and availability of weed management tools, the environmental impact of these tools and the attitude and

  2. Sweat, Brain-Power, Horsepower, and Time - The Keys to Controlling Weeds

    Science.gov (United States)

    Weed control in organic crop production is difficult and costly. Early studies on organic weed control in conservation tillage systems were disappointing. Research shifted to organic weed control in conventional tillage systems. Intense cultivation with a tine weeder was the most consistent metho...

  3. A weed compaction roller system for use with mechanical herbicide application

    Science.gov (United States)

    Adam H. Wiese; Daniel A. Netzer; Don E. Riemenschneider; Ronald S., Jr. Zalesny

    2006-01-01

    We designed, constructed, and field-tested a versatile and unique weed compaction roller system that can be used with mechanical herbicide application for invasive weed control in tree plantations, agronomic settings, and areas where localized flora and fauna are in danger of elimination from the landscape. The weed compaction roller system combined with herbicide...

  4. Weed control using ammonium nonanoate and cultivation in organic Vidalia sweet onion production

    Science.gov (United States)

    Ammonium nonanoate is registered for weed control in certified organic crop production and may be useful to control cool-season weeds in organic Vidalia® sweet onion. Cultivation with a tine weeder has been identified as a cost-effective means of weed control, but delays in cultivation cause some w...

  5. Fuels planning: science synthesis and integration; environmental consequences fact sheet 07: fire and weeds

    Science.gov (United States)

    Steve Sutherland

    2004-01-01

    Weed infestations cause an economic loss of $13 billion per year even though $9.5 billion per year is spent on weed control measures. In addition to these economic costs, weeds are replacing native species, altering native plant and animal communities, affecting ecosystem health and function, threatening biodiversity and Threatened, Endangered, and Sensitive (TES)...

  6. Viruses in weeds in Dioscorea yam fields in Nigeria | Asala | African ...

    African Journals Online (AJOL)

    The presence of viruses in yam leaves and the presence of weeds in close proximity to yam fields have been shown to be associated with diminished tuber yield. But the precise role of weeds as alternative hosts of viruses infecting yam has not been systematically studied. Therefore, leaf samples of weeds were collected ...

  7. A Survey of Passiflora foetida L. and Associated Weed Species on ...

    African Journals Online (AJOL)

    The fields of cowpea and soyabean had higher frequencies of occurrence of the alien weed compare with sole cassava and maize plots and theirintercrops with lower frequencies of occurrence. This study advocated periodic observation of weed flora by farmers to ascertain cases of invasion of farmlands by alien weed ...

  8. The effect of environmental conditions on the seasonal dormancy pattern and germination of weed seeds

    NARCIS (Netherlands)

    Bouwmeester, H.J.

    1990-01-01

    Weeds cause considerable losses in horticultural and agricultural crops. Weeds are still predominantly controlled with herbicides. To reduce the use of chemicals, a better understanding of the biology of weeds is required. In this thesis the effect of environmental conditions on dormancy

  9. Airborne hyperspectral and LiDAR data integration for weed detection

    Science.gov (United States)

    Tamás, János; Lehoczky, Éva; Fehér, János; Fórián, Tünde; Nagy, Attila; Bozsik, Éva; Gálya, Bernadett; Riczu, Péter

    2014-05-01

    Agriculture uses 70% of global available fresh water. However, ca. 50-70% of water used by cultivated plants, the rest of water transpirated by the weeds. Thus, to define the distribution of weeds is very important in precision agriculture and horticulture as well. To survey weeds on larger fields by traditional methods is often time consuming. Remote sensing instruments are useful to detect weeds in larger area. In our investigation a 3D airborne laser scanner (RIEGL LMS-Q680i) was used in agricultural field near Sopron to scouting weeds. Beside the airborne LiDAR, hyperspectral imaging system (AISA DUAL) and air photos helped to investigate weed coverage. The LiDAR survey was carried out at early April, 2012, before sprouting of cultivated plants. Thus, there could be detected emerging of weeds and direction of cultivation. However airborne LiDAR system was ideal to detect weeds, identification of weeds at species level was infeasible. Higher point density LiDAR - Terrestrial laser scanning - systems are appropriate to distinguish weed species. Based on the results, laser scanner is an effective tool to scouting of weeds. Appropriate weed detection and mapping systems could contribute to elaborate water and herbicide saving management technique. This publication was supported by the OTKA project K 105789.

  10. Economics of weed suppressive rice cultivars in flood- and furrow-irrigated systems

    Science.gov (United States)

    Weeds are a major constraint to rice production. In the U.S, weeds in rice are controlled primarily with synthetic herbicides. Intensive herbicide application in rice also has many potential drawbacks, resulting in environmental pollution, human health concerns, and development of weed resistance. B...

  11. Environmental and socio-economic impact of aquatic weeds on the ...

    African Journals Online (AJOL)

    The physico-chemical assessment of water samples of the dam was done at dry and wet season in replicates. Water samples were collected from weed infested areas and also from the control site devoid of weed, using Standard laboratory methods. Field survey was done to determine the aquatic weed species present on ...

  12. Effect of weeding frequency on the growth and yield of cowpea ...

    African Journals Online (AJOL)

    ... Department of Agricultural Technology, Federal Polytechnic, Mubi, Adamawa State between July and September, 2012, to assess the effect of weeding frequency on the growth and yield of cowpea. The experiment was laid out in a Randomized Complete Block Design with four treatments (zero weeding, weeding once, ...

  13. Narrow rows reduce biomass and seed production of weeds and increase maize yield

    NARCIS (Netherlands)

    Mashingaidze, A.B.; Werf, van der W.; Lotz, L.A.P.; Chipomho, J.; Kropff, M.J.

    2009-01-01

    Smallholder farmers in southern African countries rely primarily on cultural control and hoe weeding to combat weeds, but often times, they are unable to keep up with the weeding requirements of the crop because of its laboriousness, causing them to incur major yield losses. Optimisation of crop

  14. 7 CFR 205.206 - Crop pest, weed, and disease management practice standard.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Crop pest, weed, and disease management practice... Requirements § 205.206 Crop pest, weed, and disease management practice standard. (a) The producer must use management practices to prevent crop pests, weeds, and diseases including but not limited to: (1) Crop...

  15. Determination of critical period for weed control in intensive and non ...

    African Journals Online (AJOL)

    Field experiments were conducted in Zuenoula and Yamoussoukro for determining Critical Period for Weed Control (CPWC) in sugarcane. The treatments consisted in two sets of weed interference. In the first set, the crop was kept weed-free until 31, 61, 92, 123 days after planting (DAP) in Zuenoula and until 32, 69, 98 and ...

  16. Lawn Weed Control with Herbicides. Home and Garden Bulletin No. 123.

    Science.gov (United States)

    Agricultural Research Service (USDA), Washington, DC.

    Information and diagrams are given for identification and treatment of weed grasses and broadleaf weeds. Herbicides are suggested for use against each weed and instructions are given for proper application. Information is given for buying herbicides, and applying sprays and cleaning sprayers. (BB)

  17. 76 FR 70954 - Idaho Panhandle National Forests, Idaho; Idaho Panhandle National Forest Noxious Weed Treatment...

    Science.gov (United States)

    2011-11-16

    ... Forest Noxious Weed Treatment Project AGENCY: Forest Service, USDA. ACTION: Notice of intent to prepare... counties in Montana; and Pend Oreille County in Washington. The proposal includes both an Integrated Weed... Weed Treatment Project Team Leader, at the Priest Lake Ranger District, 32203 Highway 57, Priest River...

  18. 7 CFR 201.65 - Noxious weed seeds in interstate commerce.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious weed seeds in interstate commerce. 201.65... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious weed seeds in interstate commerce. Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to the...

  19. Effect of weed control methods on some soil properties of a newly ...

    African Journals Online (AJOL)

    Weed control constitutes a high percentage of the total field maintenance cost of newly planted cocoa. Soil samples were collected from an experiment that was designed to evaluate some weed control methods during cocoa establishment. The objective of the experiment was to assess the effect of the weed control ...

  20. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds in the District of Columbia. 201.17... ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.17 Noxious-weed seeds in the District of Columbia. (a) Noxious-weed seeds in the District of Columbia are: Quackgrass (Elytrigia repens...

  1. Phenological observations on shrubs to predict weed emergence in turf

    Science.gov (United States)

    Masin, Roberta; Zuin, Maria Clara; Zanin, Giuseppe

    2005-09-01

    Phenology is the study of periodic biological events. If we can find easily recognizable events in common plants that precede or coincide with weed emergences, these plants could be used as indicators. Weed seedlings are usually difficult to detect in turf, so the use of phenological indicators may provide an alternative approach to predict the time when a weed appears and consequently guide management decisions. A study was undertaken to determine whether the phenological phases of some plants could serve as reliable indicators of time of weed emergence in turf. The phenology of six shrubs (Crataegus monogyna Jacq., Forsythia viridissima Lindl., Sambucus nigra L., Syringa vulgaris L., Rosa multiflora Thunb., Ziziphus jujuba Miller) and a perennial herbaceous plant [Cynodon dactylon (L.) Pers.] was observed and the emergence dynamics of four annual weed species [Digitaria sanguinalis (L.) Scop., Eleusine indica (L.) Gaertner, Setaria glauca (L.) Beauv., Setaria viridis (L.) Beauv.] were studied from 1999 to 2004 in northern Italy. A correlation between certain events and weed emergence was verified. S. vulgaris and F. viridissima appear to be the best indicators: there is a quite close correspondence between the appearance of D. sanguinalis and lilac flowering and between the beginning of emergence of E. indica and the end of lilac flowering; emergences of S. glauca and S. viridis were predicted well in relation to the end of forsythia flowering. Base temperatures and starting dates required to calculate the heat unit sums to reach and complete the flowering phase of the indicators were calculated using two different methods and the resultant cumulative growing degree days were compared.

  2. Weed harrowing in winter cereal under semi-arid conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, G.; Cirujeda, A.; Aibar, J.; Cavero, J.; Zaragoza, C.

    2008-07-01

    Five field experiments on barley and wheat have been carried out in North-Eastern Spain on the same field during the cropping seasons 1999-00 to 2003-04 to compare the effect of different harrowing adjustments on weed control, weed biomass and cereal yield. The variables considered were harrowing timing (pre- or early post-emergence), one or two passes, travelling direction, harrowing depth and speed compared with an untreated control and herbicide. Excepting year 2001, with very little weed emergence, mechanical control as a whole caused a significant weed plant reduction compared to the untreated plots in all years. No influence of harrowing depth and travelling speed and of pre-emergence harrowing were found in the trials. A single harrowing treatment conducted across the sowing direction gave the same or less control compared to harrowing along the sowing direction. Two harrowing passes achieved a higher efficacy than one single pass and little differences were detected if the second pass was conducted the same day, across the sowing direction or 15 days later. Despite herbicide had generally a higher efficacy than the harrowing treatments, in three out of five years it was found a mechanical control with the same control than herbicide. The effect of the different treatments on weed biomass was lower than on weed number and no significant differences were found for grain yield. Considering that an herbicide treatment in the present conditions is three times more expensive than harrowing, a single post-emergence harrowing can be considered a valid option for low and medium-infested cereal fields. (Author) 30 refs.

  3. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

    conveyor belts fully controlled by a Siemens PLC controller (programmable logic controller), a stereo vision system consisting of two cameras, a 2-axis laser beam deflection unit and a laser source. The main challenge in this project was to accurately estimate and reconstruct the weed growth center using...... the stereo vision system. The growth center was then targeted by a laser beam controlled by a deflection unit. The preliminary test results showed a good performance of the system than can replace usage of herbicides. Keywords: laser weeding system, herbicide, stereo vision system, deflection unit...

  4. Influence of Weed Competition on Potato Growth, Production and Radiation Use Efficiency

    Directory of Open Access Journals (Sweden)

    Farzad MONDANI

    2011-08-01

    Full Text Available Weed management in potato production is one of the main cost and time consuming practices. Understanding the most effective time of weed control could reduce the costs and increase potato yield. Field study was conducted in the west region of Iran during 2006 to evaluate the effect of weeds damage in potato fields. Twelve treatments used consisted of six initial weed-free periods in which plots were kept free of weeds for 0, 10, 20, 30, 40 and 50 days after crop emergence (DAE, and then weeds were allowed to grow until harvest, and six initial weed-infested periods in which, weeds were allowed to grow for 0, 10, 20, 30, 40 and 50 DAE, then the plots were kept free of weeds until harvest. Experiment was arranged as a randomized complete block design with three replications. The results showed effect of weed competition on crop dry matter started about 40 DAE and about 90 DAE reached its maximum. The weeds competition decreased dry matter accumulation, leaf area index, crop growth rate, leaf area index duration, light absorption, light extinction coefficient and radiation use efficiency (RUE of potato. Weeds reduced the potato yield 54.8 percent. The beginning and the end of the critical period of weed control in potato (CPWC was based on 5% and 10% tuber yield loss. The onset of the CPWC ranged from 486 to 572 GDD, at 5% and 10% yield loss level corresponding to 11 and 19 days after crop emergence, respectively. The end of the CPWC varied from 1372 to 1164 GDD, at 5% and 10% yield loss level corresponding to 65 and 51 days after crop emergence, respectively. RUE in the weed infestation treatment in comparison to the weed free treatment, reduced 11.8 percent.

  5. Robotic intra-row weed hoeing in maize and sugar beet

    Directory of Open Access Journals (Sweden)

    Gerhards, Roland

    2016-02-01

    Full Text Available A prototype of robotic intra-row weed hoeing in maize and sugar beet is presented in this study. Weeds in the crop rows were identified using a bi-spectral image analysis system and shape analysis. Positions of weeds in the images were recorded. Selective weed control in the row was performed with a modified finger weeder driven by electrical motors. Speed of the finger weeder was increased at positions where only weeds were classified. The system was triggered by an encoder and controlled by a micro-controller.

  6. Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management.

    Science.gov (United States)

    Green, Jerry M; Owen, Micheal D K

    2011-06-08

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effectiveness of glyphosate. Unfortunately, the introduction of GR crops and the high initial efficacy of glyphosate often lead to a decline in the use of other herbicide options and less investment by industry to discover new herbicide active ingredients. With some exceptions, most growers can still manage their weed problems with currently available selective and HR crop-enabled herbicides. However, current crop management systems are in jeopardy given the pace at which weed populations are evolving glyphosate resistance. New HR crop technologies will expand the utility of currently available herbicides and enable new interim solutions for growers to manage HR weeds, but will not replace the long-term need to diversify weed management tactics and discover herbicides with new modes of action. This paper reviews the strengths and weaknesses of anticipated weed management options and the best management practices that growers need to implement in HR crops to maximize the long-term benefits of current technologies and reduce weed shifts to difficult-to-control and HR weeds.

  7. Efficacy of Maister OD (Foramsulfuron + Idosulfuron a New Herbicide in Controlling Weeds of Corn Fields

    Directory of Open Access Journals (Sweden)

    J. Abdi

    2012-07-01

    Full Text Available To evaluate the efficacy of a new herbicide Foramsulfuron +Idosulfuron (Maister OD against other herbicides in corn fields, this experiment was fulfielld in 2010 at Mahidasht, Research Center of Agriculture and Natural Resources of Kermanshah, Iran. It was concucted in randomized complete block design with four replications and 11 treatments. In this experiment, three doses of herbicides (38.75, 46.5 and 54.25 g/ha including foramsulfuron + idosulfuron along with Nicusulfuron, ForamSulfuron, Rimsulfuron, Foramsulfuron + Rimsulfuron , Bromicid + hand weeding narrow leaf weeds, Bromicid + Nicusulfuron and U46 + hand weeding of narrow leaf weeds and a complete weeding as the control treatments were investigated. Weeds present in the field were Xanthium stromarium,Chenopedium album, Portulaca oleracea, Sorgum halepense and Setaria virdis. The results of this study showed that doses 38.75 and 46.5 g/ha of herbicide foramsulfuron + idosulfuron after treatments of Bromicid + Nicusulfuron and, Bromicid + narrow leaf weed, hand weeding respectively could control 90 and 86 % of weeds in corn field and increase its yields significantly. Because there are presently few registered herbicide available in Iran, necessity of finding proper herbicides to control weeds in corn field and based on the results oblained from this experiment it seems using 46.5 and 38-75 grams per hectare respectively of foramsulfuron + idosulfuron could be a better option than other herbicides to control weeds in corn fields and increase its seed yield.

  8. Host Status of Seven Weed Species and Their Effects on Ditylenchus destructor Infestation of Peanut.

    Science.gov (United States)

    De Waele, D; Jordaan, E M; Basson, S

    1990-07-01

    The host suitability to Ditylenchus destructor of seven common weed species in peanut (Arachis hypogaea) fields in South Africa was determined. Based on the number of nematodes per root unit, white goosefoot (Chenopodium album), feathertop chloris (Chloris virgata), purple nutsedge (Cyperus rotundus), jimson weed (Datura stramonium), goose grass (Eleusine indica), khaki weed (Tagetes minuta), and cocklebur (Xanthium strumarium) were poor hosts. Ditylenchus destructor survived on all weed species; population densities increased in peanut hulls and caused severe damage to seeds of peanut grown after weeds. Roots of purple nutsedge left in the soil suppressed populations of D. destructor and root and pod development in peanut grown after the weed. However, nematode populations in peanut hulls and seeds were not suppressed. Some weed species, especially purple nutsedge which is common in peanut fields, can be used to indicate the presence of D. destructor in the absence of peanut.

  9. [Potential role of winter rape weeds in the extension of broomrape in Poitou-Charentes].

    Science.gov (United States)

    Gibot-Leclerc, Stéphanie; Brault, Marianne; Pinochet, Xavier; Sallé, Georges

    2003-07-01

    In the Poitou-Charentes district, among the 82 species of winter rape weeds identified, 22 displayed a strong affinity for this crop (Brassica napus L.). In fields, 50% of these weeds were parasitized by Orobanche ramosa, playing the role of host plants. Greenhouse co-cultures (weed/Orobanche ramosa) showed that weeds non-parasitized in fields could be attacked by broomrape, developing a more or less complete cycle. In vitro co-cultures (weed/Orobanche ramosa) revealed that root exudates of non-parasitized weeds, in fields or in greenhouse co-cultures, could induce Orobanche ramosa seed germination, but not attachment. These weeds could play the role of false hosts.

  10. Biology, ecology and management of the invasive parthenium weed (Parthenium hysterophorus L.).

    Science.gov (United States)

    Adkins, Steve; Shabbir, Asad

    2014-07-01

    Parthenium weed (Parthenium hysterophorus L.) is one of the most aggressive invasive weeds, threatening natural ecosystems and agroecosystems in over 30 countries worldwide. Parthenium weed causes losses of crops and pastures, degrading the biodiversity of natural plant communities, causing human and animal health hazards and resulting in serious economic losses to people and their interests in many countries around the globe. Several of its biological and ecological attributes contribute towards its invasiveness. Various management approaches (namely cultural, mechanical, chemical and biological control) have been used to minimise losses caused by this weed, but most of these approaches are ineffective and uneconomical and/or have limitations. Although chemical control using herbicides and biological control utilising exotic insects and pathogens have been found to contribute to the management of the weed, the weed nevertheless remains a significant problem. An integrated management approach is proposed here for the effective management of parthenium weed on a sustainable basis. © 2014 Society of Chemical Industry.

  11. Larvicidal Properties of Datura Stramonium (Jimson Weed) and ...

    African Journals Online (AJOL)

    User

    2011-04-19

    Apr 19, 2011 ... Abstract. Extracts of the leaf of Nicotiana tabaccum (Tobacco) (L) in the family. Solanaceace and the root of Datura Stramonium (Jimson weed) in the family. Solanaceace, were prepared from plant materials collected within Ekiti State,. Nigeria. With Datura stramonium extract treatment, there was less than ...

  12. Effects of Weed Control and Cow Dung Manure on Growth ...

    African Journals Online (AJOL)

    Field trials were conducted during the 2006, 2007 and 2008 rainy seasons at the Institute for Agricultural Research Samaru, in the Northern guinea savanna zone of Nigeria to evaluate the effects of weed control and cow dung manure treatments on growth of Quality Protein Maize. The trial consisted of factorial ...

  13. Weed killers of limited use in reforesting scrub oak barrens

    Science.gov (United States)

    W. E. McQuilkin

    1951-01-01

    Chemical weed killers have been under test for 3 years as a possible means of preparing planting sites in the scrub oak barrens of Pennsylvania. Here the problem is to kill or set back the competing brush so planted trees can get started without costly release cuttings.

  14. PRODUCTION OF BIOG S FROM COW DUNG, WEEDS ND ...

    African Journals Online (AJOL)

    USER

    2017-05-26

    May 26, 2017 ... the production of biogas could also be used as manure (Eruedede, 2012). This work is therefore aimed to demonstrate the production of biogas by the anaerobic fermentation of domestic waste, to determine the ratio of weeds, and orange peeling and corn cob which would produce optimum amount of gas ...

  15. Glyphosate resistant weeds - a threat to conservation agriculture

    Science.gov (United States)

    Glyphosate-resistant weeds are now present throughout the Southeast. Hundreds of thousands of conservation tillage cotton acres, some currently under USDA Natural Resources Conservation Service (NRCS) conservation program contracts, are at risk of being converted to higher-intensity tillage systems....

  16. Organic Weed Control in White Lupin (Lupinus albus L.)

    Science.gov (United States)

    Legumes such as white lupin (Lupinus albus L.) provide a valuable nitrogen source in organic agriculture. With organic farming becoming an increasing sector of US agriculture and white lupin interest increasing in the southeastern USA because winter hardy cultivars are available, non-chemical weed c...

  17. Effects of land preparation practices and spacing on weed growth ...

    African Journals Online (AJOL)

    Effects of four tillage practices and spacing on weed growth, seedling establishment and yield of an upland rice cultivar (FARO 11) were evaluated in two field experiments at the University of Ilorin Teaching and Research Farm in 1994 and 1995. Crop establishment and grain yield were lower in minimally tilled than in ...

  18. Response of `Alamo` switchgrass (Panicum virgatum) to weed management practices

    Energy Technology Data Exchange (ETDEWEB)

    Sledge, S.L.; Walker, R.H. [Auburn Univ., AL (United States)

    1995-11-01

    Field studies were conducted in 1992 and 1994 to evaluate herbicides that would provide weed control and biomass yield of `Alamo` switchgrass during the year of establishment. For grass weed control, bensulide was applied preplant incorporated (PPI) at 4.4 kg ai ha{sup -1}, while MSMA was applied postemergence over the top (POST) at 2.2 kg ai ha{sup -1} to switchgrass that had two to four leaves. Herbicides applied POST for control of broadleaf weed species included 2,4-D at 0.6 kg ai ha{sup -1} or metsulfuron at 0.02 kg ai ha{sup -1}. Herbicide treatments included bensulide and MSMA applied alone or in combination with s,3-D or metsulfuron. They were arranged in a randomized complete block design and replicated four times. Weed control, crop tolerance and yield data were taken over time. Bensulide or MSMA applied alone provided 80% or greater control of large crabgrass, broadleaf signalgrass and fall panicum for the two years. The addition of metsulfuron or 2,4-D provided acceptable control of smooth pigweed, prickly sida, pitted morningglory and sicklepod. MSMA treatments produced slight PANVI injury that ranged from 20 to 36%. Bensulide injury was mostly moderate ranging from 19 to 88%. Although less injury was recorded with MSMA treatments, bensulide treatments trended higher for establishment-year biomass production that averaged 5123 kg ha{sup -1} as compared to 4239 kg ha{sup -1} for MSMA treatments.

  19. 611 A QUANTITATIVE ESTIMATE OF WEEDS OF SUGARCANE ...

    African Journals Online (AJOL)

    Osondu

    References. Akobundu I.O. and Agyakwa C.W. (1998), A. Hand book of West African Weeds. IITA,. Ibadan- Nigeria. 521pp. Anonymous (2008), Ecology and Simpson's. Diversity Index : advanced applied science: GCE. A2 UNITS: 1- 9. Blackshaw, R.E. (1994), Rotation affects downy brome (Bromus tectorum) in winter wheat.

  20. Alkaline protease from senesced leaves of invasive weed Lantana ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... The easy availability of the senesced leaves of this common weed makes it a cheaper ... generate new enzymes with altered properties (Rao et al., 1998). .... The activity of the enzyme was determined by incubating the reac- ..... Microbial alkaline proteases: from bio ... Phytochemistry, 49(3): 643-649.

  1. PLANT INDUCTION OF GERMINATION OF WITCH WEED SEEDS

    African Journals Online (AJOL)

    Legume-cereal rotation can reduce density of witch weed (Striga hermonthica) seeds in soil. However, legume species and cultivars vary greatly in ability to stimulate germination of S. hermonthica seeds of same or different populations, hence the need for simple method for routine characterisation of these species and ...

  2. Effect of Multipurpose Tree Species on Soil Fauna and Weed ...

    African Journals Online (AJOL)

    ... cordifolia / Gliricidia sepium / Dactyladenia barterii / Leucaenia leucocephala < natural fallow. Similarly, soil fauna increased more in the multipurpose woody species than in natural fallow. Recommendations based on the high weed suppressing ability, good litter formation and low soil nematode diversity were address.

  3. Robust crop and weed segmentation under uncontrolled outdoor illumination

    Science.gov (United States)

    A new machine vision for weed detection was developed from RGB color model images. Processes included in the algorithm for the detection were excessive green conversion, threshold value computation by statistical analysis, adaptive image segmentation by adjusting the threshold value, median filter, ...

  4. The effects of exotic weed Flaveria bidentis with different invasion ...

    African Journals Online (AJOL)

    A new exotic weed, Flaveria bidentis, is spreading in central China where it forms dense monospecific patches modifying the structure of different native ecosystems and threatening native aboveground biodiversity. However, little is known about the consequences of such an invasion for soil bacterial community, especially ...

  5. Economic potentials of oil palm products and weed control on ...

    African Journals Online (AJOL)

    A study was carried out at the Research Farm of National Root Crops Research Institute Umudike, southeastern Nigeria (05o, 29'N, 07o 33'E and 122 m above sea level), in 2015 and 2016 cropping seasons to study the economic potentials of oil palm products and weed control on sustainable turmeric production and some ...

  6. Effect of Weeds and Sedimentation on the Hydraulic Behaviour of ...

    African Journals Online (AJOL)

    Effect of Weeds and Sedimentation on the Hydraulic Behaviour of Irrigation Main Canal System at Kano River Project, Nigeria. ... particular emphasis on understanding the interactions between the design and operational performance of the canal and provide indications of needed improvements to enhance irrigation water ...

  7. Biodiversity and Importance of Floating Weeds of Dara Ismail, Khan ...

    African Journals Online (AJOL)

    Nymphoides indica (L.) Kuntze:, Pistia stratiotes L. Potamogeton nodosus Poiret and Spirodela polyrrhiza (L.) Schleid. Floating weeds on one hand cause serious problems and on the other hand they are used for various purposes. Data inventory consists of botanical name, family, major group, habit and habitat, flowering ...

  8. Larvicidal Properties of Datura Stramonium (Jimson Weed) and ...

    African Journals Online (AJOL)

    Extracts of the leaf of Nicotiana tabaccum (Tobacco) (L) in the family. Solanaceace and the root of Datura Stramonium (Jimson weed) in the family. Solanaceace, were prepared from plant materials collected within Ekiti State, Nigeria. With Datura stramonium extract treatment, there was less than 50% mortality of larvae on ...

  9. Organic weed control in certified organic watermelon production

    Science.gov (United States)

    The increasing perception by consumers that organic food tastes better and is healthier continues to expand the demand for organically produced crops. Field research was conducted in southeast Oklahoma to determine the impact of organic production systems on weed control and watermelon (Citrullus l...

  10. Evaluation of botanical herbicides against common weed species of ...

    African Journals Online (AJOL)

    Despite the wealth of genetic diversity of Arabica coffee, the national average yield of Ethiopian coffee is very low compared with many other producer countries. Weeds are one of the most limiting constraints particularly in organic farming systems, as no synthetic herbicides are allowed due to their direct and indirect ...

  11. Weed biomass and economic yield of wheat ( Triticum aestivum ) as ...

    African Journals Online (AJOL)

    Plots treated with herbicide Buctril super (Bromoxonil + MCPA) also produced excellent results in reducing weed biomass. The highest grain yield was recorded in plots where Buctril Super was sprayed. Weedy check treatment was at the bottom with the lowest grain yield. Economic analysis indicated that Buctril super was ...

  12. Herbicides for shrub and weed tree control in western Oregon.

    Science.gov (United States)

    H. Gratkowski

    1978-01-01

    Herbicides were tested on 16 common shrubs and weed trees during the past 24 years. The woody plants included snowbrush ceanothus, deerbrush ceanothus, mountain whitethorn, varnishleaf ceanothus, sprouting and nonsprouting forms of greenleaf manzanita, hairy manzanita, hoary manzanita, golden chinkapin, golden evergreenchinkapin, Saskatoon serviceberry, Pacific madrone...

  13. Tillage as a driver of change in weed communities

    NARCIS (Netherlands)

    Armengot, L.; Blanco-Moreno, J.M.; Bàrberi, P.; Bocci, G.; Carlesi, S.; Aendekerk, R.; Berner, A.; Celette, F.; Grosse, M.; Huiting, H.; Kranzler, A.; Luik, A.; Mäder, P.; Peigné, J.; Stoll, E.; Delfosse, P.; Sukkel, W.; Surböck, A.; Westaway, S.; Sans, F.X.

    2016-01-01

    The adoption of non-inversion tillage practices has been widely promoted due to their potential benefits in reducing energy consumption and greenhouse emissions as well as improving soil fertility. However, the lack of soil inversion usually increases weed infestations and changes the composition

  14. Weeding, Wine, and Cheese: Enticing Faculty to Cull a Collection

    Directory of Open Access Journals (Sweden)

    Judith Anne Koveleskie

    2014-11-01

    Full Text Available Remodeling of a building and decreased shelf space motivated faculty and staff to complete a long overdue weeding project in a small university library. Librarians used social media, internal communication, and personal contact to motivate faculty. Every effort was made to reuse and recycle discarded materials. The result was a streamlined collection and a much improved learning space.

  15. WEED CONTROL AND BORON NUTRITION ON Eucalyptus IN SILVOPASTORAL SYSTEM

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

    2015-04-01

    Full Text Available The objective of this study was to evaluate the control of weeds in the rows of eucalyptus (Eucalyptus urograndis with herbicides applied singly or combined with boron (B, as well as, the response of Eucalyptus plants to this micronutrient. The experiments were carried out in a split-plot with randomized complete block design, with three replicates. Six treatments were applied to the plots: (i weeded control, (ii control without weeding, (iii glyphosate (1080 g ae ha-1 + chlorimuron-ethyl (10 g ai ha-1 + 0.05% v / v mineral oil, (iv glyphosate (1080 g ae  ha-1 + isoxaflutole (112.5 g ai ha-1,  (v glyphosate (1080 g ae ha-1 and  (vi oxyfluorfen (480 g ai ha-1. The sub-plots consisted of the absence or presence of 4 kg of boric acid (H3BO3 - 17% B in 100 L of water. The addition of boric acid in the solution containing the herbicides did not affect the weed control. There was an increase in boron content in the soil and consequently an increase in the boron levels in the eucalyptus leaves. The combined application of herbicides plus boric acid is perfectly suitable for preventing dry of the pointer on eucalyptus plants. Keywords: Eucalyptus urograndis; chemical control; herbicides; micronutrients; Urochloa decumbens.

  16. Effects of cover crops and weed management on corn yield

    Directory of Open Access Journals (Sweden)

    Farhood Yeganehpoor

    2015-06-01

    Full Text Available One of the most important replacement methods used instead of chemical herbicide and conventional tillage is cover and companion crops’ application which is a major factor in sustainable agriculture. In order to determine the best cover crop in controlling weeds of corn field and its further effects on corn yield, an experiment was carried out in a factorial arrangement based on RCB design with three replicates. The treatments of this experiment included companion crops (clover, hairy vetch, basil and dill as first factor and time of sowing cover and medicinal plant (synchronic sowing with corn and sowing 15 days after corn sowing as second factor. The results showed that ear weight, ear length, leaf weight, grain length and yield were significantly influenced by companion crops and sowing date. Whereas, weed biomass was influenced by cover crop type × sowing date interaction. Also, the results indicated that increasing biomass weed resulted in linear reduction of grain yield. The highest ear weight, ear length, leaf weight, grain length and yield were obtained for cultivation of clover with corn. Synchronic cultivation of companion crops with corn had higher grain length and yield compared with cultivation 15 days after corn. The lowest weed biomass was recorded for concurrent cultivation of corn with clover due to rapid growth and high competitive power of clover in the early stage of growth.

  17. Effect of fertilizer in controlling weeds under intercropping of pearl ...

    African Journals Online (AJOL)

    The plants were planted as replacement method. The results showed that the lowest dry matter for crops and total dry matter of weeds was achieved from 50% fertilizer + 50% manure treatment. Also, the highest total dry matter of millet and bean was obtained from this treatment. The highest dry matter of millet and bean was ...

  18. Economics of herbicide weed management in wheat in Ethiopia ...

    African Journals Online (AJOL)

    Effective use of herbicides for the control of annual grass and broadleaf weeds in wheat (Triticum aestivum L.) was not a reality in Ethiopia, until in recent years. This study aimed at ... Sensitivity analysis (aMRR) also remained the most profitable even when the price of herbicide increased by 20%. Hence, Mesosulfron ...

  19. De novo characterization of the alligator weed (Alternanthera ...

    Indian Academy of Sciences (India)

    As one of the three macronutrients, potassium participates in many physiological processes in plant life cycle. Recently, potassium-dependent transcriptome analysis has been reported in Arabidopsis, rice and soybean. Alligator weed is well known, particularly for its strong ability to accumulate potassium. However, the ...

  20. Funding needed for assessments of weed biological control

    Science.gov (United States)

    John L. Maron; Dean E. Pearson; Stephen M. Hovick; Walter P. Carson

    2010-01-01

    Invasive non-native plants are a serious economic and ecological problem worldwide, and major efforts are therefore devoted to reducing weed abundance in agricultural and natural settings. Effective options for reducing invasive abundance and spread are few, although one common approach is biological control - the introduction of specialist herbivores or pathogens from...

  1. Influence of weed control methods, poultry manure and planting ...

    African Journals Online (AJOL)

    Field trials were conducted during the rainy seasons (2012 and 2013) at the Research Farm of Institute for Agricultural Research, Samaru Zaria and College of Agriculture and Animal Science, Mando Kaduna, in the Northern Guinea Savannah Zone of Nigeria, to determine the Influence of weed control methods, poultry ...

  2. Management of parthenium weed by extracts and residue of wheat ...

    African Journals Online (AJOL)

    This study was carried out to investigate the prospects of using methanolic extracts and residue of wheat (Triticum aestivum L.) for the management of parthenium (Parthenium hysterophorus L.), one of the world's worst weeds. In a laboratory bioassay, the effect of methanol extracts of 1, 2, 3, 4 and 5% (w/v) concentrations of ...

  3. Effects of Weed Control and Cow Dung Manure on Growth ...

    African Journals Online (AJOL)

    ABSTRACT: Field trials were conducted during the 2006, 2007 and 2008 rainy seasons at the Institute for. Agricultural Research Samaru, in the Northern guinea savanna zone of Nigeria to evaluate the effects of weed control and cow dung manure treatments on growth of Quality Protein Maize. The trial consisted of factorial.

  4. Standardization of DNA extraction from invasive alien weed ...

    African Journals Online (AJOL)

    DNA isolation from the weed, Parthenium hysterophorus is complicated due to the presence of high amount of allelochemicals in the form of secondary metabolites that causes hindrance in extraction and enzymatic reactions. A modified and efficient DNA extraction from P. hysterophorus leaf has been developed.

  5. Interference of five problematic weed species with rice growth and ...

    African Journals Online (AJOL)

    Five weed species namely, Cyperus rotundus L., Cyperus difformis L., Echinochloa colonum (L.) Link., Paspalum paspaloides (Mich.) Scribner, and Marsilea minuta L. were selected for the assessment of their level of competition with two commonly grown rice varieties viz. Basmati-385 and Super Basmati. Root and shoot ...

  6. Herbaceous weed control in loblolly pine plantations using flazasulfuron

    Science.gov (United States)

    Andrew W. Ezell; Jimmie L. Yeiser

    2015-01-01

    A total of 13 treatments were applied at four sites (two in Mississippi and two in Texas) to evaluate the efficacy of flazasulfuron applied alone or in mixtures for providing control of herbaceous weeds. All sites were newly established loblolly pine (Pinus taeda L.) plantations. Plots were evaluated monthly until 180 days after treatment. No phytotoxicity on pine...

  7. Exploring cost-effective maize integrated weed management ...

    African Journals Online (AJOL)

    Several production constraints have led to low yields (< 2.5 t ha-1) in maize (Zea mays L.) inUganda, among which are weeds. This study investigated the most cost-effective integrated weedmanagement (IWM) approach in maize in eastern Uganda. An experiment was conducted atIkulwe station, Mayuge in 2011 and 2012 ...

  8. Critical Period of Weed Interference in Rainfed and Irrigated ...

    African Journals Online (AJOL)

    Field trials were conducted to assess the critical period of weed interference in tomato on the farm of the Institute of Agricultural Research, Samaru (11011\\'N, 07038\\'E) in the Northern Guinea Savannah ecological zone of Nigeria in 1989 and 1990 wet seasons and at the Irrigation Research Station of the Institute of ...

  9. effect of fluazitopbutyl and atrazine/metolachlor for weed control

    African Journals Online (AJOL)

    COCOYAM

    ABSTRACT. Field studies were conducted at the research farm of the National Root Crops Research. Institute (NRCRI), Umudike, south-eastern Nigeria in 2008 and 2009 cropping seasons, to determine the effect of herbicides and the economic implications of chemical weed control in sweetpotato using herbicides.

  10. Soil weed seedbank dynamic and allelopathic potential of Tithonia ...

    African Journals Online (AJOL)

    The phenomenon of allelopathy is receiving increased attention as a possible alternative weed control method that is environment-friendly when compared with the use of herbicides with a wide range of toxic side effects which pose potential hazards to the environment. This study was designed to estimate the distribution of ...

  11. Nematodes and Weeds Control Effects of Pueraria phaseoloides ...

    African Journals Online (AJOL)

    The yield of plantain (Musa spp., AAB Simmonds) declines sharply after 1–2 years of cropping in West and Central Africa, due mainly to weeds and nematodes. A trial was carried out from January 2002 to October 2005 under two land-use systems (LUS) comprising 4–5 year-old bush fallow, dominated by Chromolaena ...

  12. Weed competitiveness and yielding ability of aerobic rice genotypes

    NARCIS (Netherlands)

    Zhao, D.L.

    2006-01-01

    Keywords:    Broad-sense heritability; Crop vigour; Genetic correlation; Indirect selection index; Plant erectness; Rice germplasm; Seeding rate; Vegetative growth; Weed-suppressive ability.

  13. Efficacy of primextra gold in controlling weeds of melon ( Citrillus ...

    African Journals Online (AJOL)

    A field experiment was conducted in the Center of Ecological Studies, University of Port Harcourt, Rivers State to evaluate the efficacy of Primextra Gold (290g /l S – Metalochlor and 370g/l Atrazine) herbicide in controlling weeds in melon and to determine its safety for use in melon. The experiment was carried out between ...

  14. Chemical weed management in wheat at higher altitudes.

    Science.gov (United States)

    Khan, Ikramullah; Marwat, Khan Bahadar; Hussain, Zahid

    2007-01-01

    To evaluate the effect of different herbicides for controlling weeds in wheat (variety Fakhr-i-Sarhad),at higher attitude, an experiment was conducted at Agriculture Research Station, Chitral during Rabi season 2003-04, using Randomized Complete Block Design, keeping four replications. The experiment, sown in November comprised of eight treatments, viz; seven herbicides and a weedy check. Each treatment consisted of 5 rows each 30 cm apart and 5 m long thus giving a total size of 5 m x 1.5 m. The herbicides used included; terbutryn + triasulfuron at 0.16 kg, 2,4-D at 0.7 kg, fenoxaprop-P-ethyl at 0.93 kg, clodinafop at 0.05 kg, bromoxynil + MCPA at 0.49 kg, carfentrazon-ethyl at 0.02 kg and isoproturon at 1.0 kg a.i ha(-1). The data were recorded on weed kill efficiency (%), fresh weed biomass (kg ha(-1)), plant height (cm), spike length (cm), number of tillers m(-2), number of grains spike(-1), thousand grains weight (g), biological yield (kg ha(-1)), grain yield (kg ha(-1)) and harvest index (%). The data recorded on weed kill efficiency, weed biomass (kg ha1), grains yield (kg ha(-1)) and harvest index (%) were significantly affected by the different herbicidal treatments. Statistically isoproturon treatment exhibited the best performance, with maximum weed kill efficiency (48.26%) and minimum fresh weed biomass (433.3 kg ha(-1)) as compared to weedy check (6 %) and (1102 kg ha(-1)), respectively. Similarly, the spike length (8.34 cm), number of tillers (427 m(-2)), number of grains spike(-1) (38.0), thousand grains weight (39.85 g), biological yield (8475 kg ha(-1)), grain yield (2530 kg ha(-1)) and harvest index (31.3%) were the highest in isoproturon treatments as compared to weedy check having (7.64 cm), (356 m(-2)), (34.1), (37.12 g), (6858 kg), (1913 kg ha(-1)) and (27%), respectively.

  15. Quantifying the effect of crop spatial arrangement on weed suppression using functional-structural plant modelling.

    Science.gov (United States)

    Evers, Jochem B; Bastiaans, Lammert

    2016-05-01

    Suppression of weed growth in a crop canopy can be enhanced by improving crop competitiveness. One way to achieve this is by modifying the crop planting pattern. In this study, we addressed the question to what extent a uniform planting pattern increases the ability of a crop to compete with weed plants for light compared to a random and a row planting pattern, and how this ability relates to crop and weed plant density as well as the relative time of emergence of the weed. To this end, we adopted the functional-structural plant modelling approach which allowed us to explicitly include the 3D spatial configuration of the crop-weed canopy and to simulate intra- and interspecific competition between individual plants for light. Based on results of simulated leaf area development, canopy photosynthesis and biomass growth of the crop, we conclude that differences between planting pattern were small, particularly if compared to the effects of relative time of emergence of the weed, weed density and crop density. Nevertheless, analysis of simulated weed biomass demonstrated that a uniform planting of the crop improved the weed-suppression ability of the crop canopy. Differences in weed suppressiveness between planting patterns were largest with weed emergence before crop emergence, when the suppressive effect of the crop was only marginal. With simultaneous emergence a uniform planting pattern was 8 and 15 % more competitive than a row and a random planting pattern, respectively. When weed emergence occurred after crop emergence, differences between crop planting patterns further decreased as crop canopy closure was reached early on regardless of planting pattern. We furthermore conclude that our modelling approach provides promising avenues to further explore crop-weed interactions and aid in the design of crop management strategies that aim at improving crop competitiveness with weeds.

  16. Prediction of the competitive effects of weeds on crop yields based on the relative leaf area of weeds

    DEFF Research Database (Denmark)

    Lotz, L. A. P.; Christensen, Svend; Cloutier, D.

    1996-01-01

    . The results strongly suggest that the predictive ability of the leaf area model needs to be improved before it can be applied in weed management systems. Such improvement would require additional information about effects of abiotic factors on plant development and morphology and the definition of a time...

  17. The role of plant-microbiome interactions in weed establishment and control.

    Science.gov (United States)

    Trognitz, Friederike; Hackl, Evelyn; Widhalm, Siegrid; Sessitsch, Angela

    2016-10-01

    The soil microbiome plays an important role in the establishment of weeds and invasive plants. They associate with microorganisms supporting their growth and health. Weed management strategies, like tillage and herbicide treatments, to control weeds generally alter soil structure going alongside with changes in the microbial community. Once a weed population establishes in the field, the plants build up a close relationship with the available microorganisms. Seeds or vegetative organs overwinter in soil and select early in the season their own microbiome before crop plants start to vegetate. Weed and crop plants compete for light, nutrition and water, but may differently interact with soil microorganisms. The development of new sequencing technologies for analyzing soil microbiomes has opened up the possibility for in depth analysis of the interaction between 'undesired' plants and crop plants under different management systems. These findings will help us to understand the functions of microorganisms involved in crop productivity and plant health, weed establishment and weed prevention. Exploitation of the knowledge offers the possibility to search for new biocontrol methods against weeds based on soil and plant-associated microorganisms. This review discusses the recent advances in understanding the functions of microbial communities for weed/invasive plant establishment and shows new ways to use plant-associated microorganisms to control weeds and invasive plants in different land management systems. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Integrated pest management and weed management in the United States and Canada.

    Science.gov (United States)

    Owen, Micheal D K; Beckie, Hugh J; Leeson, Julia Y; Norsworthy, Jason K; Steckel, Larry E

    2015-03-01

    There is interest in more diverse weed management tactics because of evolved herbicide resistance in important weeds in many US and Canadian crop systems. While herbicide resistance in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate-tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. There are many tactics that help to mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides, often to the exclusion of alternative tactics. Application of integrated pest management for weeds is better characterized as integrated weed management, and more typically integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds, and the relief provided by different herbicide use practices is generally short-lived at best. More diversity of tactics for weed management must be incorporated in crop systems. © 2014 Society of Chemical Industry.

  19. Weed control in distress – can all weeds still be controlled with herbicides in future?

    Directory of Open Access Journals (Sweden)

    Drobny, Hans G.

    2016-02-01

    Full Text Available The introduction and availability of highly active and selective herbicides in all important field crops, in the last decades, enabled the simplification and money saving in crop rotations and agronomic measures. This resulted in respective specialized and adapted weed populations, and consequently an increasing selection of resistant populations. Since the introduction of the ALS-inhibitors (starting 1985 and the 4-HPPD-inhibitors (2001, no new MoA-Classes were registered, and there are none in the registration process. Several established herbicides were not registered or re-registered in the EU, or were severely restricted in their application. The cost and the risk to develop and register a new selective herbicide in the EU are hardly justified, in relation to their market potential. The only solution on problem fields, with resistant populations, is to change the agronomic practices, like crop rotation, soil tillage, seeding time, etc., as a precautionary principle also on still „normal“ fields. The different advising institutions have to integrate these aspects into their recommendations, besides the proper herbicide management.

  20. The effect of intercropping on weed infestation of a spring barley crop cultivated in monoculture

    Directory of Open Access Journals (Sweden)

    Ewa Kwiecińska-Poppe

    2012-12-01

    Full Text Available This paper presents the results of a study carried out in the years 2005-2007 in the Bezek Experimental Farm near the city of Chełm, Poland, on heavy mixed rendzina soil. The effect of intercropping, using red clover (cv. Dajana and white clover (cv. Astra, on weed infestation of a spring barley crop was studied. The species composition of weeds in the spring barley crop changed to a small extent under the influence of the application of clover intercropping, whereas the population size of particular species showed large fluctuations. In the spring barley crop with the red clover intercrop, Sonchus arvensis occurred in greatest numbers among dicotyledonous weed species. In the barley crop with white clover and without intercrop, Viola arvensis and Sonchus arvensis were the dominant dicotyledonous species. Setaria pumila was the dominant monocotyledonous species in all the treatments. Intercropping using red and white clover clearly limited the growth and development of weeds. The red clover intercrop in the spring barley crop better reduced the infestation with dicotyledonous weeds and also significantly reduced the number of monocotyledonous weeds and the total number of weeds, whereas the white clover intercrop limited only the number of monocotyledonous weeds. The application of the herbicide Chwastox Extra 300 SL significantly reduced the fresh weight of weeds found in the spring barley crop. The presence of the intercrop resulted in different total numbers of weeds in particular treatments. Intercropping distinctly limited the occurrence of the following weed species: Sonchus arvensis, Fallopia convolvulus, Melandrium album, Amaranthus retroflexus, Veronica arvensis and Medicago lupulina. The investigated intercrop species also reduced the biomass of weeds. The application of the herbicide did not differentiate the number of monocotyledonous weeds, which resulted from the application of Chwastox Extra 300 SL that controls only

  1. Impact of fertilizing pattern on the biodiversity of a weed community and wheat growth.

    Science.gov (United States)

    Tang, Leilei; Cheng, Chuanpeng; Wan, Kaiyuan; Li, Ruhai; Wang, Daozhong; Tao, Yong; Pan, Junfeng; Xie, Juan; Chen, Fang

    2014-01-01

    Weeding and fertilization are important farming practices. Integrated weed management should protect or improve the biodiversity of farmland weed communities for a better ecological environment with not only increased crop yield, but also reduced use of herbicides. This study hypothesized that appropriate fertilization would benefit both crop growth and the biodiversity of farmland weed communities. To study the effects of different fertilizing patterns on the biodiversity of a farmland weed community and their adaptive mechanisms, indices of species diversity and responses of weed species and wheat were investigated in a 17-year field trial with a winter wheat-soybean rotation. This long term field trial includes six fertilizing treatments with different N, P and K application rates. The results indicated that wheat and the four prevalent weed species (Galium aparine, Vicia sativa, Veronica persica and Geranium carolinianum) showed different responses to fertilizer treatment in terms of density, plant height, shoot biomass, and nutrient accumulations. Each individual weed population exhibited its own adaptive mechanisms, such as increased internode length for growth advantages and increased light interception. The PK treatment had higher density, shoot biomass, Shannon-Wiener and Pielou Indices of weed community than N plus P fertilizer treatments. The N1/2PK treatment showed the same weed species number as the PK treatment. It also showed higher Shannon-Wiener and Pielou Indices of the weed community, although it had a lower wheat yield than the NPK treatment. The negative effects of the N1/2PK treatment on wheat yield could be balanced by the simultaneous positive effects on weed communities, which are intermediate in terms of the effects on wheat and weeds.

  2. INVASIVE WEEDS IN BOGOR BOTANIC GARDENS, INDONESIA AND ITS IMPLICATION ON SURROUNDING LANDSCAPES

    Directory of Open Access Journals (Sweden)

    Edi Santosa

    2014-07-01

    Full Text Available Conservation areas with the objective for collection and exchange plant materials have been speculated as weed bank for surrounding areas. Objective of this study was to identify and characterize ruderal invasive weeds in the Bogor Botanic Gardens (BBG. Observations were conducted in all vak (collection blocks in the BBG in order to identify the weeds species, determine their invasiveness, dominance and distribution. Weeds associations with host plants were observed. Current weed control program and data of dead trees collection were analyzed in relevant to weed. Distribution of weeds outside BBG was observed by transects method following river and road directions. Results showed that there were seven invasive weeds, i.e., Cecropia adenopus (Cecropiaceae, Cissus nodosa Blume (Vitaceae, Cissus sicyoides Blume (Vitaceae, Dioscorea bulbifera L. (Dioscoreaceae, Ficus elastica Roxb. (Moraceae, Mikania micrantha H.B.K. (Asteraceae and Paraserianthes falcataria (L. Nielsen (Fabaceae. These seven weeds species invaded 41 out of 215 plant families in BBG. Six species of weeds, i.e., C. adenopus, C. nodosa Blume., C. sicyoides Blume., D. bulbifera L., M. micrantha H.B.K. and P. falcataria (L. Nielsen, were introduced as BBG collections for the first time while the F. elastica Roxb was considered as native. It is most likely that the weeds dispersal agents are the wind, birds, bats, visitors, and waters. All of these weeds existed in surrounding areas outside BBG. Given the detrimental impact of invasive weeds on the plant collection in BBG, it is necessary to develop long–term comprehensive control measures both inside and neighboring areas by involving other government authorities beyond BBG.

  3. Estimating economic thresholds for site-specific weed control using manual weed counts and sensor technology: an example based on three winter wheat trials.

    Science.gov (United States)

    Keller, Martina; Gutjahr, Christoph; Möhring, Jens; Weis, Martin; Sökefeld, Markus; Gerhards, Roland

    2014-02-01

    Precision experimental design uses the natural heterogeneity of agricultural fields and combines sensor technology with linear mixed models to estimate the effect of weeds, soil properties and herbicide on yield. These estimates can be used to derive economic thresholds. Three field trials are presented using the precision experimental design in winter wheat. Weed densities were determined by manual sampling and bi-spectral cameras, yield and soil properties were mapped. Galium aparine, other broad-leaved weeds and Alopecurus myosuroides reduced yield by 17.5, 1.2 and 12.4 kg ha(-1) plant(-1)  m(2) in one trial. The determined thresholds for site-specific weed control with independently applied herbicides were 4, 48 and 12 plants m(-2), respectively. Spring drought reduced yield effects of weeds considerably in one trial, since water became yield limiting. A negative herbicide effect on the crop was negligible, except in one trial, in which the herbicide mixture tended to reduce yield by 0.6 t ha(-1). Bi-spectral cameras for weed counting were of limited use and still need improvement. Nevertheless, large weed patches were correctly identified. The current paper presents a new approach to conducting field trials and deriving decision rules for weed control in farmers' fields. © 2013 Society of Chemical Industry.

  4. Benchmark study on glyphosate-resistant cropping systems in the United States. Part 7: Effects of weed management strategy (grower practices versus academic recommendations) on the weed soil seedbank over 6 years.

    Science.gov (United States)

    Gibson, David J; Young, Bryan G; Owen, Micheal D K; Gage, Karla L; Matthews, Joseph L; Jordan, David L; Shaw, David R; Weller, Stephen C; Wilson, Robert G

    2016-04-01

    Shifts in weed species composition and richness resulting from near-exclusive reliance on herbicides in glyphosate-resistant (GR) cropping systems has necessitated the implementation of alternative weed management tactics to reduce selection pressures of herbicides. We contrasted the response of the weed soil seedbank to effects of weed management strategy, comparing grower practices with academic recommendations for best management practices (BMPs) over 6 years and across five weed hardiness zones in the US Midwest at sites subject to GR cropping systems. Total weed population density and species richness varied according to cropping system, location and prior year's crop, but less so to weed management strategy. The seedbank population density for 11 of the 14 most frequent weed species was affected by weed management strategy either alone or in an interaction with hardiness zone or year, or both. In only 29% of comparisons was weed population density lower following academic recommendations, and this depended upon prior crop and cropping system. The population density of high-risk weed species was reduced by academic recommendations, but only in two of six years and under continuous GR maize. Overall, the weed population density was decreasing in field halves subject to the BMPs in the academic recommendations relative to grower practices. The soil seedbank is slow to respond to academic recommendations to mitigate glyphosate-resistant weeds, but represents a biological legacy that growers need to keep in mind even when management practices reduce emerged field weed population densities. © 2015 Society of Chemical Industry.

  5. New weed control strategies in maize considering narrow crop rotations with maize, greater ALSresistance in common weeds and application restrictions with regard to active substance

    Directory of Open Access Journals (Sweden)

    Ewert, Katrin

    2014-02-01

    Full Text Available Many herbicides with different HRAC-groups are available for weed control in maize. Because of narrow maize crop rotation summer weeds and warmth loving weeds are encouraged. On the other hand the new confirmed cases of an ALS target site resistance in the weed species Echinochloa crus-galli and Amaranthus retroflexus in Brandenburg, Stellaria media in Saxony and Matricaria recutita and Tripleurospermum perforatum in Brandenburg and Thuringia, warn that in the future the sulfonylureas must be used only according to the management of herbicide resistance. In this way the selection of resistant weed biotypes will be prevented. Moreover in protected water areas it may be a requirement to reduce and to substitute the input of some active substances, for example terbuthylazine and bentazon. The control of E. crus-galli and P. convolvulus with non-sulfonylurea or/and non-terbuthylazine herbicides according to management of herbicide resistance will be discussed.

  6. Effect of ecological management of weed control on economical income, yield and yield components of cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    A. Zare Feizabadi

    2016-04-01

    Full Text Available In order to compare of ecological management of weed control on economical income, yield and yield components of cotton (Gossypium hirsutum L., a Randomized Complete Block design with 12 treatments and four replications was conducted in Mahvelat of Khorasan Razavi province, Iran. Treatments consisted of weeding, harrowing, burning, two times weeding, weeding + harrowing, weeding + burning, harrowing + harrowing, harrowing + weeding, harrowing + burning, weeding+ harrowing+ burning, weed free and weedy as a check treatment. Investigated traits were plant height, number of boll in plant, 20 boll weight, 20 boll cotton lint weight, cotton lint yield per plant, cotton yield, number and biomass of weeds, outcome, net and gross income. The result showed that treatments had significant effect (p

  7. Impact of the timing and duration of weed control on the establishment of a rubber tree plantation.

    Science.gov (United States)

    Guzzo, Caio D; Carvalho, Leonardo B de; Giancotti, Paulo R F; Alves, Pedro L C A; Gonçalves, Elaine C P; Martins, José V F

    2014-03-01

    Rubber tree production is reduced by weeds that compete for environmental resources; therefore, the timing and duration of weed control influences weed interference. The objectives of this study were to evaluate the growth of rubber tree (Hevea brasiliensis) plants, to determine the critical period for weed control, and to evaluate the growth recovery of rubber trees that coexisted with weeds for different periods of time after planting. Two groups of treatments were established under field conditions in the first year of the investigation: one group contained crescent periods of weed infestation, while the other contained crescent periods of weed control, also including a weed-free check and a total weedy check. In the second year of the investigation, the weeds were totally controlled. Urochloa decumbens was the dominant weed (over 90% groundcover). Crop growth was greatly reduced due to the weed interference. Plant height decreased more rapidly than did any other characteristic. Plant height, leaf dry mass, and leaf area decreased by 99%, 97% and 96%, respectively, and were the most reduced characteristics. Plant height also recovered more rapidly than did any characteristic when the period of weed control was lengthened. However, stem dry mass increased by 750%, making it the most recovered characteristic. The critical period for weed control was between 4 and 9½ months after planting in the first year; however, the rubber trees showed an expressive growth recovery when the weeds were controlled throughout the second year.

  8. Evaluation of yield quality and weed infestation of common valerian (Valeriana officinalis L. in dependence on weed control method and forecrop.

    Directory of Open Access Journals (Sweden)

    Cezary Kwiatkowski

    2012-12-01

    Full Text Available A field experiment involving the cultivation of common valerian was conducted on loess soil in Abramów (Lublin region in the period 2007-2009. Qualitative parameters of herbal raw material obtained from this plant as well as in-crop weed infestation were evaluated depending on the protection method and forecrop. Hand-weeded plots, in which a hand hoe was used, were the control. In the other treatments, weeds were controlled using various herbicides and a mechanical implement (brush weeder. Potato and winter wheat + field pea cover crop were the forecrops for common valerian crops. A hypothesis was made that the use of a brush weeder and herbicides not registered for application in valerian crops would have a positive effect on this plant's productivity and weed infestation in its crops. It was also assumed that the introduction of a cover crop would allow the elimination of differences in the forecrop value of the crop stands in question. The best quantitative and qualitative parameters of common valerian raw material as well as the largest reduction of incrop weed infestation were recorded after the application of the herbicides which were not type approved. The use of the brush weeder in the interrows also had a beneficial effect on productivity of the plant in question, but secondary weed infestation at the end of the growing season of common valerian turned out to be its disadvantage. Traditional crop protection methods used in common valerian crops were less effective in weed infestation reduction and they resulted in lower plant productivity and raw material quality. Potato proved to be a better forecrop for common valerian than winter wheat + field pea; however, this positive effect was not confirmed statistically. The following annual weeds: Chenopodium album, Galinsoga parviflora, Stellaria media, were predominant in the common valerian crop. Traditional weed control methods resulted in the dominance of some dicotyledonous weeds, such

  9. Development of an Autonomous Vehicle for Weed and Crop Registration

    DEFF Research Database (Denmark)

    Pedersen, Tom Søndergaard; Nielsen, Kirsten Mølgaard; Andersen, Palle

    the free height of the vehicle being developed in this work has been set to 0.5 m. The size and weight of the vehicle implies a power consumption of max 1.5 kW making electrical motors suitable for propulsion and steering. To make the operation affordable the vehicle should be unmanned requiring a high......The extension of information technology and computers on farming tools results in new possibilities for crop/weed handling. In this paper a system using an autonomous field robot (vehicle) able to make images in the field is described. In the recent farming has come to rely on intensive use...... degree of autonomy. The vehicle is part of an autonomous information system for crop and weed registration in fields which is developed at Aalborg University and The Danish Institute of Agricultural Science. The system consists of the vehicle and a stationary base station as well as a wireless...

  10. Biogas production from the aquatic weed Pistia (Pistia stratiotes)

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, S.A.; Nipaney, P.C. (Pondicherry (Central) Univ. (IN). Salim Ali School of Ecology); Panholzer, M.B. (Institute for Environmental Research, Graz (AT))

    1991-01-01

    Pistia stratiotes, an aquatic weed, was investigated as a substrate for biogas production in batch digestion. An inoculum was necessary to obtain biogas production form the weed. With Pistia,only production of carbon dioxide alone was high during the first five days of digestion but began to level off thereafter. With inoculated Pistia, a high rate of biogas production was sustained for nearly 10 days and the average methane content was 58%-68%. The digesters charged with Pistia alone had significant concentrations of propionic, butyric, isobutyric, valeric, and isovaleric acids. These acids were not present in detectable concentrations, in the digesters running with inoculated Pistia, except during the first 4 days of the digestion when propionic acid was formed. When an inoculum was added to a 'soured' digester the performance of the latter improved dramatically. (author).

  11. A Hybrid Differential Invasive Weed Algorithm for Congestion Management

    Science.gov (United States)

    Basak, Aniruddha; Pal, Siddharth; Pandi, V. Ravikumar; Panigrahi, B. K.; Das, Swagatam

    This work is dedicated to solve the problem of congestion management in restructured power systems. Nowadays we have open access market which pushes the power system operation to their limits for maximum economic benefits but at the same time making the system more susceptible to congestion. In this regard congestion management is absolutely vital. In this paper we try to remove congestion by generation rescheduling where the cost involved in the rescheduling process is minimized. The proposed algorithm is a hybrid of Invasive Weed Optimization (IWO) and Differential Evolution (DE). The resultant hybrid algorithm was applied on standard IEEE 30 bus system and observed to beat existing algorithms like Simple Bacterial foraging (SBF), Genetic Algorithm (GA), Invasive Weed Optimization (IWO), Differential Evolution (DE) and hybrid algorithms like Hybrid Bacterial Foraging and Differential Evolution (HBFDE) and Adaptive Bacterial Foraging with Nelder Mead (ABFNM).

  12. Weed map generation from UAV image mosaics based on crop row detection

    DEFF Research Database (Denmark)

    Midtiby, Henrik Skov

    is used as input for the method. Issues related to perspective distortion are reduced by using an orthomosaic, which is a high resolution image of the entire field, built from hundreds of images taken by a UAV. A vegetation map is generated from the orthomosaic by calculating the excess green color index......To control weed in a field effectively with a minimum of herbicides, knowledge about the weed patches is required. Based on images acquired by Unmanned Aerial Vehicles (UAVs), a vegetation map of the entire field can be generated. Manual analysis, which is often required, to detect weed patches...... in this vegetation map is a major obstacle to site specific weed management based on the vegetation map. A semiautomatic method for detecting weed patches based on crop row detection is described in this study. Vegetation outside the crop rows is considered as weeds. A color image (RGB) mosaic of the entire field...

  13. Mechanical pre-planting weed control in short rotation coppice using deep forestry ploughing techniques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    This report describes a trial by Border biofuels to investigate the deep forestry plough as a mechanical pre-planting weed control method to reduce weed infestations in willow coppice and thus contribute to improved establishment and eventual yield. The results suggest that there was a considerable increase in biomass productivity from the deep ploughed area compared to the conventionally cultivated area at all three SRC sites tested. This technique also suggests that the deep forestry ploughing provides the benefit of much reduced levels of seed germination of many annual weed species and a reduction in levels of perennial weed infestation. It is not possible at this stage to predict the longer term benefits in terms of harvestable biomass productivity but it may be considered that the improved establishment and lack of weed competition would consistently produce higher yields of biomass than plantations which suffer from persistent and invasive weed competition. (author)

  14. The intensity of mechanical cultivation measures vs. the amount of weed seeds in the soil

    Directory of Open Access Journals (Sweden)

    Marian Wesołowski

    2013-12-01

    Full Text Available The effect of the number of mechanical operations in sugar beets plantation on the amount and species composition of weed seeds in the 0-5 cm deep layer of the loessial soil was studied. It has been proved that reduction in the number of weed seeds depends upon both the frequency of weeding-out operations and the level of agrotechnic. The highest decrease in the number of fruit and weed seeds was caused by eightfold weed removal which took place during the period from emergence phase to the joining of sugar beet rows. Application of increased mineral fertilization, microelements, fungicides, and insecticides caused the number of weed seeds to be reduced by 5,9%, in comparison to extensive agrotechnical level.

  15. [Diversity and classification system of weed community in Harbin City, China].

    Science.gov (United States)

    Chen, Xiao-Shuang; Liang, Hong; Song, Kun; Da, Liang-Jun

    2014-08-01

    To analyze the causes of weed community diversity and their strategies of adaption to the high heterogeneity of urban habitats, weed communities in the central urban area of Harbin, China were studied, and a classification system was established for the weed communities. There were 175 weed species, belonging to 128 genera and 38 families. The heterogeneous urban habitats and species' temporal niche differentiation resulted in the highly diversified weed communities. The high proportions of mono-species dominance and annual species dominance communities were their response to the unstable urban habitats under human disturbances with high intensities and frequencies. A four-level classification system was established in terms of plant species and habitat conditions. Within this system, the identified 1763 weed communities could be categorized into two types of life form, 5 types of dormancy form, 22 community groups, and 119 dominance communities.

  16. Composición química de los aceites esenciales de las hojas de Helicteres guazumifolia (Sterculiaceae, Piper tuberculatum (Piperaceae, Scoparia dulcis (Arecaceae y Solanum subinerme (Solanaceae, recolectadas en Sucre, Venezuela

    Directory of Open Access Journals (Sweden)

    Gabriel Ordaz

    2011-06-01

    Full Text Available Los aceites esenciales son biosintetizados por plantas aromáticas y pueden obtenerse de cualquier órgano de la misma, tienen gran aplicación en la industria farmacéutica, sanitaria, cosmética, agrícola y de alimentos. Los aceites esenciales de las hojas de las plantas Helicteres guazumifolia, Piper tuberculatum, Scoparia dulcis y Solanum subinerme fueron obtenidos mediante hidrodestilación con rendimientos de 0.004, 0.032, 0.016 y 0.005%, respectivamente. La CG/EM permitió identificar la mayoría de los constituyentes de estos aceites esenciales (88.00, 89.80, 87.50 y 89.47%, respectivamente, encontrándose en mayor proporción metabolitos no volátiles de estructura no terpenoidal en H. guazumifolia (30.28%, sesquiterpenoides oxigenados en P. tuberculatum (52.19%, sesquiterpenos en S. dulcis (26.09% y derivados oxigenados de diterpenos en S. subinerme (39.67%. Los constituyentes mayoritarios fueron el diisobutilftalato (13.11% en H. guazumifolia, (--espatulenol (11.37% en P. tuberculatum y el trans-fitol (8.29 y 36.00% para S. dulcis y S. subinerme, respectivamente. El diisooctilftalato fue el constituyente común en los aceites esenciales de todas las especies y los compuestos volátiles trans-pinano, L-linalool, β-ionona, isofitol, neofitadieno, trans-fitol, dibutilftalato y hexadecanoato de metilo, fueron detectados en tres de estas esencias. Esto sugiere que dichas plantas pueden requerir metabolitos secundarios similares para su interacción ecológica, posiblemente debido a factores ambientales comunes.

  17. Weed killers may be useful in reforesting old burns

    Science.gov (United States)

    A. F. Hough

    1950-01-01

    More than 6 million acres in the 12 Northeastern and Middle Atlantic States need to be reforested, according to Forest Service estimates. Yet many of the sites that need planting are rocky and steep and hard to plant. In many places there is a dense cover of grasses, weeds, and shrubby growth. Old burns in the northern hardwood-hemlock forests and spruce-fir forests...

  18. Non-chemical Control of Root Parasitic Weeds with Biochar

    OpenAIRE

    Hanan Eizenberg; Dina Plakhine; Hammam Ziadne; Ludmila Tsechansky; Graber, Ellen R.

    2017-01-01

    This study tested whether soil-applied biochar can impact the seed germination and attachment of root parasitic weeds. Three hypotheses were evaluated: (i) biochar adsorbs host-exuded signaling molecules; (ii) biochar activates plants’ innate system-wide defenses against invasion by the parasite; and (iii) biochar has a systemic influence on the amount of seed germination stimulant produced or released by the host plant. Three types of experiments were performed: (I) pot trials with tomato (S...

  19. Investigation of pulping and paper making potential of weeds

    OpenAIRE

    omid Ghaffarzadeh Mollabashi; Mearaj Sharari; mohammadtaghi Alebrahim

    2017-01-01

    Increasing use of wood products accompanying with resource constraint has revealed the importance of nonwood based material. In this study, pulping and papermaking potential of three varieties of weeds including Xanthium spinosum, Carthamus tinctorius and Cyperus papyrus have been considered. At first, chemical components of the samples i.e. cellulose, lignin and extractives have been measured following TAPPI standard test methods. Afterwards, pulping process based as soda and Kraft has been ...

  20. Weed control in a native rubber crop (Parthenium argentatum gray)

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, J.W.

    1978-01-01

    There is a renewed interest in the production of rubber from guayule (Parthenium argentatum). Excellent control of several weed species in guayule has been obtained with Varsol (a naphtha oil) at 30-40 gal/acre applied at the cotyledon stage. At this stage, guayule survival averaged 86-63% according to dose, but plants up to 10 days old at the time of treatment showed increasing tolerance. Paraffin was somewhat more selective that Varsol.

  1. Weed profiles and management assessment for increased finger ...

    African Journals Online (AJOL)

    Weed profiles and management assessment for increased finger millet production in Uganda. ... est une denrée de sécurité alimentaire en Uganda, qui est appréciée pour ses valeurs nutritives, sa tolérance au déficit hydrique, ses bonnes qualités de stockage, mais sa production exige beacoup de travaux, en particulier le ...

  2. Germination traits of three weed species in Kosovo

    Directory of Open Access Journals (Sweden)

    A. Mehmeti

    2010-02-01

    Full Text Available Amaranthus retroflexus, Echinochloa crus-galli and Datura stramonium are the most important weed species in Kosovo. They cause severe yield depression, contaminate fodder and negatively affect growth and reproduction of other weed species. To counteract these problems, specific strategies need to be developed. Such strategies should consider information on species germination traits. In this context, our study provides information on temperature requirements for germination. Seeds of A. retroflexus, E. crus-galli and D. stramonium were harvested in two sub-regions of Kosovo (western and eastern parts differing in climate and land use. They were set for germination experiments in growth chambers at temperatures ranging from 3 to 35 °C and under field conditions. In both experiments, the germination rate differed between species and provenances. In the growth chamber experiment, germination of all three species was negligible below 15 °C and reached the highest rates between 24 and 30 °C. Seeds originating from the western part of Kosovo had higher germination rates and required a lower temperature for germination than seeds originating from the eastern part. In the field experiment, the time-dependent germination behaviour of D. stramonium differed between provenances. In general, germination started when soil temperature was above 18 °C and continued as long as the soil was moist. The results are discussed in the context of the need to develop weed management strategies against these weeds in Kosovo.

  3. Allelopathy in crop/weed interactions--an update.

    Science.gov (United States)

    Belz, Regina G

    2007-04-01

    Since varietal differences in allelopathy of crops against weeds were discovered in the 1970s, much research has documented the potential that allelopathic crops offer for integrated weed management with substantially reduced herbicide rates. Research groups worldwide have identified several crop species possessing potent allelopathic interference mediated by root exudation of allelochemicals. Rice, wheat, barley and sorghum have attracted most attention. Past research focused on germplasm screening for elite allelopathic cultivars and the identification of the allelochemicals involved. Based on this, traditional breeding efforts were initiated in rice and wheat to breed agronomically acceptable, weed-suppressive cultivars with improved allelopathic interference. Promising suppressive crosses are under investigation. Molecular approaches have elucidated the genetics of allelopathy by QTL mapping which associated the trait in rice and wheat with several chromosomes and suggested the involvement of several allelochemicals. Potentially important compounds that are constitutively secreted from roots have been identified in all crop species under investigation. Biosynthesis and exudation of these metabolites follow a distinct temporal pattern and can be induced by biotic and abiotic factors. The current state of knowledge suggests that allelopathy involves fluctuating mixtures of allelochemicals and their metabolites as regulated by genotype and developmental stage of the producing plant, environment, cultivation and signalling effects, as well as the chemical or microbial turnover of compounds in the rhizosphere. Functional genomics is being applied to identify genes involved in biosynthesis of several identified allelochemicals, providing the potential to improve allelopathy by molecular breeding. The dynamics of crop allelopathy, inducible processes and plant signalling is gaining growing attention; however, future research should also consider allelochemical release

  4. Modelling the effects of climate change on weed population dynamics

    OpenAIRE

    García de León Hernández, David

    2014-01-01

    As the human population continues to increase –it will have surpassed 9 billion people by 2050- food supply must rise in order to sustain people. Climate change represents a threat in the provision of sufficient, secure and nutritious nourishment for everyone. Possible consequences of climate change include a reduction in global agro-ecosystem production, with Spain as one of the most affected countries in Europe. Accordingly, little is known about the possible effects on weed ...

  5. Integrated weed management (IWM): will it reduce herbicide use?

    Science.gov (United States)

    Moss, S R

    2010-01-01

    The Sustainable Use of Pesticides Directive (2009/128/EC), part of the EU Thematic Strategy for Pesticides, requires Integrated Pest Management (IPM) to be actively promoted. A key objective is to give greater priority to non-chemical methods of plant protection to reduce the impact of pesticides on human health and the environment. Integrated Weed Management (IWM) can be considered part of IPM, and many non-chemical methods are available. For example, a recent review of methods for control of Alopecurus myosuroides (black-grass) in winter wheat found the following mean annual levels of control: ploughing 67%; delayed drilling 37%; fallowing 70%; higher seed rates 30%; competitive cultivars 27%. In comparison with herbicides these efficacy levels are mediocre, and A. myosuroides would be classified as resistant (R) or moderately resistant (MR) to all these methods if the criteria used by the Chemicals Regulation Directorate in the UK for assigning ratings to herbicide efficacy were used. It is, therefore, not surprising that farmers are reluctant to embrace IWM and continue to place greater.reliance on herbicides as a more reliable and cost effective method of weed control. While non-chemical methods will not replace herbicides on most farms, reduced reliance on herbicides will be necessary both for practical (increasing resistance, lack of new herbicides) and political reasons (complying with EU legislation). Farmers will use nonchemical control methods when they have a major weed problem, and have no alternative, but they must be encouraged to adopt IWM at an earlier stage. Research into IWM must be relevant and practical, and not simply conducted as some sort of 'academic' exercise. More effective knowledge transfer is vital, and this is a challenge due to the decline in independent, state funded, advisory services in many European countries. The question arises; is it possible to achieve reductions in pesticide use by simply promoting non-chemical methods of

  6. Mycorrhizal association in soybean and weeds in competition

    Directory of Open Access Journals (Sweden)

    Cíntia Maria Teixeira Fialho

    2016-04-01

    Full Text Available The purpose of this study was to evaluate the effects of mycorrhizal association on the interference of Bidens pilosa, Urochloa decumbens and Eleusine indica on soybean culture in two conditions: a plants competing without contact with roots of another species; b with contact between roots. At 60 days after planting, growth, nutrient accumulation and mycorrhizal colonization of soybean and weeds were evaluated. The contact between roots of soybean plant and weed species increased the negative interference effects for both species, with less growth and nutrient accumulation. With the individualization of roots, higher competition occurred for soil resources up to 60 days of coexistence between species. In competition with soybean, Bidens pilosa and Urochloa decumbens stood out in accumulation of most nutrients without differing from when cultivated in monocultivation. The increase of the soybean mycorrhizal colonization was 53, 40 and 33% when in competition with Urochloa decumbens, Eleusine indica and Bidens pilosa species, respectively. A positive interaction occurred for soybean mycorrhizal colonization and competing plants irrespective of weed species or root contact.

  7. Protocols for Robust Herbicide Resistance Testing in Different Weed Species.

    Science.gov (United States)

    Panozzo, Silvia; Scarabel, Laura; Collavo, Alberto; Sattin, Maurizio

    2015-07-02

    Robust protocols to test putative herbicide resistant weed populations at whole plant level are essential to confirm the resistance status. The presented protocols, based on whole-plant bioassays performed in a greenhouse, can be readily adapted to a wide range of weed species and herbicides through appropriate variants. Seed samples from plants that survived a field herbicide treatment are collected and stored dry at low temperature until used. Germination methods differ according to weed species and seed dormancy type. Seedlings at similar growth stage are transplanted and maintained in the greenhouse under appropriate conditions until plants have reached the right growth stage for herbicide treatment. Accuracy is required to prepare the herbicide solution to avoid unverifiable mistakes. Other critical steps such as the application volume and spray speed are also evaluated. The advantages of this protocol, compared to others based on whole plant bioassays using one herbicide dose, are related to the higher reliability and the possibility of inferring the resistance level. Quicker and less expensive in vivo or in vitro diagnostic screening tests have been proposed (Petri dish bioassays, spectrophotometric tests), but they provide only qualitative information and their widespread use is hindered by the laborious set-up that some species may require. For routine resistance testing, the proposed whole plant bioassay can be applied at only one herbicide dose, so reducing the costs.

  8. Experience with GOLTIX® TITAN® controlling annual dicotyledonous weeds in beets

    Directory of Open Access Journals (Sweden)

    Fell, Martina

    2014-02-01

    Full Text Available The herbicide GOLTIX® TITAN® is the unique combination of two active ingredients, Metamitrone (525 g/L and Quinmerac (40 g/L. GOLTIX® TITAN® is used for the control of annual dicotyledonous weeds in sugar and fodder beets. Registration was granted for the post emergence splitting application with 3 x 2,0 L/ha (3 applications. This corresponds to the amount of 3150 g Metamitrone and 240 g Quinmerac per hectare at maximum application rate. The registration application for pre-emergence application has been submitted. Several field trials were carried out between 2009 and 2013. These trials revealed the optimized efficacy on important weeds in sugar beet production including Fool´s parsley (Aethusa cynapium, Cleavers (Gallium aparine and Fat-hen (Chenopodium album. Selectivity was examined in all of these trials and showed good results with all relevant mixtures at all application times. The two active ingredients have different modes of action; hence, the product plays an important role in resistance management. They can be applied flexibly and do not have any known negative influence on the environment. The successful formulation of this highly sophisticated sugar beet herbicide was confirmed by the available trial results. GOLTIX® TITAN® with its specified characteristics is the base for every weed control measure.

  9. Organic fields sustain weed metacommunity dynamics in farmland landscapes

    Science.gov (United States)

    Henckel, Laura; Börger, Luca; Meiss, Helmut; Gaba, Sabrina; Bretagnolle, Vincent

    2015-01-01

    Agro-ecosystems constitute essential habitat for many organisms. Agricultural intensification, however, has caused a strong decline of farmland biodiversity. Organic farming (OF) is often presented as a more biodiversity-friendly practice, but the generality of the beneficial effects of OF is debated as the effects appear often species- and context-dependent, and current research has highlighted the need to quantify the relative effects of local- and landscape-scale management on farmland biodiversity. Yet very few studies have investigated the landscape-level effects of OF; that is to say, how the biodiversity of a field is affected by the presence or density of organically farmed fields in the surrounding landscape. We addressed this issue using the metacommunity framework, with weed species richness in winter wheat within an intensively farmed landscape in France as model system. Controlling for the effects of local and landscape structure, we showed that OF leads to higher local weed diversity and that the presence of OF in the landscape is associated with higher local weed biodiversity also for conventionally farmed fields, and may reach a similar biodiversity level to organic fields in field margins. Based on these results, we derive indications for improving the sustainable management of farming systems. PMID:25994672

  10. Organic fields sustain weed metacommunity dynamics in farmland landscapes.

    Science.gov (United States)

    Henckel, Laura; Börger, Luca; Meiss, Helmut; Gaba, Sabrina; Bretagnolle, Vincent

    2015-06-07

    Agro-ecosystems constitute essential habitat for many organisms. Agricultural intensification, however, has caused a strong decline of farmland biodiversity. Organic farming (OF) is often presented as a more biodiversity-friendly practice, but the generality of the beneficial effects of OF is debated as the effects appear often species- and context-dependent, and current research has highlighted the need to quantify the relative effects of local- and landscape-scale management on farmland biodiversity. Yet very few studies have investigated the landscape-level effects of OF; that is to say, how the biodiversity of a field is affected by the presence or density of organically farmed fields in the surrounding landscape. We addressed this issue using the metacommunity framework, with weed species richness in winter wheat within an intensively farmed landscape in France as model system. Controlling for the effects of local and landscape structure, we showed that OF leads to higher local weed diversity and that the presence of OF in the landscape is associated with higher local weed biodiversity also for conventionally farmed fields, and may reach a similar biodiversity level to organic fields in field margins. Based on these results, we derive indications for improving the sustainable management of farming systems. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  11. Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize

    OpenAIRE

    Jordaan, Elizabeth M.; De Waele, D.

    1988-01-01

    The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae inf...

  12. Taxonomic and life history bias in herbicide resistant weeds: implications for deployment of resistant crops.

    Directory of Open Access Journals (Sweden)

    Jodie S Holt

    Full Text Available Evolved herbicide resistance (EHR is an important agronomic problem and consequently a food security problem, as it jeopardizes herbicide effectiveness and increases the difficulty and cost of weed management. EHR in weeds was first reported in 1970 and the number of cases has accelerated dramatically over the last two decades. Despite 40 years of research on EHR, why some weeds evolve resistance and others do not is poorly understood. Here we ask whether weed species that have EHR are different from weeds in general. Comparing taxonomic and life history traits of weeds with EHR to a control group ("the world's worst weeds", we found weeds with EHR significantly over-represented in certain plant families and having certain life history biases. In particular, resistance is overrepresented in Amaranthaceae, Brassicaceae and Poaceae relative to all weeds, and annuality is ca. 1.5 times as frequent in weeds with EHR as in the control group. Also, for perennial EHR weeds, vegetative reproduction is only 60% as frequent as in the control group. We found the same trends for subsets of weeds with EHR to acetolactate synthase (ALS, photosystem II (PSII, and 5-enolpyruvylshikimate-3-phosphate (EPSP synthase-inhibitor herbicides and with multiple resistance. As herbicide resistant crops (transgenic or not are increasingly deployed in developing countries, the problems of EHR could increase in those countries as it has in the USA if the selecting herbicides are heavily applied and appropriate management strategies are not employed. Given our analysis, we make some predictions about additional species that might evolve resistance.

  13. Taxonomic and life history bias in herbicide resistant weeds: implications for deployment of resistant crops.

    Science.gov (United States)

    Holt, Jodie S; Welles, Shana R; Silvera, Katia; Heap, Ian M; Heredia, Sylvia M; Martinez-Berdeja, Alejandra; Palenscar, Kai T; Sweet, Lynn C; Ellstrand, Norman C

    2013-01-01

    Evolved herbicide resistance (EHR) is an important agronomic problem and consequently a food security problem, as it jeopardizes herbicide effectiveness and increases the difficulty and cost of weed management. EHR in weeds was first reported in 1970 and the number of cases has accelerated dramatically over the last two decades. Despite 40 years of research on EHR, why some weeds evolve resistance and others do not is poorly understood. Here we ask whether weed species that have EHR are different from weeds in general. Comparing taxonomic and life history traits of weeds with EHR to a control group ("the world's worst weeds"), we found weeds with EHR significantly over-represented in certain plant families and having certain life history biases. In particular, resistance is overrepresented in Amaranthaceae, Brassicaceae and Poaceae relative to all weeds, and annuality is ca. 1.5 times as frequent in weeds with EHR as in the control group. Also, for perennial EHR weeds, vegetative reproduction is only 60% as frequent as in the control group. We found the same trends for subsets of weeds with EHR to acetolactate synthase (ALS), photosystem II (PSII), and 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase-inhibitor herbicides and with multiple resistance. As herbicide resistant crops (transgenic or not) are increasingly deployed in developing countries, the problems of EHR could increase in those countries as it has in the USA if the selecting herbicides are heavily applied and appropriate management strategies are not employed. Given our analysis, we make some predictions about additional species that might evolve resistance.

  14. Weed control and crop selectivity of post-emergence herbicides in common beans

    OpenAIRE

    Marchioretto, Lucas De Ross; Dal Magro, Taísa

    2017-01-01

    ABSTRACT: There are few options of wide spectrum selective herbicides registered for post-emergence weed control in common beans crop. The experiment aimed to test crop selectivity and weed control of post-emergence herbicides on common beans. Weed control, injury and grain yield were evaluated. Treatments consisted on: cloransulam-methyl, imazethapyr, fomesafen, bentazon and diclosulam isolated and tank-mixed with clethodim; imazamox+bentazon, fomesafen+fluazifop, clethodim; cloransulam+bent...

  15. Chemical control of curled dock (Rumex crispus L.) and other weeds in noncropped areas

    OpenAIRE

    Dimitrova Tsvetanka; Marinov-Serafimov Plamen

    2008-01-01

    Rumex crispus L. is an invasive species widespread in our country and in particular in the region of North Bulgaria. It is characterized by high biological and ecological plasticity. Owing to its great reproductive potential, the weed has been assigned to the list of economically most important weeds in the country. With the purpose of studying the possibility of chemical weed control in noncropped areas with heavy natural background infestation with R. crispus L. and other dicotyledonous wee...

  16. Evaluation and Modeling of Camel Thorn (Alhagi Maurorum Weed Cutting by Water Jet

    Directory of Open Access Journals (Sweden)

    M Naghipour Zade Mahani

    2014-04-01

    Full Text Available Due to the importance of weed control and the limitations of mechanical methods in some places, in this research the water jet cutting for weed control was investigated. The cutting tests were performed on camel thorn weed in Shahid Bahonar university of Kerman. The water jet pressure of 90 bars was achieved with the aid of a suitable pump. The cutting time was studied in a completely randomized factorial design experiment (CRD with five replications. Factors of experiments are: stem diameter in 2 levels (smaller and larger than 5 mm, distance of spraying jet from weeds in 3 levels (10, 20 and 30 cm and two types of plant holders: blade and plate. The results showed that stem diameter and jet distance from the weed stem had significant effects on cutting time (at the 1%. The mean comparison of parameters showed that with increase of stem diameter the cutting time increased and any increase in jet distance from the weeds decreased the cutting time linearly with R2=0.96 and R2=0.99 for small and large diameter weeds, respectively. The minimum cutting time was measured at 30 cm of the jet from small diameter of stems. A multivariate linear regression model was also proposed for cutting weed parameters. It can be concluded that due to the flexibility of water jet cutting for restricted places, hydrodynamic control of weeds is proposed as a complementary method and sometimes a competing substitute method.

  17. Broccoli/weed/soil discrimination by optical reflectance using neural networks

    Science.gov (United States)

    Hahn, Federico

    1995-04-01

    Broccoli is grown extensively in Scotland, and has become one of the main vegetables cropped, due to its high yields and profits. Broccoli, weed and soil samples from 6 different farms were collected and their spectra obtained and analyzed using discriminant analysis. High crop/weed/soil discrimination success rates were encountered in each farm, but the selected wavelengths varied in each farm due to differences in broccoli variety, weed species incidence and soil type. In order to use only three wavelengths, neural networks were introduced and high crop/weed/soil discrimination accuracies for each farm were achieved.

  18. Integration of agronomic practices with herbicides for sustainable weed management in aerobic rice.

    Science.gov (United States)

    Anwar, M P; Juraimi, A S; Mohamed, M T M; Uddin, M K; Samedani, B; Puteh, A; Man, Azmi

    2013-01-01

    Till now, herbicide seems to be a cost effective tool from an agronomic view point to control weeds. But long term efficacy and sustainability issues are the driving forces behind the reconsideration of herbicide dependent weed management strategy in rice. This demands reappearance of physical and cultural management options combined with judicious herbicide application in a more comprehensive and integrated way. Keeping those in mind, some agronomic tools along with different manual weeding and herbicides combinations were evaluated for their weed control efficacy in rice under aerobic soil conditions. Combination of competitive variety, higher seeding rate, and seed priming resulted in more competitive cropping system in favor of rice, which was reflected in lower weed pressure, higher weed control efficiency, and better yield. Most of the herbicides exhibited excellent weed control efficiency. Treatments comprising only herbicides required less cost involvement but produced higher net benefit. On the contrary, treatments comprising both herbicide and manual weeding required high cost involvement and thus produced lower net benefit. Therefore, adoption of competitive rice variety, higher seed rate, and seed priming along with spraying different early-postemergence herbicides in rotation at 10 days after seeding (DAS) followed by a manual weeding at 30 DAS may be recommended from sustainability view point.

  19. Airborne gamma-ray spectrometer and magnetometer survey: Weed quadrangle, California. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    Volume II contains the flight path, radiometric multi-parameter stacked profiles, magnetic and ancillary parameter stacked profiles, histograms, and anomaly maps for the Weed Quadrangle in California.

  20. Weed management in short rotation coppice: current status and future requirements

    Energy Technology Data Exchange (ETDEWEB)

    Clay, D.V. [Avon Vegetation Research, Nailsea (United Kingdom)

    1996-11-01

    The current status of weed management in short rotation coppices (SRCs) is reviewed in this updated report from the Energy Technology Support Unit, which draws on data from recently published material and from experimental work on advisory and vegetation monitoring activities from large scale SRC plantings. The report covers the need for weed control in SRCs, current methods, the properties and costs of herbicides, problem weed control. The need for the development and operation of sustainable integrated weed management systems is also highlighted. (UK)

  1. How Local Landholder Groups Collectively Manage Weeds in South-Eastern Australia

    Science.gov (United States)

    Graham, Sonia; Rogers, Sarah

    2017-09-01

    For two decades researchers and policy makers have been arguing that community-based collective action is needed to effectively control weeds. Yet there has been little social research into the ways that collective weed control emerges at local scales. The aim of this paper is to investigate the mechanisms through which three local landholder groups in south-eastern Australia collectively manage weeds and the measures they use to evaluate success. Semi-structured interviews were conducted with members of three Landcare groups—Jerrawa Creek/Upper Lachlan, MacLaughlin River and Towamba Valley—as well as government staff external to the groups. The results reveal that for all three groups collective weed control is about supporting individual weed control efforts as well as proactively engaging landholders with the worst infestations. The groups were seen to be successful because they focused on the common challenge that weeds pose to all landholders, thereby removing the shame associated with having weeds, and because they organised community events that were as much about building and maintaining social relationships as improving weed control. Groups were positive about what they had achieved as collectives of landholders, but also saw an important role for government in providing funding, engaging with landholders who were unwilling to engage directly with the group, and controlling weeds on public lands.

  2. Opportunities and challenges for harvest weed seed control in global cropping systems.

    Science.gov (United States)

    Walsh, Michael J; Broster, John C; Schwartz-Lazaro, Lauren M; Norsworthy, Jason K; Davis, Adam S; Tidemann, Breanne D; Beckie, Hugh J; Lyon, Drew J; Soni, Neeta; Neve, Paul; Bagavathiannan, Muthukumar V

    2017-11-28

    The opportunity to target weed seeds during grain harvest was established many decades ago following the introduction of mechanical harvesting and the recognition of high weed-seed retention levels at crop maturity; however, this opportunity remained largely neglected until more recently. The introduction and adoption of harvest weed seed control (HWSC) systems in Australia has been in response to widespread occurrence of herbicide-resistant weed populations. With diminishing herbicide resources and the need to maintain highly productive reduced tillage and stubble-retention practices, growers began to develop systems that targeted weed seeds during crop harvest. Research and development efforts over the past two decades have established the efficacy of HWSC systems in Australian cropping systems, where widespread adoption is now occurring. With similarly dramatic herbicide resistance issues now present across many of the world's cropping regions, it is timely for HWSC systems to be considered for inclusion in weed-management programs in these areas. This review describes HWSC systems and establishing the potential for this approach to weed control in several cropping regions. As observed in Australia, the inclusion of HWSC systems can reduce weed populations substantially reducing the potential for weed adaptation and resistance evolution. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Integration of Agronomic Practices with Herbicides for Sustainable Weed Management in Aerobic Rice

    Science.gov (United States)

    Anwar, M. P.; Juraimi, A. S.; Mohamed, M. T. M.; Uddin, M. K.; Samedani, B.; Puteh, A.; Man, Azmi

    2013-01-01

    Till now, herbicide seems to be a cost effective tool from an agronomic view point to control weeds. But long term efficacy and sustainability issues are the driving forces behind the reconsideration of herbicide dependent weed management strategy in rice. This demands reappearance of physical and cultural management options combined with judicious herbicide application in a more comprehensive and integrated way. Keeping those in mind, some agronomic tools along with different manual weeding and herbicides combinations were evaluated for their weed control efficacy in rice under aerobic soil conditions. Combination of competitive variety, higher seeding rate, and seed priming resulted in more competitive cropping system in favor of rice, which was reflected in lower weed pressure, higher weed control efficiency, and better yield. Most of the herbicides exhibited excellent weed control efficiency. Treatments comprising only herbicides required less cost involvement but produced higher net benefit. On the contrary, treatments comprising both herbicide and manual weeding required high cost involvement and thus produced lower net benefit. Therefore, adoption of competitive rice variety, higher seed rate, and seed priming along with spraying different early-postemergence herbicides in rotation at 10 days after seeding (DAS) followed by a manual weeding at 30 DAS may be recommended from sustainability view point. PMID:24223513

  4. Experimental and natural weed host-virus relations.

    Science.gov (United States)

    Kazinczi, G; Horváth, J; Takács, A P; Gáborjányi, R; Béres, I

    2004-01-01

    Weeds, as alternative hosts of plant viruses and nutrient plants of virus vectors play important role in virus ecology and epidemiology. The aim of our study was to discover new weed-virus relations. Therefore some weed species were mechanically inoculated with 28 viruses (strains or isolates) maintained in our glasshouse. Different weed species with and without visible symptoms were collected from agro-, water ecosystems and wastelands of Hungary between 1997 and 2003. Virus infections were evaluated by biotests, DAS ELISA serological methods, electronmicroscopy and immunosorbent electronmicroscopy (ISEM). Under glasshouse conditions Ambrosia artemisifolia was considered as a virophob species, showing resistance to all viruses listed above. A series of new artificial (Chenopodium album--SoMV (LH+SH)*, AMV (LH+SH); C. berlandieri--PVY(NTN) (LH), AMV (LH+SH), CMV (LH), SoMV (LH+SH), ObPV (LH+SH), ZYMV-10 (LH): C. ugandae--ObPV (LH), SoMV (L); C. glaucum--ObPV (LH), SoMV (L); Echinocystis lobata--PVX (L), ZYMV (LH+SH); Solanum nigrum--MYFV (LH+SH), PVY(N) (L), PVY(NTN) (LH+SH), SoMV (LH), TMV (SH), CMV (SH); S. dulcamara--CMV-U/246 (SH), PVY(NTN) (LH), SoMV-H (L), TMV-O (L); S. luteum--PVY(N) (SH), PVY(NTN) (LH+L), TMV(SH).) and natural (Asclepias syriaca--TMV, AMV, TSWV; Alisma plantago-aquatica--PVY, SoMV; Ambrosia artemisiifolia--CMV; Chenopodium album--CMV, PVS, PLRV; C. hybridum--CMV; Cirsium canum--CMV, PVM; Carex vulpina--CMV; Comium maculatum--PVY; Datura stramonium--PVA, PVX, PVS, PVM, CMV, TMV; Lysimachia vulgaris--ArMV, BNYVV, CMV, TMV; Lythrum salicaria--ArMV; Malva neglecta--CMV; Mercurialis annua--SoMV; Solanum nigrum--CMV, PVY, PVY(N); Solidago gigantea--CMV, RpRSV, BNYVV; Stenactis annua--PVM, PVA) weed--virus relations were detected. The epidemiological role of perennial hosts (A. syriaca, A. planlago aquatica, C. canurm, L. vulgaris, L. salicaria, S. gigantea) is especially high, because they can serve as infection sources as well as overwintering

  5. Weed control based on real time patchy application of herbicides using image analysis as a non-destructive estimation method for weed infestation and herbicide effects

    DEFF Research Database (Denmark)

    Asif, Ali

    on crop yield. The excessive use of spraying can potentially be reduced by spraying only those parts of the field where it has economic importance. The competition relation between weeds and crop was ana-lyzed in context of real time patch spray. A non-destructive image analysis method was developed...... to estimate infestation of weeds at early growth stage. The image analysis method was further developed to estimate colour response of applying increasing doses of herbicides in selectivity experiments and to evaluate the weed-suppressing effect of mulches....

  6. Ecologically sustainable weed management: How do we get from proof-of-concept to adoption?

    Science.gov (United States)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne; Childs, Dylan; Christensen, Svend; Cousens, Roger; Eizenberg, Hanan; Heijting, Sanne; Loddo, Donato; Merotto, Aldo; Renton, Michael; Riemens, Marleen

    2016-07-01

    Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade, and greater weed impacts due to changes in climate and land use. Broad-scale use of new approaches is needed if weed management is to be successful in the coming era. We examine three approaches likely to prove useful for addressing current and future challenges from weeds: diversifying weed management strategies with multiple complementary tactics, developing crop genotypes for enhanced weed suppression, and tailoring management strategies to better accommodate variability in weed spatial distributions. In all three cases, proof-of-concept has long been demonstrated and considerable scientific innovations have been made, but uptake by farmers and land managers has been extremely limited. Impediments to employing these and other ecologically based approaches include inadequate or inappropriate government policy instruments, a lack of market mechanisms, and a paucity of social infrastructure with which to influence learning, decision-making, and actions by farmers and land managers. We offer examples of how these impediments are being addressed in different parts of the world, but note that there is no clear formula for determining which sets of policies, market mechanisms, and educational activities will be effective in various locations. Implementing new approaches for weed management will require multidisciplinary teams comprised of scientists, engineers, economists, sociologists, educators, farmers, land managers, industry personnel, policy makers, and others willing to focus on weeds within whole farming systems and land management units. © 2016 by the Ecological Society of America.

  7. Weed control in dormant alfalfa (Medicago sativa L. with active ingredients’ metribuzin, imazetapyr and pronamide

    Directory of Open Access Journals (Sweden)

    Zvonko Pacanoski

    2017-03-01

    Full Text Available Field trials were conducted during 2008 – 2010 to evaluate weed control in dormant alfalfa (Medicago sativa L. with metribuzin, imazetapyr and pronamide. The weed population in all experimental years was consisted mainly of annual winter and spring grass and broadleaf weeds, and some perennial weeds. The number of weed species and weed density increased with the years of alfalfa growing, from second to the fourth year. Weed density in the untreated control plots was 201.0, 217.2 and 240.5 plants per m2 in 2008, 2009 and 2010, respectively. The most dominant weeds were Anthemis cotula, Capsell bursa-pastoris and Taraxacum officinale in 2008, Alopecurus myosuroides and Poa pratensis in 2009 and Millium vernale and Arabidopsis thaliana in 2010. Efficacy of herbicides in control of weeds was ranged of 91.8% (pronamide to 98.4% (metribuzin 1.0 kg*ha-1 in 2008, 93.1% (imazetapyr to 97.3% (metribuzin 1.0 kg*ha-1 in 2009 and 92.1% (imazetapyr to 97.3% (metribuzin 1.0 kg*ha-1 in 2010, respectively. Efficacy of herbicides in control of prevailing weeds during the 3 years field trial period was ranged of 48.5% to 100.0%. No visual alfalfa injured was determined by any rates during the experimental period, and consequently, none of the applied herbicides reduced first-harvest alfalfa yields. Alfalfa yield was markedly affected by herbicide efficacy in all experimental years, particularly in the second year, where yields of herbicide treatments were similar to that of the weed free control.

  8. Effects of long-term reduced tillage on weed infestation of pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Andrzej Woźniak

    2014-09-01

    Full Text Available The study evaluated weed infestation of pea (Pisum sativum L. cultivated under conditions of conventional (CT, reduced (RT and herbicide tillage (HT. It demonstrated the highest weed density per m2 in plots with the herbicide (HT and reduced (RT systems and significantly lower weed infestation in plots cultivated in the conventional system (CT. In addition, more weeds occurred at the third leaf stage (13/14 in BBCH scale than at the pod development stage (73/74 BBCH of pea. The highest biomass was produced by weeds in the herbicide system (HT, a lower one – in the reduced system (RT, and the lowest one – in the conventional system (CT. The air-dry weight of weeds depended also on pea development stage. At the pod development stage (73/74 BBCH, the air-dry weight of weeds was significantly higher than at the third leaf stage (13/14 BBCH. The tillage system was also observed to influence the species composition of weeds. This trait was also affected by the period of weed infestation assessment. At the third leaf stage of pea (13/14 BBCH, there occurred 26 weed species, including 24 annual ones. The most abundant species included: Chenopodium album L., Stellaria media (L. Vill., Capsella bursa-pastoris (L. Med., Matricaria inodora L., Thlaspi arvense L., and Fallopia convolvulus (L. A. Löve. At the pod development stage (73/74 BBCH, the pea crop was colonized by 24 weed species, including 3 perennial ones. At this stage the predominant species included: Avena fatua L., Amaranthus retroflexus L., Papaver rhoeas L., Echinochloa crus-galli (L. P.B., Matricaria inodora L., and Galeopsis tetrahit L.

  9. Efficacy evaluation of selected herbicides on weed control and productivity evaluation of Bt cotton in Punjab.

    Science.gov (United States)

    Singh, Kulvir; Rathore, Pankaj

    2015-07-01

    Field experiments were conducted during Kharif 2012 and 2013 to evaluate the efficacy of different herbicides for weed management in cotton. Highest seed cotton yield (3537.3 kg ha(-1)) was recorded in weed free plots followed by pendimethalin @1.0 kg a.i ha(-1) as Pre.em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage + one hoeing (3318.9 kg ha") owing to improved number of bolls per plant and boll weight. Statistically least yield was recorded underweedy check (1435.4 kg ha(-1)). Application of pyrithiobac sodium could not express any visible toxic effect on crop indicating its selectivity for cotton, although none of the tested new chemicals i.e., pyrithiobac sodium@ 62.5g a.i ha(-1) and quizalofopethyl @50g a.i ha(-1) when applied alone could not outperform the existing recommended chemicals for weed management. Yield losses to the extent of 6.2-59.4% were recorded due to weed competition. Weed control efficiency (WCE) was highest under weed free check (86.8%) followed by pendimethalin @1.0 kg a.i ha(-1) as Pre. em.+quizalofopethyl @50g a.i ha(-1), at 2-4 weed leaf stage + one hoeing (73.7%), whereas minimum values were for weedy check (24.7%). Though net returns (r94660 ha(-1)) were highest for weed free check but higher B:C ratio (2:11) was observed for pendimethalin @1.0 kg a.i ha(-1) as Pre em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage+one hoeing. Therefore, for reasons such as labor shortage besides their timely availability, using these herbicides in combination with cultural practices could be the practical solution foreconomically efficient and effective weed management.

  10. Impact of an invasive weed, Parthenium hysterophorus, on a pasture community in south east Queensland, Australia.

    Science.gov (United States)

    Nguyen, Thi; Bajwa, Ali Ahsan; Belgeri, Amalia; Navie, Sheldon; O'Donnell, Chris; Adkins, Steve

    2017-12-01

    Parthenium weed is a highly invasive alien species in more than 40 countries around the world. Along with severe negative effects on human and animal health and crop production, it also causes harm to ecosystem functioning by reducing the native plant species biodiversity. However, its impacts on native plant species, especially in pasture communities, are less known. Given parthenium weed causes substantial losses to Australian pastures' productivity, it is crucial to estimate its impact on pasture communities. This study evaluates the impact of parthenium weed upon species diversity in a pasture community at Kilcoy, south east Queensland, Australia. Sub-sites containing three levels of parthenium weed density (i.e. high, low and zero) were chosen to quantify the above- and below-ground plant community structure. Species richness, diversity and evenness were all found to be significantly reduced as the density of parthenium weed increased; an effect was evident even when parthenium weed was present at relatively low densities (i.e. two plants m -2 ). This trend was observed in the summer season as well as in winter season when this annual weed was absent from the above-ground plant community. This demonstrates the strong impact that parthenium weed has upon the community composition and functioning throughout the year. It also shows the long-term impact of parthenium weed on the soil seed bank where it had displaced several native species. So, management options used for parthenium weed should also consider the reduction of parthenium weed seed bank along with controlling its above-ground populations.

  11. The influence of tillage systems, fertilization and plant protection levels on weed infestation in winter rye cultivated on light soil

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2013-12-01

    Full Text Available The purpose of this work was to determine the influence of conventional and ploughless tillage systems upon infestation in two differentiated fertilization and plant protection levels on light soil. Before harvest winter rye there was determined weed infestation of square-frame method. There were estimated weed species composition and air dry matter of weeds in two randomly selected place. Number of monocotyledonous weeds, total weeds and dry matter of weeds was higher on the objects with ploughless tillage system compared with conventional tillage. Intensive fertilization and plant protection decreased number of dicotyledonous weeds in canopy of winter rye. Conventional tillage system decreased Apera spica-venti occurrence in a canopy of winter rye and increased number of Plantago major plants. Intensive level of fertilization and plant protection decreased weed infestation first of all through Matricaria maritima.

  12. Underseeding clovers in small grains to suppress weeds in organic farming

    Science.gov (United States)

    Organic producers are seeking alternative tactics for weed control so that they can reduce their need for tillage. In this study, we examined the impact of underseeding clovers into small grains to control weeds after harvest. Also, if the clovers winterkill, then control actions would not be need...

  13. Interactions between pre- and post-emergence weed harrowing in spring cereals

    DEFF Research Database (Denmark)

    Brandsæter, L.O.; Mangerud, K.; Rasmussen, Jesper

    2012-01-01

    Pre- and post-emergence weed harrowing were studied in spring cereals in different environments and with two types of harrows in Norway during 2004–2006. The objectives were to investigate interactions between pre- and post-emergence weed harrowing and the importance of harrow type. We hypothesised...

  14. The mechanism for weed suppression by a forage radish cover crop

    Science.gov (United States)

    In the Mid-Atlantic region, forage radish (Raphanus sativus L. var. longipinnatus) winter cover crops planted prior to 1 September suppress winter annual weeds from fall until early April. Little is known about the mechanism of this weed suppression. Published research reports suggest that allelopat...

  15. Effects of mulching, staking and tillage on weed growth in yam plots ...

    African Journals Online (AJOL)

    The effects of two levels each of mulching (mulch, no mulch), staking, no stakes) and tillage (bed, mound) on weed infestation were studied in the 1994/95 and 1995/96 dry season. Data collected at the peak of yam foliation and at tuber maturity showed that mulching had no significant effect on total fresh weight of weeds.

  16. Original Paper Weeds control through tree-crop associations in a ...

    African Journals Online (AJOL)

    2012; Ludwig et al., 2004). In sum, trees in parklands agroforestry systems seem to increase weeds problem which is known as the most pest in West. African savannah agriculture. Indeed, the major cereal crops (C4 plants) are less competitive than C3 weeds species under tree. (Bayala et al., 2015). In addition, due to the.

  17. Assessing non-chemical weeding strategies through mechanistic modelling of blackgrass (Alopecurus myosuroides Huds.) dynamics

    NARCIS (Netherlands)

    Colbach, N.; Kurstjens, D.A.G.; Munier-Jolain, N.M.; Dalbiès, A.; Doré, T.

    2010-01-01

    Because of environmental and health safety issues, it is necessary to develop strategies that do not rely on herbicides to manage weeds. Introducing temporary grassland into annual crop rotations and mechanical weeding are the two main features that are frequently used in integrated and organic

  18. Upper limit for context-based crop classification in robotic weeding applications

    DEFF Research Database (Denmark)

    Midtiby, Henrik Skov; Åstrand, Björn; Jørgensen, Ole

    2016-01-01

    Knowledge of the precise position of crop plants is a prerequisite for effective mechanical weed control in robotic weeding application such as in crops like sugar beets which are sensitive to mechanical stress. Visual detection and recognition of crop plants based on their shapes has been...

  19. Effects of weed harrowing frequency on beneficial arthropods, plants and crop yield

    DEFF Research Database (Denmark)

    Navntoft, Søren; Kristensen, Kristian; Johnsen, Ib

    2016-01-01

    * Weed harrowing is an alternative to herbicides but it may have negative effects on epigaeic arthropods. We assessed the effects of frequent (four) versus two harrowings during the growing season on the density and diversity of generalist arthropods and the weed flora. Collection by flooding was...

  20. Detection of weed locations in leaf occluded cereal crops using a fully convolutional neural network

    DEFF Research Database (Denmark)

    Dyrmann, Mads; Nyholm Jørgensen, Rasmus; Midtiby, Henrik Skov

    2017-01-01

    This pap er presents a metho d for au tomating weed detectio n in colour images despite heavy lea f occlusion. A fully convolu tio n al neural network is used to detect the weed s. The netwo rk is trained and validated on a tot al of more than 17,000 ann otations of w eeds in images from wint er w...

  1. Releases of natural enemies in Hawaii since 1980 for classical biological control of weeds

    Science.gov (United States)

    P. Conant; J. N. Garcia; M. T. Johnson; W. T. Nagamine; C. K. Hirayama; G. P. Markin; R. L. Hill

    2013-01-01

    A comprehensive review of biological control of weeds in Hawaii was last published in 1992, covering 74 natural enemy species released from 1902 through 1980. The present review summarizes releases of 21 natural enemies targeting seven invasive weeds from 1981 to 2010. These projects were carried out by Hawaii Department of Agriculture (HDOA), USDA Forest Service (USFS...

  2. Pelargonic acid for weed control in organic Vidalia sweet onion production

    Science.gov (United States)

    Cultivation using a tine weeder is a proven means to manage weeds in organic Vidalia® sweet onion production. If the initial cultivation is delayed, emerged weeds are not controlled by the tine weeder. In these cases, herbicides derived from natural products could be used to control the emerged we...

  3. Colour and shape analysis techniques for weed detection in cereal fields

    DEFF Research Database (Denmark)

    Pérez, A.J; López, F; Benlloch, J.V.

    2000-01-01

    Information on weed distribution within the field is necessary to implement spatially variable herbicide application. This paper deals with the development of near-ground image capture and processing techniques in order to detect broad-leaved weeds in cereal crops under actual field conditions. T...

  4. Parasitic weed incidence and related economic losses in rice in Africa

    NARCIS (Netherlands)

    Rodenburg, Jonne; Demont, Matty; Zwart, Sander J.; Bastiaans, Lammert

    2016-01-01

    Parasitic weeds pose increasing threats to rain-fed rice production in Africa. Most important species are Striga asiatica, S. aspera and S. hermonthica in rain-fed uplands, and Rhamphicarpa fistulosa in rain-fed lowlands. Information on the regional spread and economic importance of parasitic weeds

  5. Crinivirus and begomovirus detection in tomato plantlets and weeds associated to nurseries in Cartago province

    Science.gov (United States)

    The aim of this work was to detect plant infections caused by Tomato chlorosis virus (ToCV) and begomoviruses in tomato plantlets, as well as in weeds growing around nursery greenhouses. During one year, starting in April 2008, 168 leaf tissue samples were collected, 90 tomato plantlets and 78 weed...

  6. Effects of peanut stand uniformity and herbicide regime on weed management and yield

    Science.gov (United States)

    Crop stand directly affects ability of any crop to compete with weeds. To capture this form of cultural weed control, final crop stands need to be uniform. Peanut stands are frequently non-uniform, despite the use of precision vacuum planters. Trials were conducted from 2009 through 2011 in Tifto...

  7. Mulch your tomatoes to fight weeds, retain soil moisture and save money

    Science.gov (United States)

    An on-farm experiment was conducted to determine whether different types of mulches were a cost-effective means of weed management in organic tomato production. Three mulch treatment, bare soil, straw and grass, were applied to drip-irrigated tomatoes at a depth of 7.5 cm. Weed biomass was reduced s...

  8. Effect of plant spacing and variety on weed and performance of ...

    African Journals Online (AJOL)

    Weed density and growth decreased, but sweetpotato leaf area index (LAI), fresh shoot biomass and storage root yield increased significantly (P<0.05) at the closer spacing (20 cm) than at the wider spacings (30 and 40 cm). Umuspo 1 had higher LAI and shoot biomass; and suppressed weeds more than other varieties.

  9. Host influence on germination and reproduction of the facultative hemi-parasitic weed Rhamphicarpa fistulosa

    NARCIS (Netherlands)

    Kabiri, S.; Ast, van A.; Rodenburg, J.; Bastiaans, L.

    2016-01-01

    Rice Vampireweed, Rhamphicarpa fistulosa, was a minor parasitic weed until recently when rice cultivation in sub-Saharan Africa was expanded into marginal wetlands, that are the parasite's natural habitat. Unlike most of the parasitic weeds, R. fistulosa is facultative, meaning that the parasite

  10. Identification and genome characterization of a new virus infecting the weed Sorghum almum in Florida

    Science.gov (United States)

    Sorghum almum is a common weed in the Everglades Agricultural Area in Florida where sugarcane is a major crop. This weed was recently found to be a naturally occurring host of Sugarcane yellow leaf virus and Sugarcane mosaic virus. In this study, high throughput sequencing detected additional viruse...

  11. Report on experiments on weed management in coppice - 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    Clay, D.V.; Dixon, F.L. [Avon Vegetation Research, Nailsea (United Kingdom)

    1996-11-01

    This report includes research on various aspects of effective weed control in short rotation coppices (SRCs). Programs described here have sought to establish the level of weed control required for SRCs and the best methods of achieving this aim. Crop tolerances to contact herbicides after planting and after cutting back and to residual herbicides are also investigated. (UK)

  12. Weed control and soil management systems for short-rotation coppice: present knowledge and future requirements

    Energy Technology Data Exchange (ETDEWEB)

    Clay, D.V.

    1993-06-01

    The current information available on weed management in short-rotation coppice (SRC) in the U.K. has been reviewed and aspects where more information or action is required are indicated. Weeds clearly are the main agronomic problem facing the grower of energy coppice who must achieve maximum growth from the start to achieve an economic yield of wood by the first harvest. While there is information on the importance of weed competition in the first year, the need to weed in subsequent years is less well understood and work is needed to define the situations where control is necessary. Most successful plantations have been established with the use of herbicides. There is a need for more selective contact herbicides and better equipment for applying treatments directly to the weeds. All herbicides used in coppice must have Ministry of Agriculture, Food and Fisheries (MAFF) Approval, given after consideration of toxicology and environmental fate. More such Approvals are needed to provide farmers with the range of herbicides required for efficient production. The scope for reducing herbicide input in crops in SRC is reviewed. Other practical aspects that require more attention are: the susceptibility of many weed species to commonly-used herbicides; differing coppice variety responses to weed competition and herbicides; detailed guidance for growers on weed management and control programmes. (5 tables, 50 references). (author)

  13. Molecular mechanisms responsive to dehydration may impact the invasiveness of perennial weeds under global climate change

    Science.gov (United States)

    Leafy spurge is an invasive perennial weed in the great plains of the US and Canada. The ability of this herbaceous weed to regenerate new shoot growth from an abundance of crown and root buds after severe abiotic stress is critical for survival. Due to its adaptable and aggressive nature, global cl...

  14. Impacts of Organic Zero Tillage Systems on Crops, Weeds, and Soil Quality

    Directory of Open Access Journals (Sweden)

    Patrick M. Carr

    2013-07-01

    Full Text Available Organic farming has been identified as promoting soil quality even though tillage is used for weed suppression. Adopting zero tillage and other conservation tillage practices can enhance soil quality in cropping systems where synthetic agri-chemicals are relied on for crop nutrition and weed control. Attempts have been made to eliminate tillage completely when growing several field crops organically. Vegetative mulch produced by killed cover crops in organic zero tillage systems can suppress annual weeds, but large amounts are needed for adequate early season weed control. Established perennial weeds are not controlled by cover crop mulch. Integrated weed management strategies that include other cultural as well as biological and mechanical controls have potential and need to be incorporated into organic zero tillage research efforts. Market crop performance in organic zero tillage systems has been mixed because of weed, nutrient cycling, and other problems that still must be solved. Soil quality benefits have been demonstrated in comparisons between organic conservation tillage and inversion tillage systems, but studies that include zero tillage treatments are lacking. Research is needed which identifies agronomic strategies for optimum market crop performance, acceptable levels of weed suppression, and soil quality benefits following adoption of organic zero tillage.

  15. Annual losses of weed seeds due to predation in organic cereal fields

    NARCIS (Netherlands)

    Westerman, P.R.; Wes, J.S.; Kropff, M.J.; Werf, van der W.

    2003-01-01

    1. Post-dispersal seed losses in annual arable weed species are poorly quantified, but may be of significance for natural population control, especially if they can be manipulated. We hypothesized that weed seed predation on the soil surface was significant, so we measured rates in the field to

  16. Suppressing weed growth after wheat harvest with underseeded red clover in organic farming

    Science.gov (United States)

    Organic producers are seeking alternative tactics for weed control so that they can reduce their need for tillage. In this study, we examined cover crop strategies for suppressing weed growth after harvest of wheat. Two cover crop treatments, red clover (mammoth type) or a mixture of oat and dry p...

  17. Weeds as agricultural constraint in Benin: results of a diagnostic study

    NARCIS (Netherlands)

    Vissoh, P.V.; Gbèhounou, G.; Ahanchedé, A.; Kuyper, T.W.; Röling, N.G.

    2004-01-01

    Weeds are an emerging constraint on crop production, as a result of population pressure and more intensive use of cultivated land. A diagnostic study was carried out from June through August 2002 in the five agro-ecological zones of Benin (1) to identify the relative importance of weeds among major

  18. 75 FR 23151 - Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper

    Science.gov (United States)

    2010-05-03

    ... Inspection Service 7 CFR Parts 360 and 361 Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper... noxious weed regulations by adding Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown... Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown) and maidenhair creeper (Lygodium...

  19. Applying molecular-based approaches to classical biological control of weeds

    Science.gov (United States)

    Modern advances in molecular techniques are only recently being incorporated into programs for the classical biological control of weeds. Molecular analyses are able to elucidate information about target weeds that is critical to improving control success, such as taxonomic clarification, evidence o...

  20. Allelopathic effects of sunnhemp (Crotalaria juncea L.) on germination of vegetables and weeds

    Science.gov (United States)

    Sunnhemp (Crotalaria juncea L.) is a tropical legume that could be an important summer cover crop in the Southeastern U.S., but it has the potential for suppressing both crops and weeds. Allelopathic effects of sunnhemp on weeds, vegetable crops, and cover crops were evaluated in growth chamber an...

  1. Weed Control Strategies for Organic Peanut Production and Transition: A Lesson in Basic Agronomy

    Science.gov (United States)

    Weed control in organic peanut production is difficult and costly. The only production inputs that consistently improved weed management in organic peanut production were modified production practices and intense cultivation with a tine weeder. Research trials evaluated row patterns, seeding rates...

  2. Evaluation of tillage, cover crop, and herbicide effects on weed control, yield, and grade in peanut

    Science.gov (United States)

    Peanut production plays a large role in agriculture in the Southeastern United States. Weeds are detrimental to their production because of the competition that they create; weeds will compete with crops for resources such as nutrients and sunlight, among others. Therefore, it is important to reduce...

  3. Weed flora of cassava in west Nile zones of Uganda | Kawooya ...

    African Journals Online (AJOL)

    Information on weeds of cassava (Manihot esculenta Crantz) in eastern Africa is limited. The objective of this study was to establish the status of weed flora in selected cassava growing regions of Uganda. This study was conducted in 2013 at Abi Zonal Agricultural Research and Development Institute; (AbiZARDI) in Arua, ...

  4. Quantifying the effect of crop spatial arrangement on weed suppression using functional-structural plant modelling

    NARCIS (Netherlands)

    Evers, Jochem B.; Bastiaans, Lammert

    2016-01-01

    Suppression of weed growth in a crop canopy can be enhanced by improving crop competitiveness. One way to achieve this is by modifying the crop planting pattern. In this study, we addressed the question to what extent a uniform planting pattern increases the ability of a crop to compete with weed

  5. Weed flora of University of Benin in terms of diversity and richness ...

    African Journals Online (AJOL)

    Weeds are as important as man to himself and its environment. Weed flora in terms of diversity and richness of University of Benin, Ugbowo campus were determined from four habitable parts using two ecological models: Margalef species richness (d) and Shannon-Wiener diversity (H). Primary data were collected from an ...

  6. Weed management at ArborGen, South Carolina SuperTree Nursery

    Science.gov (United States)

    Mike Arnette

    2009-01-01

    Weed management is vital to producing healthy hardwood seedlings. Several methods are available to each nursery, and it is common knowledge that what works for one situation may not work for another. The weed control methods used in nursery beds of hardwood species at the South Carolina SuperTree Nursery (Blenheim) are listed below.

  7. Detection of corn and weed species by the combination of spectral, shape and textural features

    Science.gov (United States)

    Accurate detection of weeds in farmland can help reduce pesticide use and protect the agricultural environment. To develop intelligent equipment for weed detection, this study used an imaging spectrometer system, which supports micro-scale plant feature analysis by acquiring high-resolution hyper sp...

  8. Impact of mustard seed meal applications on direct-seeded cucurbits and weed control

    Science.gov (United States)

    Weed control in organic production systems can be a labor intensive and expensive process. Mustard seed meal (MSM) is phytotoxic and a potential pre-emergent and preplant-incorporated organic herbicide for controlling germinating and emerging weed seedlings: unfortunately, MSM may also adversely imp...

  9. Stooped postures are modified by pretask walking in a simulated weed-pulling task.

    Science.gov (United States)

    Hudson, D S; Copeland, J L; Hepburn, C G; Doan, J B

    2014-01-01

    Seasonal agricultural workers are hired in some sectors for intermittent manual weed removal, a stoop and grasp harvesting task likely similar to those associated with the high prevalence of musculoskeletal disorders in agriculture. Evaluation of this task in an experimental situation would be useful for identifying and controlling musculoskeletal injury risks, presuming a valid experimental model of the task can be created. The purpose of the present study was to examine how a relevant work-related task, namely prolonged walking, altered the biomechanics of manual weed removal in a laboratory setting. Preliminary field assessments informed the development and analysis of a simulated manual weed removal with two separate conditions: not primed, where 11 participants (4 female, mean age 21.6 years) manually removed a simulated weed six times, and primed, where 23 participants (13 female, mean age 22.1 years) walked 1600 m prior to manually removing the same simulated weed six successive times. Segment end point markers and experimental motion capture were used to determine hip, knee, and ankle angles, as well as toe-target proximity, during weed removal. Significant differences between primed and not primed participants were found for angular displacement at the ankle (t(32) = 5.08, P weed, leading to decreased trunk flexion during the harvesting task. These findings suggest that priming can positively influence whole-body postures for manual weed removal.

  10. Response of rice genotypes to weed competition in dry direct-seeded rice in India.

    Science.gov (United States)

    Mahajan, Gulshan; Ramesha, Mugalodi S; Chauhan, Bhagirath S

    2014-01-01

    The differential weed-competitive abilities of eight rice genotypes and the traits that may confer such attributes were investigated under partial weedy and weed-free conditions in naturally occurring weed flora in dry direct-seeded rice during the rainy seasons of 2011 and 2012 at Ludhiana, Punjab, India. The results showed genotypic differences in competitiveness against weeds. In weed-free plots, grain yield varied from 6.6 to 8.9 t ha(-1) across different genotypes; it was lowest for PR-115 and highest for the hybrid H-97158. In partial weedy plots, grain yield and weed biomass at flowering varied from 3.6 to 6.7 t ha(-1) and from 174 to 419 g m(-2), respectively. In partial weedy plots, grain yield was lowest for PR-115 and highest for PR-120. Average yield loss due to weed competition ranged from 21 to 46% in different rice genotypes. The study showed that early canopy closure, high leaf area index at early stage, and high root biomass and volume correlated positively with competitiveness. This study suggests that some traits (root biomass, leaf area index, and shoot biomass at the early stage) could play an important role in conferring weed competitiveness and these traits can be explored for dry-seeded rice.

  11. Density and dry weight of pigweed by various weed control methods ...

    African Journals Online (AJOL)

    This study evaluates effects of various weeds control methods and nitrogen fertilizer resources on density and dry weight of pigweed and the performance of corn forage as factorial in full random block design with 3 repetitions in research farm of Ferdowsi Mashhad University in 2014. The test treatments include weed ...

  12. Evaluation of Weed IT model 2006 MKII: spray volume and dose response tests

    NARCIS (Netherlands)

    Kempenaar, C.; Groeneveld, R.M.W.; Uffing, A.J.M.

    2006-01-01

    Common weed control methods on pavements are chemical control (herbicides), brushing, flaming, mowing and hot water treatment. Managers of pavements often choose for herbicide weed control on pavements because this method is most cost-effective and most easy to use. Four out of five municipalities

  13. Use of rhizobacteria and endophytes for biological control of weeds

    Directory of Open Access Journals (Sweden)

    Trognitz, Friederike

    2014-02-01

    Full Text Available Weeds cause severe yield losses in agriculture, with a maximum estimate of 34% of yield loss worldwide due to competition between the crops and the weeds for nutrition, light and humidity (OERKE, 2006. Invasive plants contribute partially to other problems. The pollen of common ragweed, Ambrosia artemisiifolia L., for example, is five times more allergenic than grass pollen; already ten pollen grains per m3 air can trigger allergy in sensitized patients, including rhinitis, conjunctivitis and asthma. This neophyte from America has extended the season of allergy in European patients to October. Common ragweed is currently most frequent in Hungary, France and Italy. In Austria, ragweed populations along roads have increased dramatically since 2000. The effective means to control this weed of the Asteraceae family are limited; a single plant can produce up to 6000 seeds which stay in the soil for 40 years. Control using selective herbicides is not possible within stands of the Asteraceae member sunflower. Efforts to use herbivore insects as biological control agents also failed due to the unavailability of insects specializing on this ragweed. The use of plant-associated rhizobacteria and endophytes as bio-herbicides offers a novel alternative to conventional methods. By analogy to experiences from other plant-microbe systems, the chances to find microbes of the desired characteristics are highest when isolating and testing specimens directly from ragweed plants. These organisms often have an extremely narrow host range that permits their use for the control of among several even closely related plant species growing together in a field.

  14. THE EFFECT OF SOWING TIME, TILLAGE SYSTEM AND HERBICIDES ON WEED SPECIES DENSITY, WEED BIOMASS AND YIELD OF LENTIL WITHIN A LENTIL-WHEAT SEQUENCE

    National Research Council Canada - National Science Library

    Songül Gürsoy; Cumali Özaslan; Murat Urgun; Betül Kolay; Murat Koç

    2014-01-01

    ... growing season to evaluate the effect of various forms of tillage and herbicides, and the timing of such operations on weed density and lentil (Lens culinaris, L) yield after wheat (Triticum aestivum L...

  15. Real-time weed detection, decision making and patch spraying in maize, sugarbeet, winter wheat and winter barley

    DEFF Research Database (Denmark)

    Gerhards, R; Christensen, Svend

    2003-01-01

    with weed infestation levels higher than the economic weed threshold; a review of such work is provided. This paper presents a system for site-specific weed control in sugarbeet (Beta vulgaris L.), maize (Zea mays L.), winter wheat (Triticum aestivum L.) and winter barley (Hordeum vulgare L.), including...

  16. [Effects of different fertilization regimes on weed communities in wheat fields under rice-wheat cropping system].

    Science.gov (United States)

    Yuan, Fang; Li, Yong; Li, Fen-hua; Sun, Guo-jun; Han, Min; Zhang, Hai-yan; Ji, Zhong; Wu, Chen-yu

    2016-01-01

    To reveal the effects of different fertilization regimes on weed communities in wheat fields under a rice-wheat rotation system, a survey was conducted before wheat harvest in 2014 after a 4-year long-term recurrent fertilization scheme. Weed species types, density, height and diversity index under different fertilization and straw-returning schemes in wheat fields were studied and complemented with a canonical correspondence analysis on weed community distribution and soil nutrient factors. Twenty weed species were recorded among 36 wheat fields belonging to 19 genera and 11 families. Beckmannia syzigachne, Hemistepta lyrata, Malachium aquaticum and Cnidium monnieri were widely distributed throughout the sampled area. Long-term fertilization appeared to reduce weed species richness and density, particularly for broadleaf weeds, but increased weed height. Diversity and evenness indices of weed communities were lower and dominance indices were higher in fields where chemical fertilizers were applied alone or combined with organic fertilizers, especially, where organic-inorganic compound fertilizer was used, in which it readily caused the outbreak of a dominant species and severe damage. Conversely, diversity and evenness indices of weed communities were higher and dominance indices were lower when the straw was returned to the field combined with chemical or organic fertilizers, in which weed community structures were complex and stable with lower weed density. Under these conditions weeds only caused slight reduction of wheat growth.

  17. 76 FR 43706 - Final Supplementary Rules To Require the Use of Certified Noxious-Weed-Free Forage and Straw on...

    Science.gov (United States)

    2011-07-21

    ... Bureau of Land Management Final Supplementary Rules To Require the Use of Certified Noxious-Weed-Free... straw on BLM-administered land in Idaho to use certified noxious-weed-free forage and straw. Restoration, rehabilitation, and stabilization projects also will be required to use weed-free straw bales and mulch for...

  18. 75 FR 57496 - Notice of Proposed Supplementary Rule To Require the Use of Certified Noxious-Weed-Free Forage...

    Science.gov (United States)

    2010-09-21

    ...-Weed-Free Forage and Straw on Bureau of Land Management Lands in the State of Idaho AGENCY: Bureau of... certified noxious-weed-free forage and straw. Restoration, rehabilitation, and stabilization projects also will be required to use weed-free straw bales and mulch for project work. This action is a cooperative...

  19. Establishment and Early Growth of Willow at Different Levels of Weed Competition and Nitrogen Fertilization

    DEFF Research Database (Denmark)

    Edelfeldt, Stina; Lundkvist, Anneli; Forkman, Johannes

    2016-01-01

    To evaluate the effects of weed competition and nitrogen fertilization on the early growth performance of willow, cuttings of the clone Tora (Salix schwerinii x S. viminalis) were planted in buckets together with model weeds (spring barley or white mustard) sown 15, 26, and 30 days after willow...... planting. The buckets were fertilized with 30 or 90 kg N ha−1. Willow with weeds sown after 15 days produced less biomass and smaller leaf area and had a lower maximum shoot height compared to willow planted without weeds and willow with weeds sown after 26 or 30 days. Fertilization with 90 kg N ha−1......, fertilization should be delayed....

  20. Weed flora in dill (Anethum graveolens L., Apiaceae, Apiales grown in conventional and organic production systems

    Directory of Open Access Journals (Sweden)

    Ljevnaić-Mašić Branka

    2015-01-01

    Full Text Available This study was performed to compare the weed flora in dill crops maintained conventionally and according to the principles of organic production. Out of 17 weed species noted for the two growing systems, even four (Amaranthus retroflexus L., Datura stramonium L., Sorghum halepense (L. Pers., and Veronica persica Poir. are invasive in Vojvodina region (Serbia. Weed infestation (number of individuals per m2 was significantly higher on the conventional plots (p = 0.0000**. The dominating species in conventional growing system were Convolvulus arvensis, Veronica persica and Chenopodium album (8.00, 6.67 and 5.33 individuals per m2, respectively, while Amaranthus retroflexus dominated on organic plots (8.00 individuals per m2. Regarding life forms of the recorded weed flora, therophytes dominate both in conventional (92.31% and organic (66.67% systems. The observed differences in weed flora are due to the specificities of dill conventional and organic production.