Two experiments were conducted, one in the field and the other in the greenhouse, to investigate the effects of the intensity and frequency of grass defoliation on the survival and growth of Acacia karroo seedlings. In the greenhouse, seedlings growing with heavily clipped grasses had higher biomass production than those ...
Burt R. McConnell; Justin G. Smith
Hard fescue survival rates were followed for 6 years on four different pine needle treatment plots. Needle litter had a significant effect on initial survival of fescue seedlings, but subsequent losses undoubtedly resulted from the interaction of many factors.
Hilary Parkinson; Cathy Zabinski; Nancy Shaw
Re-establishing native communities that resist exotic weed invasion and provide diverse habitat for wildlife are high priorities for restoration in sagebrush ecosystems. Native forbs are an important component of healthy rangelands in this system, but they are rarely included in seedings. Understanding competitive interactions between forb and grass seedlings is...
Engeman, Richard M.; Barnes, V.G.; Anthony, R.M.; Krupa, Heather W.
2,4-D herbicide treatment was applied to 2 treatment units to remove the forbs that are the preferred food of pocket gophers. One of these units also was seeded with grasses prior to the 2,4-D treatment. The effect of 2,4-D and grass seeding plus 2,4-D treatments were compared to an untreated control unit. Long-term monitoring (7 yr) was conducted on the 3 units for vegetative cover (7 yr), pocket gopher activity, and individual survival times and time until gopher damage for 2 cohorts of seedlings (5 and 6 yrs). The 2,4-D treatments greatly reduced vegetative cover of the forbs and seeding increased grass cover on the unit receiving that treatment. Pocket gopher activity was reduced somewhat on the unit receiving only the 2,4-D treatment and more so on the unit receiving grass seeding and 2,4-D, although gophers remained active to some degree throughout the study. Both cohorts of seedlings for both treatments units showed greater average times until gopher damage over seedlings on the control unit. However, seedling survival from all sources of mortality was not positively affected by the treatments for the first cohort of seedlings. The 2,4-D treatment appeared to have killed some of the seedlings; however, seedlings that survived the treatment were in a situation where they were less likely to be damaged by gophers and seemed to have improved growth rates.
Priadi, Dody; Arfani, Agus; Saskiawan, Iwan; Mulyaningsih, Enung Sri
The objective of this study was to investigate the response of local tomato (Lycopersicon esculentum Miller) seedlings growth on media containing grass and spent mushroom compost in the nursery. The grass compost (GC) was produced by Research Center for Biotechnology-LIPI. Whereas the spent oyster mushroom (Pleurotus ostreatus) compost (OC) and spent paddy straw mushroom (Volvariella volvacea) compost (PC) were produced by Research Center for Biology-LIPI. Growing media of tomato seedling was...
Full Text Available Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense, big bluestem (Andropogon gerardii, little bluestem (Schizachyrium scoparius and switchgrass (Panicum virgatum. We predicted that a the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b competitive effect and response would be negatively correlated and c soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass < big bluestem < little bluestem/switchgrass, while Johnsongrass responded more strongly to competition from Johnsongrass than from native species. At final harvest, native plants growing with Johnsongrass attained between 2-5% of their single-plant non-root biomass, while Johnsongrass growing with native species attained 89% of single-plant non-root biomass. Fertilization enhanced Johnsongrass' competitive effects on native species, but added little to the already severe competitive suppression. Accelerated early growth of Johnsongrass seedlings relative to native seedlings appeared to enable subsequent resource pre-emption. Size-asymmetric competition and resource
Full Text Available The increasing rate of woody plant encroachment in grasslands or savannas remains a challenge to livestock farmers. The causes and control measures of woody plant encroachment are of common interest, especially where it negatively affects the objectives of an agricultural enterprise. The objectives of this study were to determine the effects of gut passage (goats, cattle, dung (nutrients, fire, grass competition and trampling on establishment of A. nilotica and D. cinerea seedlings. Germination trials were subjected to the following treatments: 1 seed passage through the gut of cattle and goats and unpassed/ untreated seeds (i.e. not ingested, 2 dung and control (no dung, 3 grass and control (mowed grass, 4 fire and control (no fire, 5 trampling and control (no trampling. The interaction of animal species, grass and fire had an effect on seedling recruitment (P < 0.0052. Seeds retrieved from goats and planted with no grass and with fire (6.81% ± 0.33 had a significant effect on seedling recruitment than seeds retrieved from goats and planted with grass and no fire (2.98% ± 0.33. Significantly more D. cinerea and A. nilotica seeds germinated following seed ingestion by goats (3.59% ± 0.16 than cattle (1.93% ± 0.09 and control or untreated seeds (1.69% ± 0.11. Less dense grass cover, which resulted in reduced grass competition with tree seedlings for light, space and water, and improved seed scarification due to gut passage were vital for emergence and recruitment of Acacia seedlings. These results will contribute considerably to the understanding of the recruitment phase of woody plant encroachment.
Liu, Juan; Wang, Quanzhen; Karagić, Đura; Liu, Xv; Cui, Jian; Gui, Jing; Gu, Muyu; Gao, Wei
The effects of ultrasonic treatments on the germination and seedling growth of aged tall fescue (Festuca arundinacea) and Russian wild rye (Psathyrostaehys juncea Nevski) seeds were determined using orthogonal matrix experimental design with four ultrasonic factors. The multivariate analysis of variance detected significant differences and coupling effects of the pair-wise factors. The activities of Superoxide Dismutase (SOD) and Peroxidase (POD) and the Malondialdehyde (MDA) content were affected. The ultrasonic treatments had positive effects on the germination percentage (GP) of the aged seeds and the growth of the seedlings (GS) and therefore we provided a basic evidence for the application of ultrasonic treatment to pretreat aged grass seeds. For the four ultrasonic factors, the optimal conditions were a sonication time of 36.7 min, a sonication temperature of 35 °C, an output power of 367 W and a seed soaking time 4.1 h after binary quadratic regressions analyses. The ultrasonic treatment has the potential to improve seedling growth. Moreover, the longevity of the tall fescue and the Russian wild rye seeds was approximately 9.5 and 11.5 years, respectively, under natural conditions of storage. The physiological mechanisms that might contribute to the improved GP and GS were discussed.
1. Seeding native plants is a key management practice to counter land degradation across the globe, yet the majority of seeding efforts fail, limiting the ability of this tool to accelerate ecosystem recovery. 2. Seedling recruitment requires transitions through several life stages, some of which ma...
Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.
Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusariumblights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonassp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production
Elgersma, A.; Schlepers, H.
The aim was to study the effects of white clover cultivar and combinations with perennial ryegrass cultivars on seedling establishment in autumn-sown swards and on winter survival of seedlings. Large-leaved white clover cv. Alice and small-leaved white clover cv. Gwenda, and an erect and a prostrate
Jared M. Thaxton; Susan Cordell; Robert J. Cabin; Darren R. Sandquist
Invasive non-native species can create especially problematic restoration barriers in subtropical and tropical dry forests. Native dry forests in Hawaii presently cover less than 10% of their original area. Many sites that historically supported dry forest are now completely dominated by non-native species, particularly grasses. Within a grass-dominated site in leeward...
T. H. Filer
Hydrogen cyanide caused root damage to Poa pratensis, Festuca rubra, and Agrostis tenuis when the grasses were suspended 7 days above a 28-day-old viable culture Marasmius oreades (Bolt. ) Fr. The amount of HCN produced by this culture (Washington isolate 1) averaged 49 ppm per 24 hours collected in 5 ml of...
Full Text Available La diversificación de alimentos es una estrategia para abordar problemas nutricionales. Producir alimentos de consumo masivo incorporando harinas regionales sería una opción para obtener alimentos de valor nutritivo optimizado. El objetivo de este trabajo fue desarrollar galletas de calidad nutricional mejorada, para escolares, con mezclas de harinas de trigo, de algarroba y avena. Se determinó la composición proximal y Ca, Fe, Mg, P, K y Zn en harina de algarroba con metodología AOAC y disponibilidad potencial in vitro para Ca, Fe y Zn. Se evaluó la calidad proteica teórica de distintas mezclas por el método del Puntaje Químico, previa corrección por digestibilidad, utilizando como proteína de referencia los requerimientos del patrón FAO. Se diseñaron galletas con 3 mezclas porcentuales: harina de trigo:harina de algarroba 70:30 y 80:20, harina de trigo:harina de algarroba:avena 80:10:10 y un testigo con 100 % harina de trigo. Se determinaron composición proximal, contenido y disponibilidad potencial de Ca, Fe y Zn. Se midieron parámetros tecnológicos en masas y galletas (color y factor de expansión. Las galletas se evaluaron sensorialmente con 35 consumidores, usando escala hedónica de 9 puntos. El Puntaje Químico aumentó ≈ el 25 % en la mezcla 70:30, 19 % en la 80:20 y 28 % para la 80:10:10 respecto del aminoácido lisina en harina de trigo. La corrección por digestibilidad, posicionó con mejor calidad proteica a la mezcla 80:10:10. El diámetro de las galletas aumentó con la disminución del espesor. El balance entre criterios nutricionales y tecnológicos favoreció la elección de las galletas 80:20 y 80:10:10. Son fuente de fibra y minerales. En pruebas sensoriales, las galletas obtuvieron puntaje superior a 6, siendo la más aceptada la 80:10:10. Es tecnológicamente posible sustituir un 20 % de harina de trigo por los ingredientes propuestos obteniéndose galletas nutricionalmente mejoradas y aceptables para
Increased wildfires in the western U.S. are due to the cyclic accumulation and burning of invasive annual plants such as cheatgrass (Bromus tectorum) and red brome (B. rubens), which reduces native rangeland species and results in servere economic losses and land degradation. Fire was not prevalent...
Increased wildfires in the western U.S. are due to the cyclic accumulation and burning of invasive annual plants such as cheatgrass (Bromus tectorum) and red brome (B. rubens), which reduces native rangeland species and results in severe economic losses and land degradation. Fire was not prevalent ...
Andrés Felipe Cerón Cardenas
Full Text Available La papa (Solanum tuberosum se considera el cuarto cultivo más importante en el mundo y su consumo ha pasado de producto fresco a producto laborado en forma industrial. En el estudio se determinó el nivel máximo de sustitución de la harina de trigo por harina de papa de la variedad Parda Pastusa en la elaboración de galletas fermentadas dulces. Se utilizó un diseño completamente al azar, donde el factor de estudio fueron el nivel de sustitución, 0%, 30%, 40% y 50%, y las variables de respuesta: sensoriales (color, sabor, textura y aceptabilidad y químicas proximales (materia seca, proteína, ceniza y grasa. No se encontraron diferencias (P < 0.05 en color, textura y aceptación; mientras para la variable sabor fue diferente en los niveles 0% y 30% de sustitución. Para los niveles de sustitución se encontraron, respectivamente, reducciones en contenido de proteína en 7.42%, 17.40% y 23.62%, y de grasa en 25.65%, 42.59% y 55.87%; mientras que la materia seca aumentó 3.83%, 4.95% y 5.62% y el contenido de ceniza en 13.14%, 17.71% y 23.43%, respectivamente. Con la sustitución de 30% se produjeron galletas de buena aceptación mientras que niveles mayores no son recomendables.
Shim, Jaehong; Babu, A Giridhar; Velmurugan, Palanivel; Shea, Patrick J; Oh, Byung-Taek
A bacterial strain (JH 70-4) exhibiting plant growth promoting characteristics (indoleacetic acid production and 1-aminocyclopropane-1-carboxylate deaminase activity), as well as heavy metal(loid) (HM) tolerance and Pb precipitation, was isolated from HM-contaminated soil at an abandoned mine site. The bacterium was identified as Pseudomonas fluorescens based on 16S rDNA sequencing. The JH 70-4 strain induced precipitation of Pb as PbS nanoparticles, confirmed by X-ray diffraction. Solution pH, incubation time, and Pb concentration influenced removal and PbS formation. Inoculating contaminated soil with JH 70-4 decreased Pb availability; exchangeable Pb decreased while organic- and sulphide-bound Pb increased. The toxicity characteristic leaching procedure showed a 65% decrease in Pb in leachate 60 d after inoculating soil with JH 70-4. Shoot and root lengths of Sudan grass grown in the inoculated soil were greater than in the uninoculated soil. Findings suggest that microbial Pb fixation is a viable strategy for remediating soil and promoting plant growth for phytostabilization of contaminated sites.
Casal, J.J.; Clough, R.C.; Vierstra, R.D.
The occurrence of phytochrome-mediated high irradiance responses (HIR), previously characterised largely in dicotyledonous plants, was investigated in Triticum aestivum L., Zea mays L., Lolium multiflorum Lam. and in both wild-type Oryza sativa L. and in transgenic plants overexpressing oat phytochrome A under the control of a 35S promoter. Coleoptile growth was promoted (maize, ryegrass) or inhibited (wild-type rice) by continuous far-red light (FRc). However, at equal fluences, hourly pulses of far-red light (FRp) were equally effective, indicating that the growth responses to FRc were not true HIR. In contrast, in maize and rice, FRc increased anthocyanin content in the coleoptile in a fluence-rate dependent manner. This response was a true HIR as FRp had reduced effects. In maize, anthocyanin levels were significantly higher under FRc than under continuous red light. In rice, overexpression of phytochrome A increased the inhibition of coleoptile growth and the levels of anthocyanin under FRc but not under FRp or under continuous red light. The effect of FRc was fluence-rate dependent. In light-grown rice, overexpression of phytochrome A reduced leaf-sheath length, impaired the response to supplementary far-red light, but did not affect the response to canopy shade-light. In grasses, typical HIR, i.e. fluence-rate dependent responses showing reciprocity failure, can be induced by FRc. Under FRc, overexpressed phytochrome A operates through this action mode in transgenic rice. (author)
Auris Damely García Méndez
Full Text Available Para diversificar el uso de la harina de arracacha (Arracacia xanthorrhiza, se evaluó su potencialidad en la elaboración de una galleta tipo wafer con propiedades nutricionales, partiendo de una harina compuesta de trigo con 10 y 12% de harina de arracacha. La metodología permitió determinar en la galletas las características físicas (humedad, actividad de agua, pH y color, composición química proximal, funcionales (capacidad de absorción de agua y aceite de la masa y la estabilidad comercial por tres meses almacenamiento. Los resultados mostraron que la harina compuesta, contribuyó a un ligero incremento en la fracciones de fibra, ceniza y almidón resistente en las galletas. Mientras, las propiedades funcionales de la mezcla para elaborar las galletas indicaron una adecuada interacción de los ingredientes, alta absorción de agua, pero una menor capacidad de absorción de aceite en la masa, originando cambios en la textura de la galleta horneada al compararla con la galleta de trigo. En anaquel, se mantuvieron las características fisicoquímicas de la galletas, coincidiendo con las especificaciones de la normas Covenin (Comisión Venezolana de Normas Industriales nº 1483-2001, siendo esto atribuido al bajo contenido de humedad y actividad de agua. En conclusión, el uso de la harina de arracacha en una relación de 12%, resultó un ingrediente adecuado en la elaboración de galletas con alta preferencia sensorial, constituyendo una alternativa como fuente de fibra dietética.In order to diversify the use of arracacha flour (Arracacia xanthorrhiza, an evaluation was made upon its potentiality, in the manufacture of a wafer type sweet cookie, with nutritional properties; starting from a composite flour of wheat and 10-12% of arracacha flour. The methodology allowed to evaluate physical characteristics (humidity, water activity, pH and color, proximal chemical composition, functional characteristics (water and oil absorption capacity
The invasive coloniser Ipomoea hildebrandtii aggravates the problem of inadequate grass forage in Kajiado district, Kenya. To test its impact on grass biomass, nitrogen (N) mineralisation and seedling establishment, grazing and coloniser density were controlled using experimental exclosures and weeding treatments ...
Development of vegetation from seed requires a seed bank, germination, emergence and subsequent seedling survival. Reports on the influence of a number of practicably feasible treatments to the vegetation and soil on emergence and survival of grass seedlings in the Southern Tall Grassveld of Natal. Illustrates with ...
Apr 6, 2009 ... in Australia (Hayman, 1960) and is often used as a forage species for domestic and wild animals. It is also found in some parts of Africa, Asia and the Pacific. It commonly grows in grassland and opens woodland communities. Kangaroo grass is a tufted perennial that can grow up to 1.5 m tall and 0.5 m ...
Darin J. Law; Peter F. Kolb
Soil surface conditions can have profound effects on plant seedling emergence and subsequent seedling survival. To test the hypothesis that different soil-surface treatments with logging residue affect range grass seedling emergence and survival, 6 alternative forest-residual treatments were established in the summer of 1998 following thinning of mature trees from...
Akin, Danny E.
Grass lignocelluloses are limited in bioconversion by aromatic constituents, which include both lignins and phenolic acids esters. Histochemistry, ultraviolet absorption microspectrophotometry, and response to microorganisms and specific enzymes have been used to determine the significance of aromatics toward recalcitrance. Coniferyl lignin appears to be the most effective limitation to biodegradation, existing in xylem cells of vascular tissues; cell walls with syringyl lignin, for example, leaf sclerenchyma, are less recalcitrant. Esterified phenolic acids, i.e., ferulic and p-coumaric acids, often constitute a major chemical limitation in nonlignified cell walls to biodegradation in grasses, especially warm-season species. Methods to improve biodegradability through modification of aromatics include: plant breeding, use of lignin-degrading white-rot fungi, and addition of esterases. Plant breeding for new cultivars has been especially effective for nutritionally improved forages, for example, bermudagrasses. In laboratory studies, selective white-rot fungi that lack cellulases delignified the lignocellulosic materials and improved fermentation of residual carbohydrates. Phenolic acid esterases released p-coumaric and ferulic acids for potential coproducts, improved the available sugars for fermentation, and improved biodegradation. The separation and removal of the aromatic components for coproducts, while enhancing the availability of sugars for bioconversion, could improve the economics of bioconversion.
Full Text Available Even highly mutually beneficial microbial-plant interactions, such as mycorrhizal- and rhizobial-plant exchanges, involve selfishness, cheating and power-struggles between the partners, which depending on prevailing selective pressures, lead to a continuum of interactions from antagonistic to mutualistic. Using manipulated grass-endophyte combinations in a five year common garden experiment, we show that grass genotypes and genetic mismatches constrain genetic combinations between the vertically (via host seeds transmitted endophytes and the out-crossing host, thereby reducing infections in established grass populations. Infections were lost in both grass tillers and seedlings in F(1 and F(2 generations, respectively. Experimental plants were collected as seeds from two different environments, i.e., meadows and nearby riverbanks. Endophyte-related benefits to the host included an increased number of inflorescences, but only in meadow plants and not until the last growing season of the experiment. Our results illustrate the importance of genetic host specificity and trans-generational maternal effects on the genetic structure of a host population, which act as destabilizing forces in endophyte-grass symbioses. We propose that (1 genetic mismatches may act as a buffering mechanism against highly competitive endophyte-grass genotype combinations threatening the biodiversity of grassland communities and (2 these mismatches should be acknowledged, particularly in breeding programmes aimed at harnessing systemic and heritable endophytes to improve the agriculturally valuable characteristics of cultivars.
Chirara, C. (Chipangura)
In this thesis Chirara reports on his study on the competitive interaction between savanna grasses and young tree seedlings of Acacia karroo, from hereon indicated as ' Acacia seedlings' . Acacia is one of the tree species that dominates savanna grassland in situations of overgrazing (bush
Diane L. Haase
Roots are critical to seedling performance after outplanting. Although root quality is not as quick and simple to measure as shoot quality, target root characteristics should be included in any seedling quality assessment program. This paper provides a brief review of root characteristics most commonly targeted for operational seedling production. These are: root mass...
Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F
The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development. © 2017 The Society for Applied Microbiology.
This study was conducted to investigate the ability of nine low-maintenance species to establish and persist with Coastal bermuda grass (Cynodon dactylon (L.) Pers.) established on reclaimed lignite overburden; to evaluate the establishment and persistence of seventeen low-maintenance species seeded in overburden with no vegetation cover; and to examine seeding mixtures and rates for establishing low-maintenance species into three cover types (bermuda grass, oats, (Avena fatua L.) and no cover). Seventeen low-maintenance species established and persisted in overburden without fertilization during years of low precipitation. Several seeded grasses showed sufficient stand development in monoculture for erosion control. Most of the other seeded species were slower in establishment, yet persisted on the site and promoted multiple use of the reclaimed area. Recommended seeding rates were generally adequate for seedling establishment in oat, bermuda grass, and no vegetation cover types. Sod-seeding into bermuda grass resulted in higher seedling densities than those in oats and no cover because of stored moisture beneath the sod during bermuda grass dormancy. Using /sup 15/N-labelled fertilizer, Coastal bermuda grass demonstrated the ability to rapidly recovery applied N. Maximilian sunflower (Helianthus maximiliani Schrad.) was suppressed by Coastal bermuda grass in mixture at all fertilizer N rates.
Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease. (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.
Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.
U.S. Environmental Protection Agency — Eastern redcedar tree seedling growth in response to various soil, nitrogen, and photosynthetic radiation characteristics. This dataset is associated with the...
The suitability of 11 species was tested for planting on degraded land at Kogilemane in Belur Taluk, Karnataka. The soil was alkaline with no humus, litter or topsoil. The original vegetation was grass with the stemless palm Phoenix acaulis, still present at 600 plants per acre. Seedlings 4-6 months old and raised in polythene bags were planted in pits in July 1981; Bambusa vulgaris was planted as 8-month-old cuttings. No fertilizer was applied. The most successful species after the first season was Acacia auriculiformis. Satisfactory survival and growth were also obtained with Cassia siamea, Peltoforum ferruginum, Leucaena leucocephala (although this was later heavily damaged by wild rabbits) and Toona ciliata. The bamboo survived well but there was no culm formation during the experiment. In 1982 only 3 of the species were tested: A. auriculiformis, L. leucocephala (because of its fast growth rate) and Casuarina equisetifolia (which performed badly in 1981 but is suited to alkaline soils). All 3 species performed satisfactorily.
The ecological integrity of riparian areas is reduced by biological plant invaders like smooth brome grass (Bromus inermis). Smooth brome actively invades recently disturbed riparian zones by its high seed production and fast seedling establishment. Restoring native perennial grasses to these regio...
Metz, Markus; Landa, Martin; Petrasova, Anna; Petras, Vaclav; Chemin, Yann; Neteler, Markus
The upcoming GRASS GIS 7 release improves not only raster processing and general design but the vector processing in the first place. GRASS GIS, as a topological GIS, recognizes that the topology plays the key role in the vector processing and analysis. Topology ensures that adjacent geographic components in a single vector map are related. In contrast to non-topological GIS, a border common to two areas exists only once and is shared between the two areas. Topological representation of vector data helps to produce and maintain vector maps with clean geometry as well as enables the user to perform certain analyses that can not be conducted with non-topological or spaghetti data. Non-topological vector data are automatically converted to a topological representation upon import. Further more, various cleaning tools exist to remove non-trivial topological errors. In the upcoming GRASS GIS 7 release the vector library was particularly improved to make it faster and more efficient with an improved internal vector file format. This new topological format reduces memory and disk space requirements, leading to a generally faster processing. Opening an existing vector requires less memory providing additionally support for large files. The new spatial index performs queries faster (compared to GRASS GIS 6 more than 10 times for large vectors). As a new option the user can select a file-based version of the spatial index for large vector data. All topological cleaning tools have been optimized with regard to processing speed, robustness, and system requirements. The topological engine comes with a new prototype for direct read/write support of Simple Features API/OGR. Additionally vector data can be directly exchanged with topological PostGIS 2 databases. Considering the wide spread usage of ESRI Shapefile, a non-topological format for vector data exchange, it is particularly advantageous that GRASS GIS 7 offers advanced cleaning tools. For power users and programmers, the
R. Kasten Dumroese; Shi-Jean Susana Sung; Jeremiah R. Pinto; Amy Ross-Davis; D. Andrew Scott
Few pine species develop a seedling grass stage; this growth phase, characterized by strong, carrot-like taproots and a stem-less nature, poses unique challenges during nursery production. Fertilization levels beyond optimum could result in excessive diameter growth that reduces seedling quality as measured by the root bound index (RBI). We grew longleaf pine (Pinus...
Seedling Establishment and Forage Accumulation of ‘Ceres Tonic’ Plantain in Pure Stands and in Grass Mixtures Implantación y Acumulación de Forraje de Plantago ‘Ceres Tonic’ Puro y en Mezcla con Gramíneas
M. Silvia Cid; Miguel A Brizuela; Analía Mendiburu; Juan M Gariglio
This study evaluates the balance of species 2 mo after sowing, its effects on seasonal and annual dry matter accumulation of Plantago lanceolata L. ‘Ceres Tonic’ sown in pure stands, in binary mixtures with three grasses, and different initial growth rates: annual ryegrass (Lolium multiflorum Lam.), tall fescue (Festuca arundinacea Schreb.), and orchard grass (Dactylis glomerata L.). Plantain monocultures were sown at three densities (4, 8, and 12 kg seed ha-1), while halved densities were us...
Ricardo Gomes César
Full Text Available Alternative methods to control invasive fodder grasses are necessary to reduce the use of herbicides in forest restoration, which has been carried out primarily in riparian zones. We sought to investigate if inter-row cultivation of crotalaria (Crotalaria breviflora DC or pumpkin (Cucurbita moschata Duschene ex. Poir with native tree species is an efficient strategy to control invasive fodder grasses in restoration plantings. We tested five treatments in a randomized block design, namely (1 control of brachiaria grass (Urochloa decumbens (Stapf. Webster with glyphosate in the implementation and post-planting grass control of the reforestation, (2 and 3 glyphosate use in the implementation and inter-row sowing of crotalaria (2 or pumpkin (3, and control of brachiaria by mowing in the post-planting phase, (4 and 5 mowing in the implementation and inter-row sowing of crotalaria (4 or pumpkin (5, and control of brachiaria by mowing in the post-planting phase. Post-planting grass control was carried out four and nine months after tree seedling planting. Throughout 13 months, we evaluated the percentage of ground cover by brachiaria grass, pumpkin production, and native tree seedling mortality, height and crown cover. The exclusive use of glyphosate, without inter-row sowing of pumpkin or crotalaria showed the most favorable results for controlling brachiaria grass and, consequently, for tree seedling development. Hence, inter-row cultivation of green manure or short-lived crop species is not enough to control invasive grasses in restoration plantings, and complementary weeding is necessary to reduce the highly competitive potential of C4 grasses for supporting native species seedlings growth.
Full Text Available In order to reduce production costs in vegetable culture are attempting to overcome the financial inputs since to seedlings production. Therefore in this work we aimed to study the behaviour of seed germination and seedling development at the main vegetable species that lends itself to the culture based on seedling production on substrates made from recycled materials / food scraps. Coffee grounds for plants have many benefits. It can be used as fertilizer, insecticide or layer of mulch, mixed with other elements of organic mulch (dry leaves, twigs, dry grass, paper, etc.
LEE Su SEE
Full Text Available Uninoculated dipterocarp seedlings raised in normal field soil in nurseries were always found to have mycorrhizas after a few months. This study set out to determine whether dipterocarp seedlings could continue to grow and develop in the absence of mycorrhizas and also to determine possible sources of mycorrhizal infection of dipterocarp seedlings raised under laboratory conditions using Shorea acuminata as a typical example. Seedlings were planted in capped or uncapped perspex boxes containing sterile or non-sterile field soil and watered daily with sterile water or tap water. Seedling growth and development of mycorrhizas were monitored at monthly intervals for up to seven months. Seedlings grown in sterile soil remained uninfected after seven months while infection was found in some of the seedlings grown in normal soil regardless of whether they had been watered with tap water or sterile water. This showed that field soil (i.e. under grass far from the forest contained suitable inoculum for forest tree seedlings. Tap water and the air were not important sources of infection. However, mycorrhizal infection was very uneven indicating that the inoculum was probably very unevenly distributed in the soil or that the inoculum density was rather low. Seedlings grown in sterile soil showed better growth than those grown in normal soil and infection of roots by parasitic fungi in the latter was also observed.
Full Text Available This article discusses GUI development for GRASS GIS. Sophisticated native GUI for GRASS is one of the key points (besides the new 2D/3D raster library, vector architecture improvements, etc. for the future development of GRASS. In 2006 the GRASS development team decided to start working on the new generation of GUI instead of improving the current GUI based on Tcl/Tk.
tostabilize metal-contaminated soils, and sequester toxic metals. Identification of rhizospheric microbial communities that toler- ate contaminants and promote transformations that render the soil less toxic, are invaluable for phytoremediation and restoration of degraded lands. An Example of Bacterial Communities in Grass ...
Home; Journals; Resonance – Journal of Science Education; Volume 22; Issue 3. Metagenomics at Grass Roots. Sudeshna ... benefit human health, agriculture, and ecosystemfunctions. This article provides a brief history of technicaladvances in metagenomics, including DNA sequencing methods,and some case studies.
Iacona, Gwenllian D; Kirkman, L Katherine; Bruna, Emilio M
Facilitative interactions between neighboring plants can influence community composition, especially in locations where environmental stress is a factor limiting competitive effects. The longleaf pine savanna of the southeastern United States is a threatened and diverse system where seedling recruitment success and understory species richness levels are regulated by the availability of moist microsites. We hypothesized that the dominant bunch grass species (Aristida stricta Michx.) would facilitate moist seedling microsites through shading, but that the effect would depend on stress gradients. Here, we examined the environmental properties modified by the presence of wiregrass and tested the importance of increased shade as a potential facilitative mechanism promoting seedling recruitment across spatial and temporal stress gradients. We showed that environmental gradients, season, and experimental water manipulation influence seedling success. Environmental properties were modified by wiregrass proximity in a manner that could facilitate seedling success, but we showed that shade alone does not provide a facilitative benefit to seedlings in this system.
Jonathan J. Halvorson
Full Text Available Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L, or an herbicide killed (K tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E− or legumes (alfalfa, red clover, and white clover. After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover and tall fescue (especially MaxQ were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions.
Brouwer, Yvonne M.
In recent years considerable interest has been taken in the characteristics of seeds and seedlings, especially those of rainforest species. The rapid destruction of the world’s rainforests is the cause of great concern to many. Efforts at rehabilitation and reafforestation can be assisted
Kim H. Ludovici; L.A. Morris
Root responses to differences in availability of nitrogen and soil water were studied in loblolly pine (Pinus taeda L.) seedlings grown in monoculture and in competition with sweetgum (Liquidambar styraciflua L.) or crab grass (Digitaria spp.). Rhizotron cells were maintained at high soil water availability (...
Baudena, Mara|info:eu-repo/dai/nl/340303867; D'Andrea, Fabio; Provenzale, A.
1. We discuss a simple implicit-space model for the competition of trees and grasses in an idealized savanna environment. The model represents patch occupancy dynamics within the habitat and introduces life stage structure in the tree population, namely adults and seedlings. A tree can be
Research continued on tropical grasses from Saccharum and related genera as sources of intensively-propagated fiber and fermentable solids. Candidate screening for short-rotation grasses was expanded to include six sorghum x Sudan grass hybrids developed by the Dekalb Company. Sugacane and napier grass yield trends in year 3 include: (1) Increased yields with delay of harvest frequency; (2) lack of response to close spacing; (3) a superiority of napier grass over sugarcane when harvested at intervals of six months or less; and (4) a general superiority of the sugarcane variety NCo 310 over varieties PR 980 and PR 64-1791. Delayed tasseling of a wild, early-flowering S. spontaneum hybrid enabled three crosses to be made in December using commercial hybrids as female parents. Approximately 1000 seedlings were produced. The first field-scale minimum tillage experiment was completed. Sordan 77 produced 2.23 OD tons/acre/10 weeks, with winter growing conditions and a total moisture input of 4.75 inches. Mechanization trials included successful planting of napier grass with a sugarcane planter, and the mowing, solar-drying, and round--baling of napier grass aged three to six months. Production-cost and energy-balance studies were initiated during year 3 using first-ratoon data for intensively propagated sugarcane. Preliminary cost estimates for energy cane (sugarcane managed for total biomass rather than sucrose) were in the order of $25.46/OD ton, or about $1.70/mm Btus.
Full Text Available To identify and develop drought tolerant maize (Zea mays L., high-throughput and cost-effective screening methods are needed. In dicot crops, measuring survival and recovery of seedlings has been successful in predicting drought tolerance but has not been reported in C4 grasses such as maize. Seedlings of sixty-two diverse maize inbred lines and their hybrid testcross progeny were evaluated for germination, survival and recovery after a series of drought cycles. Genotypic differences among inbred lines and hybrid testcrosses were best explained approximately 13 and 18 days after planting, respectively. Genotypic effects were significant and explained over 6% of experimental variance. Specifically three inbred lines had significant survival, and 14 hybrids had significant recovery. However, no significant correlation was observed between hybrids and inbreds (R2 = 0.03, indicating seedling stress response is more useful as a secondary screening parameter in hybrids than in inbred lines per se. Field yield data under full and limited irrigation indicated that seedling drought mechanisms were independent of drought responses at flowering in this study.
Kaeppler, Shawn; de Leon Gatti, Natalia; Foerster, Jillian
The present invention relates to compositions and methods for modulating the juvenile to adult developmental growth transition in plants, such as grasses (e.g. maize). In particular, the invention provides methods for enhancing agronomic properties in plants by modulating expression of GRMZM2G362718, GRMZM2G096016, or homologs thereof. Modulation of expression of one or more additional genes which affect juvenile to adult developmental growth transition such as Glossy15 or Cg1, in conjunction with such modulation of expression is also contemplated. Nucleic acid constructs for down-regulation of GRMZM2G362718 and/or GRMZM2G096016 are also contemplated, as are transgenic plants and products produced there from, that demonstrate altered, such as extended juvenile growth, and display associated phenotypes such as enhanced yield, improved digestibility, and increased disease resistance. Plants described herein may be used, for example, as improved forage or feed crops or in biofuel production.
Boelt, Birte; Studer, Bruno
Seed yield is a trait of major interest for many fodder and amenity grass species and has received increasing attention since seed multiplication is economically relevant for novel grass cultivars to compete in the commercial market. Although seed yield is a complex trait and affected...... important aspects and components affecting the seed yield potential and the agronomic and environmental aspects affecting the utilization and realization of the seed yield potential. Finally, it discusses the potential of plant breeding to sustainably improve total seed yield in fodder and amenity grasses....
The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.
Lilian Faria de Melo
Full Text Available ABSTRACT Massai grass is an important tropical forage grass. The harvested seeds upon being received by the company, are found to be contaminated with impurities which are removable by processing machines. This procedure is necessary to produce seeds of a quality level within standards established for commercialization and sowing purposes. The objective of this project was to evaluate the effects of processing phases on the physical and physiological quality of massai grass (Panicum maximum x P. infestum, cv. Massai seeds for commercialization purposes. Seeds were sampled before processing and after leaving the air and screen machine (upper and intermediary screens and bottom; first gravity table (drift, upper and intermediate spouts; treating machine; and second gravity table (upper, intermediate, and lower spouts. Seeds were evaluated as to water content, physical (purity and 1,000 seeds weight and physiological quality (germination, first count of germination, seedling vigor classification, accelerated aging, seedling emergence in the field, speed of emergence index, and primary root length, shoot length. Massai grass seeds had their physical and physiological qualities improved when they were processed by an air and screen machine and a gravity table. Seeds from the intermediate discharge spout of the first gravity table, after going through the air and screen machine, are those of with highest physiological potential. The seeds of this species do not need to be processed to fit the germination and purity standards when the national market is the goal.
Seedling Establishment and Forage Accumulation of ‘Ceres Tonic’ Plantain in Pure Stands and in Grass Mixtures Implantación y Acumulación de Forraje de Plantago ‘Ceres Tonic’ Puro y en Mezcla con Gramíneas
M. Silvia Cid
Full Text Available This study evaluates the balance of species 2 mo after sowing, its effects on seasonal and annual dry matter accumulation of Plantago lanceolata L. ‘Ceres Tonic’ sown in pure stands, in binary mixtures with three grasses, and different initial growth rates: annual ryegrass (Lolium multiflorum Lam., tall fescue (Festuca arundinacea Schreb., and orchard grass (Dactylis glomerata L.. Plantain monocultures were sown at three densities (4, 8, and 12 kg seed ha-1, while halved densities were used in the mixtures. Each grass was sown at the density that is typical for the region (annual ryegrass = 30, tall fescue = 15, and orchard grass = 6 kg seed ha-1. The trial was carried out in Balcarce (37º45’ S, 58º18’ W; 130 m.a.s.l., Argentina in 1.4 × 5 m plots sown in April 2005 with a randomized complete block design, a factorial arrangement of pasture type and plantain sowing density, and seasons as a measurement repeated over time. Plant density 2 mo after sowing was not a good estimator of the balance between species for all pasture types at the end of the first year. Total forage accumulation throughout the experimental period was affected by pasture type (p = 0.08 and plantain sowing density (p 0.05. The plantain and annual ryegrass mixture accumulated 28% more biomass than the mean biomass of all the other pastures (7948 ± 647 vs. 6204 ± 502 kg DM ha-1 mainly because of its higher yield in fall and winter. Total precipitation during the year under study was 15% lower than the historic average so that higher accumulations could be expected in years with higher precipitation.Se evaluó si el balance de especies logrado a los 2 meses de la siembra incide en la acumulación estacional y anual de Plantago lanceolata L. ‘Ceres Tonic’ en cultivos puros y en mezclas binarias con tres gramíneas de diferente velocidad de crecimiento inicial: raigrás anual (Lolium multiflorum Lam., festuca alta (Festuca arundinaceas Schreb., y pasto ovillo
Leuchtmann, Adrian; Clay, Keith
Variation in compatibility has been documented within and among several natural plant populations infected by fungal pathogens. In this study, seeds and isolates of the fungus Atkinsonella hypoxylon (Ascomycetes, Clavicipitaceae) were collected from three populations of the grass Danthonia spicata, two populations of D. compressa, and four populations of Stipa leucotricha. Each fungal strain was reciprocally inoculated into seedlings grown in aseptic culture from its original host population, into seedlings from other conspecific host populations, and into seedlings from the other two host species. There were three distinct patterns of compatibility, as evidenced by the ability of the fungus to grow on the seedling and to colonize new tillers. Fungal strains from one host genus were incompatible with seedlings from the other host genus. Strains from the two Danthonia species were broadly compatible among Danthonia populations and had very high rates of infection, while strains from Stipa also were broadly compatible among Stipa populations but had relatively low rates of infection. Literature surveys indicate that, in contrast to pathogenic microorganisms, mutualistic microorganisms typically exhibit broad patterns of compatibility among hosts, which lack resistance to infection. The effect of A. hypoxylon on host fitness is most detrimental in Stipa, where the fewest seedlings became infected, and most beneficial in Danthonia, where most seedlings became infected. © 1989 The Society for the Study of Evolution.
White, James F.; Kingsley, Katheryn I; Kowalski, Kurt P.; Irizarry, Ivelisse; Micci, April; Soares, Marcos Antonio; Bergen, Marshall S.
Background and aimsNon-native Phragmites australis (haplotype M) is an invasive grass that decreases biodiversity and produces dense stands. We hypothesized that seeds of Phragmites carry microbes that improve seedling growth, defend against pathogens and maximize capacity of seedlings to compete with other plants.MethodsWe isolated bacteria from seeds of Phragmites, then evaluated representatives for their capacities to become intracellular in root cells, and their effects on: 1.) germination rates and seedling growth, 2.) susceptibility to damping-off disease, and 3.) mortality and growth of competitor plant seedlings (dandelion (Taraxacum officionale F. H. Wigg) and curly dock (Rumex crispus L.)).ResultsTen strains (of 23 total) were identified and characterized; seven were identified as Pseudomonas spp. Strains Sandy LB4 (Pseudomonas fluorescens) and West 9 (Pseudomonas sp.) entered root meristems and became intracellular. These bacteria improved seed germination in Phragmites and increased seedling root branching in Poa annua. They increased plant growth and protected plants from damping off disease. Sandy LB4 increased mortality and reduced growth rates in seedlings of dandelion and curly dock.ConclusionsPhragmites plants associate with endophytes to increase growth and disease resistance, and release bacteria into the soil to create an environment that is favorable to their seedlings and less favorable to competitor plants.
Amina A. Aly
Full Text Available BackgroundIn recent years, several plant species have been used as bioindicators to evaluate the toxicity of environmental contaminants on vegetal organisms. In this study, Egyptian clover and Sudan grass seedlings were grown in four cadmium (Cd concentration levels (0.0, 25, 50 and 100 µM in MS media to analyze growth responses, Cd accumulation in the shoots and roots of plantlets, proline contents, chlorophylls content and MDA levels of both plantlets. As well as RAPD analysis and leaves ultrastructure were detected.ResultsThe results showed that there was a significant decrease in root and shoot lengths, Chl a, Chl b, total Chl and carotenoids contents for both Egyptian clover and Sudan grass. However, there was a significant increase in Cd accumulation, proline and malondialdehyde (MDA levels. The genetic variation between Egyptian clover and Sudan grass were evaluated using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR markers to establish specific DNA markers associated with Cd stress. The results of transimssion electron microscopy (TEM showed a clear disorder in the Cd treated Egyptian clover and Sudan grass seedlings.ConclusionIn conclusion, biochemical, molecular and ultrastructure changes in Egyptian clover and Sudan grass could be used as a useful biomarker assay for the detection of genotoxic effects of Cd stress on plants. However, it is necessary to be further confirmed and optimized in the future research.
Chen, Zhong-Hua; Chen, Guang; Dai, Fei; Wang, Yizhou; Hills, Adrian; Ruan, Yong-Ling; Zhang, Guoping; Franks, Peter J; Nevo, Eviatar; Blatt, Michael R
Grasses began to diversify in the late Cretaceous Period and now dominate more than one third of global land area, including three-quarters of agricultural land. We hypothesize that their success is likely attributed to the evolution of highly responsive stomata capable of maximizing productivity in rapidly changing environments. Grass stomata harness the active turgor control mechanisms present in stomata of more ancient plant lineages, maximizing several morphological and developmental features to ensure rapid responses to environmental inputs. The evolutionary development of grass stomata appears to have been a gradual progression. Therefore, understanding the complex structures, developmental events, regulatory networks, and combinations of ion transporters necessary to drive rapid stomatal movement may inform future efforts towards breeding new crop varieties. Copyright © 2016 Elsevier Ltd. All rights reserved.
Literature where animal performance is quantified for. Smuts finger grass and Nile grass pastures in South Africa is limited. In some trials, animal performance on Smuts finger grass and/or Nile grass was reported (Rhind & Goodenough,. 1979, Dannhauser, 1982 Grunow, et al., 1984). The ADG achieved by .steers on Smuts ...
Background. In the subtropical climate of South Africa, grasses of the subfamily Panicoideae are predominant. Bermuda grass has previously been shown to be an important local allergen, and immunoglobulin E (IgE) epitopes of Bermuda grass extracts are known to be distinct from those of the Pooid pollen extracts.
Camila de Aquino Tomaz
Full Text Available ABSTRACTThe period for the germination test of Surinam grass seeds established by the Rules for Seeds Testing is 28 days, considered too lengthy by producers, venders, and seed analysis laboratories. So, the objective of this research was to evaluate the possibility of reducing the time for the germination test of Surinam grass seeds and to establish a method for dormancy breaking and the ideal temperature. Ten seed lots were submitted to the following treatments to overcome seed dormancy: control; substrate moistening with 0.2% KNO3; and scarification with sulfuric acid (98% 36 N for 15 minutes. After the treatments, the lots were submitted to seed water content, germination and tetrazolium tests. During the germination test, conducted with four replicates of 100 seeds per treatment for 28 days, two conditions of alternating temperatures (20-35 °C and 15-35 °C with 8 hours of light were tested. Attempting to determine the test end date, daily counts of the number of normal seedlings were made and for each lot, treatment, and temperature, a growth curve for the evaluation of germination was adjusted. The segmented regression model parameter estimations were calculated for each treatment. The germination test of Braquiaria decumbensseeds may be evaluated in 12 days after sowing using alternating temperatures of 20-35 °C and without any treatment to overcome dormancy.
Full Text Available Bakanae disease symptom were observed in barnyard grass in paddy field in Heanam, Jeonnam. The infected plants were blighted and white mass of spore were formed on the stem. Fusarium species were isolated from infected stem and the isolates were identified as Fusarium fujikuroi based on their morphological and molecular characteristics. The isolates of F. fujikuroi were assigned to reference of F. fujikuroi among related Fusarium species based on the translation elongation factor 1-alpha gene sequence. Pathogenicity of the fungal isolates was confirmed on seedlings of rice and barnyard grass by artificial inoculation. The results indicated that barnyard grass can be inoculum source of Bakanae disease on rice. Thus, effective weed management is necessary to Bakanae disease control and healthy seed production.
Duan, Xueyang; Jones, Cathleen E.
In this work, we developed an electromagnetic scattering model to analyze radar scattering from tall-grass-covered lands such as wetlands and marshes. The model adopts the generalized iterative extended boundary condition method (GIEBCM) algorithm, previously developed for buried cylindrical media such as vegetation roots, to simulate the scattering from the grass layer. The major challenge of applying GIEBCM to tall grass is the extremely time-consuming iteration among the large number of short subcylinders building up the grass. To overcome this issue, we extended the GIEBCM to multilevel GIEBCM, or M-GIEBCM, in which we first use GIEBCM to calculate a T matrix (transition matrix) database of "straws" with various lengths, thicknesses, orientations, curvatures, and dielectric properties; we then construct the grass with a group of straws from the database and apply GIEBCM again to calculate the T matrix of the overall grass scene. The grass T matrix is transferred to S matrix (scattering matrix) and combined with the ground S matrix, which is computed using the stabilized extended boundary condition method, to obtain the total scattering. In this article, we will demonstrate the capability of the model by simulating scattering from scenes with different grass densities, different grass structures, different grass water contents, and different ground moisture contents. This model will help with radar experiment design and image interpretation for marshland and wetland observations.
Full Text Available Temperate perennial grasses are important worldwide as a livestock nutritive energy source and a potential feedstock for lignocellulosic biofuel production. The annual temperate grass Brachypodium distanchyon has been championed as a useful model system to facilitate biological research in agriculturally important temperate forage grasses based on phylogenetic relationships. To physically corroborate genetic predictions, we determined the chemical composition profiles of organ-specific cell walls throughout the development of two common diploid accessions of Brachypodium distanchyon, Bd21-3 and Bd21. Chemical analysis was performed on cell walls isolated from distinct organs (i.e. leaves, sheaths, stems and roots at three developmental stages of 1 12-day seedling, 2 vegetative-to-reproductive transition, and 3 mature seed-fill. In addition, we have included cell wall analysis of embryonic callus used for genetic transformations. Composition of cell walls based on components lignin, hydroxycinnamates, uronosyls, neutral sugars, and protein suggests that Brachypodium distanchyon is similar chemically to agriculturally important forage grasses. There were modest compositional differences in hydroxycinnamate profiles between accessions Bd21-3 and Bd21. In addition, when compared to agronomical important C3 grasses, more mature Brachypodium stem cell walls have a relative increase in glucose of 48% and a decrease in lignin of 36%. Though differences exists between Brachypodium and agronomical important C3 grasses, Brachypodium distanchyon should be still a useful model system for genetic manipulation of cell wall composition to determine the impact upon functional characteristics such as rumen digestibility or energy conversion efficiency for bioenergy production.
Ali, S.S.; Jafri, S.J.H.; Jamil, M.; Ijaz, M.
Eleven local rice cultivars including Basmati 370 were evaluated for seedling vigor. Three groups of traits were evaluated viz; seed traits (Seed density, seed volume see weight, paddy length and grain length), seed emergence traits (emergence %, emergence index and emergence rate index), and seedling traits (fresh root length, dry root weight, emergence percentage, root length, dry root weight, seed weight and relative root weight were observed significant, respectively. Seed density, relative root weight, emergence rate index and root to shoot ratio were relatively more amenable to improvement. Relative expected genetic advance was the function of heritability and coefficient of phenotypic variability, latter being more important. (author)
Kas Dumroese; Thomas D. Landis
The science of growing reforestation and conservation plants in containers has continually evolved, and three simple observations may greatly improve seedling quality. First, retaining stock in its original container for more than one growing season should be avoided. Second, strongly taprooted species now being grown as bareroot stock may be good candidates...
Williams, Emma Victoria; Elia Ntandu, John; Ficinski, Paweł; Vorontsova, Maria
We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution.
Ficinski, Paweł; Vorontsova, Maria
Abstract We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution. PMID:27226761
Dahl, Ronald; Roberts, Graham; de Blic, Jacques
BACKGROUND: Allergy immunotherapy is a treatment option for allergic rhinoconjunctivitis (ARC). It is unique compared with pharmacotherapy in that it modifies the immunologic pathways that elicit an allergic response. The SQ Timothy grass sublingual immunotherapy (SLIT) tablet is approved in North...... America and throughout Europe for the treatment of adults and children (≥5 years old) with grass pollen-induced ARC. OBJECTIVE: The clinical evidence for the use of SQ grass SLIT-tablet as a disease-modifying treatment for grass pollen ARC is discussed in this review. METHODS: The review included...... the suitability of SQ grass SLIT-tablet for patients with clinically relevant symptoms to multiple Pooideae grass species, single-season efficacy, safety, adherence, coseasonal initiation, and cost-effectiveness. The data from the long-term SQ grass SLIT-tablet clinical trial that evaluated a clinical effect 2...
RENISSON NEPONUCENO DE ARAÚJO FILHO
Full Text Available The development of vetiver grass (Chrysopogon zizanioides L. has been evaluated under differ-ent levels of phosphorus on slopes of the right-side bank of the San Francisco River, in the municipality of Am-paro do São Francisco, SE. Techniques of soil bioengineering were used, characterized by the combination of vegetated riprap with stakes, seedlings of vetiver grass and sediment retainers. The experimental design was randomized blocks with five doses (0, 4, 8, 12, and 16 g pit-1 of simple superphosphate and five replicates. The growth of vetiver seedlings were observed in periods of 30, 60, 90, e 180 days, carrying out the following pa-rameters: number of roots, external root surface, root density, root length, root length density, root and shoot dry weight, root and shoot fresh weight, and shoot length, at each evaluation period. The phosphorus doses and periods of morphological development interacted in all variables of plant biomass mentioned above. Higher superphosphate doses than 9.0 g pit-1 did not offer advantages in terms of cost-benefit for the production of vetiver seedings.
Ty Swirin; Hans Williams; Bob Keeland
Stomata1 conductance, transpiration, and leaf water potential were measured during the 1996 growing season on baldcypress (Taxodium disfichum (L.) Rich.) seedlings. Seedlings were hand-planted from 1-O bareroot stock in mesic and permanently Rooded soil conditions. One-half of all seedlings were fitted with 122-cm tall polyethylene tree...
Meyer, Ane Katharina Paarup; Ehimen, Ehiazesebhor Augustine; Holm-Nielsen, Jens Bo
.5–3.0% of the present national energy production based on biogas. The estimated values for the energy return on invested energy (EROEI) was found to range from 2.17 to 2.88. The measured contents of heavy metals in the roadside vegetation was seen not to exceed the legislative levels for what can be applied......This paper presents a study of the feasibility of utilising roadside vegetation for biogas production in Denmark. The potential biomass yield, methane yields, and the energy balances of using roadside grass for biogas production was investigated based on spatial analysis. The results show...... that the potential annual yield of biomass obtainable from roadside verges varies widely depending on the local conditions. The net energy gain (NEG) from harvest, collection, transport, storage and digestion of roadside vegetation was estimated to range from 60,126–121,476 GJ, corresponding to 1...
Barbieri, Mirko; Marcel, Thierry C; Niks, Rients E; Francia, Enrico; Pasquariello, Marianna; Mazzamurro, Valentina; Garvin, David F; Pecchioni, Nicola
The potential of the model grass Brachypodium distachyon L. (Brachypodium) for studying grass-pathogen interactions is still underexploited. We aimed to identify genomic regions in Brachypodium associated with quantitative resistance to the false brome rust fungus Puccinia brachypodii . The inbred lines Bd3-1 and Bd1-1, differing in their level of resistance to P. brachypodii, were crossed to develop an F(2) population. This was evaluated for reaction to a virulent isolate of P. brachypodii at both the seedling and advanced growth stages. To validate the results obtained on the F(2), resistance was quantified in F(2)-derived F(3) families in two experiments. Disease evaluations showed quantitative and transgressive segregation for resistance. A new AFLP-based Brachypodium linkage map consisting of 203 loci and spanning 812 cM was developed and anchored to the genome sequence with SSR and SNP markers. Three false brome rust resistance QTLs were identified on chromosomes 2, 3, and 4, and they were detected across experiments. This study is the first quantitative trait analysis in Brachypodium. Resistance to P. brachypodii was governed by a few QTLs: two acting at the seedling stage and one acting at both seedling and advanced growth stages. The results obtained offer perspectives to elucidate the molecular basis of quantitative resistance to rust fungi.
Batkhuugyin, Enkhtuya; Pöschl, M.; Vosátka, Miroslav
Roč. 166, 1-4 (2005), s. 217-236 ISSN 0049-6979 R&D Projects: GA ČR(CZ) GA526/99/0895 Institutional research plan: CEZ:AV0Z60050516 Keywords : degraded ecosystems * arbuscular mycorrhizal fungi * phosphorus transfer Subject RIV: EF - Botanics Impact factor: 1.258, year: 2005
Batkhuugyin, Enkhtuya; Óskarsson, Ú.; Dodd, J. C.; Vosátka, Miroslav
Roč. 38, - (2003), s. 209-222 ISSN 0015-5551 R&D Projects: GA AV ČR KSK6005114; GA ČR GA526/99/0895 Institutional research plan: CEZ:AV0Z6005908 Keywords : arbuscular mycorrhizal fungi * ectomycorrhizal fungi * volcanic ash Subject RIV: EF - Botanics Impact factor: 1.057, year: 2003
Mutai, Collins; Njuguna, Joyce; Ghimire, Sita
Endophytic and plant-associated bacteria were isolated from plants and rhizoplane soil of naturally grown Brachiaria grasses at International Livestock Research Institute in Nairobi, Kenya. Eighty-four bacterial strains were isolated from leaf tissues, root tissues, and rhizoplane soil on nutrient agar and 869 media. All bacterial strains were identified to the lowest possible taxonomic unit using 16S rDNA primers and were characterized for the production of Indole-3-acetic acid, hydrogen cyanide, and ACC deaminase; phosphate solubilization; siderophore production; antifungal properties; and plant biomass production. The 16S rDNA-based identification grouped these 84 bacterial strains into 3 phyla, 5 classes, 8 orders, 12 families, 16 genera, and 50 unique taxa. The four most frequently isolated genera were Pseudomonas (23), Pantoea (17), Acinetobacter (9), and Enterobacter (8). The functional characterization of these strains revealed that 41 of 84 strains had a minimum of three plant beneficial properties. Inoculation of maize seedlings with Acinetobacter spp., Microbacterium spp., Pectobacterium spp., Pseudomonas spp., and Enterobacter spp. showed positive effects on seedling biomass production. The ability of Brachiaria grasses to host genetically diverse bacteria, many of them with multiple plant growth-promoting attributes, might have contributed to high biomass production and adaptation of Brachiaria grasses to drought and low fertility soils. © 2017 International Livestock Research Institute. MicrobiologyOpen published by John Wiley & Sons Ltd.
Paine, Oliver C C; Koppa, Abigale; Henry, Amanda G; Leichliter, Jennifer N; Codron, Daryl; Codron, Jacqueline; Lambert, Joanna E; Sponheimer, Matt
Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C 4 component in the diets of most taxa, and grass leaves are the single most abundant C 4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i.e., high toughness) for hominins with bunodont dentition. Here, we compare the nutritional and mechanical properties of grass leaves with the plants growing alongside them in African savanna habitats. We also compare grass leaves to the leaves consumed by other hominoids and demonstrate that many, though by no means all, compare favorably with the nutritional and mechanical properties of known primate foods. Our data reveal that grass leaves exhibit tremendous variation and suggest that future reconstructions of hominin dietary ecology take a more nuanced approach when considering grass leaves as a potential hominin dietary resource. Copyright © 2017. Published by Elsevier Ltd.
Full Text Available 10th meeting of GRASS & GFOSS users The 10th Italian Congress of GRASS GIS and Geospatial Free and Open Source Software (GFOSS was held on the26 and 27 Feb in Cagliari. Highlights included updates on major GFOSS projects (GRASS, QGIS, the presentation of new projects (SpatiaLite and the public release of a free 3D visualization application suitable for distribution over the internet (RATMAN. Many users and developers connected to forge new business relationships and share new ideas.
Full Text Available 10th meeting of GRASS & GFOSS usersThe 10th Italian Congress of GRASS GIS and Geospatial Free and Open Source Software (GFOSS was held on the26 and 27 Feb in Cagliari. Highlights included updates on major GFOSS projects (GRASS, QGIS, the presentation of new projects (SpatiaLite and the public release of a free 3D visualization application suitable for distribution over the internet (RATMAN. Many users and developers connected to forge new business relationships and share new ideas.
Jørgensen, Uffe; Lærke, Poul Erik
benefits, a reduction of nitrate leaching equivalent to 23,000 tonnes N annually was estimated. This is approximately the reduction required by the WFD for Denmark. Even though much more organic matter will be mobilized for biorefining, soil carbon levels are estimated to be largely unchanged...... production into grass production. Grasses and legumes have higher contents of protein with better quality (high lysine and methionine contents) than grain and seed crops. Thus, substituting imported soya bean protein with protein extracted from perennial grasses is an interesting option....
Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops
The different light intensities did not significantly affect the height, collar diameter, leaf production and biomass accumulation of E. angolense seedlings. Chlorophyll content of leaf was significantly affected by light intensities. The result from this study has shown that E. angolense seedlings can be easily raised in the nursery ...
Jan 8, 2014 ... RL, Radicle length; PL, plumule length; SL, seedling length; FGP, final germination percentage; SV, seeds vigour. Significance levels; * P < 0.05, ** P. < 0.001; ns, non significant; F: coefficient of Snedecor-Fisher. Table 2. One-way ANOVA of the effect of salt stress on different parameters of seedling ...
Slot, M.; Poorter, L.
Drought is an important seedling mortality agent in dry and moist tropical forests, and more severe and frequent droughts are predicted in the future. The effect of drought on leaf gas exchange and seedling survival was tested in a dry-down experiment with four tree species from dry and moist
Twenty species are endemic to the central highlands, and a further 1 4 species are restricted to Madagascar. Five ecological groups of grasses were identified in the Itremo Massif: shade species in gallery forests, open wet area species, fire grasses, anthropogenic disturbance associated grasses and rock-dwelling grasses.
Effect of five different concentrations (0, 10, 20, 30 and 40 mg/L) of arsenic was studied on 11 different parameters of two important leguminous crops, namely Trigonella foenum-graecum L. (fenugreek) and Lathyrus sativus L. (grass pea) during germination and early seedling growth stage. Mean value of germination percentage, germination index and relative germination rate decreased with concomitant increase in arsenic-induced injury level in increasing concentration of arsenic in both plants ...
The fortified Susquehanna Flats, the largest bed of underwater grasses in the Chesapeake Bay, seems able to withstand a major weather punch. Its resilience is contributing to an overall increase in the Bay’s submerged aquatic vegetation.
Karl Konrad Grass oli 19. sajandil Dorpati keiserliku ülikooli usuteaduskonna Uue Testamendi õppejõud, kes tegeles hobi korras idakristluse (vene sektid) uurimisega. Tema peateoseks on uurimus "Die russischen Sekten". Ettekanne konverentsil 15.-16. aprill 2005. a.
Full Text Available Savannas occur where trees and grasses interact to create a biome that is neither grassland nor forest. Woody and gramineous plants interact by many mechanisms, some negative (competition) and some positive (facilitation). The strength and sign...
California Department of Resources — This dataset provides the known distribution of pampas grass (Cortaderia selloana) in southern Orange County. The surveys were conducted from May to June, 2007 and...
The shortage of feed, particularly during the dry season is one of the major factor limiting productivity of livestock in the tropics. Napier or elephant grass (Pennisetum purpureum Schum.) shows a great potential to alleviate the problem because it is drought resistant and has high dry matter yield potential. As an attempt to generate information useful for improving the utilization of the grass, its potential and limitation are described. Its chemical composition and nutritive value as rela...
Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W. Derek; Ficinski, Paweł; Savva, George M.; Nanjarisoa, Olinirina P.; Razanatsoa, Jacqueline; Randriatsara, Fetra O.; Kimeu, John M.; Luke, W. R. Quentin; Kayombo, Canisius; Linder, H. Peter
Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612
A. K. M. Mominul Islam
Full Text Available Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum, lettuce (Lactuca sativa, alfalfa (Medicago sativa, Italian ryegrass (Lolium multiflorum, barnyard grass (Echinochloa crus-galli, and timothy (Phleum pratense at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1 reduced significantly the total germination percent (GP, germination index (GI, germination energy (GE, speed of emergence (SE, seedling vigour index (SVI, and coefficient of the rate of germination (CRG of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50 and mean germination time (MGT were increased at the same or higher than this concentration. The increasing trend of T50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. The I50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds.
Ellis, Anne K; Frankish, Charles W; O'Hehir, Robyn E; Armstrong, Kristen; Steacy, Lisa; Larché, Mark; Hafner, Roderick P
Synthetic peptide immunoregulatory epitopes are a new class of immunotherapy to treat allergic rhinoconjunctivitis (ARC). Grass allergen peptides, comprising 7 synthetic T-cell epitopes derived from Cyn d 1, Lol p 5, Dac g 5, Hol l 5, and Phl p 5, is investigated for treatment of grass pollen-induced ARC. We sought to evaluate the efficacy, safety, and tolerability of intradermally administered grass allergen peptides. A multicenter, randomized, double-blind, placebo-controlled study evaluated 3 regimens of grass allergen peptides versus placebo in patients with grass pollen-induced allergy (18-65 years). After a 4-day baseline challenge to rye grass in the environmental exposure unit (EEU), subjects were randomized to receive grass allergen peptides at 6 nmol at 2-week intervals for a total of 8 doses (8x6Q2W), grass allergen peptides at 12 nmol at 4-week intervals for a total of 4 doses (4x12Q4W), or grass allergen peptides at 12 nmol at 2-week intervals for a total of 8 doses (8x12Q2W) or placebo and treated before the grass pollen season. The primary efficacy end point was change from baseline in total rhinoconjunctivitis symptom score across days 2 to 4 of a 4-day posttreatment challenge (PTC) in the EEU after the grass pollen season. Secondary efficacy end points and safety were also assessed. Two hundred eighty-two subjects were randomized. Significantly greater improvement (reduction of total rhinoconjunctivitis symptom score from baseline to PTC) occurred across days 2 to 4 with grass allergen peptide 8x6Q2W versus placebo (-5.4 vs -3.8, respectively; P = .0346). Greater improvement at PTC also occurred for grass allergen peptide 8x6Q2W versus placebo (P = .0403) in patients with more symptomatic ARC. No safety signals were detected. Grass allergen peptide 8x6Q2W significantly improved ARC symptoms after rye grass allergen challenge in an EEU with an acceptable safety profile. Copyright © 2017 American Academy of Allergy, Asthma & Immunology
D'Onofrio, Donatella; Baudena, Mara; D'Andrea, Fabio; Rietkerk, Max; Provenzale, Antonello
Arid and semiarid savannas are characterized by the coexistence of trees and grasses in water limited conditions. As in all dry lands, also in these savannas rainfall is highly intermittent. In this work, we develop and use a simple implicit-space model to conceptually explore how precipitation intermittency influences tree-grass competition and savanna occurrence. The model explicitly includes soil moisture dynamics, and life-stage structure of the trees. Assuming that water availability affects the ability of both plant functional types to colonize new space and that grasses outcompete tree seedlings, the model is able to predict the expected sequence of grassland, savanna, and forest along a range of mean annual rainfall. In addition, rainfall intermittency allows for tree-grass coexistence at lower mean annual rainfall values than for constant precipitation. Comparison with observations indicates that the model, albeit very simple, is able to capture some of the essential dynamical processes of natural savannas. The results suggest that precipitation intermittency affects savanna occurrence and structure, indicating a new point of view for reanalyzing observational data from the literature.
Cone, J.W.; Gelder, van A.H.; Soliman, I.A.; Visser, de H.; Vuuren, van A.M.
Grass samples were harvested during the 1993 growing season after a precut on April 27, 1993 and were stored frozen or left to ensile in 30-L buckets. Effects on chemical composition and fermentation kinetics of the maturation of the grass and of ensiling were investigated. Chemical composition and
Simpson, Kimberley J; Ripley, Brad S; Christin, Pascal-Antoine; Belcher, Claire M; Lehmann, Caroline E R; Thomas, Gavin H; Osborne, Colin P
Tropical grasses fuel the majority of fires on Earth. In fire-prone landscapes, enhanced flammability may be adaptive for grasses via the maintenance of an open canopy and an increase in spatiotemporal opportunities for recruitment and regeneration. In addition, by burning intensely but briefly, high flammability may protect resprouting buds from lethal temperatures. Despite these potential benefits of high flammability to fire-prone grasses, variation in flammability among grass species, and how trait differences underpin this variation, remains unknown.By burning leaves and plant parts, we experimentally determined how five plant traits (biomass quantity, biomass density, biomass moisture content, leaf surface-area-to-volume ratio and leaf effective heat of combustion) combined to determine the three components of flammability (ignitability, sustainability and combustibility) at the leaf and plant scales in 25 grass species of fire-prone South African grasslands at a time of peak fire occurrence. The influence of evolutionary history on flammability was assessed based on a phylogeny built here for the study species.Grass species differed significantly in all components of flammability. Accounting for evolutionary history helped to explain patterns in leaf-scale combustibility and sustainability. The five measured plant traits predicted components of flammability, particularly leaf ignitability and plant combustibility in which 70% and 58% of variation, respectively, could be explained by a combination of the traits. Total above-ground biomass was a key driver of combustibility and sustainability with high biomass species burning more intensely and for longer, and producing the highest predicted fire spread rates. Moisture content was the main influence on ignitability, where species with higher moisture contents took longer to ignite and once alight burnt at a slower rate. Biomass density, leaf surface-area-to-volume ratio and leaf effective heat of combustion
Full Text Available Peats are the mostly used material in making rice seedling substrate. However, mining peats could cause environmental problems. In order to reduce or replace peats in rice seedling substrate industry, this paper studied suitable way to configure rice seedling. The coal gangue was used to experiment cultivating rice. Four rice seeding experiments were carried out based on physical and chemical properties of materials attributes. The results showed:(1 Coal gangue was feasible for rice seedling; (2 The maximum adding amount of coal gangue was 80%(volume ratio though the coal gangue need to be activated; (3 In the case of no activated treatment only 38%(volume ratio of coal gangue could be added to the substrate.
Full Text Available In in vitro conditions, virulence of 91 isolates of species Fusarium genus (F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. arthrosporioides, F. prolifera- tum, F. avenaceum, F. semitectum, F. tricinctum, F. sporotrichioides and F. graminearum towards alfalfa seedlings was investigated. Isolates of investigated species originated from diseased alfalfa plants collected at four locations in Serbia based on symptoms of wilting caused by Fusarium and root rotting. Pathogenicity and virulence of investigated isolates of Fusarium spp. were determined by visual evaluation of inoculated seedlings of cultivar K28 in laboratory conditions. All isolated of investigated species had pathogenic effect on alfalfa seedlings which expressed symptoms such as necrosis of root, moist rotting and "melting of seedlings". Colour of necrotic root tissue varied from light brown, brown lipstick red to explicit black, depending on the Fusarium species. Strong virulence was established in 48 isolates, medium virulence in 31 and weak virulence in 12 isolates.
Full Text Available In in vitro conditions, virulence of 91 isolates of species Fusarium genus (F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. arthrosporioides, F. proliferatum, F. avenaceum, F. semitectum, F. tricinctum, F. sporotrichioides and F. graminearum towards alfalfa seedlings was investigated. Isolates of investigated species originated from diseased alfalfa plants collected on four locations in Serbia based on symptoms of wilting caused by fusarium and root rotting. Pathogenicity and virulence of investigated isolates of Fusarium spp. were determined by visual evaluation of inoculated seedlings of cultivars K28 in laboratory conditions. All isolated of investigated species had pathogenic effect on alfalfa seedlings, which expressed symptoms such as necrosis of root, moist rotting and "melting of seedlings". Colour of necrotic root tissue varied from light brown, brown, lipstick red to explicit black, depending on the Fusarium species. Strong virulence was established in 48 isolates, medium virulence in 31 and weak virulence in 12 isolates.
Jagtap, T.G.; Untawale, A.G.
seen. General damage in both the species were burning, yellowing and wilting of the leaves associated with root damage causing retardation of growth. Extensive leaf fall in Avicennia seedlings resulted in its mortality...
Full Text Available Methylene blue is widely used in various industrial branches. Due to insufficient treatment, its occurrence in wastewater is frequently detected, which may result in serious environment problems to aquatic organisms. Hydroponic experiments were conducted with rice seedlings (Oryza sativa L. cv. XZX 45 exposed to methylene blue to determine the effective concentration using relative growth rate and water use efficiency as response endpoints. Results showed that acute toxicity of methylene blue to rice seedlings was evident. Although a linear decrease in relative growth rate and water use efficiency was observed in rice seedlings with increasing methylene blue concentrations, relative growth rate of rice seedlings was more sensitive to change of methylene blue than water use efficiency. Using non-linear regression, EC-48 h values for 10%, 20% and 50% inhibition of the relative growth rate were estimated to be 1.54, 3.22 and 10.13 mg MB/L for rice seedlings exposed to methylene blue, respectively, while smaller EC were obtained for 96 h exposure. In conclusion, the toxic response of young rice seedlings to methylene blue is obvious and inhibitory effects are highly dependent on response endpoints and the duration of exposure period.
Rigney, Michael P.; Kranzler, Glenn A.
Almost two billion conifer seedlings are produced in the U.S. each year to support reforestation efforts. Seedlings are graded manually to improve viability after transplanting. Manual grading is labor-intensive and subject to human variability. Our previous research demonstrated the feasibility of automated tree seedling inspection with machine vision. Here we describe a system based on line-scan imaging, providing a three-fold increase in resolution and inspection rate. A key aspect of the system is automatic recognition of the seedling root collar. Root collar diameter, shoot height, and projected shoot and root areas are measured. Sturdiness ratio and shoot/root ratio are computed. Grade is determined by comparing measured features with pre-defined set points. Seedlings are automatically sorted. The precision of machine vision and manual measurements was determined in tests at a commercial forest nursery. Manual measurements of stem diameter, shoot height, and sturdiness ratio had standard deviations three times those of machine vision measurements. Projected shoot area was highly correlated (r2 equals 0.90) with shoot volume. Projected root area had good correlation (r2 equals 0.80) with root volume. Seedlings were inspected at rates as high as ten per second.
Miller, J.K.; Madsen, F.C.; Lentz, D.E.; Hansard, S.L.
Clinical hypomagnesemia is confined primarily to beef cattle in the United States but also occurs in dairy cattle in other countries, probably due to different management practices. During periods when grass tetany is likely, early vegetative temperate zone grasses are usually low in total readily available carbohydrates and magnesium but high in potassium and nitrogen. The tetany syndrome may include hypoglycemia and ketosis, suggesting an imbalance in intermediary energy metabolism. Many enzyme systems critical to cellular metabolism, including those which hydrolyze and transfer phosphate groups, are activated by Mg. Thus, by inference, Mg is required for normal glucose utilization, fat, protein, nucleic acid and coenzyme synthesis, muscle contraction, methyl group transfer, and sulfate, acetate, and formate activation. Numerous clinical and experimental studies suggest an intimate relationship between metabolism of Mg and that of carbohydrate, glucagon, and insulin. The objective is to review this literature and suggest ways in which these relationships might contribute to a chain of events leading to grass tetany.
Korres, N.E.; Thamsiriroj, T.; Smith, B.
Many factors enforce the intensification of grassland utilization which is associated with significant environmental impacts subjected to various legislative constraints. Nevertheless, the need for diversification in agricultural production and the sustainability in energy within the European Union...... have advanced the role of grassland as a renewable source of energy in grass biomethane production with various environmental and socio-economic benefits. It is underlined that the essential question whether the gaseous biofuel meets the EU sustainability criteria of 60% greenhouse gas emission savings...... by 2020 can be met since savings up to 89.4% under various scenarios can be achieved. Grass biomethane production compared to other liquid biofuels either when these are produced by indigenous of imported feedstocks is very promising. Grass biomethane, given the mature and well known technology...
Würtzen, Peter A; Gupta, Shashank; Brand, Stephanie; Andersen, Peter S
During allergen immunotherapy (AIT), the allergic patient is exposed to the disease-inducing antigens (allergens) in order to induce clinical and immunological tolerance and obtain disease modification. Large trials of grass AIT with highly standardized subcutaneous and sublingual tablet vaccines have been conducted to document the clinical effect. Induction of blocking antibodies as well as changes in the balance between T-cell phenotypes, including induction of regulatory T-cell subtypes, have been demonstrated for both treatment types. These observations increase the understanding of the immunological mechanism behind the clinical effect and may make it possible to use the immunological changes as biomarkers of clinical effect. The current review describes the recent mechanistic findings for subcutaneous immunotherapy and sublingual immunotherapy/tablet treatment and discusses how the observed immunological changes translate into a scientific foundation for the observed clinical effects of grass pollen immunotherapy and lead to new treatment strategies for grass AIT.
Full Text Available Biogas production in the Czech Republic has expanded substantially, including marginal regions for maize cultivation. Therefore, there are increasingly sought materials that could partially replace maize silage, as a basic feedstock, while secure both biogas production and its quality.Two samples of rye grass (Lolium multiflorum var. westerwoldicum silage with different solids content 21% and 15% were measured for biogas and methane yield. Rye grass silage with solid content of 15% reached an average specific biogas yield 0.431 m3·kg−1 of organic dry matter and an average specific methane yield 0.249 m3·kg−1 of organic dry matter. Rye grass silage with solid content 21% reached an average specific biogas yield 0.654 m3·kg−1 of organic dry matter and an average specific methane yield 0.399 m3·kg−1 of organic dry matter.
Papastefanou, C.; Manolopoulou, M.; Stoulos, S.; Ioannidou, A.; Gerasopoulos, E.
Grass ecosystem was monitored for 137 Cs, a relatively long-lived radionuclide, for about 16 years since the Chernobyl reactor accident occurred on April 26, 1986. Cesium-137 in grass gramineae or poaceae the species, ranged from 122.9 Bq kg -1 (September 4, 1986) to 5.8 mBq kg -1 (October 16, 2001) that is a range of five orders of magnitude. It was observed that there was a trend of decreasing 137 Cs with time reflecting a removal half-time of 40 months (3 1/3 years), which is the ecological half-life, T ec of 137 Cs in grassland
Breeding of clover grass on fallow areas as a resource for methane generation has several important advantages. It does not require any additional nitrogen fertilizer as it can fix the atmospheric nitrogen.Herbicides are unnecessary as most weeds are one-year plants, while clover is perennial. From methane generation data for clover-grass the gross energy generation has been calculated to 11.08 MJ per kg dry matter. Net energy generation (with account for electric power) is calculated to 14.00 MJ/kg dry matter. (EG)
A. P. Zvedenuk
Full Text Available The results of research work on carrot seed growing through wintering seedlings carried out at laboratory of seed studies and seed production of Transnistrian Research Institute of Agriculture, on the soil of the first terrace at the rive Dniester were presented in the article. Seed bearing plants of garden carrot ‘Krasavka’ were the object of the study. The seeds were sown to produce the seedlings on 15-16 August. In the first decade of December the plants were covered with white agrotextile with density 23g/m2 that was removed at the beginning of April. The proportion of plant that passed the winter depending on a year of cultivation was 95-100% under argotextile, and 50-80% in open plot. The plants under agrotextile reached 28 cm a high and had 5-7 well-developed leaves, while those on the open plot were at phase of active foliage growing about 10-13 cm. long. Thus, for early mechanized planting in optimal terms the wintering seedlings grown under agrotextile had the best biometrical characteristics. Moreover the outcome of carrot seedlings was 1.2-1.25 million per hectare. Such quantity of seedlings was sufficient to plant 9-10 ha of carrot plants, where the coefficient of multiplication reached 9-10, and only 3 when growing seeds through mother plant as biennial culture. Viability of seed plants grown through seedlings was 100%. Losses of plant with weight 120-150 grams from damage caused by diseases was 23%. The seed yield, when growing seedlings was 639 kg/ha, but growing through plants was 332 kg/ha. The seed outcome suitable for precise mechanized sowing through seedling growing was 77%, where seed germination was 90%, with seed fraction 1.51 and >2.0 mm. It was essentially improved their yielding characteristics. Seed outcome from this fraction obtained through planting method was 32%. The proportion of seeds in fraction 1-1.5 mm was 68%. For mechanized single-seed sowing, the seeds can be used only after mini-coating. The seed
Anderson, T.M.; Kumordzi, B.B.; Fokkema, W.; Valls Fox, H.; Olff, H.
Premise of research. African grass communities are dominated by two distinct functional types: tall, caespitose bunch grasses and short, spreading lawn grasses. Functional type coexistence has been explained by differences in defoliation tolerance, because lawn grasses occur in intensively grazed
, guinea grass (panicum maximum) and forest which comprises iroko (milicia ezcelea) and white afara (terminalia superba) trees in the ratio of 2:1 approximately. Excess noise attenuation spectra have been plotted for the grass and forest for ...
Nano, Catherine E M; Clarke, Peter J
Predicting changes in vegetation structure in fire-prone arid/semi-arid systems is fraught with uncertainty because the limiting factors to coexistence between grasses and woody plants are unknown. We investigated abiotic and biotic factors influencing boundaries and habitat membership in grassland (Triodia or 'spinifex' grassland)-shrubland (Acacia aneura or 'mulga' shrubland) mosaics in semi-arid central Australia. We used a field experiment to test for the effects of: (1) topographic relief (dune/swale habitat), (2) adult neighbour removal, and (3) soil type (sand/clay) on seedling survival in three shrub and two grass species in reciprocal field plantings. Our results showed that invasion of the shrubland (swale) by neighbouring grassland species is negated by abiotic limitations but competition limits shrubland invasion of the grassland (dune). All species from both habitats had significantly reduced survival in the grassland (dune) in the presence of the dominant grass (Triodia) regardless of soil type or shade. Further, the removal of the dominant grass allowed the shrubland dominant (A. aneura) to establish outside its usual range. Seedling growth and sexual maturation of the shrubland dominant (A. aneura) was slow, implying that repeated fire creates an immaturity risk for this non-sprouter in flammable grassland. By contrast, rapid growth and seed set in the grassland shrubs (facultative sprouters) provides a solution to fire exposure prior to reproductive onset. In terms of landscape dynamics, we argue that grass competition and fire effects are important constraints on shrubland patch expansion, but that their relative importance will vary spatially throughout the landscape because of spatial and temporal rainfall variability.
The main reasons for changes in botanical names are briefly reviewed, with examples from the lists. At this time, about 1040 grass species and subspecific taxa are recognized in the subcontinent. Keywords: botanical research; botanical research institute; botany; grass; grasses; identification; name change; nomenclature; ...
Low rainfall in range areas restricts germination, growth and development of majority of range grasses. However, germination and establishment potential of forage grasses vary and depends on environmental conditions. Themeda triandra is an excellent known grass to grow under different environmental conditions.
A new species of grass frog of the genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schilJukorum and Ptychadsna mossambica. the new species differs In advenisemen1 call, and erlernal charaders. An examination of a series of published sonagrams indicates.
Ratajová, A.; Tříska, Jan; Vrchotová, Naděžda; Kolář, L.; Kužel, S.
Roč. 26, č. 4 (2013), s. 199-203 ISSN 2151-321X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : grass pollen pollution * biofuel s farming * temperate climate * PK-fertilization * N-fertilization * phenolic Subject RIV: EH - Ecology, Behaviour Impact factor: 0.556, year: 2013
Full Text Available Bromus carinatus Hook. & Arn., Bromus hordeaceus L., Bromus pubescens Muhl. ex Willd. and Bromus secalinus L. were recently found at middle elevations of southern and central Taiwan, respectively. We present taxonomic treatments, distribution map, and line-drawings of these introduced alien brome grasses.
Jørgensen, Rasmus Nyholm; S. Nadimi, Esmaeil
The Technology The technology is one of a kind, as there is no such mathematical model estimating animal feed uptake available today. The estimation of grass uptake, is based on real time wireless sensor data, cow merit and climate data. Relevant cow behaviour data (such as location, movement vel...
Korres, N.E.; Thamsiriroj, T.; Smith, B.
have advanced the role of grassland as a renewable source of energy in grass biomethane production with various environmental and socio-economic benefits. It is underlined that the essential question whether the gaseous biofuel meets the EU sustainability criteria of 60% greenhouse gas emission savings...
Kumar, Shiv; Bejiga, G; Ahmed, S; Nakkoul, H; Sarker, A
Grass pea is a promising crop for adaptation under climate change because of its tolerance to drought, water-logging and salinity, and being almost free from insect-pests and diseases. In spite of such virtues, global area under its cultivation has decreased because of ban on its cultivation in many countries. The ban is imposed due to its association with neurolathyrism, a non-reversible neurological disorder in humans and animals due to presence of neurotoxin, β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP) in its seedlings and seeds. The traditional varieties of grass pea contain 0.5-2.5% β-ODAP. Exploitable genetic variability for β-ODAP has been observed for development of low ODAP varieties, which along with improved agronomic and detoxification practices can help reduce the risk of lathyrism. Collaborative efforts between ICARDA and NARS have resulted in development of improved varieties such as Wasie in Ethiopia, Ratan, Prateek and Mahateora in India, and BARI Khesari-1 and BARI Khesari-2 in Bangladesh with pea requires paradigm shift in its approach for a possible genetic breakthrough. Copyright © 2010 Elsevier Ltd. All rights reserved.
Full Text Available Efficient utilization of allelopathy in the agricultural practice requires searching for some species and developmental stages when the allelopathic substances are generated in bioactive concentrations. That also requires the knowledge of allelopathy mechanisms and primarily its separation from the other aspects of plant activity, mainly from competition for environmental resources. This task, however, has remained vital in the studies on plant interference, being extremely difficult to perform under field conditions. Therefore, the studies were conducted in the laboratory. To determine the activity of an allelopathic agent of the selected grass species, the density dependent phytotoxicity model was employed. The model is based on the fact that an increase of acceptor plants density evokes a decrease of their response to the allelopathic compounds, whereas the negative effects of the competition become more intense. A higher rate of acceptor plants growth accompanying their density increase in the given object does not agree with the competition rules and thus, it may imply an allelopathic background of the observed changes. In the presented studies, the allelopathic properties of grasses - donors were evaluated by studying the effect of two densities of the emerging seeds and two- and four weeks aged seedlings of F. arundinacea, L. multiflorum, L. perenne and P. pratensis. The tested species - acceptor Ph. pratensis was sown in the density of 10 and 20 seeds in a pan. The results revealed that the germination of acceptor seeds was differentiated depending on their density in the pan, and on the species, density and the age of the donor. Inhibition of Ph. pratense seed germination in objects with a lover density may prove allelopathic effects of the studied donor grasses.
Abundance (g/m 2 ) and diaspore weight are positively correlated in seven species of perennial grasses that occur in prairies. The rare grasses (10.0 g/m 2 ) have heavy dispersal units (2.23 to 2.80 mg). This result is the first reported differentiating trait between related rare and common organisms occurring in same habitat.Three hypotheses that explain this phenomenon are compared; the third most likely holds. First, rare grasses may be rare because their small seeds are less successful in establishment than those of common grasses. Second, if the persistence of small populations is marginal, rare grasses may devote less energy (or other currency) to seed production. Third, rare grasses may be colonizers of spatially and temporally rare microsites appropriate for growth and thus have seeds adapted for longer distance dispersal than those of common grasses. This last hypothesis suggests a new pathway for the evolution of weeds.
Savage, M. J.
Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass
Full Text Available When 136 samples of dying carrot seedlings from several fields were analyzed Alternaria rudicina proved to be the most common seedling pathogen (41%, followed by some Fusarium species (27%, mostly F. avenaceum.The less common seedling pathogens were Pythium spp. (13%, Phoma spp.(2,5% and Botrytis cinerea (1,4%. Some other fungi (Bipolaris sorokiniana, Sclerotinia sclerotiorum, Stemphylium botryosym and Ulocladium consortiale were found in less than 1% of seedlings examined.
R. Kasten Dumroese; Gale Thompson; David L. Wenny
Although a commercial growing medium with incorporated agricultural lime had been successfully used for years, it caused growth distortion of coniferous and deciduous seedlings during 1988. Seedlings grown in the amended medium were stunted and chlorotic, often with disfigured needles and multiple tops. Seedlings grown in the same medium without incorporated lime grew...
Pepper seedlings inoculated with arbuscular mycorrhizal AM fungus, Glomus etunicatum, produced cellulase, polygal-acturonase and pectin methylestrase enzymes. The activities of the enzymes increased as the pepper seedlings matured in age, showing that the activity of the enzymes in the seedlings was age mediated.
Paula C. Gnehm; Brad Hadley
We investigated the effects of a single arson wildfire by comparing its impact on pine seedling recruitment with that of both prescribed fire and unburned compartments. Although a t-test detected no significant difference in pine seedling recruitment (p = 0.38), the "wildfire" treatment produced 127 more seedlings than the unburned...
Qu, Y. H.; Wei, X. M.; Hou, Y. F.; Chen, B.; Chen, G. Q.; Lin, C.
Most seedlings of crops are produced in solar greenhouse or nursery, from which some problems about energy waste and environment pollution arise. This study aims at investigating the characteristics and effect of an environmental friendly type seedling breeding system. The results demonstrate that crops can grow with a short period and little pollution in the new seedling breeding system with total manpower controllable environment that is not influenced by geography, climate and other natural conditions. By multilayer, nonplanar seedling breeding and annual batches arrangement, utilization ratio of unit area land and seedlings yield can be improved for several times and even more than 10 times. Conclusions can be obtained from the tomato seedling breeding experiments: (1) each growth index of tomato seedlings that are under the conditions of 291 μmol/m2 s artificial illumination intensity is remarkably better than those produced in greenhouse with natural lights. (2) The environment of the seedling breeding system can be accurately controlled. The segmented temperature changed management can be applied according to the photosynthetic characteristics of plants, and not affected by the outside environment, which makes each growth index of tomato seedling constant in different seasons. The seedlings thus grow strong and can achieve the level of commodity seedlings after 20-30 days. (3) The temperature and humidity environment of the seedling breeding system can be accurately controlled according to plants growth demands.
The Montana Conservation Seedling Nursery (MCSN) in Missoula produces 750,000 container seedlings annually in containers ranging in size from 66 cm3 (4 in3) up to 61 L (16 gal) pots. The MCSN is a production facility with no research funding. When we encounter a promising idea for improving our seedlings or the efficiency of nursery operations, we rarely perform...
More than 75% of newly emerged seedling losses were attributed to water stress, which suggests that abiotic factors (mainly rainfall) may account for most of the ... Most seedlings resprouted after aboveground organs were killed by fire. ... Key Words: Colophospermum mopane; Germination; Seedling; Recruitment; Fire
Stephen W. Fraedrich; L. David Dwinell; Michelle M. Cram
Pine seedling production and pest problems were evaluated in methyl bromide-fumigated and nonfumigated plots in two fields at a South Georgia nursery. In one field, fumigation increased loblolly pine seedling bed density in only 1 of 4 years. Seedlings were often significantly larger in fumigated than nonfumigated plots. In the other field, no differences were observed...
In this study, the genetic variation of some seedling characteristics of Turkish fir was investigated. A total of 303 trees were selected from 17 plots and 10 seedlings from each tree were used. Fifteen morphological characteristics were determined, including root collar diameter, seedling height, total needle, bud length and ...
Andrea Vita Reis Mendonça
Full Text Available The aim of this study was to assess the technical feasibility of using biodegradable containers made of fiber waste of Attalea funifera Martius to produce seedling of Eucalyptus camaldulensis Dehnh. The work was carried out in three stages: manufacture of piassava fiber containers, seedling production and field simulation. The experiment of seedling production was in completely randomized design, with two treatments (polyethylene tube and biodegradable container and 10 repetitions, with 64 seedlings per repetition. After 93 days, seedlings were evaluated based on quality variables. The simuation of initial growth of seedlings in the field consisted in planting seedlings in containers of 11L, in completely randomized design, with three treatments: seedlings produced in polyethylene tubes; seedlings produced in biodegradable containers, without removal of the container during planting; and seedlings produced in biodegradable containers, with removal of the container at planting, with ten repetitions, with one seedling by repetition. The biodegradable container withstood the production cycle and resulted in seedlings within acceptable standards quality. The use of biodegradable container, made of palm fibers, waived the removal of this vessel in the final planting.
Photosynthetic activity of exposed cotyledons of Telfairia occidentalis during seed germination and the growth of seedlings with removed or attached cotyledons were investigated. The experiment investigated how early cotyledon removal affects seedling growth. Seedlings from seeds germinated in light and those ...
Responses tested were seedling recruitment, species turnover, species' biomass, mortality of seedlings, total number of perennial and woody species recruited and leguminous species. There were high significant correlations of 0.85 and 0.87 between seedling recruitment and mortality in both sites, indicating that other ...
Raymond D. Ratliff; Renee G. Denton
Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the...
R. Kasten Dumroese
Continuing to fertilize bareroot and container seedlings during the hardening process (from cessation of height growth until lifting) can improve seedling viability. The process of fertilizing during hardening has many names, but in the last decade a new term, nutrient loading, has come into use. The process of nutrient loading seedlings leads to luxury consumption...
Full Text Available The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively. Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment.
George A. Schier; Carolyn J. McQuattie
Manganese (Mn) toxicity may play an important role in the poor survival of seedlings in declining sugar maple (Acer saccharum Marsh.) stands in northern Pennsylvania. To determine the effect of Mn on the growth of sugar maple seedlings, 1-year-old seedlings inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi and growing in sand-vermiculite-...
White spruce seedlings--20, 19, 18, and 17 inches tall--were selected among 2-2 transplants; controls from the same beds averaged 7.7 inches tall. After 18 years in the field, the selected seedlings continued to have a 30 percent height growth advantage over the controls. This note discusses how to incorporate super spruce seedlings into a tree breeding program....
V. N. Bubenchikova; E. A. Nikitin
The article present results of the study for a anatomic structure of Campanula rotundifolia grass from Campanulaceae family. Despite its dispersion and application in folk medicine, there are no data about its anatomic structure, therefore to estimate the indices of authenticity and quality of raw materials it is necessary to develop microdiagnostical features in the first place, which could help introducing of thisplant in a medical practice. The purpose of this work is to study anatomical s...
Kolb, Rosana Marta; Pilon, Natashi Aparecida Lima; Durigan, Giselda
Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i) recently collected seeds and seeds after six months storage, ii) under constant and alternating temperatures, and iii)...
Wilson, Gail W T; Hickman, Karen R; Williamson, Melinda M
Soil organisms play important roles in regulating ecosystem-level processes and the association of arbuscular mycorrhizal (AM) fungi with a plant species can be a central force shaping plant species' ecology. Understanding how mycorrhizal associations are affected by plant invasions may be a critical aspect of the conservation and restoration of native ecosystems. We examined the competitive ability of old world bluestem, a non-native grass (Caucasian bluestem [Bothriochloa bladhii]), and the influence of B. bladhii competition on AM root colonization of native warm-season prairie grasses (Andropogon gerardii or Schizachyrium scoparium), using a substitutive design greenhouse competition experiment. Competition by the non-native resulted in significantly reduced biomass production and AM colonization of the native grasses. To assess plant-soil feedbacks of B. bladhii and Bothriochloa ischaemum, we conducted a second greenhouse study which examined soil alterations indirectly by assessing biomass production and AM colonization of native warm-season grasses planted into soil collected beneath Bothriochloa spp. This study was conducted using soil from four replicate prairie sites throughout Kansas and Oklahoma, USA. Our results indicate that a major mechanism in plant growth suppression following invasion by Bothriochloa spp. is the alteration in soil microbial communities. Plant growth was tightly correlated with AM root colonization demonstrating that mycorrhizae play an important role in the invasion of these systems by Bothriochloa spp. and indicating that the restoration of native AM fungal communities may be a fundamental consideration for the successful establishment of native grasses into invaded sites.
Luciano S. Lima
Full Text Available Objective. This experiment was conducted to evaluate the best concentration of peanut cake in the ensiling of massai grass of the chemical-bromatological composition, fermentative characteristics, forage value rate, ingestion estimates, and digestibility of dry matter in the silage. Materials and methods. The experiment was carried out at the Experimental Farm of São Gonçalo dos Campos at the Federal University of Bahia, Brazil. The treatments consisted of massai grass that was cut at 40 days and dehydrated, in addition to 0%, 8%, 16%, and 24% peanut cake in the fresh matter and treatment without cake. The material was compressed in experimental silos (7 liter that were opened after 76 days. Results. The addition of 8-24% peanut cake improved the silage’s chemical-bromatological parameters, increased the dry matter and non-fiber carbohydrates and reduced the fibrous components. There was a linear increase in the estimated values of digestibility and the ingestion of dry matter depending on the levels of peanut cake in the silage. There was an improvement in the fermentative characteristics, with a quadratic effect positive for levels of ammoniacal nitrogen. The forage value rate increased linearly with the inclusion of peanut cake. Conclusions. The inclusion of up to 24% peanut cake during ensiling of massai grass increases the nutritive value of silage and improves fermentation characteristics.
Harold J. Derr; William F. Mann
Direct seeding of the southern pines is a versatile reforestation technique that is being widely accepted by land managers. On many sites it is more economical than planting nursery-grown seedlings or waiting for natural reproduction. It is applicable on some sites where access, terrain, or drainage conditions make planting difficult. Commercial trials have proved it...
The effects of nut-sowing orientations on the germination of cashew nuts and the responses of the resultant seedlings to cotyledon removed were studied in the nursery. While cashew nuts sown flat and those with stylar-end up had highest mean germination of 91.67 % and 92.50 % respectively the nuts sown with ...
AND POTASSIUM DISTRIBUTIONS IN THE MANGROVE. SPECIES (Avicennia germinans L. ... EFFET DE LA SALINITE SUR LA CROISSANCE, LA DISTRIBUTION DES TENEURS EN EAU, SODIUM ET POTASSIUM. D'UNE ESPECE DE .... distilled water and stored for germination studies. After three days, seedlings were ...
Jones, Lisa C.; Schwinning, Susanne; Esque, Todd C.
Increases in fire frequency are disrupting many ecological communities not historically subjected to fire. In the southwestern United States, the blackbrush (Coleogyne ramosissima) community is among the most threatened, often replaced by invasive annual grasses after fire. This long-lived shrub is vulnerable because it recruits sporadically, partially due to mast seeding and the absence of a seed bank. The goal of this study was to evaluate if shrub restoration can be enhanced by identifying and ameliorating recruitment limitations. Specifically, we tested the effect of encapsulating seeds in predation-deterring “seed balls.” We also tested the effects of nurse plants and mammalian exclusion cages on seedling emergence, growth, and survivorship. These experiments were conducted in a full-factorial design across three sites differing in elevation. Over 2 years, 13% of all planted seeds emerged and the effect of seed balls was overwhelmingly negative because of low emergence. Nurse plants had overall positive effects at Low Elevation, but negative effects at Mid- and High Elevation. Emergence and survival were highest in caged plots everywhere, and effect sizes increased with elevation. Interactions between the cage and the nurse plant treatments indicated that nurse plants tended to attract mammalian predators, lowering emergence and seedling survivorship, particularly at higher elevations. Findings conform to the stress-gradient hypothesis in that interactions among seedlings and mature plants shifted from facilitation to competition as environmental stress decreased with increasing elevation, suggesting that they are transferable to ecologically similar communities elsewhere. Knowledge of site-specific recruitment limitations can help minimize ineffective restoration efforts.
Full Text Available Cessation of the management of semi-natural habitats such as grasslands and meadows contributes to secondary succession and encroachment of native and alien tall-growing perennials, large tussock grasses, shrubs, and trees. Thus, the formation of gaps in the plant canopy and litter, enabling seedling recruitment, appears to be a very effective method for the restoration of several plant communities. The main objective of the research was to assess the effect of the shape of openings on microenvironmental conditions and seedling recruitment in Molinietum caeruleae patches in various habitat conditions. In all study patches, circular and linear openings, comparable in area, were randomly created through the removal of plant canopy and litter layer. The circular gaps presented greater light availability and lower soil humidity than linear openings, while soil temperature within differently shaped openings was similar. Regardless of differences in microenvironmental conditions, the total number of seedlings in differently shaped gaps did not vary considerably. Three plant categories were found: (i those recruited mostly in circular openings, (ii those recruited mostly in linear gaps, (iii those colonizing circular and linear gaps similarly. The colonizers of circular gaps represented various synecological groups (ruderal, grasslands and meadows, young tree communities and diverse life forms (therophytes, hemicryptophytes, chamaephytes, phanerophytes, while the colonizers of linear gaps were meadow and grassland hemicryptophytes. The formation of linear openings contributes to increases in the abundance of meadow taxa, while the creation of circular openings may have a negative effect, contributing to the promotion of the secondary succession process.
Ichsan Nurul Bari
Full Text Available Exploration of allelochemicals with phytotoxic effects is intended to minimize a current dependency on synthetic herbicides in weed management. Several allelochemicals from the tropical tree Cerbera manghas (sea mango have been reported as termiticides and bactericides. The present study investigated possible phytotoxic effects of C. manghas leaf extracts under laboratory conditions. Four monocots: barnyard grass (Echinochloa crus-galli, foxtail fescue (Vulpia myuros, Italian ryegrass (Lolium multiflorum, and timothy (Phleum pratense and four dicots: alfalfa (Medicago sativa, garden cress (Lepidium sativum, lettuce (Lactuca sativa, and rapeseed (Brassica napus were used as test species. Elongation of both shoots and roots of seedlings was measured to assess any phytotoxic effects. The results showed that the sensitivities of shoots and roots were different between the test species, and the inhibition of seedling elongation significantly increased with increasing concentration of leaf extracts of C. manghas for all the test species. The IC50 (50% inhibitory concentration values showed that 8.50–32.30 and 4.26–34.67 mg dry weight equivalent extract mL−1 of C. manghas inhibited seedling elongation by 50%, for shoots and roots respectively. Isolation and identification of the phytotoxic substances from C. manghas are suggested for future investigation.
Calderón, Moisés; Brandt, Tove
Immunotherapy is the only treatment for allergy that has the potential to alter the natural course of the disease. Sublingual immunotherapy (SLIT) for grass pollen-induced rhino-conjunctivitis has been developed to make immunotherapy available to a broader group of allergic patients. In the largest clinical programme ever conducted with allergen-specific immunotherapy, over 1,700 adults and 260 children have been exposed to Grazax(®). Grazax is formulated as an oral lyophilisate (tablet) for sublingual administration, containing 75,000 SQ-T standardized allergen extract of grass pollen from Phleum pratense. Grazax is indicated for treatment of grass pollen-induced rhinitis and conjunctivitis in adult patients with clinically relevant symptoms and diagnosed with a positive skin prick test and/or specific IgE test to grass pollen. In phase I trials doses from 2,500 to 1,000,000 SQ-T were tested. All doses were well tolerated and 75,000 SQ-T, with approximately 15 mug major allergen protein, was chosen as the optimal dose. Three phase III trials are ongoing, one being a long-term trial. Results from GT-08 trial first and second treatment years showed a reduction of 30% and 36%, respectively, in daily rhino-conjunctivitis symptom scores and a reduction of 38% and 46% of daily rhino-conjunctivitis medication scores compared with placebo over the entire grass pollen season. Subjects treated with Grazax also had an increased number of well days and improved quality of life, and more subjects experienced excellent rhino-conjunctivitis control. The most common adverse events related to Grazax are local reactions, such as pruritus, edema mouth, ear pruritus, throat irritation, and sneezing. We conclude that Grazax is efficacious and safe for treatment of rhino-conjunctivitis due to grass pollen allergy.
Full Text Available According to the data obtained from in vivo and in vitro testing in Serbia, a significant number of patients have allergic symptoms caused by grass pollen. We examined the protein composition of grass pollens (Dactylis glomerata, Lolium perenne and Phleum pratense and cross-reactivity in patients allergic to grass pollen from our region. The grass pollen allergen extract was characterized by SDS-PAGE, while cross-reactivity of single grass pollens was revealed by immunoblot analysis. A high degree of cross-reactivity was demonstrated for all three single pollens in the sera of allergic patients compared to the grass pollen extract mixture. Confirmation of the existence of cross-reactivity between different antigenic sources facilitates the use of monovalent vaccines, which are easier to standardize and at the same time prevent further sensitization of patients and reduces adverse reactions. [Projekat Ministarstva nauke Republike Srbije, br. 172049 i br. 172024
The viability of using rye-grass in the UK as a wet energy crop was investigated in this project. The harvesting of rye-grass, the operation of pilot-scale digesters fed with cut rye-grass, and the operation of a biogas plant are described. Use of the digestate as a fertilizer for the grass was examined and the need for added farm manure or slurry to enrich the nutrient content of the grass and produce better yields is noted. Details are given of the digester design and the design of a commercial-scale biogas plant able to take a variety of liquid and solid feeds. Energy balance, the economics of the commercial design, the ensiling of the grass, and methane yields are considered.
Smyth, Beatrice M.; Smyth, Henry; Murphy, Jerry D.
Research highlights: → We identified assessment criteria for determining the regional potential for grass biomethane. → Grass biomethane is distributed via the natural gas grid. → The criteria include: land use; grass yields; gas grid coverage; availability of co-substrates. → The county with the highest potential can fuel 50% of cars or supply 130% of domestic gas consumption. - Abstract: Grass biogas/biomethane has been put forward as a renewable energy solution and it has been shown to perform well in terms of energy balance, greenhouse gas emissions and policy constraints. Biofuel and energy crop solutions are country-specific and grass biomethane has strong potential in countries with temperate climates and a high proportion of grassland, such as Ireland. For a grass biomethane industry to develop in a country, suitable regions (i.e. those with the highest potential) must be identified. In this paper, factors specifically related to the assessment of the potential of a grass biogas/biomethane industry are identified and analysed. The potential for grass biogas and grass biomethane is determined on a county-by-county basis using multi-criteria decision analysis. Values are assigned to each county and ratings and weightings applied to determine the overall county potential. The potential for grass biomethane with co-digestion of slaughter waste (belly grass) is also determined. The county with the highest potential (Limerick) is analysed in detail and is shown to have ready potential for production of gaseous biofuel to meet either 50% of the vehicle fleet or 130% of the domestic natural gas demand, through 25 facilities at a scale of ca. 30 kt yr -1 of feedstock. The assessment factors developed in this paper can be used in other resource studies into grass biomethane or other energy crops.
Full Text Available The aim of this study was to know effects of saline condition to crop physiology, growth andforages yield. A factorial completed random design was used in this study. The first factor was type ofgrass, these were king grass (Pennisetum hybrid, napier grass (Pennisetum purpureum, panicum grass(Panicum maximum, setaria grass (Setaria sphacelata and star grass (Cynodon plectostachyus. Thesecond factor was salt solution (NaCl with concentration 0, 100, 200 and 300 mM. Parameters of thisexperiment were the percentage of chlorophyll, rate of photosynthesis, number of tiller, biomass and drymatter yield. Data were analyzed by analysis of variance and followed by Duncan’s multiple range testwhen there were significant effects of the treatment. Panicum grass had the highest chlorophyll content(1.85 mg/g of leaf. Photosynthesis rate of setaria grass was the lowest. The increasing of NaClconcentration up to 300 mM NaCl reduced chlorophyll content, rate of photosynthesis, tiller number,biomass yield and dry matter yield. Responses of leaf area, biomass and dry matter yield to salinitywere linear for king, napier, panicum and setaria grasses. In tar grass, the response of leaf area andbiomass ware linear, but those of dry matter yield was quadratic. The response of tiller number tosalinity was linear for all species.
V. N. Bubenchikova
Full Text Available The article present results of the study for a anatomic structure of Campanula rotundifolia grass from Campanulaceae family. Despite its dispersion and application in folk medicine, there are no data about its anatomic structure, therefore to estimate the indices of authenticity and quality of raw materials it is necessary to develop microdiagnostical features in the first place, which could help introducing of thisplant in a medical practice. The purpose of this work is to study anatomical structureof Campanula rotundifolia grass to determine its diagnostic features. Methods. Thestudy for anatomic structure was carried out in accordance with the requirements of State Pharmacopoeia, edition XIII. Micromed laboratory microscope with digital adjutage was used to create microphotoes, Photoshop CC was used for their processing. Result. We have established that stalk epidermis is prosenchymal, slightly winding with straight of splayed end cells. After study for the epidermis cells we established that upper epidermis cells had straight walls and are slightly winding. The cells of lower epidermishave more winding walls with prolong wrinkled cuticule. Presence of simple one-cell, thin wall, rough papillose hair on leaf and stalk epidermis. Cells of epidermis in fauces of corolla are prosenchymal, with winding walls, straight or winding walls in a cup. Papillary excrescences can be found along the cup edges. Stomatal apparatus is anomocytic. Conclusion. As the result of the study we have carried out the research for Campanula rotundifolia grass anatomic structure, and determined microdiagnostic features for determination of raw materials authenticity, which included presence of simple, one-cell, thin-walled, rough papillose hair on both epidermises of a leaf, along the veins, leaf edge, and stalk epidermis, as well as the presence of epidermis cells with papillary excrescences along the edges of leaves and cups. Intercellular canals are situatedalong the
Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula
, we address crucial topics to implement hybrid breeding, such as the availability and development of heterotic groups, as well as biological mechanisms for hybridization control such as self-incompatibility (SI) and male sterility (MS). Finally, we present potential hybrid breeding schemes based on SI...... of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods...
Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)
Results described in this presentation are from a large EU-project - Development of a new crop production system based on delayed harvesting and system for its combined processing to chemical pulp and biofuel powder. This is a project to develop the use of Reed Canary Grass (Phalaris Arundinaceae) both for pulp industry and energy production. The main contractor of the project is Swedish University of Agricultural Sciences (coordinator), task coordinators are United Milling Systems A/S from Denmark, and Jaakko Poeyry Oy and VTT Energy from Finland In addition, there are partners from several countries participating in the project
Three aboveground treatments (full light competition, no light competition and clipping to simulate grazing), and two belowground treatments (full belowground competition and belowground competition excluded by a root tube), were used. On all soil depths the three grass species differed in mean mass, with E. racemosa ...
weighing). Fish were fed once a-day. The feed refusal was measured daily by siphoning out the debris on the bottom of the aquaria which was collected on a sieve .... raising grass carp without the need for supplementary feeding. Cabbage is widely produced on both a subsis- tence and commercial scale by local farmers.
Full Text Available Moisés Calderón1, Tove Brandt21Section of Allergy and Clinical Immunology, Royal Brompton Hospital, Imperial College, NHLI, London, UK; 2Group Clinical Development, ALK-Abelló A/S, Hørsholm, DenmarkAbstract: Immunotherapy is the only treatment for allergy that has the potential to alter the natural course of the disease. Sublingual immunotherapy (SLIT for grass pollen-induced rhino-conjunctivitis has been developed to make immunotherapy available to a broader group of allergic patients. In the largest clinical programme ever conducted with allergen-specific immunotherapy, over 1,700 adults and 260 children have been exposed to Grazax®. Grazax is formulated as an oral lyophilisate (tablet for sublingual administration, containing 75,000 SQ-T standardized allergen extract of grass pollen from Phleum pratense. Grazax is indicated for treatment of grass pollen-induced rhinitis and conjunctivitis in adult patients with clinically relevant symptoms and diagnosed with a positive skin prick test and/or specific IgE test to grass pollen. In phase I trials doses from 2,500 to 1,000,000 SQ-T were tested. All doses were well tolerated and 75,000 SQ-T, with approximately 15 µg major allergen protein, was chosen as the optimal dose. Three phase III trials are ongoing, one being a long-term trial. Results from GT-08 trial first and second treatment years showed a reduction of 30% and 36%, respectively, in daily rhino-conjunctivitis symptom scores and a reduction of 38% and 46% of daily rhinoconjunctivitis medication scores compared with placebo over the entire grass pollen season. Subjects treated with Grazax also had an increased number of well days and improved quality of life, and more subjects experienced excellent rhino-conjunctivitis control. The most common adverse events related to Grazax are local reactions, such as pruritus, edema mouth, ear pruritus, throat irritation, and sneezing. We conclude that Grazax is efficacious and safe for treatment
Milene Rodrigues Peres
Full Text Available This research studied the growth of lettuce seedlings (Lactuca sativa L. cv. Veronica cultivated under greenhouse conditions, using polystyrene trays with 128 cells and three different commercial substrates: Golden Mix, Plantmax and Plugmix. The statistical design was in the form of randomized blocks, with eight (8 replications. Fifteen days after sowing the seeds, samples (five in total of plants were taken to evaluate the height, number of leaves, leaf area, leaf specific area, leaf specific weight, absolute and relative growth rates and net assimilation rates. The evaluated growth indexes showed that seedlings produced with the Plantmax and Plugmix substrates could be planted 25 days after sowing, since they have at least four definitive leaves. The Plantmax substrate showed, at the end of the evaluation, the best results in height, dry weight, leaf specific area, absolute growth rates and net assimilation rates.
Rosana Marta Kolb
Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.
Czako, M.; Liang Dali; Marton, L. [Dept. of Biological Sciences, Univ. of South Carolina, Columbia, SC (United States); Feng Xianzhong; He Yuke [National Lab. of Plant Molecular Genetics, Shanghai Inst. of Plant Physiology, Chinese Academy of Sciences, Shanghai, SH (China)
Wetland grasses and grass-like monocots are very important natural remediators of pollutants. Their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. Tissue culture is prerequisite for genetic manipulation, and methods are reported here for in vitro culture and micropropagation of a number of wetland plants of various ecological requirements such as salt marsh, brackish water, riverbanks, and various zones of lakes and ponds, and bogs. The monocots represent numerous genera in various families such as Poaceae, Cyperaceae, Juncaceae, and Typhaceae. The reported species are in various stages of micropropagation and Arundo donax is scaled for mass propagation for selecting elite lines for pytoremediation. Transfer of key genes for mercury phytoremediation into the salt marsh cordgrass (Spartina alterniflora) is also reported here. All but one transgenic lines contained both the organomercurial lyase (merB) and mercuric reductase (merA) sequences showing that co-introduction into Spartina of two genes from separate Agrobacterium strains is possible. (orig.)
Rerisson José Cipriano dos Santos
Full Text Available Ensiling warm-season grasses often requires wilting due to their high moisture content, and the presence of low-soluble sugars in these grasses usually demands the use of additives during the ensiling process. This study evaluated the bromatological composition of the fodder and silage from five Pennisetum sp. clones (IPA HV 241, IPA/UFRPE Taiwan A-146 2.114, IPA/UFRPE Taiwan A-146 2.37, Elephant B, and Mott. The contents of 20 Polyvinyl chloride (PVC silos, which were opened after 90 days of storage, were used for the bromatological analysis and the evaluation of the pH, nitrogen, ammonia, buffer capacity, soluble carbohydrates, and fermentation coefficients. The effluent losses, gases and dry matter recovery were also calculated. Although differences were observed among the clones (p < 0.05 for the concentrations of dry matter, insoluble nitrogen in acid detergents, insoluble nitrogen in neutral detergents, soluble carbohydrates, fermentation coefficients, and in vitro digestibility in the forage before ensiling, no differences were observed for most of these variables after ensiling. All of the clones were efficient in the fermentation process. The IPA/UFRPE TAIWAN A-146 2.37 clone, however, presented a higher dry matter concentration and the best fermentation coefficient, resulting in a better silage quality, compared to the other clones.
Iodine-131 is one of the important fission products since it is selectively accumulated in the thyroid gland of man. The transfer of this isotope from contaminated grass to cows' milk is therefore of particular importance since milk is a major constituent of the diet especially for infants. The purpose of this paper is to discuss the transfer rate of this isotope from grass to milk of lactuating cows and its distribution in milk. It is said that the orally administered iodide is rapidly absorbed through the rumen wall and excreted mainly to urine. The absorbed iodine is accumulated highly in the thyroid gland and the considerable amount is secreted to milk. Garner et al. showed that about 5% of a dose of 131 I was found in the milk within 7 days. The extremes were 1.43 to 16.4%. Present author obtained that 18 - 30% of the dosed 131 I was secreted into milk within 7 days, indicating somewhat higher transfer rate than that of Garner et al. It was reported that more than 90% of 131 I was found in milk serum in the ionic form. The countermeasures for diminishing 131 I in milk were also presented. (author)
Slow establishment of the genus Leucaena from seed has been attributed to law seedling vigor and late nodulation. Observation of early seedling growth indicated that partitioning of a large proportion of resources to the root of young Leucaena seedlings could account, in part, for the slow initial shoot growth observed in this genus. Therefore, a series of experiments were conducted to examine the partitioning of stored seed reserves, photosynthate, and nitrogen in developing Leucaena seedlings. The effects of nodulation and nitrogen fertilization on partitioning of nutrients in the seedling were also examined. Seed reserves were initially used for radicle growth in dark grown seedlings; however, partitioning soon shifted to the hypocotyl. By four days after imbibition, hypocotyl weight exceeded radicle weight in both species tested (L. leucocephala and L. retusa), at all temperatures above 20 0 C. Two experiments were conducted examining the carbon partitioning of L. leucocephala cultivar K-8 using 14 CO 2 pulse labeling techniques
Although an adequate knowledge of growth patterns and defoliation effects in perennial grasses is a prerequisite for the rational use of veld and pastures for animal production, our knowledge of this subject is far from adequate. The results of various physiological and clipping studies on tropical and sub-tropical grasses are ...
Lisa M. Ellsworth; Creighton M. Litton; Alexander P. Dale; Tomoaki Miura
How does potential fire behavior differ in grass-invaded non-native forests vs open grasslands? How has land cover changed from 1950â2011 along two grassland/forest ecotones in Hawaii with repeated fires? A study on non-native forest with invasive grass understory and invasive grassland (Megathyrsus maximus) ecosystems on Oahu, Hawaii, USA was...
Variation in important pasture grasses. II. Cytogenetic and reproductive variation. Spies J.J., Gibbs Russell G.E.. Abstract. The chromosome numbers and reproductive variation of seven important pasture grasses from South Africa are compared. This comparison indicates that all these species form polyploid complexes, ...
Jack D. Cohen; Richard D. Stratton
The Grass Valley Fire started October 22, 2007 at approximately 0508, one-mile west of Lake Arrowhead in the San Bernardino Mountains. Fuel and weather conditions were extreme due to drought, dry Santa Ana winds, and chaparral and conifer vegetation on steep terrain. The fire proceeded south through the Grass Valley drainage one-mile before impacting an area of dense...
Grass, seeded on a steep roadcut in western Oregon, reduced erosion but caused increased surface runoff during a 3-year period of observation. These results were obtained at H. J. Andrews Experimental Forest from a study designed to measure effectiveness of grass in controlling soil erosion from exposed roadbanks. Additional measurements for varying soil types will be...
Potentials of some agricultural waste and grasses were investigated. Potassium hydroxide from wood ash was used as alkali for pulping. Results from visopan Microscope showed that banana stalk has the highest fibre length of 2.60 mm and Bahaman grass has the least fibre length of 0.85 mm. Runkel Ratio (RK) for ...
Despite the forage potential of elephant grass, controlling canopy structure during grazing has limited its use in pasture. This study was conducted to determine the effect of grazing frequency and post-grazing height on canopy structural characteristics of elephant grass genotypes. The treatments consisted of the factorial ...
Antioxidant potential of bamboo and elephant grass leaf extracts were evaluated in cooked and raw broiler meat stored under refrigeration at 3±20C. To a separate 350g of minced broiler meat, 1.5% bamboo leaf extract (BLE) or elephant grass extract (EGE) was added. There was a negative control without additive while a ...
Developing a method of agricultural field reclamation to native grasses in the Lower San Pedro Watershed could prove to be a valuable tool for educational and practical purposes. Agricultural field reclamation utilizing native grass crop production will address water table depletion, soil degradation and the economic viability of the communities within the watershed....
Abstract. The objective of this study was to compare the ruminal degradability of neutral detergent fibre (NDF) .... Felina were evaluated in the present study. The grass was harvested from the primary growth of monocultured grasses on 19 and 26 May of 2004 and 27 May and 10 ...... Nutritional Ecology of the Ruminant.
S. H. Faeth; S. M. Haase; S. S. Sackett; T. J. Sullivan; R. H. Remington; C. E. Hamilton
Systemic endophytic fungi in agronomic and turf grasses are well known for conferring increased resistance to herbivores and to abiotic stresses, such as drought, and increasing competitive abilities. Many native grasses also harbor high frequencies of the asexual and vertically-transmitted endophyte, Neotyphodium. In Festuca arizonica...
Full Text Available The high concentration of sodium chloride (NaCl in saline soils has negative effects on the growth ofmost plants. The experiment was designed to evaluate macro nutrient uptake (Nitrogen, Phosphorus andPotassium of forage grasses at different NaCl concentrations in growth media. The experiment wasconducted in a greenhouse at Forage Crops Laboratory of Animal Agriculture Faculty, Diponegoro University.Split plot design was used to arrange the experiment. The main plot was forage grasses (Elephant grass(Pennisetum purpureum and King grass (Pennisetum hybrida. The sub plot was NaCl concentrationin growth media (0, 150, and 300 mM. The nitrogen (N, phosphorus (P and potassium (K uptake in shootand root of plant were measured. The result indicated increasing NaCl concentration in growth mediasignificantly decreased the N, P and K uptake in root and shoot of the elephant grass and king grass. Thepercentage reduction percentage of N, P and K uptake at 150 mM and 300 mM were high in elephant grassand king grass. It can be concluded that based on nitrogen, phosphorus and potassium uptake, elephantgrass and king grass are not tolerant to strong and very strong saline soil.
Erika L. Geiger; Guy R. McPherson
Semi-desert grasslands flank the âSky Islandâ mountains in southern Arizona and Northern Mexico. Many of these grasslands are dominated by nonnative grasses, which potentially alter native biotic communities. One specific concern is the potential for a predicted feedback between nonnative grasses and fire. In a large-scale experiment in southern Arizona we investigated...
Forty-one populations in twenty-two species of highveld grasses were grown in pots of soil fertilized with solutions for comparing ammonium and nitrate nutrition. Cotton, tomato, cereal crops and pasture grasses were included for comparison. Roots and shoots were harvested separately, weighed and analysed for major ...
A two-year study was conducted in lightly grazed areas of Matopos Research Station, Zimbabwe, to evaluate the impact of widely spaced trees on understorey grass composition, yield and quality. The study trees were Terminalia sericea and Acacia karroo. Ordination techniques using grass density and biomass as indices ...
Grass-alfalfa mixtures have a number of benefits that make them attractive to producers. However, they can be problematic to establish and maintain. Research programs have made progress in understanding the benefits and challenges of alfalfa-grass mixtures. Mixtures may have greater winter survival ...
An experiment to determine the effects of lemon grass, Andropogon citratus L. extract on the rootknot nematodes (Meloidogyne spp.) of okra was conducted. Phytochemical analyses of the bioactive ingredients in lemon grass were carried out to determine the chemical compounds with nematicidal activities present in lemon ...
Bruinenberg, M.H.; Honing, Y. van der; Agnew, R.E.; Yan, T.; Vuuren, A.M. van; Valk, H.
Production performance of grass-fed dairy cows is often lower than expected from the estimated energy supply. To explain the overestimation of the energy content of grass for dairy cows, data from energy balance trials from three different laboratories (Wageningen, Lelystad and Hillsborough) were
Grassland and savannah constitute important biomes in southern Africa, and a long surruner period, high temperatures and wind are major factors contributing to the production of large amounts of anemophilous grass pollen for most of the year. Grass pollen was reported by David Ordmanl to be the major aero-allergen.
The increased deposition of trace metals from vehicle exhausts on plants has raised concerns about the risks of the quality of food consumed by humans since the heavy metals emitted through the exhaust by vehicles can enter food chain through deposition on grass grazed by animals. Grass (Paspalum Orbiculare) and ...
The use of anatomical features of the abaxial epidermis of grasses is discussed for the identification of fragments of epidermis present in samples of rumen. The reliability of this technique, and the variation of the epidermal characters in two widely distributed species of grass, is given. A "Key" to identity certain genera of ...
Reports on a trial which was conducted over a period of three seasons in which the advantages of the removal of grass weeds from dryland lucerne and medic pastures determined. Two herbicide treatments, an unsprayed control and a grass herbicide treatment were compared for three seasons. Illustrates with graphs and ...
Sampling with more than 100 readings is not, however, recommended owing to the poor reward (precision) per unit of sampling effort. Keywords: coastal forest; disc meter; fire management; fuel load; grass; grasses; herbage mass; pastures; precision; regression model; sample size; south africa; standing crop; thornveld; ...
J. P. Barnett; D. P. Jackson; R. K. Dumroese
A subset of seedlings from a larger study (Jackson and others 2006, 2007) were selected and evaluated for two growing seasons to relate bud development, and root-collar diameter (RCD), and height growth with three nursery fertilization rates. We chose seedlings in the 0.5 (lowest), 2.0 (mid-range), and 4.0 (highest) mg of nitrogen per seedling treatments. Buds moved...
Phillips, Allison J; Leger, Elizabeth A
• The ability to respond to environmental change via phenotypic plasticity may be important for plants experiencing disturbances such as climate change and plant invasion. Responding to belowground competition through root plasticity may allow native plants to persist in highly invaded systems such as the cold deserts of the Intermountain West, USA.• We investigated whether Poa secunda, a native bunchgrass, could alter root morphology in response to nutrient availability and the presence of a competitive annual grass. Seeds from 20 families were grown with high and low nutrients and harvested after 50 d, and seeds from 48 families, grown with and without Bromus tectorum, were harvested after ∼2 or 6 mo. We measured total biomass, root mass fraction, specific root length (SRL), root tips, allocation to roots of varying diameter, and plasticity in allocation.• Plants had many parallel responses to low nutrients and competition, including increased root tip production, a trait associated with tolerance to reduced resources, though families differed in almost every trait and correlations among trait changes varied among experiments, indicating flexibility in plant responses. Seedlings actively increased SRL and fine root allocation under competition, while older seedlings also increased coarse root allocation, a trait associated with increased tolerance, and increased root mass fraction.• The high degree of genetic variation for root plasticity within natural populations could aid in the long-term persistence of P. secunda because phenotypic plasticity may allow native species to persist in invaded and fluctuating resource environments. © 2015 Botanical Society of America, Inc.
Bodil K Ehlers
Full Text Available Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms.To explore if the allelopathic effects on a grass by the common thyme monoterpene "carvacrol" are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms or not (soil microorganisms present in soil. The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene.The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions.
Ehlers, Bodil K.
Background Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms. Methodology/Principal findings To explore if the allelopathic effects on a grass by the common thyme monoterpene “carvacrol” are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms) or not (soil microorganisms present in soil). The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene. Conclusions/Significance The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions. PMID:22125596
Jordan, N.R.; Larson, D.L.; Huerd, S.C.
Invasive plants are capable of modifying attributes of soil to facilitate further invasion by conspecifics and other invasive species. We assessed this capability in three important plant invaders of grasslands in the Great Plains region of North America: leafy spurge (Euphorbia esula), smooth brome (Bromus inermis) and crested wheatgrass (Agropyron cristatum). In a glasshouse, these three invasives or a group of native species were grown separately through three cycles of growth and soil conditioning in both steam-pasteurized and non-pasteurized soils, after which we assessed seedling growth in these soils. Two of the three invasive species, Bromus and Agropyron, exhibited significant self-facilitation via soil modification. Bromus and Agropyron also had significant facilitative effects on other invasives via soil modification, while Euphorbia had significant antagonistic effects on the other invasives. Both Agropyron and Euphorbia consistently suppressed growth of two of three native forbs, while three native grasses were generally less affected. Almost all intra- and interspecific effects of invasive soil conditioning were dependent upon presence of soil biota from field sites where these species were successful invaders. Overall, these results suggest that that invasive modification of soil microbiota can facilitate plant invasion directly or via 'cross-facilitation' of other invasive species, and moreover has potential to impede restoration of native communities after removal of an invasive species. However, certain native species that are relatively insensitive to altered soil biota (as we observed in the case of the forb Linum lewisii and the native grasses), may be valuable as 'nurse'species in restoration efforts. ?? 2007 Springer Science+Business Media B.V.
Ryon, Michael G [ORNL; Parr, Patricia Dreyer [ORNL; Cohen, Kari [ORNL
Land managers at the Department of Energy's Oak Ridge National Laboratory in East Tennessee are restoring native warm-season grasses and wildflowers to various sites across the Oak Ridge Reservation (ORR). Some of the numerous benefits to planting native grasses and forbs include improved habitat quality for wildlife, improved aesthetic values, lower long-term maintenance costs, and compliance with Executive Order 13112 (Clinton 1999). Challenges to restoring native plants on the ORR include the need to gain experience in establishing and maintaining these communities and the potentially greater up-front costs of getting native grasses established. The goals of the native grass program are generally outlined on a fiscal-year basis. An overview of some of the issues associated with the successful and cost-effective establishment and maintenance of native grass and wildflower stands on the ORR is presented in this report.
Arabi, M.I.E.; Al-Safadi, B.; Mir Ali, N.
The effect of three barley genotypes (Igri, Arabi abiad, and Taqa 76), three irradiation doses (0, 5, and 10 Gy), and two media (FW, modified FW), on the number of formed embryos, and the ratio between regenerated embryos to green seedlings and albinos, were studied using anther culture. Also the study involved the compatibility between seedling morphology and chromosome number. results indicated significant differences among the genotypes, and media in callus and embryos formation and also in the ratio and albino seedlings. However, the effect of gamma rays dose was significant only on embryos regeneration. A high percentage of compatibility (90%) was obtained between the seedling morphology and chromosome number. (author)
Barnes, T.G.; Larkin, J.L.; Arnett, M.B. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Forestry
The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat.
Barnes, T.G.; Larkin, J.L.; Arnett, M.B.
The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat
Christopher M. McGlone; Carolyn Hull Sieg; Thomas E. Kolb; Ty Nietupsky
Competition and resource availability influence invasions into native perennial grasslands by nonnative annual grasses such as Bromus tectorum. In two greenhouse experiments we examined the influence of competition, water availability, and elevated nitrogen (N) and phosphorus (P) availability on growth and reproduction of the invasive annual grass B. tectorum and two...
Juliana Teodora de Assis Reges
Full Text Available Fungal species from the Pyricularia genus are associated with blast disease in plants from the Poaceae family, causing losses in economically important crops such as rice, oat, rye, barley, wheat and triticale. This study aimed at characterizing the pathogenicity spectrum of P. pennisetigena and P. zingibericola to signal grass, barley and wheat, as well as comparing them with those from the species P. grisea and P. oryzae pathotype Triticum, which occur widely in the Brazilian agroecosystem. Twenty isolates of Pyricularia spp. were obtained from infected leaf samples of invasive plant species from wheat fields. The isolates classification into distinct Pyricularia species was done using molecular phylogeny based on actin and calmodulin genes. Pyricularia pennisetigena and P. zingibericola inoculated on plant leaves, at a concentration adjusted to 105 conidia mL-1, were pathogenic to signal grass, barley and wheat, with varying levels of aggressiveness.
Moisés Calderón1, Tove Brandt21Section of Allergy and Clinical Immunology, Royal Brompton Hospital, Imperial College, NHLI, London, UK; 2Group Clinical Development, ALK-Abelló A/S, Hørsholm, DenmarkAbstract: Immunotherapy is the only treatment for allergy that has the potential to alter the natural course of the disease. Sublingual immunotherapy (SLIT) for grass pollen-induced rhino-conjunctivitis has been developed to make immunotherapy available t...
Calder?n, Mois?s; Brandt, Tove
Immunotherapy is the only treatment for allergy that has the potential to alter the natural course of the disease. Sublingual immunotherapy (SLIT) for grass pollen-induced rhino-conjunctivitis has been developed to make immunotherapy available to a broader group of allergic patients. In the largest clinical programme ever conducted with allergen-specific immunotherapy, over 1,700 adults and 260 children have been exposed to Grazax?. Grazax is formulated as an oral lyophilisate (tablet) for su...
Orozco-Hernandez, J R; Brisson, G J; Girard, V
Eighteen midlactation Holstein cows, averaging 80 to 125 d of lactation, were used in a trial of switchback design to evaluate two timothy silages, wilted or direct-cut and treated with formic acid, and three treatments, control, NaHCO3 added at 2% of DM, or juice-extracted grass pellets replacing 30% silage DM. Cows fed direct-cut silage that had been treated with formic acid consumed more DM (19.8 vs. 18.6 kg/d) than those fed wilted silage. The DMI was also increased with NaHCO3 and grass pellet treatments. However, NaHCO3 reduced digestibility of most nutrients without affecting pH of rumen fluid or degradation of DM and NDF. Compared with wilted silage, direct-cut silage that had been treated with formic acid contained more degradable NDF (86 vs. 84.5%). Milk yield (24.9 vs. 23.6 kg/d) was higher for cows fed direct-cut than wilted silage, but 4% FCM yield remained unchanged. Addition of NaHCO3 tended to increase yields of milk and 4% FCM. Treatments did not affect milk composition. Serum urea N was higher for cows fed the direct-cut silage than for cows fed wilted silage. Silage type had more impact on feed intake and performance than did NaHCO3 or juice-extracted grass pellets.
David F. Olson; Stephen G. Boyce
Acorn production is extremely variable and unpredictable. Flowering is copious, but many climatic factors influence acorn development from initiation of flowers to acorn maturity. Acorns are consumed by birds, animals, insects, and microorganisms. The establishment of seedlings is more closely related to favorable site factors than to size of crops. A majority of oaks...
Nyoka, Betserai I.; Roshetko, James M.; Jamnadass, Ramni
The paper reviews tree seed and seedling supply systems in sub-Saharan Africa, Asia and Latin America. Across these regions, the review found that some of the germplasm supply systems do not efficiently meet farmers’ demands and environmental expectations in terms of productivity, species...... African countries play a prominent role in the supply of germplasm which is usually given to farmers without charge. The practice of giving farmers free germplasm by NGOs in many African countries and also government participation in germplasm supply in some Asian countries has been blamed for crowding...
Deoli, Naresh; Hasenstein, Karl H.
Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue
Kauppinen, Miia; Saikkonen, Kari; Helander, Marjo; Pirttilä, Anna Maria; Wäli, Piippa R
There is an urgent need to create new solutions for sustainable agricultural practices that circumvent the heavy use of fertilizers and pesticides and increase the resilience of agricultural systems to environmental change. Beneficial microbial symbionts of plants are expected to play an important role in integrated pest management schemes over the coming decades. Epichloë endophytes, symbiotic fungi of many grass species, can protect plants against several stressors, and could therefore help to increase the productivity of forage grasses and the hardiness of turf grasses while reducing the use of synthetic pesticides. Indeed, Epichloë endophytes have successfully been developed and commercialized for agricultural use in the USA, Australia and New Zealand. Many of the host grass species originate from Europe, which is a biodiversity hotspot for both grasses and endophytes. However, intentional use of endophyte-enhanced grasses in Europe is virtually non-existent. We suggest that the diversity of European Epichloë endophytes and their host grasses should be exploited for the development of sustainable agricultural, horticultural and landscaping practices, and potentially for bioremediation and bioenergy purposes, and for environmental improvement.
Aurora Armienta, M.; Beltrán-Villavicencio, Margarita; Ruiz-Villalobos, Carlos E.; Labastida, Israel; Ceniceros, Nora; Cruz, Olivia; Aguayo, Alejandra
Green house experiments were carried out to evaluate the growth and Sb assimilation of a grass assemblage: Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp, in tailings and Sb-rich soils. Tailings and soil samples were obtained at the Mexican historical mining zone of Zimapán, Central México. More than 6 tailings impoundments are located at the town outskirts and constitute a contamination source from windblown and waterborne deposit on soils, besides acid mine drainage. Four substrates were used in the experiments: 100% tailings, 20% tailings + 80% soil, 50% tailings + 50% soil , and a soil sample far from tailings as a background. Concentrations of Sb ranged from 310 mg/kg to 413 mg/kg in tailings. A pH of 7.43, 1.27% organic matter, and high concentrations of N, K and P indicated adequate conditions for plant growth. The grass assemblage was raised during 21 days as indicated by OECD (Organisation for Economic Co-operation and Development) Guideline 208 Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test. The highest Sb concentrations were measured in plants grown on tailings with 139 mg/kg in the aerial part and 883 mg/kg in roots. Concentrations of Sb decreased as the proportion of tailings diminished with 22.1 mg/kg in the aerial part and 10 mg/kg in roots corresponding to the plants grown in the 20 % tailings + 80% soil . Bioaccumulation (BAC) and bioconcentration factors (BF) of plants grown on tailings (BAC= 0.42, BCF=3.93) indicated their suitability as a phyto-stabilization option. The grass mixture may be thus applied to control windblown particulate tailings taking advantage to their tolerance to high Sb levels.
Eduardo Righi dos Reis
Full Text Available Even whith the advance in the techniques of seedlings production, many problems still remain to be solved, mainly thoseproblems related to seedlings delivery. This work verified the variability of the growth parameters in seedlings of Pinus elliottii indifferent positions inside the production tray, along the time, seeking to identify the best time and form of delivery of homogeneous andhigh quality seedlings. In order to achieve these purposes, an experiment was installed in the forest nursery of Santa Maria FederalUniversity RS. Ten evaluations of height, diameter of the collar and height/diameter relationship were performed, in intervals of 15days. It was simulated each tray of the repetition parcel in order to determine the best form of seedlings delivery from the green house.It was verified that, 135 days after germination, uniformity among morphologic parameters of seedlings delivery were achieved forthe simulations when dividing the tray in Border x Center (BxC, Right x Center x Left (DxCxE, and Quadrants, and that after 180days, Front x Center x Bottom (FrxCxF standardization was achieved. Differences in the quality pattern of seedlings collected indifferent places and submitted to the same development condition were observed and that seedlings delivered on a regular scheduleallows obtaining homogeneous quality pattern.
Critical water stress levels in Pinus patula seedlings and their relation to measures of seedling morphology. ... Southern Forests: a Journal of Forest Science ... A pot trial was implemented to determine the effect of soil water stress following transplanting on shoot water potential and stomatal conductance of Pinus patula ...
Aug 18, 2008 ... seeds survived even at the lower osmotic potential of PEG and NaCl; whereas, seedling obtained from small seeds did not survive in the intensive stress. Key words: xTriticosecale Witm, seed size, drought, germination, seedling growth. INDRODUCTION. Seed germination is an essential process in plant.
Massuo Jorge Kato
Full Text Available The major secondary metabolites and fatty acids occurring in the seeds of Virola surinamensis were monitored by GC-MS during germination and seedling development. The role as carbon source for seedling development was indicated considering that both classes of compounds were similarly consumed in the seeds and that no selective consumption of compounds could be detected.
Within two weeks of culture, spherules emerged out due to cracking of the seed coat. The spherules developed into protocorms with a leaf primordium at apical portion after 3 to 4 weeks and gradually produced complete seedlings. Strong and stout root system was induced in in vitro seedlings on transferring in half strength ...
... different aluminium (Al) concentrations on the seedling parameters of wheat and the effect of malate and citrate treatments as chelates for reducing the noxious effect of Al in medium culture and seedlings of two wheat cultivars, Darab (Al sensitive) and Maroon (Al tolerant) were grown on hydroponic solution (non modified ...
Mar 4, 1991 ... S.-Afr. Tydskr. Dierk. 1992,27(2). Effects of seed and seedling predation by small mammals on seedling recruitment of Protea neriifolia in Swartboskloof, Cape Province. S.A. Botha .... Midgley & Clayton 1990). As the vegetation .... Trap stations on permanent s~1I mam~ltr~plng grid In Iynbos o Trap stations ...
Feb 28, 2011 ... height, root collar diameter (RCD), number of leaves and branches were recorded for both experiments (water application rate and frequency). Seedling height was measured from root collar to the tip of the seedling shoot. Root collar diameter was measured using the calliper (Grossnickle et al., 1991).
Dec 3, 2017 ... Morphological Adaptation of Cercis Griffithii Seedlings in Response to Progressive. Drought ... 2Department of Forest Sciences, Research Division of Natural Resources, Isfahan Agricultural and Natural Resources Research and. Education .... each seedling five leaf selection of basic randomized to using ...
Oct 20, 2008 ... for seed germination and seedling growth of Cymbidium elegans and Coelogyne punctulata (Sharma et al., 1991). Mariat (1949) reported that vitamin B favoured germi- nation and differentiation in Cattleya seedlings; thiamine, nicotinic acid and biotin were most effective in Cattleya hybrids. Pyridoxine was ...
The effect of six temperatures ranging from 20 to 45°C on the germination and seedling length of six grain pearl millet genotypes (KS, AM, HG, EC, ZZ and D) was determined. There was significant variation in germination and seedling length across temperatures and among genotypes. As a result, significant temperature ...
A.W. Ezell; J.D. Hodges
Shumard oak seedlings were planted on a cutoversite in the Mississippi River floodplain, which had received both chemical and mechanical site preparation treatments. Soil at the site was a commerce silt loam and the elevation was such that the area does not flood. Planting stock was 1-0, bareroot seedlings. A total of seven active herbicide treatments were applied at a...
The germination of Salvia officinalis L. (sage) seeds is a problem of great concern that may be overcome by employing seed priming techniques. Seed priming is an efficient technique for improvement of seed vigor, increasing germination and seedling growth. Little information has been reported on seedling development ...
Sep 21, 2011 ... E-mail: firstname.lastname@example.org. Tel/Fax: +86. 25 84396293. have been used for animal feeds and beer malts. Recently, young barley seedlings have been used as food material for people in Asian countries such as China,. Japan, and Korea. Young barley seedlings are rich in dietary fiber, chlorophyll, carotene ...
A major impediment to the development of a mangosteen (Garcinia mangostana L.) industry is the long pre-bearing stage that seedlings take to produce fruits. A field study was conducted to determine the effect of Promalin on the growth of mangosteen seedlings. Promalin was applied as a foliar spray...
Arnulfo Aldrete; John G. Mexal
Many countries grow seedlings for reforestation in polybags where root spiraling and root egression can decrease seedling survival and growth following outplanting. The overall objectives of this study were to investigate the effect of chemical root pruning on root spiraling, root egression, and nursery performance of Pinus pseudostrobus, P...
Graae, Bente J; Ejrnæs, Rasmus; Lang, Simone I
gradient in dry tundra. A survey of natural seed rain and seedling density in vegetation was combined with observations of the establishment of 14 species after sowing into intact or disturbed vegetation. Although seed rain density was closely correlated with natural seedling establishment...
Drought and soil fertility are the major factors that influence seedling survival and growth in arid areas, thus it is of paramount importance to establish optimum water requirements for ... Two weeks old seedlings in polythene bag (2kg) containing the standard potting mixture as growing media were used for the experiments.
The seedling growth performance of Adenanthera pavonina L. in polluted soils of different railway tracks viz. Karachi Cantt. Station, Malir Halt, Malir 15, Landhi Junction and University Campus (control) was studied under in pots under natural field conditions. The results showed that the root, shoot and seedling size, number ...
ABSTRACT: The seedling growth performance of Adenanthera pavonina L. in polluted soils of different railway tracks viz. Karachi Cantt. Station, Malir Halt, Malir 15, Landhi Junction and. University Campus (control) was studied under in pots under natural field conditions. The results showed that the root, shoot and seedling ...
Brian Roy Lockhart; John D. Hodges; Emile S. Gardiner; Andrew W. Ezell
Summary We used 14C tracers to determine photosynthate distribution in cherrybark oak (Quercus pagoda Raf.) seedling sprouts following release from competing mid-story vegetation. Fall acquisition of labeled photosynthates by seedlings followed expected source--sink patterns, with root and basal stem tissues...
Sep 1, 2009 ... Finally, dried seeds were used in both a germination test in a chamber and a growing test in a greenhouse. Differences among cultivars in response were observed in germination and seedling growth. Although germination in petri dishes and seedling emergence in plug trays declined, suppression of ...
In the present investigation, the impact of drought and heavy metal in fenugreek was critically monitored. Fenugreek seedlings were exposed to 1- bar polyethylene glycol (PEG) solution (osmotic stress) and 10 ppm solution of HgCl2 (heavy metal). Within 3 days of seedling growth, mercury exposure induced relatively high ...
Sep 1, 2009 ... Woo Gun Shin1,2,3, Seung Jae Hwang1,2, Iyyakkannu Sivanesan1 and Byoung Ryong Jeong1,2*. 1Department of ... in petri dishes and seedling emergence in plug trays declined, suppression of hypocotyl length and seedling height was ..... ciently regulated by uniconazole 100 mgl-1 (1 day soaking) ...
Semere, T.; Slater, F.
The ecological impact on local wildlife of biomass plantations of three different species of grasses has been monitored in the years 2002 to 2004 inclusive at farms in Herefordshire UK. Two of the grasses were not native to Britain. Wildlife monitored included ground flora, beetles, insects, birds, small mammals, butterflies, bees and hoverflies. The results provide a baseline of biodiversity data from biomass farms in England, although due to poor crop growth, the data from the switch-grass plantation was incomplete. The surveys were carried out by Cardiff University supported financially by the DTI.
Semere, T.; Slater, F.
The ecological impact on local wildlife of biomass plantations of three different species of grasses has been monitored in the years 2002 to 2004 inclusive at farms in Herefordshire UK. Two of the grasses were not native to Britain. Wildlife monitored included ground flora, beetles, insects, birds, small mammals, butterflies, bees and hoverflies. The results provide a baseline of biodiversity data from biomass farms in England, although due to poor crop growth, the data from the switch-grass plantation was incomplete. The surveys were carried out by Cardiff University supported financially by the DTI
Flores, Enrique R.
I studied the acquisition of foraging skills by lambs eating shrub or grass in three experiments. The general approach was to isolate those skills involved in prehending forage from those related to the acceptance of novel foods. Treatment lambs received 15 times more exposure to grass or shrub than did control lambs. Lambs were tested in 2.5 x 2.5 meter monocultures of shrub or grass 5 min/d, on two separate occasions. Height, bulk density and spatial arrangement of plant material were contr...
Winkel, V.K.; Ostler, W.K.; Gabbert, W.D.; Lyon, G.E.
Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with plutonium. As part of a cleanup effort, both the indigenous vegetation and the top 5--10 cm of soil may be removed, and the soil may or may not be replaced. Technologies must be developed to stabilize and revegetate these lands. A study was developed to determine adaptable plant species, methods to prepare seedbeds for direct seeding and water harvesting, and proper irrigation rates. Plots were cleared of indigenous vegetation, and then prepared with various seedbed/water harvesting treatments including, pitting, land imprinting, and mulching. Other plots were treated with large water harvesting structures. Three irrigation treatments were superimposed over the seedbed/water harvesting treatments. Seedling emergence data was collected, and the treatment combinations compared. Supporting meteorological and soil data were collected with an automatic data-logger. Specific data included precipitation, and air temperature. In a year of above-average precipitation, irrigation did not generally aid germination and emergence of seeded species, and only slightly increased densities of species from the native seedbank. With the exception of increased shrub seedling densities in desert strips, there were no strong seedbed preparation/water harvesting treatment effects. In years of above-average rainfall, mulching and water harvesting treatments, irrigation may not be necessary to insure adequate germination and emergence of adapted perennial grasses, forbs, and shrubs in the Mojave/Great Basin Transition Desert. Future collection of survival data will determine whether a maintenance irrigation program is necessary to ensure establishmnent of native plants
Full Text Available Hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (VI or chromium nitrate chromium (III. Although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (III than those in chromium (VI, majority being in roots rather than shoots. Results also showed that the accumulation capacity of chromium by rice seedlings was positively correlated to chromium concentrations supplied in both chromium variants and the accumulation curve depicted an exponential trend in both chromium treatments over the entire period of exposure. Proline assays showed that both chromium variants induced the change of endogenous proline in shoots and roots of rice seedlings. Chromium (VI of 12.8 mg/L increased proline content significantly (p
Zhang, Ming; Gao, Bin, E-mail: email@example.com [University of Florida, Department of Agricultural and Biological Engineering (United States); Chen, Jianjun [University of Florida, Department of Environmental Horticulture and Mid-Florida Research & Education Center (United States); Li, Yuncong [University of Florida, Soil and Water Science Department Tropical Research & Education Center (United States)
The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.
Full Text Available Ensiling is a method of preserving moist forage based on natural fermentation where lactic acid bacteria (LAB ferment water soluble carbohydrate into organic acids mainly lactic acid under anaerobic condition. The aim of this study was to evaluate the quality of king grass (Pennisetum purpureophoides ensiled with addition of LAB prepared from fermented grass extract (LBFG. Four treatment were (G0 king grass without additive; (G1 king grass with 2% (v/w of LBFG; (G2 king grass with 3% (v/w of LBFG; (G3 king grass with 4% (v/w of LBFG. Ensiling was conducted in bottle silos of 225 g capacity at room temperatures (27.0 ± 0.20C for 30 days. The results showed that crude protein content in silage G1, G2 and G3 were relatively higher than that in silage G0. The pH value, butyric acid, total VFA and NH3-N concentrations decreased linearly with increasing level of LBFG addition, while lactic acid concentration increased linearly with LBFG addition. It was concluded that addition of 3% (v/w of LBFG resulting a better fermentation quality of king grass silage than 2% and 4% (v/w of LBFG.
Polley, H.W.; Johnson, H.B.; Mayeux, H.S. (Department of Agriculture, Temple, TX (United States))
Woody C[sub 3] Prosopis glandulosa (honey mesquite) and C[sub 4] perennial grass Schizachyrium scoparium (little bluestem) were grown along a gradient of daytime carbon dioxide concentrations from near 340 to 200 [mu]mol/mol air in a 38 m long controlled environment chamber. The authors studied the effects of historical and prehistorical increases in atmospheric CO[sub 2] concentration on growth, resource use, and competitive interactions of a species representative of C[sub 4]-dominated grasslands in the SW United States and the invasive legume P. glandulosa. Increasing CO[sub 2] concentration stimulated N[sub 2] fixation by individually grown P. glandulosa and elicited in C[sub 3] seedlings a similar relative increase in leaf intercellular CO[sub 2] concentration, net assimilation rate, and intrinsic water use efficiency (leaf net assimilation rate/stomatal conductance). Aboveground biomass of P. glandulosa was not altered by CO[sub 2] concentration, but belowground biomass and whole-plant water and nitrogen use efficiencies increased linearly with CO[sub 2] concentration in seedlings that were grown alone. Biomass produced by P. glandulosa that was grown with S. scoparium was not affected by CO[sub 2] concentration. Stomatal conductance declined and leaf assimilation rates of S. scoparium at near maximum incident light increased at higher CO[sub 2] concentration, but there was no effect of CO[sub 2] concentration on biomass production or whole-plant water use efficiency of the C[sub 4] grass. Rising CO[sub 2] concentration, especially the 27% increase since the beginning of the 19th century, may have contributed to more abundant P. glandulosa on C[sub 4] grasslands by stimulating the shrub's growth or reducing the amount of resources that the C[sub 3] required. Much of the potential response of P. glandulosa to CO[sub 2] concentration, however, appears to be contingent on the shrub's escaping competition with neighboring grasses. 62 refs., 10 figs., 1
Shakuntala Sharma; Joshua P. Adams; Jamie L. Schuler; Robert L. Ficklin; Don C. Bragg
This study assessed the effects of spacing and genotype on the growth and physiology of improved loblolly pine (Pinus taeda L.) seedlings from three distinct genotypes planted in Drew County, Arkansas (USA). Genotype had a significant effect on survival and height. Clone CF Var 1 showed greater height and survival compared to other seedlings....
Fatima, Qaseem; Zahin, Maryam; Khan, Mohd Sajjad Ahmad; Ahmad, Iqbal
Effect of growing seedling, seeds and seedlings extracts from seven leguminous plants (Pisum sativum, Vigna radiata, Vigna mungo, Cajanus cajan, Lentil culinaris, Cicer arietinum and Trigonella foenum graecum) were screened for their ability to influence quorum sensing controlled pigment production in Chromobacterium violaceum indicator strains (CV12472 and CVO26). Germinating seedling and seedling extracts of only P. sativum (pea) showed inhibition of violacein production. Interestingly, the T. foenum graecum (fenugreek) seed extracts enhances the pigment production. Quorum sensing regulated swarming motility in Pseudomonas aerugionsa PAO1 was reduced by pea seedling extract while enhanced by the fenugreek seed extracts. These findings suggest that plant metabolites of some legumes interact actively with bacterial quorum sensing and could modulate its associated functions.
Full Text Available Unlike animals, plants, being sessile, cannot escape from exposure to severe abiotic stresses such as extreme temperature and water deficit. The dynamic structure of plant cell wall enables them to undergo compensatory changes, as well as maintain physical strength, with changing environments. Plant hormones known as brassinosteroids (BRs play a key role in determining cell wall expansion during stress responses. Cell wall deposition differs between grasses (Poaceae and dicots. Grass species include many important food, fiber, and biofuel crops. In this article, we focus on recent advances in BR-regulated cell wall biosynthesis and remodeling in response to stresses, comparing our understanding of the mechanisms in grass species with those in the more studied dicots. A more comprehensive understanding of BR-mediated changes in cell wall integrity in grass species will benefit the development of genetic tools to improve crop productivity, fiber quality and plant biomass recalcitrance.
Peel, Robert George; Orby, P.V.; Skjoth, C. A.
In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...
Language: English. Keywords: cenchrus ciliaris; cynodon dactylon; digitaria eriantha; distribution; ecotypes; environmental conditions; eragrostis curvula; geographical distribution; Geography; grasses; heteropogon contortus; morphological variation; Morphology; natal; northern cape; orange free state; pasture; pasture ...
Lynch, D H; Voroney, R P; Warman, P R
Perennial forages may be ideally suited for fertilization with slow N release amendments such as composts, but difficulties in predicting N supply from composts have limited their routine use in forage production. A field study was conducted to compare the yield and protein content of a binary legume-grass forage mixture and a grass monocrop cut twice annually, when fertilized with diverse composts. In all three years from 1998-2000, timothy (Phleum pratense L.)-red clover (Trifolium pratense L.) and timothy swards were fertilized with ammonium nitrate (AN) at up to 150 and 300 kg N ha(-1) yr(-1), respectively. Organic amendments, applied at up to 600 kg N ha(-1) yr(-1) in the first two years only, included composts derived from crop residue (CSC), dairy manure (DMC), or sewage sludge (SSLC), plus liquid dairy manure (DM). Treatments DM at 150 kg N ha(-1) yr(-1) and CSC at 600 kg N ha(-1) yr(-1) produced cumulative timothy yields matching those obtained for inorganic fertilizer. Apparent nitrogen recovery (ANR) ranged from 0.65% (SSLC) to 15.1% (DMC) for composts, compared with 29.4% (DM) and 36.5% (AN). The legume component (approximately 30%) of the binary mixture acted as an effective "N buffer" maintaining forage yield and protein content consistently higher, and within a narrower range, across all treatments. Integrating compost utilization into livestock systems that use legume-grass mixtures may reduce the risk of large excesses or deficits of N, moderate against potential losses in crop yield and quality, and by accommodating lower application rates of composts, reduce soil P and K accumulation.
Olsson, Aaryn D.; Betancourt, Julio; McClaran, Mitchel P.; Marsh, Stuart E.
Aim Biological invasions facilitate ecosystem transformation by altering the structure and function, diversity, dominance and disturbance regimes. A classic case is the grass–fire cycle in which grass invasion increases the frequency, scale and/or intensity of wildfires and promotes the continued invasion of invasive grasses. Despite wide acceptance of the grass–fire cycle, questions linger about the relative roles that interspecific plant competition and fire play in ecosystem transformations. Location Sonoran Desert Arizona Upland of the Santa Catalina Mountains, Arizona, USA. Methods We measured species cover, density and saguaro (Carnegiea gigantea) size structure along gradients of Pennisetum ciliare invasion at 10 unburned/ungrazed P. ciliare patches. Regression models quantified differences in diversity, cover and density with respect to P. ciliare cover, and residence time and a Fisher's exact test detected demographic changes in saguaro populations. Because P. ciliare may have initially invaded locations that were both more invasible and less diverse, we ran analyses with and without the plots in which initial infestations were located. Results Richness and diversity decreased with P. ciliare cover as did cover and density of most dominant species. Richness and diversity declined with increasing time since invasion, suggesting an ongoing transformation. The proportion of old-to-young Carnegiea gigantea was significantly lower in plots with dominant P. ciliare cover. Main conclusions Rich desert scrub (15–25 species per plot) was transformed into depauperate grassland (2–5 species per plot) within 20 years following P. ciliare invasion without changes to the fire regime. While the onset of a grass–fire cycle may drive ecosystem change in the later stages and larger scales of grass invasions of arid lands, competition by P. ciliare can drive small-scale transformations earlier in the invasion. Linking competition-induced transformation rates with
Melcher, Cynthia P.; Skagen, Susan K.
This bibliography and associated literature synthesis (Melcher and Skagen, 2005) was developed for the Playa Lakes Joint Venture (PLJV). The PLJV sought compilation and annotation of the literature on grass buffers for protecting playas from runoff containing sediments, nutrients, pesticides, and other contaminants. In addition, PLJV sought information regarding the extent to which buffers may attenuate the precipitation runoff needed to fill playas, and avian use of buffers. We emphasize grass buffers, but we also provide information on other buffer types.
Full Text Available The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85–38.51, 31.13–42.61, and 3.10–5.64, respectively. The samples were initially pretreated with alkaline peroxide followed by enzymatic hydrolysis to investigate the enzymatic saccharification. The total reducing sugars in most grasses ranging from 500–600 mg/g grasses (70–80% yield were obtained. Subsequently, 11 types of grasses were selected as feedstocks for the ethanol production by simultaneous saccharification and cofermentation (SSCF. The enzymes, cellulase and xylanase, were utilized for hydrolysis and the yeasts, Saccharomyces cerevisiae and Pichia stipitis, were applied for cofermentation at 35°C for 7 days. From the results, the highest yield of ethanol, 1.14 g/L or 0.14 g/g substrate equivalent to 32.72% of the theoretical values was obtained from Sri Lanka ecotype vetiver grass. When the yields of dry matter were included in the calculations, Sri Lanka ecotype vetiver grass gave the yield of ethanol at 1,091.84 L/ha/year, whereas the leaves of dwarf napier grass showed the maximum yield of 2,720.55 L/ha/year (0.98 g/L or 0.12 g/g substrate equivalent to 30.60% of the theoretical values.
Wongwatanapaiboon, Jinaporn; Kangvansaichol, Kunn; Burapatana, Vorakan; Inochanon, Ratanavalee; Winayanuwattikun, Pakorn; Yongvanich, Tikamporn; Chulalaksananukul, Warawut
The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85-38.51, 31.13-42.61, and 3.10-5.64, respectively. The samples were initially pretreated with alkaline peroxide followed by enzymatic hydrolysis to investigate the enzymatic saccharification. The total reducing sugars in most grasses ranging from 500-600 mg/g grasses (70-80% yield) were obtained. Subsequently, 11 types of grasses were selected as feedstocks for the ethanol production by simultaneous saccharification and cofermentation (SSCF). The enzymes, cellulase and xylanase, were utilized for hydrolysis and the yeasts, Saccharomyces cerevisiae and Pichia stipitis, were applied for cofermentation at 35 °C for 7 days. From the results, the highest yield of ethanol, 1.14 g/L or 0.14 g/g substrate equivalent to 32.72% of the theoretical values was obtained from Sri Lanka ecotype vetiver grass. When the yields of dry matter were included in the calculations, Sri Lanka ecotype vetiver grass gave the yield of ethanol at 1,091.84 L/ha/year, whereas the leaves of dwarf napier grass showed the maximum yield of 2,720.55 L/ha/year (0.98 g/L or 0.12 g/g substrate equivalent to 30.60% of the theoretical values).
Dabney, Clemon; Ostergaard, Jason; Watkins, Eric; Chen, Changbin
Background The deposition of silicon into epidermal cells of grass species is thought to be an important mechanism that plants use as a defense against pests and environmental stresses. There are a number of techniques available to study the size, density and distribution pattern of silica bodies in grass leaves. However, none of those techniques can provide a high-throughput analysis, especially for a great number of samples. Results We developed a method utilizing the autofluorescence of si...
Full Text Available For the windward group, there was a significant correlation (TableV only between the amount of rainfall and the order of the plots on theX-axis. It has been shown in the ordination diagram (Fig. 4 that threecommunity types can be recognized, the Rhynchelytrum repens, Melinisminutiflora and Andropogon virginicus community types. The relationshipbetween the change of the grass dominance and the rainfall gradient alongthe X- axis is shown in Fig. 9. In this diagram the X-axis was dividedinto ten segments: 0.0 — 9.9; 10.0 — 19.9; 20.0 — 29.9; 30.0 — 39.9;40.0 — 49.9; 50.0 — 59.9; 60.0 — 69.9; 70.0 — 79.9; 80.0 — 89.9 and90.0 — 100.0. The intervals 20.0 — 39.9 and 50.0 — 69.9 were consideredas individual units because there was only one plot in the intervals20.0 — 29.9 and 50.0 — 59.9, respectively.
Fernanda Aparecida Sales
Full Text Available The objective of this study was to evaluate the biomass production of elephant grass and leucaena in Paraná state, Brazil, for the generation of renewable energy. Two field studies were conducted in the municipality of Ibiporã (23° S, 51° 01?W. In the first study, the dry matter accumulation curves were calculated, with sampling at 30, 60, 90, 120, and 180 days after cultivation. The second study was conducted in a randomized complete block design with split plots. The total aboveground biomass production of elephant grass and leucaena was estimated in the main plot. Cutting times of 60 and 120 days after cultivation were evaluated in the subplots. The productivity of dry matter (kg.ha-1 was estimated using the biomass data. In addition, the potential production of energy from the burning of elephant grass biomass, and the potential production of total aboveground biomass and energy of elephant grass (in Paraná was estimated using an agrometeorological model. Elephant grass can be potentially used as an alternative energy source. Leucaena has slow initial growth, and it must therefore be evaluated over a longer period in order to determine its potential. Simulation analyses of the capability of power generation, conducted based on the annual dry matter production, revealed that elephant grass could be an important source of renewable energy in the state of Paraná.
Full Text Available The concept of plants and microbes utilization for remediation measure of pollutant contaminated soil is the newest development in term of petroleum waste management technique. The research objective was to obtain wild grass types and hydrocarbonoclastic bacteria which are capable to synergize in decreasing petroleum concentration within petroleum contaminated soil. This research was conducted in a factorial by using a randomized completely block design. The first factor was wild grass type which were without plant, Tridax procumbens grass and Lepironia mucronata grass. The second factor was hydrocarbonoclastic bacteria type which were without bacterium, single bacterium of Alcaligenes faecalis, single bacterium of Pseudomonas alcaligenes, and mixed bacteria of Alcaligenes faecalis with P. alcaligenes. The results showed that mixed bacteria (A. faecalis and P. alcaligenes were capable to increase the crown and roots dry weights of these two grasses and bacteria population, decreased percentage of TPH (total petroleum hydrocarbon and had better pH value than that of single bacterium. The highest TPH decrease with magnitude of 70.1% was obtained on the treatment of L. mucronata grass in combination with mixed bacteria.
Qie, Lufeng; Jia, Guanqing; Zhang, Wenying; Schnable, James; Shang, Zhonglin; Li, Wei; Liu, Binhui; Li, Mingzhe; Chai, Yang; Zhi, Hui; Diao, Xianmin
Drought tolerance is an important breeding target for enhancing the yields of grain crop species in arid and semi-arid regions of the world. Two species of Setaria, domesticated foxtail millet (S. italica) and its wild ancestor green foxtail (S. viridis) are becoming widely adopted as models for functional genomics studies in the Panicoid grasses. In this study, the genomic regions controlling germination and early seedling drought tolerance in Setaria were identified using 190 F7 lines derived from a cross between Yugu1, a S. italica cultivar developed in China, and a wild S. viridis genotype collected from Uzbekistan. Quantitative trait loci were identified which contribute to a number of traits including promptness index, radical root length, coleoptile length and lateral root number at germinating stage and seedling survival rate was characterized by the ability of desiccated seedlings to revive after rehydration. A genetic map with 128 SSR markers which spans 1293.9 cM with an average of 14 markers per linkage group of the 9 linkage groups was constructed. A total of eighteen QTLs were detected which included nine that explained over 10% of the phenotypic variance for a given trait. Both the wild green foxtail genotype and the foxtail millet cultivar contributed the favorite alleles for traits detected in this trial, indicating that wild Setaria viridis populations may serve as a reservoir for novel stress tolerance alleles which could be employed in foxtail millet breeding.
Didier, A; Malling, H-J; Worm, Marcel
Sustained efficacy over three pollen seasons of pre- and co-seasonal treatment with 300IR 5-grass pollen sublingual tablet has been demonstrated in adults with moderate-severe grass pollen-associated allergic rhinoconjunctivitis....
Ronan Carlos Colombo
Full Text Available Over the past decade the desert rose received fame in the flower market due to its striking and sculptural forms; however, the commercial production of these species is quite recent and little is known about its crop management, including substrates recommendation. The objectives of this study were to investigate the effect of different substrates on desert rose seed germination and production of its seedlings. Experiment I: freshly harvested seeds of desert rose were sown in different substrates e.g. sand, coconut fiber, semi-composted pine bark, sand + coconut fiber, semi-composted pine bark + sand and coconut fiber + semicomposted pine bark. These substrates were evaluated to study the emergence percentage of seeds, initial growth of seedlings and seedling emergence speed index (ESI. Experiment II: desert rose from the experiment I were transferred to plastic pots filled with the same substrates as in experiment I. The pH and electrical conductivity (EC of the substrates were noted every 30 days while the growth parameters of seedlings were recorded after 240 days. Results from experiment I showed higher germination rate and seedling growth in substrates containing semi-composted pine bark. Similarly, in experiment II, better quality seedlings were observed in substrates containing semi-composted pine bark. Thus, for desert rose seed germination and seedling growth, it is recommended to use substrates containing semi-composted pine bark.
Iakovoglou, V; Radoglou, K; Kostopoulou, P; Dini-Papanastasi, O
This study investigated how nurseries could benefit by inducing "short" photoperiods as low as 4 hr to produce "better" seedlings characterized by more vigorous roots; a substantial feature to overcome transplanting stress. The carryover effect of the photoperiod was also investigated on seedlings that grew for 30 days more underthe consistent 14 hr photoperiod. Seedlings of Pinus brutia were subjected to 4, 6, 8 and 14 hr photoperiod for 3 week. Fifteen seedlings were used to evaluate the leaf area, the root and shoot dry weight and their ratio. Six and sixteen seedlings were used to evaluate the shoot electrolyte leakage and the root growth potential, respectively. Based on the results, the 6 and 8 hr photoperiod indicated greater root allocation (4.8 and 4.9 mg, respectively) and chlorophyll content (3.7 and 4.4, respectively). They also indicated greater leaf area values (3.3 and 3.5 cm2, respectively) along with the 14 hr (3.4 cm2). The photoperiod effect continued even after seedlings were subjected at consistent photoperiod. Overall, "short" photoperiods could provide "better" P. brutia seedlings to accommodate immediate massive reforestation and afforestation needs.
Alan H. M. de Abreu
Full Text Available ABSTRACT This study aimed to verify the potential of urban solid wastes as substrate for production of seedlings of Lafoensia pacari. Five treatments were tested, four with solid wastes and one standard substrate, namely: sewage sludge from Alegria Wastewater Treatment Plant (WTP; sewage sludge from Ilha do Governador WTP; sewage sludge from Sarapuí WTP; domestic garbage compost (Fertlurb; and a commercial substrate made of biostabilized pine bark (standard substrate. The wastes received 20% (in volume of shredded coconut fiber. At 105 days after sowing, the seedlings were evaluated for different quality parameters. Seedlings produced with Sarapuí WTP sewage sludge showed the best results in all the parameters, followed by seedlings produced with sewage sludge from Alegria and Ilha do Governador WTPs, which did not differ. Seedlings produced with domestic garbage compost showed satisfactory results, higher than the ones observed for seedlings produced with commercial substrate. The urban solid wastes with 20% of coconut fiber showed high potential and can be recommended for the composition of substrate in the production of Lafoensia pacari seedlings.
Silvana de Paula Quintão Scalon
Full Text Available Aroeira has great economic importance due to its wood useful, tannins extraction and use in the pharmacology. The aim of this work was to evaluate the germination aspects and initial seedlings development of aroeira, under gibberellins, substrata and shading effects, and for that two experiments were led out. In the first one, seeds were previously soaked for 24 hours in water and in 100 mg.L-1 gibberellin solution and were sowed directly in cells trays in the following substrata: land and sand (1:1 and 1:2 and Plantmax . In the second experiment, 15 cm length seedlings were transplanted to polyethylene sacks filled out land+sand+poultry manure (1:1:1 partly decomposed and they were maintained at greenhouse for 15 days. Soon after, seedlings were transferred for the following conditions: shading (50% and full sun and they were 50 mg.L-1 and 150 mg.L-1 gibberellins solutions pulverized, as control seedlings water pulverized. Aroeira seeds should not be previously water or gibberellins imbibed before being sowed. The best substrata for aroeira seeds germination was Plantmax without germinative treatments to reach higher than 80% of seedlings survival. The seedlings developed better at full sun light and the gibberellin. It was observed increment in height, diameter, foliar area and fresh and dry mass from aerial and root part when compared to shading situation. The gibberellins applications did not influence the aroeira seedlings initial growth characteristics.
Randall Hughes, A; Hanley, Torrance C; Schenck, Forest R; Hays, Cynthia G
Genetic diversity can influence ecological processes throughout ontogeny, yet whether diversity at early life history stages is important in long-lived taxa with overlapping generations is unclear. Seagrass systems provide some of the best evidence for the ecological effects of genetic diversity among adult shoots, but we do not know if the genetic diversity of seeds and seedlings also influences seagrass ecology. We tested the effects of seagrass (Zostera marina) seed diversity and relatedness on germination success, seedling morphology, and seedling production by comparing experimental assemblages of seeds collected from single reproductive shoots ("monocultures") to assemblages of seeds collected from multiple reproductive shoots ("polycultures"). There was no difference in seedling emergence, yet seedlings from polycultures had larger shoots above and below ground than seedlings from monocultures at the end of the 1-yr experiment. Genetic relatedness of the seedlings predicted some aspects of shoot morphology, with more leaves and longer roots and shoots at intermediate levels of relatedness, regardless of seed diversity. Our results suggest that studies of only adult stages may underestimate the importance of genetic diversity if the benefits at early life history stages continue to accrue throughout the life cycle. © 2016 by the Ecological Society of America.
Narukawa, Megumi; Kanbara, Kaori; Tominaga, Yuji; Aitani, Yurika; Fukuda, Kazumasa; Kodama, Takaaki; Murayama, Noriko; Nara, Yoshiki; Arai, Takashi; Konno, Masae; Kamisuki, Shinji; Sugawara, Fumio; Iwai, Masako; Inoue, Yasunori
Root hairs, which arise from root epidermal cells, are tubular structures that increase the efficiency of water absorption and nutrient uptake. A low pH (pH 4) medium induced root hair formation in lettuce (Lactuca sativa L.) seedlings, and the decapitation of shoots inhibited root hair formation. The addition of shoot extract to the medium restored root hair formation in the decapitated lettuce seedlings. These results suggest that factors essential to the formation of root hairs may be present in the shoot. We purified one factor from the shoot that facilitates root hair formation. This factor was identified as chlorogenic acid (CGA), a common polyphenol in higher plants. The presence of exogenous CGA in the medium induced root hair formation in decapitated lettuce seedlings at pH 4.0 and in intact lettuce seedlings at pH 6.0. The optimum concentration of CGA for root hair formation was identified as 10(-5) M. Decapitation of the shoots reduced the CGA content in the roots to approximately one-third that in intact plants. Application of the CGA biosynthesis inhibitor L-alpha-aminooxy-beta-phenylpropionic acid (AOPP, 10(-6) M) to intact seedlings grown at pH 4.0 reduced both the CGA content of the roots and the total amount of root hairs. The addition of exogenous CGA restored root hair formation in intact seedlings treated with AOPP. These results suggest that CGA is essential for root hair formation in lettuce seedlings.
Full Text Available Benzoic acid (BA and Cd exhibit cumulative effects on plants due to their accumulation in the soil. The present study reports the effects of BA an allelochemical, Cd and their combinations on seed germination, seedling growth, biochemical parameters, and response of antioxidant enzymes in Triticum aestivum L. The experiment was conducted in sand supplemented with Hoagland nutrient solution. Benzoic acid was applied at concentrations of 0.5, 1.0, and 1.5 mM with or without Cd (7 mg L-1 to observe effects of allelochemical and Cd alone and in combination on wheat. Both stresses exhibited inhibitory effect on growth and metabolism of wheat seedlings. The allelochemical in single and combined treatments with Cd decreased seedling growth as compared to Cd stress. The two stresses significantly enhanced malondialdehyde content of wheat seedlings. The activity of other antioxidant enzymes, viz. superoxide dismutase (SOD, catalase (CAT, ascorbate peroxidase (APX, and guaiacol peroxidase (POX were also recorded. SOD increased in seedlings under the two stresses. CAT more prominently ameliorates the toxic effects of H2O2 as compared with APX and POX and protected wheat seedlings from oxidative stress. Allelochemical buttressed the toxic effect of Cd on wheat seedlings.
Mayne, R.G.; Kende, Hans
More than 80% of the radioactivity from (U- 14 C)glucose metabolised by anaerobic rice seedlings or by excised roots or coleoptiles was recovered as ethanol plus CO 2 ; less than 5% was recovered as water-soluble acidic components. Rates of 14 CO 2 formation from (U- 14 C)glucose were similar in roots and coleoptiles in both N 2 and air atmospheres. More 14 C0 2 was formed from (U- 14 C)glucose than could be accounted for by ethanolic fermentation, and the specific yields of 14 CO 2 from (6- 14 C)glucose and (1- 14 C)glucose gave unusually high C-6/C-1 ratios (1.7) in the anaerobic coleoptile. The results may indicate that appreciable pentan synthesis occurs in the anaerobic coleoptile. (author)
Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander
Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL – mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191
Domisch, Timo; Martz, Françoise; Repo, Tapani; Rautio, Pasi
Future climate scenarios predict increased air temperatures and precipitation, particularly at high latitudes, and especially so during winter. Soil temperatures, however, are more difficult to predict, since they depend strongly on the fate of the insulating snow cover. 'Rain-on-snow' events and warm spells during winter can lead to thaw-freeze cycles, compacted snow and ice encasement, as well as local flooding. These adverse conditions could counteract the otherwise positive effects of climatic changes on forest seedling growth. In order to study the effects of different winter and snow conditions on young Scots pine (Pinus sylvestris L.) seedlings, we conducted a laboratory experiment in which 80 1-year-old Scots pine seedlings were distributed between four winter treatments in dasotrons: ambient snow cover (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow (NO SNOW). During the winter treatment period and a 1.5-month simulated spring/early summer phase, we monitored the needle, stem and root biomass of the seedlings, and determined their starch and soluble sugar concentrations. In addition, we assessed the stress experienced by the seedlings by measuring chlorophyll fluorescence, electric impedance and photosynthesis of the previous-year needles. Compared with the SNOW treatment, carbohydrate concentrations were lower in the FLOOD and NO SNOW treatments where the seedlings had almost died before the end of the experiment, presumably due to frost desiccation of aboveground parts during the winter treatments. The seedlings of the ICE treatment showed dead needles and stems only above the snow and ice cover. The results emphasize the importance of an insulating and protecting snow cover for small forest tree seedlings, and that future winters with changed snow patterns might affect the survival of tree seedlings and thus forest productivity.
Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.
The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.
Anthony S. Davis; Jeremiah R. Pinto; Douglass F. Jacobs
Koa (Acacia koa A. Gray [Fabaceae]) seedlings were grown with subirrigation and overhead irrigation systems in an effort to characterize post-nursery field performance. One year following outplanting, we found no differences in seedling height or survival, but root-collar diameter was significantly larger for subirrigated seedlings. This indicates that koa seedlings,...
He, Yongxing; Jiang, Yousheng; Lu, Liqun
Frequent outbreaks of grass carp hemorrhagic disease, caused by grass carp reovirus (GCRV) infection, pose as serious threats to the production of grass carp Ctenopharyngodon idella. Although various nucleic acids-based diagnostic methods have been shown effective, lack of commercial monoclonal antibody against grass carp IgM has impeded the development of any reliable immunoassays in detection of GCRV infection. The present study describes the preparation and screening of monoclonal antibodies against the constant region of grass carp IgM protein, and the development of a Western blot (WB) protocol for the specific detection of antibodies against outer capsid VP7 protein of GCRV that serves as antibody-capture antigen in the immunoassay. In comparison to a conventional RT-PCR method, validity of the WB is further demonstrated by testing on clinical fish serum samples collected from a grass carp farm in Jiangxi Province during disease pandemic in 2011. In conclusion, the WB technique established in this study could be employed for specific serodiagnosis of GCRV infection. Copyright © 2013 Elsevier B.V. All rights reserved.
Anders K. Mortensen
Full Text Available The clover-grass ratio is an important factor in composing feed ratios for livestock. Cameras in the field allow the user to estimate the clover-grass ratio using image analysis; however, current methods assume the total dry matter is known. This paper presents the preliminary results of an image analysis method for non-destructively estimating the total dry matter of clover-grass. The presented method includes three steps: (1 classification of image illumination using a histogram of the difference in excess green and excess red; (2 segmentation of clover and grass using edge detection and morphology; and (3 estimation of total dry matter using grass coverage derived from the segmentation and climate parameters. The method was developed and evaluated on images captured in a clover-grass plot experiment during the spring growing season. The preliminary results are promising and show a high correlation between the image-based total dry matter estimate and the harvested dry matter ( R 2 = 0.93 with an RMSE of 210 kg ha − 1 .
Takahashi, H; Kamada, M; Yamazaki, Y; Fujii, N; Higashitani, A; Aizawa, S; Yoshizaki, I; Kamigaichi, S; Mukai, C; Shimazu, T; Fukui, K
Seedlings of most cucurbitaceous plants develop a peg (protuberance caused by cell outgrowth) on the transition zone between the hypocotyl and root. The peg is necessary for removing the seed coat after germination. In our spaceflight experiments on the STS-95 space shuttle, Discovery, we found that cucumber (Cucumis sativus L.) seedlings grown under microgravity conditions developed two pegs symmetrically at the transition zone. Thus, cucumber seedlings potentially develop two pegs and do not require gravity for peg formation itself, but on the ground the development of one peg is suppressed in response to gravity. This may be considered as negative control of morphogenesis by gravity.
A.V. Korsukova; T.G. Gornostai; O.I. Grabelnych; N.V. Dorofeev; T.P. Pobezhimova; N.A. Sokolova; L.V. Dudareva; V.K. Voinikov
The fatty acid composition of shoots of unhardened and hardened to cold etiolated winter wheat seedlings grown from seeds treated with tebuconazole-based protectant «Bunker» (content of tebuconazole 60 grams per liter, g/L), and the seedlings frost resistance has been studied. It is shown that treatment of winter wheat seeds by «Bunker» preparation (1,5 microliter per gram of seeds, µl/g) is accompanied by an increase of the fatty acids unsaturation in the shoots and increase of the seedlings...
Stenstroem, Elna [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology; Arvidsson, Bernt [Svenska Skogsplantor AB, Joenkoeping (Sweden)
During the 1990s, there were serious outbreaks of the pathogen Lophodermium seditiosum on pine seedlings in Swedish forest nurseries, even though the seedlings had been treated with the fungicide propiconazole. The present experiment was carried out to evaluate two other fungicides, fluazinam and azoxystrobin, as possible alternatives to propiconazole. In the tests, which were all carried out in the same forest nursery, seedlings were treated with either propiconazole, fluazinam. or azoxystrobin, and the proportion of needles with ascocarps of L. seditiosum and the number of ascocarps per needle were recorded over the following 2 yrs. Seedlings treated with azoxystrobin already appeared healthier than control seedlings in September of the first year, and by November all azoxystrobin-treated seedlings had fewer ascocarps per needle compared with control seedlings. In autumn of the second year, there were no ascocarps on seedlings treated with fluazinam or azoxystrobin, whereas seedlings treated with propiconazole had similar numbers of ascocarps to non-treated control seedlings.
The feasibility of RCG for commercial utilization depends primarily on its applicability for pulp production and its use in energy production will be based on the residue that will be available after extracting the pulp fraction of the RCG. Roughly 20 ..30% of the material will be available for energy production purposes. However, the percentage may be higher/lower depending on the quality standards of the pulp fiber material. The harvesting period has a significant effect on the fuel characteristics of RCG. For instance the contents of N, S, Cl, K are clearly lower if the RCG is harvested in the spring (delayed) instead of summer/autumn. These elements affect significantly overall emission formation and ash behaviour and its melting temperature. The combustion related research in this project has been focused on the spring-harvested RCG. The project aims to evaluate the feasibility of delayed harvested RCG for energy production. In order to reach this goal, the following combustion methods will be tested and studied: combustion of pelletized RCG; gasification; combustion of pulverized RCG. In addition, pelletizing, reactivity and NO conversion of pulverized RCG will be studied. The research described here is a part of `Reed Canary Grass` project (in AIR programme). The contractors of the project are Swedish University of Agricultural Sciences (coordinator), United Milling Systems from Denmark, Jaakko Poeyry Oy and VTT Energy. In addition, there are partners from several countries participating in the project. The project has been divided in five tasks, VTT Energy being responsible for combustion related task `Upgraded fuel` that includes the research topics discussed in this paper
Gebbert, Sören; Leppelt, Thomas
GRASS GIS is a full featured, general purpose Open Source geographic information system (GIS) with raster, 3D raster and vector processing support. Recently, time was introduced as a new dimension that transformed GRASS GIS into the first Open Source temporal GIS with comprehensive spatio-temporal analysis, processing and visualization capabilities. New spatio-temporal data types were introduced in GRASS GIS version 7, to manage raster, 3D raster and vector time series. These new data types are called space time datasets. They are designed to efficiently handle hundreds of thousands of time stamped raster, 3D raster and vector map layers of any size. Time stamps can be defined as time intervals or time instances in Gregorian calendar time or relative time. Space time datasets are simplifying the processing and analysis of large time series in GRASS GIS, since these new data types are used as input and output parameter in temporal modules. The handling of space time datasets is therefore equal to the handling of raster, 3D raster and vector map layers in GRASS GIS. A new dedicated Python library, the GRASS GIS Temporal Framework, was designed to implement the spatio-temporal data types and their management. The framework provides the functionality to efficiently handle hundreds of thousands of time stamped map layers and their spatio-temporal topological relations. The framework supports reasoning based on the temporal granularity of space time datasets as well as their temporal topology. It was designed in conjunction with the PyGRASS  library to support parallel processing of large datasets, that has a long tradition in GRASS GIS [4,5]. We will present a subset of more than 40 temporal modules that were implemented based on the GRASS GIS Temporal Framework, PyGRASS and the GRASS GIS Python scripting library. These modules provide a comprehensive temporal GIS tool set. The functionality range from space time dataset and time stamped map layer management
Nizami, A.S.; Orozco, A.; Groom, E.; Dieterich, B.; Murphy, J.D.
Highlights: ► We highlight the various results for biomethane potential that may be obtained from the same grass silage. ► The results indicated that methane potential varied from 350 to 493 L CH 4 kg −1 VS added for three different BMP procedures. ► We compare two distinct digestion systems using the same grass. ► A two stage wet system achieved 451 L CH 4 kg −1 VS added over a 50 day retention period. ► A two phase system achieved 341 L CH 4 kg −1 VS added at a 30 day retention time. -- Abstract: Grass biomethane has been shown to be a sustainable gaseous transport biofuel, with a good energy balance, and significant potential for economic viability. Of issue for the designer is the variation in characteristics of the grass depending on location of source, time of cut and species. Further confusion arises from the biomethane potential tests (BMP) which have a tendency to give varying results. This paper has dual ambitions. One of these is to highlight the various results for biomethane potential that may be obtained from the same grass silage. The results indicated that methane potential from the same grass silage varied from 350 to 493 L CH 4 kg −1 VS added for three different BMP procedures. The second ambition is to attempt to compare two distinct digestion systems again using the same grass: a two stage continuously stirred tank reactor (CSTR); and a sequentially fed leach bed reactor connected to an upflow anaerobic sludge blanket (SLBR–UASB). The two engineered systems were designed, fabricated, commissioned and operated at small pilot scale until stable optimal operating conditions were reached. The CSTR system achieved 451 L CH 4 kg −1 VS added over a 50 day retention period. The SLBR–UASB achieved 341 L CH 4 kg −1 VS added at a 30 day retention time.
Gordon, Sean; Reguera, Maria; Sade, Nir; Cartwright, Amy; Tobias, Christian; Thilmony, Roger; Blumwald, Eduardo; Vogel, John
We are using the perennial model grass Brachypodium sylvaticum to identify combinations of transgenes that enhance tolerance to multiple, simultaneous abiotic stresses. The most successful transgene combinations will ultimately be used to create improved switchgrass (Panicum virgatum L.) cultivars. To further develop B. sylvaticum as a perennial model grass, and facilitate our planned transcriptional profiling, we are sequencing and annotating the genome. We have generated ~40x genome coverage using PacBio sequencing of the largest possible size selected libraries (18, 22, 25 kb). Our initial assembly using only long-read sequence contained 320 Mb of sequence with an N50 contig length of 315 kb and an N95 contig length of 40 kb. This assembly consists of 2,430 contigs, the largest of which was 1.6 Mb. The estimated genome size based on c-values is 340 Mb indicating that about 20 Mb of presumably repetitive DNA remains yet unassembled. Significantly, this assembly is far superior to an assembly created from paired-end short-read sequence, ~100x genome coverage. The short-read-only assembly contained only 226 Mb of sequence in 19k contigs. To aid the assembly of the scaffolds into chromosome-scale assemblies we produced an F2 mapping population and have genotyped 480 individuals using a genotype by sequence approach. One of the reasons for using B. sylvaticum as a model system is to determine if the transgenes adversely affect perenniality and winter hardiness. Toward this goal, we examined the freezing tolerance of wild type B. sylvaticum lines to determine the optimal conditions for testing the freezing tolerance of the transgenics. A survey of seven accessions noted significant natural variation in freezing tolerance. Seedling or adult Ain-1 plants, the line used for transformation, survived an 8 hour challenge down to -6 oC and 50% survived a challenge down to -9 oC. Thus, we will be able to easily determine if the transgenes compromise freezing tolerance. In the
Full Text Available Original, natural grass geocomposites (sods were developed on the basis of combination from unstuffy, needle-drive textile material, geo-net and soil-manure-peat or peat with grass cover from grass mixtures. The natural grass geocomposites have the next priorities: quickly grassing and reinforcing of eroded and degraded terrains; large uniformity and compactness of grass cove; long exploiting period; grassing of terrains with big slopes where the mechanization is difficult to use; the articles are with low mass, small thickness and high stability; they limit the growing of weed. The natural grass geocomposites are intend for control of soil erosion and reconstruction of natural landshaft. They can to reinforce ditches, grass collectors, side of the road slopes, as well as lay out lawn, parks, stadiums, ski racing tourist's beauty spot, etc.
National Aeronautics and Space Administration — ABSTRACT: The reflectance spectra of Douglas-fir and bigleaf maple seedling canopies were measured. Canopies varied in fertilizer treatment and leaf area density...
M. I. Ivanova
Full Text Available The assortment of salad crops, process parameters for production of seedlings (Baby leaf and sprouts (Microgreens is presented. The principles of the selection and sale of salad crops in the local market are recommended.
Elisa del Carmen Martínez Ochoa
Full Text Available The objective of this work was to evaluate the occurrence of polyembryony in the mango cultivars Manila and Ataulfo, and to determine whether seedlings cultured in vitro are zygotic or nucelar. Percentage of polyembryony was calculated and the number of embryos in 100 seeds of each cultivar was recorded. 'Manila' exhibited 97% polyembryony with 3.4 embryos per seed, while 'Ataulfo' had 95% polyembryony with 3.2 embryos per seed. Later, 20 seeds of each cultivar were established in vitro, and it was analyzed those in which all embryos germinated (12 seeds from 'Manila' and 7 from 'Ataulfo'. DNA was extracted from seedling leaf tissue, and its origin was identified with 14 RAPD primers. The polymorphic markers recognized the seedlings of sexual origin in seven of nine 'Manila' polyembryonic seeds, and in four of seven 'Ataulfo' ones. Also, in polyembryonic seeds not all zygotic seedlings were produced by small embryos located at the micropyle.
Variability of volatile organic compounds emitted by seedlings of seven African maize varieties when infested by adult Cicadulina storeyi China leafhopper vectors of maize streak virus. S Oluwafemi, MA Birkett, J Caulfield, JA Pickett ...
Re-use of seedling containers and Fusarium circinatum association with asymptomatic Pinus patula planting stock. Andrew R Morris, Gerda Fourie, Izette Greyling, Emma T Steenkamp, Nicoletta B Jones ...
National Aeronautics and Space Administration — On Earth plants are constantly exposed to a gravitational field of 1g. Gravity affects a plant in every step of its development. Germinating seedlings orient their...
Ou, Xiao-Hong; Fang, Yan; Shi, Ya-Na; Guo, Lan-Ping; Wang, Li; Yang, Yan; Jin, Hang; Liu, Da-Hui
In order to improve the irrigation for Panax notginseng growing seedlings, different mulching ways were carried out to investigate the effects of double mulching. Field experiment was applied to study soil moisture, soil temperature and bulk density of different mulching ways while the germination rate and seedlings growth also were investigated. Compared with the traditional single mulching with pine leaves or straw, double mulching using plastic film combined with pine leaves or straw could reduce 2/3 volumes of irrigation at the early seedling time Double mulching treatments didn't need to irrigate for 40 days from seeding to germination, and kept soil moisture and temperature steady at whole seedling time about 30% and 9.0-16.6 degrees C, respectively. The steady soil moisture and temperature benefited to resist late spring cold and germinate earlier while kept germination regularly, higher rate and seedlings quality. In contrast, single mulching using pine leaves or straw had poor soil moisture and temperature preserving, needed to irrigate every 12-day, meanwhile dropped the germination and booming time 14 days and 24-26 days, respectively, reduced germination rate about 11.3%-8.7%. However, single pine leaves mulching was better than straw mulching. In addition, though better effects of soil moisture and temperature preserving as well as earlier and higher rate of germination with single plastic films mulching had, some disadvantages had also been observed, such as daily soil temperature changed greatly, seedling bed soil hardened easily, more moss and weeds resulted difficulty in later management. To the purpose of saving water and labor as well as getting higher germination rate and seedlings quality, double mulching using plastic films combined pine leaves at the early time and single mulching removing plastic films at the later time is suggested to apply in the growing seedlings of P. notoginseng.
Shaik, Shahnoor S.; Carciofi, Massimiliano; Martens, Helle J.; Hebelstrup, Kim H.; Blennow, Andreas
Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphospho...
George A. Schier; Carolyn J. McQuattie
To determine the effect of aluminum (Al) on sugar maple (Acer saccharum Marsh.), seedlings were grown in sand irrigated with nutrient solution (pH 3.8) containing 0, 2.5, 5, 10, 20, or 40 mg L-1 Al. Seedling growth was enhanced at 2.5 and 5mgL-1 Al. Although higher levels of Al reduced calcium (Ca) and...
Valovirta, Erkka; Petersen, Thomas H; Piotrowska, Teresa; Laursen, Mette K; Andersen, Jens S; Sørensen, Helle F; Klink, Rabih
Allergy immunotherapy targets the immunological cause of allergic rhinoconjunctivitis and allergic asthma and has the potential to alter the natural course of allergic disease. The primary objective was to investigate the effect of the SQ grass sublingual immunotherapy tablet compared with placebo on the risk of developing asthma. A total of 812 children (5-12 years), with a clinically relevant history of grass pollen allergic rhinoconjunctivitis and no medical history or signs of asthma, were included in the randomized, double-blind, placebo-controlled trial, comprising 3 years of treatment and 2 years of follow-up. There was no difference in time to onset of asthma, defined by prespecified asthma criteria relying on documented reversible impairment of lung function (primary endpoint). Treatment with the SQ grass sublingual immunotherapy tablet significantly reduced the risk of experiencing asthma symptoms or using asthma medication at the end of trial (odds ratio = 0.66, P year posttreatment follow-up, and during the entire 5-year trial period. Also, grass allergic rhinoconjunctivitis symptoms were 22% to 30% reduced (P years). At the end of the trial, the use of allergic rhinoconjunctivitis pharmacotherapy was significantly less (27% relative difference to placebo, P < .001). Total IgE, grass pollen-specific IgE, and skin prick test reactivity to grass pollen were all reduced compared to placebo. Treatment with the SQ grass sublingual immunotherapy tablet reduced the risk of experiencing asthma symptoms and using asthma medication, and had a positive, long-term clinical effect on rhinoconjunctivitis symptoms and medication use but did not show an effect on the time to onset of asthma. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Dabney, Clemon; Ostergaard, Jason; Watkins, Eric; Chen, Changbin
The deposition of silicon into epidermal cells of grass species is thought to be an important mechanism that plants use as a defense against pests and environmental stresses. There are a number of techniques available to study the size, density and distribution pattern of silica bodies in grass leaves. However, none of those techniques can provide a high-throughput analysis, especially for a great number of samples. We developed a method utilizing the autofluorescence of silica bodies to investigate their size and distribution, along with the number of carbon inclusions within the silica bodies of perennial grass species Koeleria macrantha. Fluorescence images were analyzed by image software Adobe Photoshop CS5 or ImageJ that remarkably facilitated the quantification of silica bodies in the dry ash. We observed three types of silica bodies or silica body related mineral structures. Silica bodies were detected on both abaxial and adaxial epidermis of K. macrantha leaves, although their sizes, density, and distribution patterns were different. No auto-fluorescence was detected from carbon inclusions. The combination of fluorescence microscopy and image processing software displayed efficient utilization in the identification and quantification of silica bodies in K. macrantha leaf tissues, which should applicable to biological, ecological and geological studies of grasses including forage, turf grasses and cereal crops.
Tjandraatmadja, M; Norton, B W; Mac Rae, I C
The effects of adding two legumes, Gliricidia sepium and Leucaena leucocephala, cv. Cunningham, and molasses on the fermentation characteristics of silages made from two tropical grasses (Pangola grass, Digitaria decumbens, and Setaria sphacelata cv. Kazungula) were investigated. Pangola grass silages contained significantly higher contents of water-soluble carbohydrates and lactic acid than did setaria silages after 100 days fermentation, but there were no significant differences between the two silages in populations of lactic acid bacteria and contents of total N and NH3-N. Addition of either species of legume had no significant effect on fermentation acids and NH3-N contents, and numbers of lactic acid bacteria. Addition of both legumes reduced NH3-N production in the silages by 59% after 5 days' fermentation. Numbers of lactic acid bacteria were not significantly affected by the different treatments. Enterococcus faecalis represented 60% of the lactic acid bacteria isolated from the treated herbages prior to ensiling. By 100 days of fermentation, only lactobacilli were isolated: 82% homo-fermenters and 18% hetero-fermenters. Lactobacillus mesenteroides subsp. dextranicum was found only in the silage supplemented with 33% (w/w) legume. It was concluded that the low quality of tropical grasses used as feeds for ruminants may be significantly improved by ensiling these grasses with small amounts of molasses and with high-protein tree leaves.
Tanaka, Wakana; Pautler, Michael; Jackson, David; Hirano, Hiro-Yuki
Plant development depends on the activity of various types of meristems that generate organs such as leaves and floral organs throughout the life cycle. Grass species produce complex inflorescences and unique flowers. The grass inflorescence is composed of different types of branches, including a specialized branch called a spikelet. The spikelet is a special unit of the inflorescence and forms one to several florets, depending on the species. In the floret, floral organs such as perianth organs, carpels and stamens are formed. In Arabidopsis, because the inflorescence meristem (IM) forms the floral meristems (FMs) directly on its flanks, the change of meristem fate is relatively simple. In contrast, in grasses, different types of meristem, such as the IM, the branch meristem (BM), the spikelet pair meristem (SPM) in some grasses, the spikelet meristem (SM) and the FM, are responsible for the elaboration of their complex inflorescences and flowers. Therefore, sequential changes of meristem fate are required, and a number of genes involved in the specification of the fate of each meristem have been identified. In this review, we focus on the following issues concerning the fate of the reproductive meristems in two grass species, maize (Zea mays) and rice (Oryza sativa): (i) meristem regulation during inflorescence development; (ii) specification and fate change of the BM and the SM; (iii) determinacy of the FM; and (iv) communication between the meristem and lateral organs.
MacLeod, C.; Binley, A.; Humphreys, M.; King, I. P.; O'Donovan, S.; Papadopoulos, A.; Turner, L. B.; Watts, C.; Whalley, W. R.; Haygarth, P.
Sustainable management of water in landscapes requires balancing demands of agricultural production whilst moderating downstream effects like flooding. Pasture comprises 69% of global agricultural areas and is essential for producing food and fibre alongside environmental goods and services. Thus there is a need to breed forage grasses that deliver multiple benefits through increased levels of productivity whilst moderating fluxes of water. Here we show that a novel grass hybrid that combines the entire genomes of perennial ryegrass (Lolium perenne - the grass of choice for Europe’s forage agriculture) and meadow fescue (Festuca pratensis) has a significant role in flood prevention. Field plot experiments established differences in runoff generation with the hybrid cultivar reducing runoff by 50% compared to perennial ryegrass cultivar, and by 35% compared to a meadow fescue cultivar (34 events over two years, replicated randomized-block design, statistically significant differences). This important research outcome was the result of a project that combined plant genetics, soil physics and plot scale hydrology to identify novel grass genotypes that can reduce runoff from grassland systems. Through a coordinated series of experiments examining effects from the gene to plot scale, we have identified that the rapid growth and then turnover of roots in the L. perenne x F. pratensis hybrid is likely to be a key mechanism in reducing runoff generation. More broadly this is an exciting first step to realizing the potential to design grass genomes to achieve both food production, and to deliver flood control, a key ecosystem service.
Xiao Wen Hu
Full Text Available Studying seed dormancy and its consequent effect can provide important information for vegetation restoration and management. The present study investigated seed dormancy, seedling emergence and seed survival in the soil seed bank of Stipa bungeana, a grass species used in restoration of degraded land on the Loess Plateau in northwest China. Dormancy of fresh seeds was determined by incubation of seeds over a range of temperatures in both light and dark. Seed germination was evaluated after mechanical removal of palea and lemma (hulls, chemical scarification and dry storage. Fresh and one-year-stored seeds were sown in the field, and seedling emergence was monitored weekly for 8 weeks. Furthermore, seeds were buried at different soil depths, and then retrieved every 1 or 2 months to determine seed dormancy and seed viability in the laboratory. Fresh seeds (caryopses enclosed by palea and lemma had non-deep physiological dormancy. Removal of palea and lemma, chemical scarification, dry storage (afterripening, gibberellin (GA3 and potassium nitrate (KNO3 significantly improved germination. Dormancy was completely released by removal of the hulls, but seeds on which hulls were put back to their original position germinated to only 46%. Pretreatment of seeds with a 30% NaOH solution for 60 min increased germination from 25% to 82%. Speed of seedling emergence from fresh seeds was significantly lower than that of seeds stored for 1 year. However, final percentage of seedling emergence did not differ significantly for seeds sown at depths of 0 and 1 cm. Most fresh seeds of S. bungeana buried in the field in early July either had germinated or lost viability by September. All seeds buried at a depth of 5 cm had lost viability after 5 months, whereas 12% and 4% seeds of those sown on the soil surface were viable after 5 and 12 months, respectively.
Full Text Available Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer versus mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations.
Bruce A. Kimball
Full Text Available A multiyear study was conducted to determine if soil amendment combined with topical application of elemental sulfur could be employed to reduce deer browse damage to four conifer species. Fertilizer and sulfur were applied to conifer seedlings at seven sites near Corvallis, OR. Growth and browse damage data were collected for all seedlings over a period of 17 months. Additionally, foliar concentrations of monoterpenes and simple carbohydrates were assessed in western redcedar (Thuja plicata seedlings over a period of three years. Fertilization and sulfur treatments had a moderate impact on growth and no influence on browse damage or the chemical responses. Over the course of the study, browse damage diminished while foliar monoterpene concentrations increased in redcedar. It appears that silvicultural manipulation via sulfur application and/or soil amendment cannot accelerate or alter the ontogenetical changes that may naturally defend seedlings against mammalian herbivores. In a brief trial with captive deer, redcedar browse resistance was influenced by seedling maturation, but not monoterpene content. Other maturation effects may yield significant browse protection to young seedlings.
Marichel Canazza de Macedo
Full Text Available The objective of this work was to evaluate the white tabebuia (Tabebuia roseo-alba (Ridl. Sandwith seedlings emergence and growth in the beds according to different substrates. Two independent experiments were conducted. The emergence study was carried out in six substrates: 1- Plantmax®; 2- vermiculite; 3- sand; 4- soil + sand (1:1; 5- soil + carbonized rice husk (1:1; 6- soil + sand + carbonized rice husk (2:1:1 (v/v, and the experiment was set up according to a three-replicate randomized complete-block design. The growth study of seedlings was carried out according to a five-replicate randomized complete-block design with five substrates: 1- soil + sand (1:1; 2- soil + semi decomposed chicken manure (1:1; 3- soil + carbonized rice husk (1:1; 4- soil + sand + semi decomposed chicken manure (1:1:1; 5- soil + sand + carbonized rice husk (1:1:1 (v/v. The height results of seedling emergence, emergence speed index and the stem height were observed with Plantmax®, vermiculite, soil + carbonized rice husk and soil + sand + carbonized rice husk. The best results of seedling height, stem diameter, chlorophyll index, leaf area, root length and the stem dry mass weight and root were observed in the substrates with semi decomposed chicken manure. It is recommended the use of P, V, SC or SAC for seedling germination and emergence and SACF or SCF for seedling growth of white tabebuia.
Ronan Carlos Colombo
Full Text Available The in vitro propagation techniques are commonly used to produce ornamental pineapple seedlings in commercial scale, aiming to attend the growers with genetic and sanitary quality seedlings. However, the choice of the ideal substrate is essential for the acclimatization and growth stage of the seedlings propagated by this technique, since some substrates can increase the seedling mortality and/or limit the seedling growth due to its physical and chemical characteristics. Thus, the aim of this study was to evaluate the acclimatization of ornamental pineapple [Ananas comosus (L. Merr. var. ananassoides (Baker Coppens & Leal] on different substrates. Seedlings with approximately seven centimeters, obtained from in vitro culture, were transplanted into styrofoam trays filled with the following substrates: sphagnum; semi-composed pine bark; carbonized rice husk; sphagnum + semicomposed pine bark; sphagnum + carbonized rice husk; and semi-composed pine bark + carbonized rice husk. Each treatment was replicated five times using 10 plants. At 180 days, there were evaluated the following variables: survival percentage, plant height, number of leaves, leaf area, largest root length, and shoot and root dry matter. The substrate semi-composed pine bark + carbonized rice husk presented the lowest mean (62% for survival percentage. The semi-composed pine bark and semi-composed pine bark + carbonized rice husk treatments presented significant increments in some evaluated biometric characteristics. The semi-composed pine bark is the most favorable substrate for the A. comosus var. ananassoids acclimatization.
Sylvia Rocha e Silveira
Full Text Available ABSTRACT: Due to scarce nutritional data, this study assessed the productivity and nutritional value of Echinolaena inflexa (EI grass, native to the Cerrado biome. It was compared to B. brizantha (BB, one of the most cultivated grasses in Brazil, during a whole year (rainy; RS and dry season; DS. Sampling was held in accordance with pasture management (entry / exit height; 50 / 5cm and 80 / 25cm for EI and BB, respectively. Dry matter production (DMP, crude protein (CP, neutral and acid detergent fiber (NDF; ADF, hemicellulose (HCEL, PB insoluble neutral and acid detergent (PIDN; PIDA, total and non-fibrous carbohydrates (TC; NFC, ether extract (EE, and mineral matter (MM, and in vitro fermentation kinetics and DM degradability (DMD were evaluated. A completely randomized design (season as a fixed term and average treatment compared by Tukey post test were applied. EI produced 38.5% of the DMP of BB. A higher CP (75.3; 73.5 in the RS and DS, PIDA (12.5; 8.7, PIDN (47.1; 40.1, NDF (714.4; 749.5 and ADF (396.0; 419.0 were obtained by EI in relation to BB (CP (60.3; 33.5, PIDA (6.0; 3.5, PIDN (21.4; 10.8, NDF (673.0; 675.1 and ADF (335.5; 351.4 during the RS and DS, respectively (g kg-1 DM. In vitro data were directly associated with chemical composition, resulting in lower DMD of EI compared to BB. EI showed productive similarity (DMP during RS and DS (939.3; 809.8kg DM respectively. Although EI showed greater nutritional stability (CP between seasons, 17% of CP was linked to ADF and therefore, not available for rumen microorganisms.
an efficient production of ethanol. Lastly, the conversion of xylan was extremely low in both grass and grass silage. Optimization of the enzymatic saccharification of grass was attempted through improvement of the hemicellulase content in the enzyme blend. However, neither additional xylanases (Cellic HTec2......Development of sound technologies of biomass conversion will be increasingly important for many years to come as planetary bounderies drive the development towards a biobased society. Pretreatment of lignocellulosic biomass is, in this regard, an essential technology. Current pretreatment methods...... method with low cost and low energy requirements, plus brings about multiple advantages with regards to agricultural management. However, the pretreatment effect of ensiling, and the overall effects for further conversion are limited. In this study, ensiling was evaluated as a method of pretreatment...
Full Text Available Lemon grass essential oil has been used for decades to treat respiratory infections, sinusitis, bladder infections, high cholesterol, digestive problem, varicose veins and also for regeneration of connective tissue. It has anti spasmodic, anti-pyretic, anti-fungal, anti-bacterial, anti-inflammatory, anti-septic, insect repellent, sedative, vasodilator and flavoring properties. In china, it has been used traditionally as a remedy for stomach and liver diseases and also to treat rheumatism. Since lemon grass oil possess various pharmacological actions, it is also quite useful in dentistry. Hence, the objective of this article is to highlight various uses of lemon grass oil in the dental field and in the medical field in order to aid the professionals for future research.
Asnani, Vivake M.; Krantz, Timothy L.; Delap, Damon C.; Stringer, David B.
The vibration ring was conceived as a driveline damping device to prevent structure-borne noise in machines. It has the appearance of a metal ring, and can be installed between any two driveline components like an ordinary mechanical spacer. Damping is achieved using a ring-shaped piezoelectric stack that is poled in the axial direction and connected to an electrical shunt circuit. Surrounding the stack is a metal structure, called the compression cage, which squeezes the stack along its poled axis when excited by radial driveline forces. The stack in turn generates electrical energy, which is either dissipated or harvested using the shunt circuit. Removing energy from the system creates a net damping effect. The vibration ring is much stiffer than traditional damping devices, which allows it to be used in a driveline without disrupting normal operation. In phase 1 of this NASA Seedling Fund project, a combination of design and analysis was used to examine the feasibility of this concept. Several designs were evaluated using solid modeling, finite element analysis, and by creating prototype hardware. Then an analytical model representing the coupled electromechanical response was formulated in closed form. The model was exercised parametrically to examine the stiffness and loss factor spectra of the vibration ring, as well as simulate its damping effect in the context of a simplified driveline model. The results of this work showed that this is a viable mechanism for driveline damping, and provided several lessons for continued development.
Mustaffa, N.; Ahmad, N. A.; Razi, M. A. M.
Grassed swales are the best management practice (BMP), which has been widely used to reduce the peak flow, reduce water pollution through vegetated filtration, and improve the groundwater recharge. Universiti Tun Hussein Onn Malaysia (UTHM) is using the approach of grassed swales recommended by the Department of Irrigation and Drainage Malaysia (DID) for reducing the risk of flooding and controlling the water pollution. This paper investigates the variations of roughness coefficients with the flow depth of grassed swales in the campus of UTHM. Fieldwork was carried out on the grassed swale to collect the hydraulic data, which including the levelling work, measuring the flow depth and flow velocity of the swale. The flow depth of swale was taken at three points divided along the width of swale and the flow velocity is captured three times at each of the point. The variations of roughness coefficients of grassed swales are presented in Manning's equation, and the results reveal that the n value increases with the increasing of flow depth. Manning's coefficient value found in this study is in the range of 0.110 to 0.756, which are higher than the value proposed by the Urban Stormwater Management Manual for Malaysia (MSMA). The relationships of flow depth and velocity at each section of the swale are portrayed in graphs, which show that the velocity increases with the decreasing of flow depth. The outcomes of this study can be concluded that the variation of Manning's coefficient value is influenced by the swale profile, flow depth, flow velocity, and as well as the vegetation used in the grassed swale concerned.
This summary outlines the main conclusions of the project which aims to provide information on the growth, yields, and combustion characteristics of Miscanthus, switchgrass, Spartina, rye, and reed canary grass. Details are given of the small-plot trials of the non-wood biomass fuels, the planting, pests and diseases, the falling over of crops, the time of harvest, moisture content, yields, combustion trials, fuel and ash characterisation, and costs/income. Tables are provided illustrating the cumulative yield, the costs of the different species of energy grasses, and the annual mean gross margins over 5, 10, 15, and 20 years.
Bajo, S.; Keil, R.
A radiochemical method for the determination of 90 Sr in non-contaminated grass and soil is presented. The method is based on the leaching of 90 Sr from the mineralized samples followed by liquid-liquid extraction of 90 Y, its short lived daughter, by tributylphosphate and precipitation of Y-oxalate, which is counted in a low-level proportional counter. Based on dried samples of 30 g of soil and 100 g of grass the limit of detection is about 0.1 Bq/kg for both materials. (author) figs., tabs., 43 refs
Valovirta, Erkka; Petersen, Thomas H; Piotrowska, Teresa
compared with placebo on the risk of developing asthma. METHODS: A total of 812 children (5-12 years), with a clinically relevant history of grass pollen allergic rhinoconjunctivitis and no medical history or signs of asthma, were included in the randomized, double-blind, placebo-controlled trial......, comprising 3 years of treatment and 2 years of follow-up. RESULTS: There was no difference in time to onset of asthma, defined by prespecified asthma criteria relying on documented reversible impairment of lung function (primary endpoint). Treatment with the SQ grass sublingual immunotherapy tablet...... significantly reduced the risk of experiencing asthma symptoms or using asthma medication at the end of trial (odds ratio = 0.66, P year posttreatment follow-up, and during the entire 5-year trial period. Also, grass allergic rhinoconjunctivitis symptoms were 22% to 30% reduced (P
Hou, Xingwang; Zhang, Haiyan; Li, Yanlin; Yu, Miao; Liu, Jiyan; Jiang, Guibin
Hexachlorobutadiene (HCBD) has been listed as a persistent organic pollutant (POP) in the Stockholm Convention, and is now drawing more and more research interest. However, the understanding of its bioaccumulation, especially in plants, is still very limited. In this work, the behavior of HCBD in aqueous solution and pumpkin seedlings was studied through in-lab hydroponic exposure experiments. It was found that 69% of HCBD volatilized from water to the atmosphere after one day of exposure, and only 1% remained in the solution after four days. This high volatility might be the main cause of the low HCBD levels in aqueous environments. Although a great amount of HCBD volatilized into the atmosphere, only a small proportion of airborne HCBD was captured by the leaves and stems of the blank pumpkin seedling controls. The translocation of HCBD from the leaves to the bottom roots, as well as its release from the roots into the water, was detected. For the exposure groups, the pumpkin seedlings absorbed HCBD from both the hydroponic solution and the air via the roots and leaves, respectively. The concentration of HCBD in the exposed pumpkin roots linearly increased with the continuous addition of HCBD into the exposure system. Upward translocation from the roots to the leaves and downward translocation from the leaves to the roots existed simultaneously in the exposed pumpkin seedlings. However, the concentrations of HCBD in the leaves, stems and roots in the exposure group were much higher than those of the blank plant controls, suggesting little contribution from the airborne HCBD in the hydroponically exposed pumpkin seedlings. The lipid content did not show obvious effects on the bioaccumulation and biodistribution of HCBD in the pumpkin seedlings, indicating that the translocation of HCBD within the pumpkin seedlings might be an active process. This study provided new findings on the environmental behavior of HCBD, which will be helpful for understanding the exposure
Full Text Available at various scales such as local, regional and global scale. Traditional field techniques to measure grass nutrient concentration have been reported to be laborious and time consuming. Remote sensing techniques provide opportunity to map grass nutrient...
Jiang, Jinglong; Su, Miao; Wang, Liyan; Jiao, Chengjin; Sun, Zhengxi; Cheng, Wei; Li, Fengmin; Wang, Chongying
During germination in distilled water (dH(2)O) on a horizontally positioned Petri dish, emerging primary roots of grass pea (Lathyrus sativus L.) grew perpendicular to the bottom of the Petri dish, due to gravitropism. However, when germinated in exogenous hydrogen peroxide (H(2)O(2)), the primary roots grew parallel to the bottom of the Petri dish and asymmetrically, forming a horizontal curvature. Time-course experiments showed that the effect was strongest when H(2)O(2) was applied prior to the emergence of the primary root. H(2)O(2) failed to induce root curvature when applied post-germination. Dosage studies revealed that the frequency of primary root curvature was significantly enhanced with increased H(2)O(2) concentrations. This curvature could be directly counteracted by dimethylthiourea (DMTU), a scavenger of H(2)O(2), but not by diphenylene iodonium (DPI) and pyridine, inhibitors of H(2)O(2) production. Exogenous H(2)O(2) treatment caused both an increase in the activities of H(2)O(2)-scavenging enzymes [including ascorbate peroxidase (APX: EC 220.127.116.11), catalase (CAT: EC 18.104.22.168) and peroxidase (POD: EC 22.214.171.124)] and a reduction in endogenous H(2)O(2) levels and root vitality. Although grass pea seeds absorbed exogenous H(2)O(2) during seed germination, DAB staining of paraffin sections revealed that exogenous H(2)O(2) only entered the root epidermis and not inner tissues. These data indicated that exogenously applied H(2)O(2) could lead to a reversible loss of the root gravitropic response and a horizontal curvature in primary roots during radicle emergence of the seedling. Copyright © 2012 Elsevier Masson SAS. All rights reserved.
Full Text Available Plant growth-promoting bacteria (PGB induce positive effects in plants, for instance, increased growth and reduced abiotic stresses susceptibility. The mechanisms by which these bacteria impact the host plant are numerous, diverse and often specific. Here, we studied the agronomical, molecular and biochemical effects of the endophytic PGB Bacillus subtilis B26 on the full life cycle of Brachypodium distachyon Bd21, an established model species for functional genomics in cereal crops and temperate grasses. Inoculation of Brachypodium with B. subtilis strain B26 increased root and shoot weights, accelerated growth rate and seed yield as compared to control plants. B. subtilis strain B26 efficiently colonized the plant and was recovered from roots, stems and blades as well as seeds of Brachypodium, indicating that the bacterium is able to migrate, spread systemically inside the plant, establish itself in the aerial plant tissues and organs, and is vertically transmitted to seeds. The presence of B. subtilis strain B26 in the seed led to systemic colonization of the next generation of Brachypodium plants. Inoculated Brachypodium seedlings and mature plants exposed to acute and chronic drought stress minimized the phenotypic effect of drought compared to plants not harbouring the bacterium. Protection from the inhibitory effects of drought by the bacterium was linked to upregulation of the drought-response genes, DREB2B-like, DHN3-like and LEA-14-A-like and modulation of the DNA methylation genes, MET1B-like, CMT3-like and DRM2-like, that regulate the process. Additionally, total soluble sugars and starch contents increased in stressed inoculated plants, a biochemical indication of drought tolerance. In conclusion, we show a single inoculation of Brachypodium with a PGB affected the whole growth cycle of the plant, accelerating its growth rates, shortening its vegetative period, and alleviating drought stress effects. These effects are relevant to
Gagné-Bourque, François; Mayer, Boris F; Charron, Jean-Benoit; Vali, Hojatollah; Bertrand, Annick; Jabaji, Suha
Plant growth-promoting bacteria (PGB) induce positive effects in plants, for instance, increased growth and reduced abiotic stresses susceptibility. The mechanisms by which these bacteria impact the host plant are numerous, diverse and often specific. Here, we studied the agronomical, molecular and biochemical effects of the endophytic PGB Bacillus subtilis B26 on the full life cycle of Brachypodium distachyon Bd21, an established model species for functional genomics in cereal crops and temperate grasses. Inoculation of Brachypodium with B. subtilis strain B26 increased root and shoot weights, accelerated growth rate and seed yield as compared to control plants. B. subtilis strain B26 efficiently colonized the plant and was recovered from roots, stems and blades as well as seeds of Brachypodium, indicating that the bacterium is able to migrate, spread systemically inside the plant, establish itself in the aerial plant tissues and organs, and is vertically transmitted to seeds. The presence of B. subtilis strain B26 in the seed led to systemic colonization of the next generation of Brachypodium plants. Inoculated Brachypodium seedlings and mature plants exposed to acute and chronic drought stress minimized the phenotypic effect of drought compared to plants not harbouring the bacterium. Protection from the inhibitory effects of drought by the bacterium was linked to upregulation of the drought-response genes, DREB2B-like, DHN3-like and LEA-14-A-like and modulation of the DNA methylation genes, MET1B-like, CMT3-like and DRM2-like, that regulate the process. Additionally, total soluble sugars and starch contents increased in stressed inoculated plants, a biochemical indication of drought tolerance. In conclusion, we show a single inoculation of Brachypodium with a PGB affected the whole growth cycle of the plant, accelerating its growth rates, shortening its vegetative period, and alleviating drought stress effects. These effects are relevant to grasses and cereal
Oskarsson, Hreinn; Sigurgeirsson, Adalsteinn; Raulund-Rasmussen, Karsten
Ledeb. and Picea sitchensis (Bong.) Carr. After six growing seasons, seedlings provided with controlled-release-fertilizer (Osmocote®: 25 g per seedling) or smaller amounts of easily soluble nitrogen–phosphorus fertilizer (e.g. 1.2 g N per seedling and 1.4 g P per seedling) showed significantly improved...... seedlings, compared to control seedlings. It is concluded that fertilization during afforestation in Iceland and other areas in the world with similar climatic and soil properties could make the difference between plantation success or failure. Growth; Survival; Foliar nutrient concentration; Frost heaving...
Full Text Available Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, β-oxidation and triacylglycerol (TAG synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3, DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1 and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6 in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1 and LATE ELONGATED HYPOCOTYL (LHY from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis.
S. M. Widyastuti
Full Text Available Pinus merkusii or tusam is an original Indonesian plant and it is naturally distributed in Aceh and North Sumatra. Damping-off disease is the main problem in its nurseries. Fusarium subglutinans is one of the leading causes of damping-off disease. The knowledge of fungal infections process of tusam seedlings is essential to control damping- off disease effectively.The aim of this research is to understand (1 infection process of F. subglutinans in tusam seedlings and the defence response of seedlings against the infection of F. subglutinans. The methods used in this research were (1 identification of fungal pathogens that causing the disease, (2 pathogenicity test of F. subglutinans, (3 detection the accumulation of lignin, accumulation of callose and hypersensitive reactions by staining of seedling tissue using phloroglucinol, aniline blue and lactophenol trypan blue.The results of this study revealed that spores germination occurred in two days after inoculation. Direct penetration through cell wall and stomata was observed on the third day after inoculation. There was hypersensitive reaction in stomata. Accumulation of callose and lignin appeared on the third day after inoculation. However, defence response of seedlings was not effective, as F. subglutinans is a necrotroph fungus.
Fernanda Aparecida Rodrigues Guimarães
Full Text Available In nature, orchid seeds obtain the nutrients necessary for germination by degrading intracellular fungal structures formed after colonization of the embryo by mycorrhizal fungi. Protocols for asymbiotic germination of orchid seeds typically use media with high concentrations of soluble carbohydrate and minerals. However, when reintroduced into the field, seedlings obtained via asymbiotic germination have lower survival rates than do seedlings obtained via symbiotic germination. Tree fern fiber, the ideal substrate for orchid seedling acclimatization, is increasingly scarce. Here, we evaluated seed germination and protocorm development of Cyrtopodium glutiniferum Raddi cultivated in asymbiotic media (Knudson C and Murashige & Skoog and in oatmeal agar (OA medium inoculated with the mycorrhizal fungus Epulorhiza sp., using non-inoculated OA medium as a control. We also evaluated the performance of tree fern fiber, pine bark, eucalyptus bark, corncob and sawdust as substrates for the acclimatization of symbiotically propagated plants. We determined germination percentages, protocorm development and growth indices at 35 and 70 days of cultivation. Relative growth rates and the effects of substrates on mycorrhizal formation were calculated after 165 days of cultivation. Germination efficiency and growth indices were best when inoculated OA medium was used. Corncob and pine bark showed the highest percentages of colonized system roots. The OA medium inoculated with Epulorhiza sp. shows potential for C. glutiniferum seedling production. Corncob and pine bark are promising substitutes for tree fern fiber as substrates for the acclimatization of orchid seedlings.
Devaney, John L; Lehmann, Michael; Feller, Ilka C; Parker, John D
Recent climate warming has led to asynchronous species migrations, with major consequences for ecosystems worldwide. In woody communities, localized microclimates have the potential to create feedback mechanisms that can alter the rate of species range shifts attributed to macroclimate drivers alone. Mangrove encroachment into saltmarsh in many areas is driven by a reduction in freeze events, and this encroachment can further modify local climate, but the subsequent impacts on mangrove seedling dynamics are unknown. We monitored microclimate conditions beneath mangrove canopies and adjacent open saltmarsh at a freeze-sensitive mangrove-saltmarsh ecotone and assessed survival of experimentally transplanted mangrove seedlings. Mangrove canopies buffered night time cooling during the winter, leading to interspecific differences in freeze damage on mangrove seedlings. However, mangrove canopies also altered biotic interactions. Herbivore damage was higher under canopies, leading to greater mangrove seedling mortality beneath canopies relative to saltmarsh. While warming-induced expansion of mangroves can lead to positive microclimate feedbacks, simultaneous fluctuations in biotic drivers can also alter seedling dynamics. Thus, climate change can drive divergent feedback mechanisms through both abiotic and biotic channels, highlighting the importance of vegetation-microclimate interactions as important moderators of climate driven range shifts. © 2017 by the Ecological Society of America.
Carlos Alberto Franco Tucci
Full Text Available The production of seedlings is one of the most important phases of the cultivation of forest species. Seedlings ofappropriate quality are fundamental in the growth and development of the species. In the production of seedlings, the substratum isfundamental for the good development of the plants. However, the subsoil in general, is acid and it contains low levels of nutritious.The acidity of the soil and the deficiency of nutrients can be corrected through liming and mineral fertilization. The objective of thepresent work was to evaluate the effect of liming and of the fertilization of the soil for the production of mahogany seedlings. Theexperiment was carried out in the period of 120 days, in the Federal University of Amazonas, UFAM. The experimental design wasrandomized complete blocks with statistical analysis in split plot. The plots were composed with eight treatments and four repetitionsand the subplots were eight sampling times of the plants. The treatments were control (natural soil, liming, corrective phosphate,fertilizing with NPK, liming + corrective phosphate, corrective phosphate + fertilizing with NPK, liming + fertilizing with NPK andliming + corrective phosphate + fertilizing with NPK. It was concluded that the associated liming and corrective phosphate and withthe fertilizing with nitrogen, phosphorous and potassium promoted the smallest levels of exchangeable aluminum and the largestlevels of calcium, magnesium, phosphorous and potassium in the soil. These levels of nutrients in the soil caused larger levels ofnutrients in the plants, providing larger growth rate. The liming, corrective phosphate and fertilizing are a fundamental practices inthe formation of mahogany seedlings.
Larrea-Alcázar, Daniel M.; Simonetti, Javier A.
We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.
Pier, P.A.; Thornton, F.C.; McDuffie, C. Jr. (Tennessee Valley Authority, Muscle Shoals, AL (USA))
Potted native and Phyton-grown (Phyton Technologies) red spruce seedlings were placed in open-top field chambers constructed on Whitetop Mountain, VA (elevation 1680 m) to evaluate the effect of ozone and acid cloud deposition on seedling growth and metabolism. Chamber treatments were (1) exclusion of clouds and an approximate 50% reduction in ambient ozone, (2) ambient ozone with clouds excluded, and (3) exposure to clouds and ambient ozone (control). No differences were detected between chamber treatments for diameter growth, total chlorophyll, chl a and b, chl a/b ratio, and carotenoids. No enhancement of photosynthesis and respiration was seen in exclusion chambers for current and previous year's growth of native seedlings during the growing season. Photosynthesis of Phyton-grown seedlings was consistently higher in exclusion chambers compared to control chambers over the course of the growing season, although differences were not statistically significant. After one growing season, neither pollutant had significant effects on seedling growth and metabolism.
Full Text Available The fatty acid composition of shoots of unhardened and hardened to cold etiolated winter wheat seedlings grown from seeds treated with tebuconazole-based protectant «Bunker» (content of tebuconazole 60 grams per liter, g/L, and the seedlings frost resistance has been studied. It is shown that treatment of winter wheat seeds by «Bunker» preparation (1,5 microliter per gram of seeds, µl/g is accompanied by an increase of the fatty acids unsaturation in the shoots and increase of the seedlings frost resistance (–8°C, 24 h. The most pronounced decrease in the content of saturated palmitic acid and increase in the content of unsaturated α-linolenic acid were observed during cold hardening of winter wheat seedlings grown from seeds treated by tebuconazole-based protectant. It is concluded that the seeds treatment with tebuconazole-based protectant causes changes of fatty acid composition of winter wheat seedlings to increase their frost resistance.
Florina Maria Copaciu
Full Text Available After germination process, the green seedlings accumulate important quantities of bioactive compounds such as: enzymes, vitamins, minerals, chlorophylls and nutrients. The current study presents a comparison between different bioactive compounds and their antioxidant capacity, after the seedling germination and growth of five seeds (arugula, lentil, wheat, beans and mustard both on soil, in a pot (natural system, and directly on cotton wool soaked, in water (artificial system. In this study the carotenoids content and the antioxidant capacity were analysed. The data of the present study showed that the highest amount of zeaxanthin and β - carotene was found in cultivars of wheat grown in natural system, while the highest antioxidant activity was found in cultivars of wheat, lentils and beans, though in this case with no statistical differences between the systems. The results show statistical differences between the values of bioactive compounds in the five types of seedlings but also in the values obtained for the same seedlings in different systems. The best cultivars for improving the nutritional quality for human consumption are wheat seedlings followed by lentil ones.
Verhagen, H.J.; Van Gerven, K.A.J.; Van der Meer, J.W.; Van Heereveld, M.A.; Akkerman, G.J.
In the present report, a Smart Grass Reinforcement for overtopping resistant sea defences is elaborated on a theoretical basis, within the framework of ComCoast, Work Package 3 (WP3). The smart grass revetment concept aims at strengthening the present grass revetments at the crests and inners slopes
Jacobs, A.A.A.; Scheper, J.A.; Benvenutti, M.A.; Gordon, I.J.; Poppi, D.P.; Elgersma, A.
The intake of forage grasses by grazing ruminants is closely related to the mechanical fracture properties of grasses. The relationship between the tensile fracture properties of grasses and foraging behaviour is of particular importance in tropical reproductive swards composed of both stems and
Os, van M.
In Northern- and Western-Europe, grass silage is a major component in winter feeding rations for ruminants. The intake of ensiled grass is often lower than the intake of hay or the fresh grass of similar digestibility. This intake depression is attributed to the fermentation products
The results provide valuable guidelines for the use of fire in controlling bush encroachment. Keywords: Bush; Bush encroachment; Eastern Cape; effect of fire; Fire; Fire intensity; fire regime; Grass; grass sward; grasses; recovery; Savanna; south africa; Thornveld; Vegetation recovery; Veld burning. Journal of the Grassland ...
It is clear from these results that Smuts finger grass can play an important role during the winter period as animal feed. Keywords: afrikaans; animal production; digitaria eriantha; foggage; grasses; grazing capacity; literature review; management; semi-arid regions; smuts fingergrass; tropical grass; western transvaal ...
Green, Ole; Jørgensen, Rasmus Nyholm; Sørensen, Claus Aage Grøn
Traffic intensities have been shown to have a negative influence on the yield of grass and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 different traffi...
Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian
Different traffic intensities have been shown to have a negative influence on the yield of grass and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 differ...
College of Agriculture, South China Agricultural University, Guangzhou 510642, People's Republic of China. Abstract. Genetic variability and relationships among elephant grass cultivars were estimated by the SRAP (sequence-related amplified polymorphism) assay. A total of 60 individuals collected from five cultivars in ...
Pukalskas, A.; Beek, van T.A.; Venskutonis, R.P.; Linssen, J.P.H.; Veldhuizen, van A.; Groot, de Æ.
Extracts from aerial parts of sweet grass (Hierochloe odorata) were active DPPH free radical scavengers, The active compounds were detected in extract fractions using HPLC with on-line radical scavenging detection. After multistep fractionation of the extract, two new natural products possessing
Weijde, van der R.T.; Alvim Kamei, C.L.; Torres Salvador, A.F.; Vermerris, W.; Dolstra, O.; Visser, R.G.F.; Trindade, L.M.
With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the
An experiment was conducted at Bunda College, Malawi, to determine the effect of magadi (a sodium sesquicarbonate- Na2CO3, NaHCO3.2H2O) treated forages on their intake and digestibility and growth of sheep. Rhodes grass (Chloris gayana Kunth), Cedrela (Toona ciliata, M. Roem) and Sesbania [Sesbania sesban ...
This paper reviews some of the reasons why a majority of Japanese university students are not interested in study-abroad, international-education type programs. A general consensus in Japan is that disinterest in studying abroad is reflective of the values held by many Japanese young people, often referred to as the "grass-eating"…
The assessment of macromineral concentration of Panicum/Stylosanthes mixtures was carried out at the Cattle Production Venture, Federal University of Agriculture, Abeokuta, in Southwest Nigeria. The study aimed to determine the concentration of some macromineral elements in the grass/legume pasture grazed by the ...
Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...
Carcass mass gains of steers grazing dryland Cynodon aethiopicus cv. No. 2 Star grass pastures during the growing season were determined for each of 16 treatments comprising four levels of nitrogen fertilisation in combination with four overlapping sets of stocking rates. The treatments were repeated over four growing ...
Tropical-subtropical grasses have shown a wide range of response to photoperiod. Some of the response patterns which they exhibit are extremely complex and often seem unrelated to the conditions to which the plants are adapted. However, there is an increasing realisation of the possible role of factors of the ...
Some grass species occur more frequently in certain habitats than in others, but uncertainty as to exactly which factors are responsible for this phenomenon exist. Species composition as well as habitat data were collected from plots situated on the mild slopes of the study area, and the data were analysed by means of a ...
A new species of grass frog of lhe genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schillukorum and Ptychadena mossambica, the new species differs In advertisement call, and external characters. An examination of a series of published sonagrams indicates that ...
Nuclear power plants experiencing personnel recruitment problems are trying a grass-roots approach to increase the manpower pool. The Philadelphia Electric Co. and the Toledo Edison Co. are working with local educational institutions to offer nuclear-technology training specific to the needs of nuclear plants. The utilities' investment covers much of the cost of instruction as well as continued training for employees
Abstract. Book Title: Grasses and Grazers of Botswana and the Surrounding Savanna. Book Author: Veronica Roodt. 2015, Struik Publishers, PO Box 1144, Cape Town 8001, South Africa. 344 pages, softcover. ISBN 978-1-775-84115-9. Price R290.00 ...
1973-01-01The small amount of viable seed that can be harvested from tropical ley grasses such as Chloris gayana, Setaria sphacelata and Panicum spp. is largely due to the wide range in maturity between different heads and in maturity between seeds in any head. Ripe seed is also liable
Evapotranspiration (Et) and water use efficiency (WUE) were determined for each of seven grass species during the 1986/87 seasons. The highest and lowest mean daily Et of 2, 39 and 1, 66 mm were recorded respectively for Themeda triandra and Sporobolus fimbriatus. Between species, the average Et for the two ...
W. Lopushinsky; G.O. Klock
Seasonal trends of soil water content in plots of snowbrush (Ceanothus velutinus Dougl.), orchard grass (Dactylis glomerata L), and pinegrass (Calamagrostis rubes- cens Buckl.) and in bare plots were measured on a burned-over forest watershed in north-central Washington. A comparison of soil water contents at depths of 12, 24,...
Conclusion: Results of the present study indicate that LGEO has a noteworthy potential for the development of drugs for the treatment of fungal infections and skin inflammation that should be explored in future studies. Keywords: lemon grass; essential oil; antifungal activity; anti-inflammatory effect; citral; aromatherapy ...
STRIATUS IN THE RUWENZORI NATIONAL PARK, UGANDA (RODENTIA: MURIDAE). B R NEAL-. Department of Zoology, University of Southampton. Accepted: January 1977. ABSTRACT. A total of 730 puncta ted grass-mice was dissected to study their biology. Breeding occurred during the rains and ceased during the ...
Alexandre Magno Brighenti
Full Text Available ABSTRACT Elephant grass (Pennisetum purpureum Schum. is an important forage crop that has been proposed as a potential feedstock for bioenergy production. However, weed interference is a major factor limiting elephant grass production. Field experiments were conducted in 2014 and 2015 to evaluate preemergence herbicides for selective weed control in an elephant grass pasture. Herbicide treatments included atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, diuron + hexazinone, sulfentrazone, imazethapyr, and atrazine at label use rates. Weedy and weed-free treatments were included. Atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, sulfentrazone, and atrazine did not cause phytotoxicity on elephantgrass 35 days after treatment (DAT. However, diuron + hexazinone and imazethapyr were the most phytotoxic on elephantgrass, resulting in 81 and 70% phytotoxicity in 2014, and 7 and 6% phytotoxicity in 2015 respectively 35 DAT. All treatments provided effective weed control (>81% with the exception of ethoxysulfuron (0 and 11% in 2014 and 2015, respectively, and atrazine (59% in 2014. These results show that atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, sulfentrazone, and atrazine were selectives when applied in preemergence in elephant grass pasture.
Vuuren, van A.M.
Until recently, young, highly digestible grass was considered an ideal feed for dairy cows. However, research during the last decades has shown that the nutrient supply of grazing animals is insufficient for milk productions above c. 29 kg per day. Experiments in England and New Zealand
Overseeding cool-season grasses into dormant or nearly dormant warm-season pasture can increase total year-round forage production. Reduced input sowing methods and minimal ground preparation prior to overseeding are of interest for cost-reduction, but there is concern that any cost savings may be o...
Eriksen, Marlene Stenberg Hagen; Laursen, Theresa Back; Rode, Carsten
In the attempt to obtain knowledge of the hygrothermal properties of sea grass as thermal insulation, experiments have been carried out in the laboratory to determine the thermal conductivity, sorption properties and the water vapour permeability of the material. In order to investigate...
India Joelma Gatass Monteiro
Full Text Available The goal was to evaluate the chemical composition and fermentation pattern of elephant grass (Pennisetum purpureum Schum. cv. Roxo silage with different levels of soybean hulls or rice bran. Two trials were conducted, comprising of a completely randomized design, with four replicates each. Treatments consisted on the addition of 0%, 5%, 10%, and 15% of soybean hulls or rice bran to unwilted green elephant grass forage. Large PVC silos were used adopting a density of 600 kg of green mass m-3. The silos were opened 40 days after ensiling. The results revealed that the inclusion of 10% soybean hulls increased elephant grass forage dry matter (DM content to 31%, but did not alter the water soluble carbohydrate (WSC content or buffering capacity. The resultant silages exhibited good fermentation patterns in terms of pH (less than 3.97 and NH3-N (4.07% total N levels. The inclusion of rice bran increased both DM and WSC content in the forage, improving the fermentation pattern of silages (P < 0.05. This too was verified by a pH lower than 3.92 and a maximum NH3-N of 4.23% of the total N. The inclusion of 10% rice bran to the elephant grass improved the nutritional value of the forage to be ensiled and, hence, of the produced silage.
Reflecting that grass cutters domestication in southwestern Nigeria is possible if only, social infrastructures such as constant electricity supply, pipe borne water and good network of roads, incentives like pups, feed and funds are provided by concerned authorities. These may arouse the interest of prospective farmers to ...
The growth response of two decreasers, three Increaser II grasses, and an Increaser III species to frequent, severe defoliation under three levels of competition from neighbours and two levels of soil nutrients was examined in a pot trial. The effects of competition and especially nutrients markedly modified the defoliation ...
Plant-growth-promoting (PGP) bacteria include a diverse group of soil bacteria thought to stimulate plant growth by various mechanisms. Brachiaria forage grasses, of African origin, are perennials that often grow under low-input conditions and are likely to harbour unique populations of PGP bacteria. Three bacterial strains ...
Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian
Effect of machinery wheel load on grass Ole Green1, Rasmus N. Jørgensen2, Kristian Kristensen3, René Gislum3, Dionysis Bochtis1, & Claus G. Sørensen1 1University of Aarhus, Dept. of Agricultural Engineering 2University of Southern Denmark, Inst. of Chemical Eng., Biotechnology and Environmental...
Book Title: Identification Guide to Southern African Grasses: an Identification Manual with Keys, Descriptions and Distributions. Book Authors: L Fish, A.C. Machau, M.J. Moeaha & M.T. Nembudani. 2015, South African National Biodiversity Institute, Private Bag X101, Silverton 0184, South Africa 798 pages, hardcover
The radioactivity in some grasses in the environment of nuclear research facilities located within the Oau Ile-Ife, Nigeria. MK Akinloye, JB Olomo. Abstract. No Abstract. Nigerian Journal of Physics Vol. 17 (Supplement) 2005: pp. 219-225. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...
Fire and the dynamics of two unpalatable grass species ( Cymbopogon pospischilii and Elionurus muticus ) in a semi-arid climate. ... Cymbopogon pospischilii and Elionurus muticus are unpalatable for most of the growing season and form a reasonably large component of the vegetation composition in semi-arid grassland ...
Minuto, A.; Huisman, Gijs; Nijholt, Antinus; Herrlich, Marc; Malaka, Rainer; Masuch, Maic
Smart materials offer new possibilities for creating engaging and interesting forms of interaction and ways of displaying information in a material way. In this paper we describe Follow the Grass, a concept of an interactive pervasive display for public spaces. The display will be built up out of a
Perennial, temperate, C4 warm-season grasses, such as switchgrass and miscanthus have been tabbed as sources of herbaceous biomass for the production of green fuels and chemicals based on a number of positive agronomic traits. Although there is important literature on the management of these specie...
Grasses have developed through natural selection to deter, escape and tolerate herbivory, and to escape and tolerate fire. In the semi-arid grassveld of the Eastern Cape, the species Themeda triandra and Sporobolus fimbriatus have been classified as Decreaser and Increaser II plants respectively. Both species have ...
Grazing habits were determined by analysis of rumina from slaughtered springbok and sheep where springbok grazed together with Merino sheep in False Upper Karoo and together with Dorper sheep in Kalahari Thornveld. Results show that in both veld types, grass constituted about 39 percent of the dry mass intake of ...
The Vaal River, South Africa, historically had a rich diversity of native submerged macrophytes with at least 13 species from 5 families recorded. ... in the populations of invasive alien grass carp Ctenopharyngodon idella Cuvier & Valenciennes (Cyprinidae) in the river, where populations have been a concern since 2005.
Oct 16, 2006 ... reduction in dietary protein intake of rabbits in the latter stages of growth where rabbits are raised up to 2.5-2.8 kg live weight. This study was designed therefore to evaluate the utilization of combinations of concentrate, grass and legume forages on performance and nutrient digestibility of grower rabbits.
Performance of Sahiwal and Friesian heifers fed on napier grass supplemented with ... In the tropics, the majority of dairy cattle depend on low quality natural pastures and crop residues. (Preston & Leng ... level is below the. ARC (1980) recommended dietary CP levels for growing heifers of 10 to 12 g.kg- DM CP and as a.
Genetic variability and relationships among elephant grass cultivars were estimated by the SRAP (sequence-related amplified polymorphism) assay. A total of 60 individuals collected from five cultivars in China were analysed. Sixty-two selected primer combinations generated 1395 bands, with an average of 22.5 per ...
Dec 14, 2011 ... Grass plants crop water consumption model in urban parks located in three different ... The result of calculations, using the climate data of July, value of the province of Antalya were. ETo=7,10464 mm/day, for Ankara .... method is recommended by Food and Agriculture. Organisation (FAO) (Allen et al., ...
In two pot experiments radioactive paraquat was applied to certain important veld grasses (Experiment I-Aristida junciformis, Themeda triandra, Elyonuris argenteus, Andropogon filifolius, Eragrostis curvula; Experiment II-A. junciformis, E. argenteus) to determine the extent of translocation at a young stage of growth with ...
Ide, Janet L.
Describes "Snakes in the Grass," a weaving project used with special needs students. Discusses the preliminary skill-building activities used, the process for creating the students' individual snakes, and the preparation and process for how the students wove the snakes. (CMK)
Productivity of irrigated gamba grass ( Andropogon Gayanus Kunth ) as influenced by flood irrigation and compost manure levels in zaria. ... A field experiment was conducted to evaluate the effect of varying levels of irrigation volume, irrigation frequency and compost manure application on growth components, forage yield ...
Bingham, Marcus A; Simard, Suzanne W
Ectomycorrhizal (EM) networks (MN) are thought to be an important mode of EM fungal colonization of coniferous seedlings. How MNs affect EM communities on seedlings, and how this varies with biotic and abiotic factors, is integral to understanding their importance in seedling establishment. We examined EM fungal community similarity between mature trees and conspecific interior Douglas-fir (Pseudotsuga menziesii var. glauca) seedlings in two experiments where seed and nursery-grown seedlings originating from different locations were planted at various distances from trees along a climatic gradient. At harvest, trees shared 60% of their fungal taxa in common with outplanted seedlings and 77% with germinants, indicating potential for seedlings to join the network of residual trees. In both experiments, community similarity between trees and seedlings increased with drought. However, community similarity was lower among nursery seedlings growing at 2.5 m from trees when they were able to form an MN, suggesting MNs reduced seedling EM fungal richness. For field germinants, MNs resulted in lower community similarity in the driest climates. Distance from trees affected community similarity of nursery seedlings to trees, but there was no interaction of provenance with MNs in their effect on similarity in either nursery seedlings or field germinants as hypothesized. We conclude that MNs of trees influence EM colonization patterns of seedlings, and the strength of these effects increases with climatic drought. © Springer-Verlag 2012
Leonard, Kurt J; Szabo, Les J
shown to infect 74 species in 34 genera in artificial inoculations of seedlings, but only 28 of those species belonging to eight genera were known to be natural hosts of the fungus. Other formae speciales of P. graminis have narrower host ranges than P. graminis f. sp. tritici. Disease symptoms: Infections in cereals or grasses occur mainly on stems and leaf sheaths, but occasionally they may be found on leaf blades and glumes as well. The first macroscopic symptom is usually a small chlorotic fleck, which appears a few days after infection. About 8-10 days after infection, a pustule several millimetres long and a few millimetres wide is formed by rupture of the host epidermis from pressure of a mass of brick-red urediniospores produced in the infection. These uredinial pustules are generally linear or diamond shaped and may enlarge up to 10 mm long. The powdery masses of urediniospores appear similar to rust spots on a weathered iron surface. With age, the infection ceases production of brick-red urediniospores and produces a layer of black teliospores in their place, causing the stems of heavily infected plants to appear blackened late in the season.
Full Text Available Background: In many countries around the world, the most damaging invasive plant species are grasses. However, the status of grass invasions in South Africa has not been documented recently. Objectives: To update Sue Milton’s 2004 review of grasses as invasive alien plants in South Africa, provide the first detailed species level inventory of alien grasses in South Africa and assess the invasion dynamics and management of the group. Method: We compiled the most comprehensive inventory of alien grasses in South Africa to date using recorded occurrences of alien grasses in the country from various literature and database sources. Using historical literature, we reviewed past efforts to introduce alien grasses into South Africa. We sourced information on the origins, uses, distributions and minimum residence times to investigate pathways and patterns of spatial extent. We identified alien grasses in South Africa that are having environmental and economic impacts and determined whether management options have been identified, and legislation created, for these species. Results: There are at least 256 alien grass species in the country, 37 of which have become invasive. Alien grass species richness increased most dramatically from the late 1800s to about 1940. Alien grass species that are not naturalised or invasive have much shorter residence times than those that have naturalised or become invasive. Most grasses were probably introduced for forage purposes, and a large number of alien grass species were trialled at pasture research stations. A large number of alien grass species in South Africa are of Eurasian origin, although more recent introductions include species from elsewhere in Africa and from Australasia. Alien grasses are most prevalent in the south-west of the country, and the Fynbos Biome has the most alien grasses and the most widespread species. We identified 11 species that have recorded environmental and economic impacts in the
Full Text Available A green-house study was conducted to investigate the ability of an isolate of Trichoderma harzianum (P52 and arbuscular mycorrhizal fungi (AMF in enhancing growth in tomato seedlings, tea and napier grass cuttings. The effect of these bio-inoculants on growth was compared with the influence of Diammonium phosphate (DAP fertilizer and the interactions of these three factors (P52, AMF and DAP. The plants were grown in plastic pots filled with sterilized soils. A completely randomized design was used and growth measurements taken on height shoot and root dry weights. Â It was observed that isolate P52 and DAP fertilizer individually enhanced growth in tomatoes, tea and napier while AMF only enhanced growth in tomatoes. Combinations of P52 and DAP; P52, AMF and DAP enhanced growth significantly (P
Full Text Available With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulose feedstock for biofuel production is discussed. These include three important field crops - maize, sugarcane and sorghum - and two undomesticated perennial energy grasses - miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of
Full Text Available The seedlings of two tree species, the black poplar hybrid (Populus canadiensis Moench. and the pedunculate oak (Quercus robur L., among the most important for the temperate region, were treated with various concentrations of oil-ferrofluid based on natural hydrocarbons. The experiment has revealed the ferrofluid influence on the assimilatory pigments as well as on the nucleic acids (spectral measurements in young plantlets aged of 3 months. It was found that the levels of assimilatory pigments are generally diminished though the ratio chlorophyll a/chlorophyll b is generally enhanced for ferrofluid samples suggesting the seedlings sensitivity to the chemical and magnetic stimuli consistent with the ferrofuid addition. The LHC II system (Light Harvesting Complex II sensitivity to external factors might be associated with the ferrofluid influence on the young seedlings photosynthesis.
Salahbiah Abdul Majid; Zaiton Ahmad; Mohd Rafaie Abdul Salam; Nurhayati Irwan; Affrida Abu Hassan; Rusli Ibrahim
Aquilaria malaccensis or karas is the principal source of gaharu resin, which is used in many cultures for incense, perfumes and traditional medicines. The species is mainly propagated conventionally through seeds, cuttings and graftings. Propagation by seeds is usually a reliable method for other forest species, but for karas, this technique is inadequate to meet the current demand of seedling supplies. This is principally due to its low seed viability, low germination rate, delayed rooting of seedlings, long life-cycle and rare seed production. Tissue culture has several advantages over conventional propagation, especially for obtaining large number of uniform and high-yielding plantlets or clones. This paper presents the current progress on mass-propagation of Aquilaria malaccensis seedlings through tissue culture technique at Nuclear Malaysia. (author)
Vegetative reproduction from belowground bud banks is the primary driver of grassland systems. Despite the importance of vegetative reproduction, the timing of belowground bud recruitment is unknown for most dominant, perennial native grasses as is the relationship between bud development and envir...
Balke, T.; Bouma, T.J.; Horstman, Erik; Webb, E.L.; Erftemeijer, P.L.A.; Herman, P.M.J.
Physical processes limiting colonization of bare tidal flats by pioneer mangrove species have commonly been described but not yet quantified. Understanding thresholds to early seedling establishment is critical for successful restoration and management of mangrove forests. We determined how seedling
Rigney, Michael P.; Kranzler, Glenn A.
A PC-based machine vision system providing rapid measurement of bare-root tree seedling morphological features has been designed. The system uses backlighting and a 2048-pixel line- scan camera to acquire images with transverse resolutions as high as 0.05 mm for precise measurement of stem diameter. Individual seedlings are manually loaded on a conveyor belt and inspected by the vision system in less than 0.25 seconds. Designed for quality control and morphological data acquisition by nursery personnel, the system provides a user-friendly, menu-driven graphical interface. The system automatically locates the seedling root collar and measures stem diameter, shoot height, sturdiness ratio, root mass length, projected shoot and root area, shoot-root area ratio, and percent fine roots. Sample statistics are computed for each measured feature. Measurements for each seedling may be stored for later analysis. Feature measurements may be compared with multi-class quality criteria to determine sample quality or to perform multi-class sorting. Statistical summary and classification reports may be printed to facilitate the communication of quality concerns with grading personnel. Tests were conducted at a commercial forest nursery to evaluate measurement precision. Four quality control personnel measured root collar diameter, stem height, and root mass length on each of 200 conifer seedlings. The same seedlings were inspected four times by the machine vision system. Machine stem diameter measurement precision was four times greater than that of manual measurements. Machine and manual measurements had comparable precision for shoot height and root mass length.
Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara
Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several
L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK
Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts
Jaroslava Novotná; Barbora Badalíková
Infiltration of water into the soil was monitored from 2012 to 2015 in two fishpond dikes of three different variants of grass species composition: variant 1 – grass mix for extensively dry conditions, variant 2 – heavy duty grass mix, variant 3 – grass mix for intensively moist areas. The monitored grass vegetation was mowed twice a year. The Rohatec pond is situated in Jindřichův Hradec district, in terms of texture its dike is made of sandy soil. The Horní Šatlava pond in Hodonín district ...
Dominguez-Nuñez JA; Delgado-Alvez D; Berrocal-Lobo M; Anriquez A; Albanesi A
Pinus halepensis seedlings are currently used to regenerate arid Mediterranean regions. Optimized methods for seedling fertilization in nurseries improve plant growth and are essential for successful reforestation. Previously, we showed that inoculation of P. halepensis seedlings with Pseudomonas fluorescens CECT 844 rhizobacteria improved plant growth and N uptake. The aim of this study was to determine the physiological and morphological response of P. halepensis seedlings to a combined tre...
was granted, the alcalde placed the Rio Puerco damsite.) Duran de Chaves testi - petitioners in receipt of the land, their names fied in behalf of his...haematocarpus Barberry Distichilis stricta Salt grass Cercocarpus breviflorus Mountain Mahogany Hilaria jamesii Galleta Chrysothamnus nauseosis Rubber
Full Text Available Fish muscle, the main edible parts with high protein level and low fat level, is consumed worldwide. Diet contributes greatly to fish growth performance and muscle quality. In order to elucidate the correlation between diet and muscle quality, the same batch of juvenile grass carp (Ctenopharyngodon idellus were divided into two groups and fed with either grass (Lolium perenne, Euphrasia pectinata and Sorghum sudanense or artificial feed, respectively. However, the different two diets didn't result in significant differences in all the detected water quality parameters (e.g., Tm, pH, DO, NH3/NH4+-N, NO3--N, NO2-, TN, TP, and TOC between the two experimental groups. After a 4-month culture period, various indexes and expression of myogenic regulatory factor (MRFs and their related genes were tested. The weight gain of the fish fed with artificial feed (AFG was nearly 40% higher than the fish fed with grass (GFG. Significantly higher alkaline phosphatase, total cholestrol, high density cholestrol and total protein were detected in GFG as compared to AFG. GFG also showed increased hardness, resilience and shear force in texture profile analysis, with significantly bigger and compact muscle fibers in histologic slices. The fat accumulation was most serious in the abdomen muscle of AFG. Additionally, the expression levels of MyoG, MyoD, IGF-1, and MSTNs were higher, whereas Myf-5, MRF4, and IGF-2 were lower in most positional muscles of GFG as compared to AFG. Overall, these results suggested that feeding grass could promote muscle growth and development by stimulating muscle fiber hypertrophy, as well as significantly enhance the expression of CoL1As. Feeding C. idellus with grass could also improve flesh quality by improving muscle characteristics, enhancing the production of collagen, meanthile, reducing fat accumulation and moisture in muscle, but at the cost of a slower growth.
Ott, Jacqueline P; Hartnett, David C
Tiller recruitment from the belowground bud bank of caespitose grasses influences their ability to monopolize local resources and, hence, their genet fitness. Differences in bud production and outgrowth among tiller types within a genet and among species may explain co-occurrence of caespitose grasses. This study aimed to characterize genet bud-bank and tiller production and dynamics in two co-occurring species and compare their vegetative reproductive strategies. Bud-bank and tiller dynamics of Hesperostipa comata and Nassella viridula, dominant C3 caespitose grasses in the northern mixed-grass prairie of North America, were assessed throughout an annual cycle. The two species showed similar strategies, maintaining polycyclic tillers and thus creating mixed-age genet bud banks comprising multiple bud cohorts produced in different years. Vegetative tillers produced the majority of buds, whereas flowering tillers contributed little to the bud bank. Buds lived for at least 2 yr and were maintained in multiple developmental stages throughout the year. Because bud longevity rarely exceeded tiller longevity, tiller longevity drove turnover within the bud bank. Tiller population dynamics, more than bud production per tiller, determined the differential contribution of tiller types to the bud bank. Nassella viridula had higher bud production per tiller, a consistent annual tiller recruitment density, and greater longevity of buds on senesced and flowering tillers than H. comata. Co-occurring C3 caespitose grasses had similar bud-bank and tiller dynamics contributing to genet persistence but differed in bud characteristics that could affect genet longevity and species coexistence. © 2015 Botanical Society of America.
Mendes-Rodrigues, Clesnan; Ranal, Marli A; Oliveira, Paulo E
Competition between siblings affect their growth and survival ability. An extreme situation is polyembryony, whereby siblings are exposed to competition from the beginning of their development. But its effect on plant reproduction is seldom tested. Eriotheca pubescens is a tree in the Cerrado, the Neotropical Savannas in Brazil, with apomictic/polyembryonic and sexual/monoembryonic populations. We tested the effect of polyembryony on germination, emergence, and growth in E. pubescens. This may have ecological consequences within the Cerrado, where seedling establishment is critical for species persistency and distribution. We tested the effect of embryonic origin on germinability- and time-related parameters using seeds from different populations. We measured cultivated seedling growth continuously for 70 d and exhumed them after 9 mo to measure seedling biometry traits such as shoot, root, and seedling mass. We compared these traits with the number of seedlings emerged per seed and fitted data to a linear regression model. Polyembryony reduced germinability and seedlings' initial growth in E. pubescens. Seedling traits and biomass decreased with the number of seedlings arising per seed. But the effect of polyembryony was mostly on initial seedling size and not on seedling growth rate. Polyembryony and apomixis affected germination and led to smaller seedlings compared with monoembryonic sexual counterparts. Although smaller, these extra seedlings may enhance per-seed survival chances in the Cerrado conditions of seasonal drought and frequent fires and explain the predominance of polyembryonic populations.
Full Text Available Four-year-old seedlings of Pinus thunbergii, Pinus densiflora and Pinus rigida were inoculated with Fusarium circinatum isolate (FT-7, the pitch canker fungus, from P. thunbergii, to evaluate the effects of the pathogen on disease development and gas exchange rate. Needle dehydration was evident on 2 of 10 seedlings of P. thunbergii and P. rigida at 18 and 21 days after inoculation, respectively, while no symptoms were observed in P. densiflora seedlings throughout the experiment. Gas exchange stopped completely in 4 of 5 measured seedlings of P. thunbergii and 2 of 5 measured seedlings of P. rigida at 25 days after inoculation, and in the remaining 3 seedlings of P. rigida at 39 days after inoculation. Disease development in P. thunbergii seedlings was faster than that in P. rigida seedlings. By the time, the experiment was ended at 78 days after inoculation, 9 of 10 seedlings of P. rigida and 8 of 10 seedlings of P. thunbergii seedlings treated with FT-7 was almost dead, but all seedlings of P. densiflora were still healthy. We suggest that P. densiflora is resistant to F. circinatum in the current study, and gas exchange rate of the species after inoculation does not differ significantly compared to that of untreated control.
Abyan M. V.; Gish R. A.; Podushin Y. V.
The article presents a research of reaction of seedlings of lettuce on light duration with sodium lamps when grown in a greenhouse. It was shown that in winter conditions of the Krasnodar Region the intensity of natural light to produce quality seedlings of lettuce is insufficient and additional lighting has a significant influence on the morphology of lettuce seedlings
Philip M. McDonald; Gary Fiddler; Martin Ritchie; Paula Anderson
The purpose of this article was to determine whether natural regeneration or planted seedlings should be used in group-selection openings. The answer dependson the survival and growth rate of both types of seedlings, and that could depend on the size of the openings and the effect of trees on their edge. In thisside-by-side study, the natural pine seedlings originated...
D. Paul Jackson; R. Kasten Dumroese; James P. Barnett
Container longleaf pine (Pinus palustris) seedlings often survive and grow better after outplanting than bareroot seedlings. Because of this, most longleaf pine are now produced in containers. Little is known about nursery fertilization effects on the quality of container longleaf pine seedlings and how that influences outplanting performance. We compared various...
Shi-Jean Susana Sung; Dave Haywood
Longleaf pine (Pinus palustris) seedlings were cultured with air lateral root pruning (side-ventedÂ containers, VT) or without (solid-walled containers, SW). Seedling root system morphology and growthÂ were assessed before planting and 8 and 14 months after planting. Although VT seedlings had greater rootÂ collar diameter than the SW before planting,...
Full Text Available To investigate susceptibility of young Scots pine seedlings to four Phytophthora species: Phytophthora cactorum, Phytophthora cambivora, Phytophthora plurivora and Phytophthora pini; seven-day-old seedlings of Scots pine (15 seedlings per experiment were infected using agar plugs of the respective species. Control group also consisted of 15 seedlings and was inoculated with sterile agar plugs. Results unambiguously show that after 4.5 days, all seedlings show clear signs of infection and display severe symptoms of tissue damage and necrosis. Moreover, three and two seedlings in the P. cactorum and P. cambivora infected seedlings groups, respectively, collapsed. The length of largest necrosis measured 13.4±3.90 mm and was caused by P. cactorum. To rule out any putative contamination or infection by secondary pathogens, re-isolations of pathogens from infection sites were performed and were positive in 100% of plated pieces of infected seedlings. All re-isolations were, however, negative in the case of the control group. Detailed microscopic analyses of infected tissues of young seedlings confirmed the presence of numerous Phytophthora species inside and on the surface of infected seedlings. Therefore, our results suggest Phytophthora spp. and mainly P. cactorum and P. cambivora as aggressive pathogens of Scots pine seedlings and highlight a putative involvement of these species in the damping off of young Scots pine seedlings frequently observed in forest nurseries.
Full Text Available The presence of Al in the rhizosphere of rice in acid soil restricts root growth and significantly reduces crop productivity. In this study, the effects of Al (30, 60 and 90 µg/mL on seedling root growth, number of primary roots per seedling, seedling shoot length, number of leaves per seedling, seedling fresh weight, and seedling dry weight were studied. Rice genotypes were classified into three different classes, namely, tolerant, moderately tolerant, and susceptible, based on root tolerance index. The method of hydroponic culture was modified, and elaborated in the text. Toxic levels of Al in nutrient solution significantly decreased seedling root growth, number of primary roots, seedling shoot length, number of leaves per seedling, seedling fresh weight, and seedling dry weight. Few genotypes showed longer root length at 30 µg/mL Al in nutrient solutions compared with the control. High levels of Al in nutrient solutions were highly toxic for rice seedlings. Based on root tolerance index, Radhunipagal, Gobindobhog, Badshabhog, Kalobhog, UBKVR-11, UBKVR-16, UBKVR-18, Khasha and IVT4007-B were classified as tolerant genotypes, and these genotypes may be used as donors for breeding of Al-toxicity tolerance.
Sumarsih, S.; Sulistiyanto, B.; Utama, C. S.
The aim of the research was to evaluate microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp as starter. The completely randomized design was been used on this research with 4 treaments and 3 replications. The treatments were P0 ( Panicum maximum grass silage without addition Lactobacillus sp ), P1 ( Panicum maximum grass silage with 2% addition Lactobacillus sp), P2 (Panicum maximum grass silage with 4% addition Lactobacillus sp) and P3 (Panicum maximum grass silage with 6% addition Lactobacillus sp).The parameters were microbial populations of Panicum maximum grass silage (total lactic acid bacteria, total bacteria, total fungi, and Coliform bacteria. The data obtained were analyzed variance (ANOVA) and further tests performed Duncan’s Multiple Areas. The population of lactic acid bacteria was higher (PMicrobiological quality of Panicum maximum grass silage with addition Lactobacillus sp was better than no addition Lactobacillus sp.
Hidaka, Taira; Wang, Feng; Sakurai, Kensuke; Tsumori, Jun; Minamiyama, Mizuhiko
Grass is drawing attention for its high potential for biogas production. Anaerobic digesters in wastewater treatment plants can be used for producing biogas by processing grass without having to invest in the construction of new treatment facilities. Batch and continuous digestion experiments were conducted to assess the feasibility of codigestion of sewage sludge and grass. The focus was on a thermophilic condition, starting-up from existing mesophilic anaerobic digestion of sewage sludge only. The batch and continuous experiments used two different sewage sludges. Results demonstrated a methane generation of approximately 0.2 normal liter-methane/g volatile solids-grass. The addition of grass did not affect the ammonia concentration and improved the dewaterability of the digested sludge. The start-up performance from mesophilic digested sewage sludge to thermophilic codigestion with grass was confirmed. A feasibility analysis demonstrated that codigestion is applicable in terms of energy recovery and greenhouse gas emission, depending on the transport distance of grass.
Levy, I M; Skovron, M L; Agel, J
Part I of this two part study reviews the development and characteristics of artificial grass, and the influence of this surface on the American football player. Artificial grass was initially developed to provide city children with increased play space and thus enable them to maintain a fitness level equal to their peers in more rural locales. Today, artificial grass fields allow for increased use when field availability is limited, or for a grass substitute where grass will not grow. However, epidemiologic studies suggest that there is an increased risk of lower extremity injury to the football athlete playing on an artificial grass field. By reviewing available studies, a knowledge base can be formed that can serve to direct future investigations concerning the influence of artificial grass surfaces and injury and, ultimately, how that influence can be affected.
Yue, Xiaoyu; Han, Xin; Song, Qianhong; Yang, Xu; Zhou, Qingyun
The screening of salt-tolerant plants can provide suitable tree species for the afforestation of coastal salinity and maintain biodiversity and ecological stability. The research was based on the study of seven grasses, such as high fescue, the bermuda grass, the thyme, the rye grass, the precocious grass, the third leaf, and the red three leaves. Each pasture was planted in three different kinds of soil, such as salt alkali soil, salt alkali soil + ecological bag and non-saline alkali soil. The effect of salt alkali soil on germinating time, germination rate and grass growth was analyzed. The effects of ecological bag on soil salt and the growth and germination of grass was also analyzed in order to provide the reference basis for the widespread and systematic selection of salt-tolerant plants, with the grass being selected for the suitable ecological bag.
Irungu, K.R.G.; Mbugua, P.N.
Majority of dairy farmers in Kenya produce milk from cows fed on roughage. The cow performance follows seasonal variability in quality and quantity of roughage. The objective of the current study was to increase cow performance and maintain productivity of a rhodes grass (chloris gayana) ley. Twenty-four Freisian cows in their second to third lactation were strip grazed on fertilized irrigated Rhodes grass at a stocking rate of 0.034 ha per cow. Four dietary groups of six cows were allocated to one of our diets. one group got no dairy meal while the other three groups were supplemented at a 1kg of dairy meal per 10, 5 and 2.5 kg of 4% fat corrected milk dairy. this amount to 0, 386, 750 and 1542 kg dairy meal (89.4%, DM, 93.7 OM, 16.8, CP and CF) during the lactation. during the 43 - week lactation, records on pasture nutrient yield, nutrient intake, milk yield, liveweight, reproduction and subsequent calf birth weight were collected. The Rhodes grass ley produced 20.7 (ranging from 16.7 to 28.7) t of dry matter (DM) per hectare and cows harvested 16.0 (12.0 to 24.0) t during the 43 weeks.The Rhodes grass contained 32.1, 87.7, 10.8, and 32.3% DM, organic matter (OM), crude protein (CP) and crude fiber (CF) respectively. Mean stubble of 4.7 (3.9 to 6.0) t DM per hectare was left at pasture. Feeding dairy meals significantly increased (P 0.05) affect batter fat content (3.78 to 3.96%). It maintained (P > 0.05) cow liveweight and increased (P < 0.05) calf birth weight from 32.7 to 37.2 kg. Feeding dairy meal did not affect oestrus cycling. Extreme supplementation, 1542 kg dairy meal, decreased (P < 0.05) fertility. Insemination per conception and calving interval increased (P < 0.05) from 1.5 to 3.5 and 522 days. The findings in the current study show that pasture yield can be increased by over 590% dry matter from 3.5 t obtained from natural pasture containing Kikuyu and Star grasses. The Rhodes grass yield can be increased to 232% of national average yield of 1300
Edilane Aparecida da Silva
Full Text Available The present study aimed to estimate the photosynthetically active radiation of tropical forage grasses in ten cutting dates, under irrigation. The following treatments were used: Brachiaria decumbens grass (Brachiaria decumbens cultivar Basilisk, Marandu grass (Brachiaria brizantha cultivar Marandu, Xaraes grass (Brachiaria brizantha, cultivar Xaraes, Mombaça grass (Panicum maximum cultivar Mombaça, Tanzania grass (Panicum maximum, cultivar Tanzania and Tifton 85 grass (Cynodon spp cultivar Tifton 85. The weather parameters were collected by an automatic meteorological station installed in the location and used for irrigation management. The experiment was arranged in a split-plot completely randomized block design, considering the grasses as plots and cutting seasons as subplots, with four replications in a 6 × 10 factorial arrangement, six grasses and ten cutting seasons. The results indicated increased use of photosynthetically active radiation in the wet season, in relation to the dry-wet season transition. Basilisk presented the highest values of photosynthetically active radiation (1,648.9 mE. The variables studied were affected by photosynthetically active radiation. The grass cultivars presented different light interceptions. The values of 87; 90; 90; 88; 92 and 77% were found for grass cultivars Basilisk, Marandu, Mombaça, Tanzania, Xaraes and Tifton 85, respectively. Differences were observed in forage accumulation rates for the grass plants studied. The grasses with the best productive performance were Brachiaria decumbens cultivar Basilisk and B. brizantha cultivar Xaraes. The highest values of crude protein and neutral detergent fiber were observed for Tifton 85. The use of photosynthetically active radiation was different among the grasses evaluated. There is a positive association between photosynthetically active radiation and dry matter production. Besides, photosynthetically active radiation indirectly affects crude protein
Mortensen, Anders Krogh; Karstoft, Henrik; Søegaard, Karen
the dry matter ratio of clover and grass in clover grass fields from sparse close up images. First, the light conditions is determined, which is used for selecting model parameters to estimate the coverage of both clover and grass. Next, the clover and grass coverage are transformed to give the dry matter...
LaBrecque, J.J.; Schelenz, R.; Perkins, R.W.
The radioactive debris cloud from the Chernobyl reactor accident resulted in some deposition over essentially all of the Northern Hemisphere. Shortly after the accident invitations were sent out by the IAEA to Member States to collect grass samples according to specific instructions so that the ratio of the various radionuclides in the fallout debris could be established over a wide area of Europe. In response to this request, 20 grass samples were provided by Member States. To establish a protocol for analysis of these valuable samples and to recommend a protocol for future sample collection, a Consultants Meeting was called by the IAEA for 23-25 September 1986. This document contains the considerations and recommendations of the consultants
Hertel, Ole; Gerorge Peel, Robert; Kennedy, Roy
In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre...... street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found...... source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were...
Ohiagu, C E; Wood, T G
Annual grass production in ungrazed plots was 2,731 kg ha -1 , litter production was 1,619 kg ha -1 and decomposition was 1,789 kg ha -1 . In grazed plots the corresponding figures were 3,157 kg ha -1 , 1,440 kg ha -1 , and 1,475 kg ha -1 respectively; cattle consumed 1,405 kg ha -1 . Litter disappearance was greatest in the dry season: 1,226 kg ha -1 (69% of the annual total) disappearing in the 4 months of December to March in the ungrazed plots, largely due to consumption (790 kg ha -1 in December to March) by fungus-growing termites (Macrotermitinae). A positive linear relationship was found between maximum grass biomass and annual rainfall in West Africa.
de Araújo Morandim-Giannetti, Andreia; Albuquerque, Tiago Santos; de Carvalho, Renata Kobal Campos; Araújo, Ramires Menezes Silva; Magnabosco, Rodrigo
Recently, much research on the evaluation of new cellulose sources has been developed. In this context, a promising source is "napier grass", which contains 30.40% lignin, 36.34% cellulose, and 34.12% hemicellulose. In this work, conditions for the delignification of "napier grass" in the laboratory were studied by using calcium oxide (CaO) and hydrogen peroxide (H(2)O(2)). The best pulping conditions were 9.00% CaO for a period of 2.73 h, which resulted in 74.99% delignification and 66.58% cellulose. The best conditions for the bleaching process were pH 12 and hydrogen peroxide at concentration of 4.2% for 6h, at a temperature of 40 °C, which gave 90.98% delignification and 99.21% cellulose. The analyses were performed by using weight percent. Copyright © 2012 Elsevier Ltd. All rights reserved.
Aug 17, 2011 ... Seed characteristics of legume species used in this study. Species. Cultivar. Collect location. Seed mass (mg). T. repens. -. Jilin Province. 0.58±0.002 .... The effects of depth (D), light (L), species (S) and their interaction on germination characteristics, morphological ..... Early seedling growth of pine (Pinus.
John T.A. Proctor
Full Text Available Three greenhouse experiments with American ginseng seedlings growing under light levels from 4.8% to 68% showed a quadratic response for root dry weight, giving an optimal root dry weight of 239 mg (range 160–415 mg at an optimal light level of 35.6% (range 30.6–43.2%.
Aug 15, 2011 ... a result of evaporation and capillary rise of water. Selection of salt tolerant red clover genotypes would allow one to cultivate this crop on saline soils or with saline waters (Sidari et al., 2008). Germination and seedling characteristics are the most viable criteria used for selecting salt tolerance in plants.
Pietras, Justyna; Stojanović, Marko; Knott, R.; Pokorný, Radek
Roč. 9, č. 4 (2016), s. 529-535 ISSN 1971-7458 R&D Projects: GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67179843 Keywords : drought stress * sap flow * transpiration * biomass Production * sessile Oak * sprout * seedling Subject RIV: EF - Botanics Impact factor: 1.623, year: 2016
Fusarium circinatum is an important fungal pathogen of Pinus species. In South Africa, it is the most significant pathogen of Pinus patula seedlings in forestry nurseries where it presents a substantial constraint to productivity and can continue to cause mortality in-field for up to two years after establishment. This study ...
R. Kasten Dumroese; Jeremiah R. Pinto; Anthony S. Davis
Crop lighting is an energy-intensive necessity for nursery production of high-quality native plants and forest tree seedlings. During the winter months (especially in northern USA latitudes) or overcast or cloudy days, the amount of solar radiation reaching greenhouse crops is insufficient resulting in growth cessation, early terminal bud formation, and failure of...
A field study compared the seedling emergence and structure of five forage legumes (Trifolium repens L., Medicago falcata L., Melilotus suaveolens Ledeb, Medicago sativa L. and Lespedeza davurica Schindler) at five planting depths (1, 2, 4, 6 and 8 cm) and two light levels (full light and shade) on the 21st day after ...
implies that growth and biomass production is directly proportional to the supply and use of water. (Sale, 2015; Mukhtar, 2016b). Table 4: Effect of watering frequency on seedlings. NAR, RGR and AGR of B. aegyptiaca. Treatment. NAR. RGR. AGR. Once daily. 0.01017a. 0.01431ab. 0.05107a. Once after 3 days. 0.00866a.
This study was conducted to compare the effect of NaCl levels on germination and seedling growth, and ion accumulation in five bitter vetch lines. Germination percentage (%), mean germination time (MGT, day), emergence percentage (%), shoot and root length (mm), shoot and root fresh and dry weight (mg/plant) and the ...
Indirect selection is a useful means for improving yield in cotton crop. The objective of the present study was to determine the genetic variability, broad sense heritability, genetic advance and correlation among the six seedling traits and their direct and indirect effects on cotton yield by using path coefficient analysis.
The effect of Arbuscular mycorrhizal fungus (AMF), specifically, Glomus moseae and cow dung on the growth of Neem (Azadiracchta indica, A. Juss) seedlings was investigated at the forestry quarters, Lagos Street, Maiduguri, Borno State, Nigeria. The study included three treatments: the cow dung, mycorrhizal treatments ...
Oct 3, 2011 ... investigated. The effect of mutagen dosage on seed viability was also assessed using the tetrazolium staining test. Results revealed the significant effects of mutagen dosages and treatment periods on seed viability and seed germination as well as on seedling characteristics for all the mutagens tested.
Full Text Available Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C (soil water regime in pots was maintained at the level of field water capacity and treated (water-stressed, WS (soil water regime was maintained in the range of wilting point and lentocapillary capacity. The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively, which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively. Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½. Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.
Cold stratification, but not stratification in salinity, enhances seedling growth of wheat under salt treatment. L Wang, HL Wang, CH Yin, CY Tian. Abstract. Cold stratification was reported to release seed dormancy and enhance plant tolerance to salt stress. Experiments were conducted to test the hypothesis that cold ...
Full Text Available The effect of ecomycorrhizal fungi (Hebelon crustuliniforme(Bull.: Fr. Quél. 5392 and Pisolithus tinctorius (Pers. Coker et Couch 5335 and bacteria (Bacillus polymyxa and Azospirillum brasilense. associated with mycorrhizas on the growth of pine seedligs was investigated. In addition the influence of bacteria on fungal biomass production and the relationship between ectomycorrhizal fungi and fungi pathogenic to root of pine seedlings were determined. In general, the shoot/root ratio was higher in plants inoculated with Hebeloma crustuliniforme and bacteria than in the control seedlings (grown only under sterile conditions. In non-sterile substrate the root/shoot ratio of the mycorrhizal seedlings was lower as compared to the control. Similar phenomenon was noted in plants inoculated with the mycorrhizal fungus Pisolithus tinetorius. The bacteria used as well as the time of introduction of these organisms into the cultures of mycorrhiza fungi affected the production of fungal biomass. Hebeloma crustuliniforme and Pisolithus tinctorius inhibited the growth of Rizoctonia solani and Fusarium oxysporum fungi pathogenic to pine seedlings.
Jul 19, 2010 ... This study was conducted to determine and compare the inhibitory effects of chromium on seed germination and early seedling growth of melon (Cucumis melo L.). Chromium applications were controls; 2.5, 5, 10, 25, 50, 75, 100, 200 and 300 mgl-1 Cr in germination stage, and controls; 2.5, 5, 10,. 20, 30 ...
ABSTRACT. This research investigates the effects of E indica) seedlings grown in hydroponic sol collected from the garden of the Departme. Science and Technology Wudil, replanted in and EDTA. All plants grown in treated hydro time varied highly significantly (Pr < 0.00 values of treated hydroponics were signific.
Target detectionis one of research focues for precision chemical application. This study developed a method to identify seedling cabbages and weeds using hyperspectral spectral imaging. In processing the image data, with ENVI software, after dimension reduction, noise reduction, de-correlation for h...
The decision has to be made between those three alternatives aiming at achievement of optimal/best economic result for the family farm. Summarizing results obtained from the decision tree, simulation and sensitivity analysis, the optimal solution for the family farm should be to continue production of walnut seedlings with ...
Piliostigma thonningii exits and flourishes in arid ecological zones of Nigeria where aforestation and reforestation is required. Seed germination and seedling growth of Piliostigma thonningii was studied. Seeds of P. thonningii were collected, separated into five batches and soaked in concentrated H2SO4 at four different ...
Poor crop establishment is a major problem in edamame (Glycine max (L.) Merr.), a specialty type of soybean being produced in locations throughout the U.S. The objective of this research was to quantify the extent to which seed treatment with fludioxonil+mefenoxam improves seedling emergence of edam...
Oct 26, 2011 ... Cold stratification was reported to release seed dormancy and enhance plant tolerance to salt stress. Experiments were conducted to test the hypothesis that cold stratification and cold stratification in salinity could enhance seedling growth of wheat under salt treatment. The results clearly demonstrated.
Eucalyptus grandis is commercially important in Zimbabwe and a breeding program has been in progress since 1962. A classical breeding strategy was used initially but, in 1981, the Multiple Population Breeding Strategy (MPBS) was implemented and the concept of the Breeding Seedling Orchard (BSO) became central to ...
Apr 25, 2011 ... Key words: Triticum aestivum L., hydroponic, aluminium-tolerant, length of root, regression analysis. ... cat-ions those immediately surrounding the apical root ... A separate model statement is required for linear, quadratic and cubic trends. RESULTS. ANOVA revealed that, for seedling growth parameters.
Jeremiah R. Pinto
Morphology is classically defined as the form and structure of individual organisms, as distinct from their anatomy or physiology. We use morphological targets in the nursery because they are easy to measure, and because we can often quantitatively link seedling morphological traits with survival and growth performance in the field. In the 20 years since the Target...
The effects of seed storage on germination and seedling growth of Dacryodes edulis (Don G.I and A.J.) was investigated. There were five treatments in all as follows: Sharp sand, shade, fresh water, stagnant water, and ambient temperature; they were replicated three times. The results showed that seeds stored in sharp ...
In this study, the effects of three Trichoderma isolates including Trichoderma harzianum isolate T969, T. harzianum isolate T447 and Trichoderma sp. isolate T in tomato seedling vigor and their nutrient uptake via two inoculants introduction methods (inoculating seed with Trichoderma spore suspension and inoculating ...
Mode of germination and seedling characteristics of four Savanna palm trees; Borassus aethiopum, Hyphaene thebaica, Phoenix reclinata and Raphia sudanica were studied. In the course of their germination, the radicle was found to be cotyledonary in nature, and it carried the undeveloped plumule below ground before ...
Investigations were conducted to identify types of seedlings occurring in Telfairia occidentalis (Hook F.). Attempts were made to trace their origins. Multiple embryos were observed to occur on the embryonic axis in separate and conjoined forms. A set of completely independent twins was found. Morphological differences ...
Variations in seedling vigour and the effectiveness of emergence (E%), emergence index (E1), emergence rate index (ERI), growth rate (GR) and relative growth rate (RGR) as selection criteria among 10 Nigerian cowpea (Vigna unguiculata (L.) Walp.) genotypes were examined. Genotypes were grown under two locations ...
Gorissen, Antonie; Kraut, Nicolai U.; de Visser, Ries; de Vries, Marcel; Roelofsen, Han; Vonk, Roel J.
The isothiocyanate sulforaphane, present in significant amounts in broccoli (Brassica oleracea L.) seedlings in the form of its precursor glucoraphanin, has been identified as an inducer of quinine reductase, a phase-II detoxification enzyme known for its anticarcinogenic properties. Its
ABSTRACT. Two pot experiments were carried out in the screen house of the Faculty of Agriculture Bayero. University Kano (Latitudes 80 421N and 90301N) during the wet and dry seasons of 2008/2009 to investigate the effects of Sowing Media and Gibberellic acid (GA3) concentrations on the seedling establishment and ...
After the fire small mammal abundance decreased in burnt fynbos and increased in unburnt forest refuges until eight months after the fire when it increased again in the fynbos to a maximum of 41 animals per 100 trapnights two years after the fire. Seedling predation by small mammals had a limited impact after the fire ...
The effects of rangeland degradation on the size and species composition of the seed bank and seedling establishment in the field were quantified over a two year period (2000–2001 and 2001–2002 growing seasons). Soil seed bank sampling was carried out at three-monthly intervals from 0.25m2 blocks 50mm deep.
A true triacylglycerol lipase was detected in germinating sunflower (Helianthus annuus L.) seedlings associated to oleosomes. This enzyme that has not yet been identified was partially purified as shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) (10%); two protein bands, P-61 and P-66 ...
Daniele Rodrigues Gomes
Full Text Available The sewage sludge is a waste from sewage treatment plants, which can be used in formulations of substrates for seedling production. This study aimed to evaluate the effects of different proportions of sewage sludge, soil and commercial substrate on the growth characteristics of Tectona grandis seedlings in tubes of 120 cm³ volume capacity. The sewage sludge used came from the STP's Cachoeiro de Itapemirim / ES. The seedlings were grown in the forest nursery / CCA / UFES. The statistical design used in the experiment was completely randomized design (CRD with six treatments and five replications. The treatments constituted of sewage sludge : commercial substrate: soil (v: v: v, which corresponded to 20:70:10 (T1, 40:50:10 (T2, 60:30:10 (T3, 80 : 10:10 (T4, 90:0:10 (T5 and the control treatment with 0:90:10 (T6. All variables assessed were significant at the 5% level of probability. The control (T6 showed results statistically equal to or lower than the treatments T3 with 60% of sewage sludge concentration (T3. It follows then that the use of sewage sludge in seedling production is feasible and promising, however, used in a proper proportion.
Kubasek, WL; Shirley, BW; McKillop, A; Goodman, HM; Briggs, W; Ausubel, FM
Many higher plants, including Arabidopsis, transiently display purple anthocyanin pigments just after seed germination. We observed that steady state levels of mRNAs encoded by four flavonoid biosynthetic genes, PAL1 (encoding phenylalanine ammonia-lyase 1), CHS (encoding chalcone synthase), CHI (encoding chalcone isomerase), and DFR (encoding dihydroflavonol reductase), were temporally regulated, peaking in 3-day-old seedlings grown in continuous white light. Except for the case of PAL1 mRNA, mRNA levels for these flavonoid genes were very low in seedlings grown in darkness. Light induction studies using seedlings grown in darkness showed that PAL1 mRNA began to accumulate before CHS and CHI mRNAs, which, in turn, began to accumulate before DFR mRNA. This order of induction is the same as the order of the biosynthetic steps in flavonoid biosynthesis. Our results suggest that the flavonoid biosynthetic pathway is coordinately regulated by a developmental timing mechanism during germination. Blue light and UVB light induction experiments using red light- and dark-grown seedlings showed that the flavonoid biosynthetic genes are induced most effectively by UVB light and that blue light induction is mediated by a specific blue light receptor. PMID:12297632
Two pot experiments were carried out in the screen house of the Faculty of Agriculture Bayero University Kano (Latitudes 80 421N and 90301N) during the wet and dry seasons of 2008/2009 to investigate the effects of Sowing Media and Gibberellic acid(GA3) concentrations on the seedling establishment and growth of ...
Sugars have pronounced effects on many plant processes like gene expression, germination and early seedling development. Several screens for sugar insensitive mutants were performed to identify genes involved in sugar response pathways using the model plant Arabidopsis. These include sun, gin and
Based on the understanding that the development of tree species such as Eucalyptus sp. can be influenced by endophytic fungi that act directly as plant growth-promoting species, cloned seedlings of Eucalyptus grandis x Eucalyptus urophylla hybrids grown from minicuttings we stimulated with three species of endophytic ...
Mutation induction is considered as an effective way to enrich plant genetic variation, particularly for traits with a very low level of genetic variation. The objectives of this study were to evaluate the effect of different dosages of chemical mutagens on seed germination, seed viability and seedling growth characteristics and to ...
Kordali, Saban; Cakir, Ahmet; Sutay, Sunay
Monoterpenes, the chemical constituents of essential oils found in plants, are known biologically active compounds. The present study was conducted to investigate the inhibitory effects of 30 monoterpenes including monoterpene hydrocarbons and oxygenated monoterpenes on seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus under laboratory conditions. The monoterpenes were applied at contents of 10 and 20 microl for liquid compounds and 10 and 20 microg for solid compounds. The results show that most of the monoterpenes significantly inhibited seed germination and seedling growth of the tested plants. Oxygenated monoterpenes including beta-citronellol, nerol and terpinen-4-ol completely inhibited seed germination and seedling growth of all tested plants. Their inhibitory effects were also stronger than that of the herbicide 2,4-D. In general, monoterpenes were less effective against seed germination and seedling growth of C. album as compared with R. crispus and A. retroflexus. Phytotoxic effects of monoterpene hydrocarbons were found to be lower than those of oxygenated monoterpenes. The alcohol derivatives of oxygenated monoterpenes were also found to be more phytotoxic as compared with their acetate derivatives. Based on the present results, it can be concluded that the oxygenated monoterpenes can be used as potential bio-herbicides.
A greenhouse investigation was carried out to determine the influence of Arbuscular Mycorrhiza (AM) fungus and two phosphate fertilizers on the growth of cashew seedlings from different nut sizes. Twelve treatment combinations comprising two phosphate fertilizers application using SSP single superphosphate, SRP ...
Drought is an abiotic factor that limits the productivity of crop plants survival and productivity. This study was conducted to evaluate the effects of simulated drought on the malondialdehyde (MDA) and antioxidant enzymes activity in Zea mays. Seedlings were grown for 8 weeks in nursery bags filled with sandy-loam soil in ...
Takase, Ryo; Hasegawa, Tsuyoshi; Yamada, Kosumi; Hasegawa, Koji; Shigemori, Hideyuki
A new iridoid glucoside, sesinoside (1), was isolated from the seedlings of Sesamum indicum. The structure of 1 was elucidated by spectroscopic analyses and by methanolysis of 1, which produced the known compounds, phlorigidosides C (2) and (6Z)-foliamenthic acid methyl ester (3). This is the first report of an iridoid glucoside with 3.
Michael P. Walsh; Jerry Van Sambeek; Mark Coggeshall; David. Gwaze
Artificial regeneration of oak species in floodplains presents numerous challenges because of the seasonal flooding associated with these areas. Utilizing not only flood-tolerant oak species, but also flood tolerant seed sources of the oak species, may serve to enhance seedling survival and growth rates. Despite the importance of these factors to hardwood forest...
cocoa seeds at stake are feasible options in marginal cocoa-growing areas if such activity is properly timed to coincide with the rains. However, the polythene bag method of transplanting cocoa seedlings remains the best option for field planting of cocoa in marginal cocoagrowing areas of Ghana. Les féves de cacao étaient ...
Mar 16, 2016 ... based detoxification of methylglyoxal. In this study the effects of various abiotic stresses on the up- regulation of methylglyoxal levels and glyoxalase I activities in Hevea brasiliensis seedlings were investigated. Most of the stresses caused significant increase in methylglyoxal level and glyoxalase I activity ...
The SNP was sprayed over cucumber seedlings using different doses at 4°C. The results indicated that malondehyde (MDA) content was decreased however, soluble sugar and chlorophyll content increased upon treatment with 1.0 mmoll-1 SNP. Further investigations showed that treatment with NO donor stimulated the ...
Dec 21, 2011 ... depositing money in the bank instead of dealing with the seedling production. MATERIALS AND METHODS. The paper has been done on the basis of the case study for typical small family farm located in the central part of Serbia, a region well known for its fruit production, where the average size of a farm ...
Cold stress is one of the major abiotic stresses limiting the productivity and the geographical distribution of many important crops. To gain a better understanding of cold stress responses in tobacco (Nicotiana tabacum), we carried out a comparative proteomic analysis. Five-week-old tobacco seedlings were treated at 4°C ...
Timothy B. Harrington
Scotch broom is a large, leguminous shrub that has invaded 27 U.S. states. The species produces seeds with a hard coat that remain viable in the soil for years. Growth-chamber studies were conducted to determine effects of temperature regime and cold-stratification period on seed germination. Seedling emergence, mortality, and biomass also were studied in response to...
The effect of gibberellic acid on germination and seedling growth of lettuce variety, Vista, under salinity conditions was studied. A reduction in germination percentage, roots and shoots length and fresh weight were observed under salt stress. At the same time, acid phosphatase and phytase activities in roots were reduced ...
Yulan Xu; Nianhui Cai; Bin He; Ruili Zhang; Wei Zhao; Jianfeng Mao; Anan Duan; Yue Li; Keith Woeste
We studied seed germination and early seedling growth of Pinus densata to explore the range of variability within the species and to inform afforestation practices. Phenotypes were evaluated at a forest tree nursery under conditions that support Pinus yunnanensis, one of the presumed parental species of P. densata...
Height suppression of tomato plug seedlings by an environment friendly seed treatment of plant growth retardants. ... Then seeds were washed in tap water and were dried in a 5°C chamber for 1 day. Finally, dried seeds were used in both a germination test in a chamber and a growing test in a greenhouse. Differences ...
Adequate amount of water is critical to successful tree nursery operation among resource-constrained smallholder farmers in Africa. Two experiments were undertaken with the objectives of evaluating effects of water application rate and frequency on seedling growth and survival of Persea americana and Vangueria ...
The study aimed at determining the root yield potential of the sweetpotato seedlings, the variation in storage root flesh colour and response of the storage roots to major pests and diseases attacking sweetpotato in the field .The experiment was carried out in the screen house and at the Eastern experimental field of National ...
Nov 17, 2014 ... Response of Raphia (Raphia Hookeri) Palm Seedlings to Fertilizer Application. 266. Table 8: The physical and chemical properties of the soil after crop harvest. Soil Properties. Values (post). Sand (g kg-1). Silt (g kg-1). Clay (g kg-1). Texture Class. Bulk density (g/cm-3). pH. Organic Matter ((g kg-1). Total ...
Paul P. Kormanik; Shi-Jean S. Sung; T.L. Kormanik
After a soil fertility baseline had been determined for the Georgia Forestry Commission's (GFC) Morgan Nursery, and single nursery protocol consistently produced high quality oak seedlings. The fertility baseline developed at the Institute of Tree Root Biology's Whitehall Experimental Nursery and adjusted for three GFC nurseries has a background target level...
The aim of this study is to investigate germination of A. marina seeds and subsequent growth parameters of their seedlings in response to three different salinity levels composed of tap water, 50 % and 100 % seawater (0, 21, 42 ‰ salinity). Experimental results indicate that 21 ‰ salinity (50% seawater) has the highest ...
Full Text Available It is commonly assumed that the dead, hardened floral bracts of the dispersal unit of grasses have been evolved to protect seeds from predation and / or assist in fruit/caryopsis dispersal. While these structures have important agronomical and economical implications, their adaptive value has not been fully explored. We investigated the hypothesis that the maternally derived hardened floral bracts have been evolved not just as a means for caryopsis protection and dispersal, but also as storage for substances that might affect seed germination and seedling vigor. Dead glumes as well as lemmas and paleas of wild emmer wheat (Triticum turgidum var dicoccoides were found to store and release upon hydration active hydrolases including nucleases and chitinases. High nuclease activity was released upon hydration from glumes derived from wild strains of wheat including Triticum urartu and wild emmer wheat, while very low nuclease activity was detected in glumes derived from domesticated, free-threshing wheat cultivars (e.g., durum wheat. Germination from the intact dispersal unit of wild emmer wheat was delayed, but post germination growth was better than those of separated caryopses. Most notable was a significant increase in lateral root production on seedlings germinated from the intact dispersal unit. Proteome analysis of wild emmer wheat glumes revealed many proteins stored and released upon hydration including S1-type nucleases, peptidases, antifungal hydrolases such as chitinases and β-1,3-glucanase as well as pectin acetylesterase, a protein involved in cell wall degradation and remodeling. Also, reactive oxygen species (ROS-detoxifying enzymes such as superoxide dismutase and ascorbate peroxidase were overrepresented in dead glumes of wild emmer wheat. Thus our study highlighted previously unknown features of the dispersal unit in wild wheat in which the dead, hardened floral bracts enclosing the caryopsis store active hydrolases and
F. Robert Gartner; Carolyn Hull Sieg
Presettlement explorers described the regionâs landscape as a âsea of grass.â Yet, this âseaâ was quite varied, and included a wealth of less obvious forested communities. Both physiographic and climatic gradients across the state of South Dakota contributed to the development of variable vegetation types of South Dakota. The diverse flora truly identifies the state as...
Full Text Available of the copyright owner. Further reproduction prohibited without permission. Convex Relationships in Ecosystems Containing Mixtures of Trees and Grass R.J. Scholes Environmental and Resource Economics; Dec 2003; 26, 4; ABI/INFORM Global pg. 559 Reproduced... with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further...
Carlos Eduardo Avelino Cabral
Full Text Available A pot trial in greenhouse conditions was carried out to identify at which defoliation height Mulato II grass (Urochloa hibrida cv. Mulato II should be managed and to determine whether potassium fertilization is necessary in soil with high potassium content. The experiment was carried out in a greenhouse in a randomized block design with six treatments and five replications. Treatments consisted of a 3 × 2 factorial arrangement, with three defoliation heights (50, 65, and 80 cm and with or without potassium maintenance fertilization. The production characteristics and chemical composition of the forage plant were evaluated. There was no interaction effect between defoliation height and fertilization with or without potassium on any of the analyzed variables, except for mineral content in Mulato II grass. The tillers and leaves number, shoot dry matter, leaf+sheath, root system, and residue were influenced by defoliation heights and potassium fertilization, except for the leaf blades and root dry matter, leaf blade/stem+sheath ratio, and leaves number, which were not influenced by potassium fertilization. Higher shoot dry matter was observed at the heights of 65 and 80 cm; however, comparing these two heights, leaf + sheath dry matter was lower at 65 cm. Regarding the grass’s chemical composition, there was an increase in neutral and acid detergent fiber and indigestible neutral detergent fiber contents as the defoliation height increased, which resulted in lower production of potentially digestible dry matter, which can compromise the potential use of the forage by animals. Among evaluated treatments, Mulato II grass defoliation is recommended for a maximum height of 65 cm. Potassium fertilization increases the yield and the potentially digestible dry matter content of Mulato II grass, even when cultivated in soil with high potassium content.
Welch, A.H.; Sorey, M.L.; Olmsted, F.H.
Southern Grass Valley is a fairly typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163 to 176/sup 0/C. Results of geologic, hydrologic, geophysical and geochemical investigations are discussed in an attempt to construct an internally consistent model of the system.
Z. TASAWAR, S. ZAFAR, M. H. LASHARI AND C. S. HAYAT1
Full Text Available The present study was conducted to investigate the prevalence of lernaeid ectoparasites in grass carp (Ctenopharyngodon idella. For this purpose, 597 fishes (Ctenopharyngodon idella were examined for lernaeid ectoparasites at a private fish farm located in Multan, Pakistan. Four species of the genus Lernaea i.e. L. cyprinacea, L. polymorpha, L. oryzophila, and L. lophiara were recorded. It was observed that L. polymorpha had the highest (P20 cm.
Published version. Source at http://doi.org/10.1186/s13002-015-0070-y. Background: Some grass species are richer in coumarin and thus more sweetly scented than others. These have been eagerly sought after in parts of Norway, but the tradition has been weakly documented, both in terms of the species collected, their vernacular names, and uses. Methods: Based on literature data and a substantial body of information collected during my own ethnobotanical field work, artefacts and ...
Full Text Available Several efforts have been done in the last years to trace grass feeding directly in the herbivore products and different methods, based on carotenoid pigments (Priolo et al., 2002; Prache et al., 2003 have been proposed. Some volatile compounds, such as 2,3-octanedione or 3-methylindole (skatole have been indicated as excellent indicators of pasture diets (Young et al., 1997...
Booth, A. L.; Wooller, M. J.
The spatial variation of isotope signatures in organic material is a useful forensic tool, particularly when applied to the task of tracking the production and distribution of plant-derived illicit drugs. In order to identify the likely grow-locations of drugs such as marijuana from unknown locations (i.e., confiscated during trafficking), base isotope maps are needed that include measurements of plants from known grow-locations. This task is logistically challenging in remote, large regions such as Alaska. We are therefore investigating the potential of supplementing our base (marijuana) isotope maps with data derived from other plants from known locations and with greater spatial coverage in Alaska. These currently include >150 samples of modern C3 grasses (Poaceae) as well as marijuana samples (n = 18) from known grow-locations across the state. We conducted oxygen, carbon and nitrogen stable isotope analyses of marijuana and grasses (Poaceae). Poaceae samples were obtained from the University of Alaska Fairbanks (UAF) Museum of the North herbarium collection, originally collected by field botanists from around Alaska. Results indicate that the oxygen isotopic composition of these grasses range from 10‰ to 30‰, and broadly mirror the spatial pattern of water isotopes in Alaska. Our marijuana samples were confiscated around the state of Alaska and supplied to us by the UAF Police Department. δ13C, δ15N and δ18O values exhibit geographic patterns similar to the modern grasses, but carbon and nitrogen isotopes of some marijuana plants appear to be influenced by additional factors related to indoor growing conditions (supplementary CO2 sources and the application of organic fertilizer). As well as providing a potential forensic resource, our Poaceae isotope maps could serve additional value by providing resources for studying ecosystem nutrient cycling, for tracing natural ecological processes (i.e., animal migration and food web dynamics) and providing
Merrild, Marie Porret; Ambus, Per; Rosendahl, Søren
) seedlings grew into established networks of Rhizophagus irregularis and cucumber (Cucumis sativus) in two experiments. One experiment studied seedling uptake of 32P in the network in response to cutting of cucumber shoots; the other analysed seedling uptake of P and nitrogen (N) in the presence of intact...... or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre‐established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed...
Zanin, Sandra Maria Warumby; Miguel, Obdulio Gomes; Montrucchio, Deise Prehs; Costa, Camila Klocker; Lagos, Jesse Boquett; Lordello, Ana Luisa Lacava
This work describes the occurrence and contents of aporphinoids alkaloids in seedlings of Ocotea puberula from germination until 12 months old and in leaves from adult plants. Seedling leaves showed an alkaloids profile similar to leaves of adult plant. However, leaves in seedlings showed higher contents of the alkaloids boldine, dicentrine, leucoxine and isodomesticine when compared to adult plants. The alkaloids concentration in stems and leaves increased during the development of the seedlings, followed by a remarkable decrease of these compounds in roots. Cultivation in a seedling-nursery method is also described. (author)
Francisco Eduardo Torres
Full Text Available This study aimed to evaluate the forage production of three tropical forage grasses under different shading levels. The experiment was conducted in a greenhouse at Universidade Estadual de Mato Grosso do Sul, University Unit of Aquidauana (UEMS/UUA, in a soil classified as Ultisol sandy loam texture. The treatments consisted of three grasses species combinations (B. brizantha cv. Marandu, B. decumbens cv. Basilisck and Panicum maximum cv. Tanzania, submitted to four shading levels (0, 30, 50 and 75%, arranged in a completely randomized blocks design in a factorial 3 x 4, with eight replications. After harvest, the plants were separated into shoot and roots for determination of shoot fresh mass (SFM, shoot dry mass (SDM and roots dry mass production. After analysis of variance, the qualitative factor was subjected to comparison of averages by Tukey’s test, and the quantitative factor to analysis of polynomial regression, being interactions appropriately unfolded. It was verified that B. decumbens, by its linearly increasing production of forage and less decrease of root formation, is the most recommended for shading conditions compared to grasses Tanzania and Marandu.
Jorge Cardoso de Azevedo
Full Text Available The purpose of this study was to evaluate the potential use of fruticulture waste as an additive in elephant grass (Pennisetum purpureum cultivar Napier silage at different densities, defining the effect of fermentative quality, microbiological characteristics and bromatological composition. The experimental design was completely randomized with four replications in a 4 x 3 factorial scheme, comprising a control, banana waste (BW, mango waste (MW, and passion fruit waste (PFW at three densities (400, 500 and 600 kg green matter [GM] m-3. The effect of ensiling density was greatest in the exclusively elephant grass silage, where a compaction of 600 kg GM m-3 contributed to improvements in fermentation and microbiological processes. The addition of banana waste to the elephant grass silage promoted improvements only in bromatological composition, raising the dry matter (DM, crude protein (CP, and non-fiber carbohydrate (NFC content and reducing fiber components (neutral detergent fiber [NDFap] and acid detergent fiber [ADFap] corrected for ash and protein, but the addition of banana waste did not favor the fermentative or microbiological processes. The addition of passion fruit and mango by-products promoted increased DM and favored the fermentative, microbiological, and bromatological silage processes, regardless of density.
Felipe Barros Macedo
Full Text Available Conservation of summer forage excess represents a management strategy to meet animals' needs for dry matter in the shortage period, but has been poorly studied. Silage can be used for this purpose. This study analyzed the production of palisade grass silage from pasture subjected to different grazing intensities with and without additive, determining losses by gases and effluents and chemical composition of silage. The experiment was a 4 x 3 factorial completely randomized design, with four replications. The factors were: 1st – herbage allowance of 5% (5 kg dry matter 100 kg-1 of animal weight day-1, 10, 15 and 20%. The pasture was managed under rotational stocking with 35-day grazing cycles (7 days of occupation and 28 days of rest and 2nd - additives: a control; b citrus pulp pellets; c biological inoculant for grass silage. The forage of palisade grass harvested from pastures subjected to low-intensity grazing showed quantitative and qualitative characteristics for ensiling. However, high humidity and low fermentable carbohydrate require the use of additive, favor the fermentation process and increase the nutritional quality of silage.
Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy
Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).
Steven A. Hughes
Full Text Available Engineers require estimates of tolerable overtopping limits for grass-covered levees, dikes, and embankments that might experience steady overflow. Realistic tolerance estimates can be used for both resilient design and risk assessment. A simple framework is developed for estimating tolerable overtopping on grass-covered slopes caused by slowly-varying (in time overtopping discharge (e.g., events like storm surges or river flood waves. The framework adapts the well-known Hewlett curves of tolerable limiting velocity as a function of overflow duration. It has been hypothesized that the form of the Hewlett curves suggests that the grass erosion process is governed by the flow work on the slope above a critical threshold velocity (referred to as excess work, and the tolerable erosional limit is reached when the cumulative excess work exceeds a given value determined from the time-dependent Hewlett curves. The cumulative excess work is expressed in terms of overflow discharge above a critical discharge that slowly varies in time, similar to a discharge hydrograph. The methodology is easily applied using forecast storm surge hydrographs at specific locations where wave action is minimal. For preliminary planning purposes, when storm surge hydrographs are unavailable, hypothetical equations for the water level and overflow discharge hydrographs are proposed in terms of the values at maximum overflow and the total duration of overflow. An example application is given to illustrate use of the methodology.
Huang Xiaodong; El-Alawi, Yousef; Penrose, Donna M.; Glick, Bernard R.; Greenberg, Bruce M.
Phytoremediation of creosote-contaminated soil was monitored in the presence of Tall fescue, Kentucky blue grass, or Wild rye. For all three grass species, plant growth promoting rhizobacteria (PGPR) were evaluated for plant growth promotion and protection of plants from contaminant toxicity. A number of parameters were monitored including plant tissue water content, root growth, plant chlorophyll content and the chlorophyll a/b ratio. The observed physiological data indicate that some plants mitigated the toxic effects of contaminants. In addition, in agreement with our previous experiments reported in the accompanying paper (Huang, X.-D., El-Alawi, Y., Penrose, D.M., Glick, B.R., Greenberg, B.M., 2004. A multi-process phytoremediation system for removal of polycyclic aromatic hydrocarbons from contaminated soil. Environ. Poll. doi: 10.1016/j.envpol.2003.09.031), PGPR were able to greatly enhance phytoremediation. PGPR accelerated plant growth, especially roots, in heavily contaminated soils, diminishing the toxic effects of contaminants to plants. Thus, the increased root biomass in PGPR-treated plants led to more effective remediation. - Plant growth promoting rhizobacteria enhanced growth and remediation of three grass species
Full Text Available Franco Frati1,2, Silvia Scurati1, Paola Puccinelli1, Marie David3, Cecile Hilaire4, Maurizio Capecce4, Francesco Marcucci2, Cristoforo Incorvaia51Medical and Scientific Department, Stallergenes, Milan, Italy; 2University Department of Medical and Surgical Specialties and Public Health, Perugia, Italy; 3Laboratoire Stallergenes, Antony, France; 4Marketing Department, Stallergenes, Milan, Italy; 5Allergy/Pulmonary Rehabilitation Unit, ICP Hospital, Milan, ItalyAbstract: Grass pollen is a very common cause of allergic rhinitis and asthma. The only treatment targeting the underlying causes of allergy is immunotherapy (IT. Sublingual immunotherapy (SLIT has been introduced to solve the problem of systemic reactions to subcutaneous IT (SCIT. This article evaluates the characteristics of the allergen extract, Staloral, in terms of practical administration, effectiveness, safety, and mechanism of action. Efficacy data were obtained from double-blind, placebo-controlled studies using Staloral in patients sensitized to grass pollen, while practical administration, cost-effectiveness, and mechanism of action data were provided by well designed studies. The efficacy and safety of Staloral, as demonstrated by review of published studies which used doses up to 1125 times those administered with SCIT, shows that this allergen extract has optimal characteristics for treating patients with seasonal allergies due to grass pollens. The main mechanism of action is the interaction between dendritic cells of the oral mucosa and the subsequent tolerance induced in T-cells.Keywords: allergen extracts, high-dose, efficacy, safety, sublingual immunotherapy
Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A; Anandan, Sambandam; Murugan, Ramaswamy
Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a). Copyright © 2014 Elsevier B.V. All rights reserved.
Philip M. McDonald; Gary O. Fiddler
Foresters often need information on the cost effediveness of manual and chemical release treatments for individual and combined species in young mixed-shrub communities. A study in northern Califomia evaluated five manual and chemical treatmcnts and their effect on several shrubs and grasses. Treatments were grubbing at age 1 to 2- and 4 ft (0.6- and 1.2-m) radii,...
Full Text Available Salinity is one of the most serious problems in rice cultivation. Salinity drastically reduced plant growth and yield, especially at seedling stage. Several rice genotypes have been produced, but their tolerance to salinity has not yet been evaluated. The study aimed to evaluate salinity tolerance of rice genotypes at seedling stage. The glasshouse experiment was conducted at Cimanggu Experimental Station, Bogor, from April to May 2013. Thirteen rice genotypes and two check varieties, namely Pokkali (salt tolerant and IR29 (salt sensitive were tested at seedling stage. The experiment was arranged in a randomized complete block design with three replications and two factors, namely the levels of NaCl (0 and 120 mM and 13 genotypes of rice. Rice seedlings were grown in the nutrient culture (hydroponic supplemented with NaCl at different levels. The growth and salinity injury levels of the genotypes were recorded periodically. The results showed that salinity level of 120 mM NaCl reduced seedling growth of all rice genotypes, but the tolerant ones were survived after 14 days or until the sensitive check variety died. Based on the visual injury symptoms on the leaves, five genotypes, i.e. Dendang, Inpara 5, Inpari 29, IR77674-3B-8-2-2-14-4-AJY2, and IR81493-BBB-6-B- 2-1-2 were tolerant to 120 mM salinity level, while Inpara 4 was comparable to salt sensitive IR29. Hence, Inpara 4 could be used as a salinity sensitive genotype for future research of testing tolerant variety. Further evaluation is needed to confirm their salinity tolerance under field conditions.
Joshua D. Klein
Full Text Available Establishment of seedlings of economic crops is often reduced if there is not a steady supply of water. Essential oils (EO from plants are increasingly used instead of synthetic chemicals to protect plant and animal products against biotic and abiotic stresses. We investigated priming radish seeds by soaking or by matriconditioning with synthetic or natural compounds as a means of inducing resistance to drought stress, thus maintaining crop yield. Priming radish seeds for two hours in solutions of essential oils (EO thymol and carvacrol derived from Origanum syriacum, with “oregano natural product” (ONP; a solution of the residue remaining after EO extraction, or with the gibberellin synthesis inhibitor trinexapac ethyl (TE, was much more effective in inducing drought resistance than was matriconditioning with the same compounds in sawdust for two days. The latter treatment induced considerable fungal and bacterial infection in treated seeds if the substrate-matrix was not heat-treated beforehand. The increase in specific leaf area in plants from treated seeds was mostly consistent with an increase in leaf water content. Seed treatments with EO, ONP, and especially TE led to a three-fold increase in radish seedling survival compared with water-treated controls, when 21 day-old seedlings were irrigated after 6 days of drought. Under drought conditions, seedlings from treated seeds had a 2–3-fold increase in relative water content increased 2–3-fold, while membrane permeability decreased 20–50-fold as a result of the treatments. However, the physical benefits of the treatments often did not correlate with treatment-induced increases in physiological parameters such as pigments (chlorophyll, carotenoid, anthocyanin, pigment ratios (chlorophyll a/b, carotenoid/chlorophyll, or antioxidant activity. Seed treatments with biostimulants can be as effective as treatments with synthetic compounds in inducing drought resistance in seedlings.
Shaik, Shahnoor S; Carciofi, Massimiliano; Martens, Helle J; Hebelstrup, Kim H; Blennow, Andreas
Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and β-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. α-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination β-amylase deposition was low in the AO grains and β-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Müller, W D; Karamfilov, T; Bufe, A; Fahlbush, B; Wolf, I; Jäger, L
Selected human T cell clones reactive with group 5 allergens of timothy grass (Phl p 5) were cross-stimulated in specific proliferation assays with group 1 allergens of rye grass (Lol p 1). Such interspecies cross-reactivities result obviously from structural motifs presented on defined Phl p 5 fragments as shown with recombinant Phl p 5 products.
Schils, R.L.M.; Snijders, P.J.M.
The combined effect of reduced nitrogen ( N ) and phosphorus ( P ) application on the production of grass- only and grass/ clover swards was studied in a five- year cutting experiment on a marine clay soil, established on newly sown swards. Furthermore, changes in soil N, P and carbon ( C ) were
Full Text Available Because growth environment is affected by climate change, Dacrydium pierrei resources are becoming less and less. Therefore, understanding the effects of environmental variables on seedling-sapling distributions can help gain insight into changes in population recruitment in the context of climate change. The seedling-saplings distribution and variability of Dacrydium pierrei in environmental variables at Bawangling, Hainan, China, was surveyed over a 3-year period. In addition, laboratory experiments measuring the effects of soil moisture on seedling emergence were conducted to identify seedling development characteristics; principal component analysis (PCA and Gaussian mixture model (GMM were used to assess how different factors influenced Dacrydium pierrei seedlings-saplings distribution. The results demonstrated that the influence degree of seedling-sapling distribution is soil temperature>litter thickness>available phosphorus>canopy density> available potassium>nitrate nitrogen; a large number of seedling-saplings occurring at altitudes 1140-1300 m; a GMM trained with a C2-L3-H4-A5-I6 combination yielded an accuracy of 72.23% in simulating seedling-saplings distribution; temperature and precipitation have strong impact on seedling-sapling distribution, with increasing soil moisture, seedling emergence shows a positive relationship. This study focuses more on developing a new method for research on the seedling-sapling distribution of Dacrydium pierrei to get reference for its adaptive management with the intense extreme climate change.
Li, S. S.; Yu, L.; Lin, W. G.; Pingi, T. F.
Which factors limit plant seedling recruitment in alpine meadow of the Qinghai-Tibetan Plateau (QTP), China? This study examined the relative influence of seed mass and microsites (resulted from grazing disturbance) on field seedling emergence and survival of nineteen alpine herbaceous species with a range of traits in QTP. Seed mass had significant effects on seedling emergence and survival eliminating influence of light and nutrient variances among these species. The larger-seed species had more advantageous than the smaller-seed species in seedling survival, but it was disadvatage for seedling emergence, especially under high nutrient availability and low light intensity conditions. Light had obvious effects on seedling survival, but less effects on seedling emergence for these species. Moreover, nutrient and light treatments altered the regression relationships of seed mass and seedling emergence and survival and the order of significances was L25>L50>L100>L10>L4. These results suggested that seed mass may restrict seedling recruitment processes, however, light and nutrient availability all have significant effects on seedling emergence and survival for these alpine species. Moderate light intensity was propitious to seedling emergence and survival in alpine grassland. This suggests that ecological factors in alpine grassland provide a stochastic influence on different seed-mass species. These trends may help to explain why many small-seeded species of Asteraceae and Gramineae tend to be more abundant in disturbed habitats. (author)
Ortmans, William; Mahy, Grégory; Monty, Arnaud
Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: 1) How the seed traits of the invasive Ambrosia artemisiifolia L. vary among mothers and populations, as well as along the latitude; 2) How do seed traits influence seedling performance; 3) Is the influence on seedlings temperature dependent. With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.
Moustakas, Aristides; Kunin, William E; Cameron, Tom C; Sankaran, Mahesh
Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP) mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm), with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm), grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients.
Full Text Available Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm, with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm, grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients.