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Weed Science

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2024

Grass

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Full-Text Articles in Agronomy and Crop Sciences

Average Annual Requirements, Production, Import And Export Of Legumes And Grass Seeds In Yugoslavia (Serbia And Montenegro) Up To The Year 2000, B Radenovic Jun 2024

Average Annual Requirements, Production, Import And Export Of Legumes And Grass Seeds In Yugoslavia (Serbia And Montenegro) Up To The Year 2000, B Radenovic

IGC Proceedings (1997-2023)

F.R. Yugoslavia (Serbia and Montenegro), in the period from 1995 to 2000, will have sufficient lucerne seeds, of the local varieties and production, and will be able to produce for export from 300 to 500 tons of seeds for foreign varieties registered in our Variety List. For the known customer in Yugoslavia, Serbia, the production of lucerne seeds can be organized in accordance with wishes of foreign partners including varieties that have not been registered, but in such a case a special permit from relevant state authorities would be required, and provided that all produced quantities of lucerne variety that …


Agronomic Evaluation Of Novel Germplasm Under Grazing: Arachis Pintoi Bra-031143 And Paspalum Atratum Bra-009610, A O. Barcellos, E A. Pizarro, N L. Costa Jun 2024

Agronomic Evaluation Of Novel Germplasm Under Grazing: Arachis Pintoi Bra-031143 And Paspalum Atratum Bra-009610, A O. Barcellos, E A. Pizarro, N L. Costa

IGC Proceedings (1997-2023)

The effect of the animal on the pasture and their reverse consequence was studied on two replicated areas of 0.27 and 0.18 ha in a grasslegume sward established in a poorly humid drained soil in the Brazilian Cerrado. The A. pintoi BRA-031143 and P. atratum BRA- 009610 sward was evaluated during four consecutive years under two grazing pressures (GP). The imposed GP affected the botanical composition and pasture availability. Mean live weight gain/animal/ day under the two imposed GP varied from 387+17g, 578+68g, 697+35g and 687+123g between the 1992/93 and 1995/96 rainy seasons. During the dry season the LWG/animal/day varied …


Emergence Of Small And Large Seeded Grasses: Importance Of Shoot Strength, M Andrews, M E. Andrews, C Watson, S M. Percival Jun 2024

Emergence Of Small And Large Seeded Grasses: Importance Of Shoot Strength, M Andrews, M E. Andrews, C Watson, S M. Percival

IGC Proceedings (1997-2023)

Inter-specific relationships between mean seed weight (MSW), coleoptile and mesocotyl length and width, shoot strength and emergence from 15 mm sowing depth were examined for six temperate pasture grass species ranging in MSW from 0.34 - 10.4 mg. For all species, coleoptile + mesocotyl length was greater for emerged than non-emerged seedlings. Across species, emergence % was not significantly correlated with coleoptile + mesocotyl length but it was significantly correlated with mean seed weight and coleoptile and mesocotyl width. Shoot strength increased with increased coleoptile width. It is proposed that decreased emergence % with decreased seed weight across species at …


Rumen Fermentation Kinetics Of Grass Measured In Sacco And With The Gas Production Technique, J W. Cone, H Valk Jun 2024

Rumen Fermentation Kinetics Of Grass Measured In Sacco And With The Gas Production Technique, J W. Cone, H Valk

IGC Proceedings (1997-2023)

Rumen fermentation kinetics of grass and silage, differing in age and yield (1500 -7900 kg DM ha-1), were studied in sacco and in vitro, using the gas production test and the Tilley and Terry technique. An increasing yield increased the content of NDF and lignin in grass and decreased protein content, in vitro degradability measured by the Tilley and Terry method, and rate of fermentation measured with the gas production technique and the nylon bag method. The same ranking in fermentation characteristics was observed using the gas production test, the nylon bag method and the Tilley and Terry method. The …


Mineral Intake And Utilization By Dairy Cows Offered Grass Fertilized With Different Levels Of Nitrogen, H Valk, A M. Van Vuuren Jun 2024

Mineral Intake And Utilization By Dairy Cows Offered Grass Fertilized With Different Levels Of Nitrogen, H Valk, A M. Van Vuuren

IGC Proceedings (1997-2023)

In four zero-grazing experiments, the effects ofN fertilizer (450 to 300 to 150 kg/ha/yr) on intake and utilization of some grass minerals (Ca, P and Mg), were investigated. Grass was offered ad lib to 12 cows per N treatment. A reduction in N fertilizer resulted in lower mean contents and intakes of Ca and Mg while P content and intake increased in late summer/autumn. The output of these minerals in milk and urine was relatively low. Therefore, a reduced intake of Ca and Mg resulted in a lower faecal output of these minerals. The ratio between intake and requirement varied …


Performance Of Grazing Bull Calves Supplemented With Increasing Levels Of Ruminally Undegradable Portein, J R. Kawas, O Osmin, J Hernandez, R Leal, F Garza, J L. Danelon Jun 2024

Performance Of Grazing Bull Calves Supplemented With Increasing Levels Of Ruminally Undegradable Portein, J R. Kawas, O Osmin, J Hernandez, R Leal, F Garza, J L. Danelon

IGC Proceedings (1997-2023)

The objective of this study was to determine the effect of increasing levels of ruminally undegradable protein (ECP) on the performance of bull calves grazing Coastcross-1 Bermudagrass during the dry season. One hundred and twelve Zebu-Brown Swiss bull calves weighing an average of 265 kg, were randomly assigned to four treatment groups in a completely random design. Calves received a self-feeding supplement (1 kg) with 40% crude protein (CP) and 31, 38, 44, or 52% ECP. During a 96-day preliminary phase without supplementation, weight gains of the four treatment groups ranged from 0.357 to 0.394 kg/day. A linear (P<0.0 I) response of calf weight gain was observed with an increase in ECP of the supplement (0.668, 0.672, 0.823 and 0.893 kg/day, respectively). Plasma urea concentration was reduced (P<0.05) from 17.8 to 9.85 mg/di with the highest level ofECP, which may reflect a reduced supply of NH -N for ruminal bacteria.


Characterization Of Legume And Grass Residues Following In Vitro And In Sacco Ruminal Digestion, D.J R. Cherney, J H. Cherney, A H. Davidson Jun 2024

Characterization Of Legume And Grass Residues Following In Vitro And In Sacco Ruminal Digestion, D.J R. Cherney, J H. Cherney, A H. Davidson

IGC Proceedings (1997-2023)

Objectives were to characterize the influence of forage species and maturity on dry matter degradation. Averaged across maturities, alfalfa and red clover were lower in NDF content (39 and 30% NDF, respectively) than reed canarygrass and timothy (59 and 54% NDF, respectively). The NDF of the DM residues in grass remained relatively unchanged over time, while NDF of the DM residue in legume increased rapidly for 9 h before becoming relatively constant. Alfalfa incubated in vitro (42% NDF) compared to reed canarygrass (58% NDF) contained more ND soluble material (39% vs. 25%), and more pepsin soluble material (22 vs. 18%). …


Intake, Growth And Feed Preference By Steers Fed Combinations Of Alfalfa And Annual Ryegrass Silage, E Charmley Jun 2024

Intake, Growth And Feed Preference By Steers Fed Combinations Of Alfalfa And Annual Ryegrass Silage, E Charmley

IGC Proceedings (1997-2023)

Nutritive value and intake of legumes is generally considered superior to grasses when ensiled at similar digestibility. The objectives of this experiment were to determine the optimum combination of annual ryegrass (Lolium multiflorum) and alfalfa (Medicago sativa) silages to maximize growth rate of steers fed silage, determine chemical components which influenced performance, and to determine if steers selected the optimum mixture when given a choice. Both silages contained similar concentrations of dry matter, acid detergent fibre and organic acids, but alfalfa silage had higher concentrations of nitrogen (N), soluble N and ammonia N. Annual ryegrass contained …


Mineral Contents Of White Clover Grass And Nitrogen Fertilized Grass Pastures For Lambs, R Sormunen-Cristian, P Nykänen-Kurki, J Peltola Jun 2024

Mineral Contents Of White Clover Grass And Nitrogen Fertilized Grass Pastures For Lambs, R Sormunen-Cristian, P Nykänen-Kurki, J Peltola

IGC Proceedings (1997-2023)

The mineral contents (Ca, P, Mg, K, Na, Fe, Cu, Zn, and Mn) of white clover grass without nitrogen and grass-only pastures with annual nitrogen rates of 0, 120 and 250 kg ha-1 were studied in 1994 and 1995. The pastures were grazed twice per season by growing lambs. The white clover contents averaged 25% and 42%, respectively. The Ca and Mg contents and the Ca/P ratio were higher, and the K/(Ca+Mg) equivalent ratio lower in white clover grass than in grass-only swards. The P content of white clover grass was similar to that of grass, and the K content …


A Predictive Model Of Vegetation Dynamics Under Grazing, C.P. D. Birch, B R. Werkman, L W. Partridge Jun 2024

A Predictive Model Of Vegetation Dynamics Under Grazing, C.P. D. Birch, B R. Werkman, L W. Partridge

IGC Proceedings (1997-2023)

This quantitative model predicts changes in the species composition of grazed vegetation. It is based on growth equations for each species represented. The three parameters in each equation represent maximum production rate, maximum standing biomass, and the decline of production rate at high total plant density. Parameters may be varied with environmental factors. The model is generic, but is illustrated using values for four taxa growing under red deer (Cervus elaphus) grazing on the Isle of Rhum, Scotland: bent/fescue grassland (Agrostis/Festuca), purple moor-grass (Molinia caerulea), mat-grass (Nardus stricta) and heather (Calluna …


Interpreting Indicators Of A Transfer Of N From Legume To Grass In Competition Studies, P G. Tow Apr 2024

Interpreting Indicators Of A Transfer Of N From Legume To Grass In Competition Studies, P G. Tow

IGC Proceedings (1997-2023)

The transfer of N from legume to grass in mixtures is important for regulating competition. In competition studies which include both monocultures and mixtures, N transfer should be detectable by grass N measurements but may be masked by competitive reductions in grass growth. In the study reported here, whole plant DM and N were measured in Panicum maximum var trichoglume and Neonotonia wightii grown in monocultures and additively in mixtures. While competition reduced whole grass plant DM and N in mixture relative to monoculture, higher grass shoot % N and N yield in the mixture at early harvests appeared reliable …


Relationship Of Visual And Quantitative Methods Of Grass Sward Development, R B. Mitchell, L E. Moser, K J. Moore Apr 2024

Relationship Of Visual And Quantitative Methods Of Grass Sward Development, R B. Mitchell, L E. Moser, K J. Moore

IGC Proceedings (1997-2023)

The objective of this study was to determine the relationship between visual and quantitative estimates of the morphological development of perennial grass swards. Pure stands of intermediate wheatgrass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey] and switchgrass (Panicum virgatum L.) were hand-clipped to ground level at 2-wk intervals in 1991 at Mead, NE, morphologically classified as mean stage count (MSC), and visually estimated for sward development. Visual estimations of sward development for both species were representative of quantitative measurements during vegetative growth. However, as sward development advanced to the elongation and heading stages, visual methods over-estimated the population …


Intake And Diet Selection By Sheep Grazing Grass/Clover Patches, I J. Gordon, A W. Illius Mar 2024

Intake And Diet Selection By Sheep Grazing Grass/Clover Patches, I J. Gordon, A W. Illius

IGC Proceedings (1997-2023)

The effects of the spatial dispersion of ryegrass (Lolium perenne L) and clover (Trifolium repens L), at the feeding station scale, on diet composition and feeding behaviour were studied for sheep. There were no significant changes in diet composition with changes in the spatial dispersion of sward components. Bite size, bite rate and intake rate did increase as the species became more aggregated.


Monitoring Productivity And Quality Of Grass-Legume Pastures Under Irrigated Condition, L Tahtacioglu, A Mermer, M Avcy Feb 2024

Monitoring Productivity And Quality Of Grass-Legume Pastures Under Irrigated Condition, L Tahtacioglu, A Mermer, M Avcy

IGC Proceedings (1997-2023)

The performance of six grass-white clover mixtures were evaluated in winter cold zone of Eastern Anatolia. In combination with white clover, ryegrass (Lolium perenne L) cocksfoot, (Dactylis glomerata L) and smooth brome (Bromus inermis Leyss) were used in double and triple plant mixtures. Average DM production ranged from 7.5 to 10 t/ha , with no significant differences observed among the mixed swards. DM production of all mixed swards significantly varied between cutting periods and years. A gradual decrease in DM production was observed both from the first to forth cut and from the first to third year. …


Conservation Of Grass Collections At The Western Regional Plant Introduction Station, V L. Bradley, R C. Johnson Feb 2024

Conservation Of Grass Collections At The Western Regional Plant Introduction Station, V L. Bradley, R C. Johnson

IGC Proceedings (1997-2023)

Germplasm managers at the Western Regional Plant Introduction Station (WRPIS) have focused on improving seed regeneration in forage and turf grass species through studies of diversity maintenance, using isozyme markers in annual ryegrass (Lolium multiflorum Lam.) and through studies of pollen isolation, using strains of dominant pubescent and recessive glabrous smooth bromegrass (Bromus inermis Leyss.). Balanced samples of annual ryegrass (an equal number of seeds per plant) from field plots were best for maintaining allelic frequencies, but genetic diversity (heterozygosity and allelic richness) was maintained nearly as well in bulk samples (seeds proportionally assembled according to seeds per …


Development Of Megathyrsus Maximus Genotypes For Intensification Of Cattle Rearing In Brazil, Liana Jank, M. F. Santos, Sanzio Carvalho Barrios, Cacilda Borges Do Valle, Rosangela Maria Simeão Feb 2024

Development Of Megathyrsus Maximus Genotypes For Intensification Of Cattle Rearing In Brazil, Liana Jank, M. F. Santos, Sanzio Carvalho Barrios, Cacilda Borges Do Valle, Rosangela Maria Simeão

IGC Proceedings (1997-2023)

Megathyrsus maximus is a forage species used over 30 million hectares in Brazil and in the surrounding countries for intensification of the cattle production systems. Due to the large area and distinct biomes in which it is used, there is a need to continuously develop more productive and adapted cultivars to each biome and use. Three apomictic accessions were crossed with five sexual plants at Embrapa Beef Cattle in Campo Grande, MS, Brazil in 2014. More than 1100 hybrids were planted in a spaced-plant field and evaluated visually for regrowth after cuts and for disease and pest damage. In 2016, …


Herbage Accumulation And Mass In Massai Grass Plots Mixed With Forage Peanut And Fertilized With Nitrogen, Carlos A. B. Carvalho, M. O. Leal Junior, P. P. Carneiro, J. V. B. Ramos, N. Schultz, J. C. C. Almeida, A. J. Paiva Jan 2024

Herbage Accumulation And Mass In Massai Grass Plots Mixed With Forage Peanut And Fertilized With Nitrogen, Carlos A. B. Carvalho, M. O. Leal Junior, P. P. Carneiro, J. V. B. Ramos, N. Schultz, J. C. C. Almeida, A. J. Paiva

IGC Proceedings (1997-2023)

The objective of this work was to evaluate herbage accumulation and mass during the growing season of Massai grass mixed with peanut forage and fertilized with nitrogen. The work was carried out at Federal Rural University of Rio de Janeiro, Brazil, from 11/2021 to 03/2022. A randomized block experimental design was used, in plots of Massai grass Megathyrsus maximus, in a factorial arrangement, with seven replications. Four treatments formed by the combination of the presence or absence of Archis pintoi and nitrogen fertilization (0 and 50 kg ha-1 of N). Canopy heights of the plots were evaluated weekly …