Identification And Validation Of High
Ld Hotspot Genomic Regions
Harboring Stem Rust Resistant Genes
On 1b, 2a (Sr38), And 7b
Chromosomes In Wheat,
2021
University of Sadat City
Identification And Validation Of High Ld Hotspot Genomic Regions Harboring Stem Rust Resistant Genes On 1b, 2a (Sr38), And 7b Chromosomes In Wheat, Shamseldeen Eltaher, Amira M.I. Mourad, P Stephen Baenziger, Stephen Wegulo, Vikas Belamkar, Ahmed Sallam
Department of Agronomy and Horticulture: Faculty Publications
Stem rust caused by Puccinia graminis f. sp. tritici Eriks. is an important disease of common wheat globally. The production and cultivation of genetically resistant cultivars are one of the most successful and environmentally friendly ways to protect wheat against fungal pathogens. Seedling screening and genome-wide association study (GWAS) were used to determine the genetic diversity of wheat genotypes obtained on stem rust resistance loci. At the seedling stage, the reaction of the common stem rust race QFCSC in Nebraska was measured in a set of 212 genotypes from F3:6 lines. The results indicated that 184 genotypes (86.8%) had different …
Response Of Mixed C4 Grasses To Various Multiple Paddock Grazing Strategies,
2021
University of Nebraska-Lincoln
Response Of Mixed C4 Grasses To Various Multiple Paddock Grazing Strategies, B. E. Anderson, W. H. Schacht
IGC Proceedings (1977-2023)
The botanical composition of mixed grass pastures may change during grazing due to the various grazing period/recovery period lengths associated with multiple-paddock grazing strategies. This 4-year study compared changes in relative species composition and basal plant cover of a C4 grass mixture grazed using a nested paddock design to simulate 2, 4, 6 and 12- paddock grazing cells in eastern Nebraska. Total basal plant cover declined from 11.6% prior to grazing to 7.3% after one year of grazing and then remained nearly constant thereafter. Neither relative species composition nor basal density were affected greatly by grazing strategy. Within grazing …
Spatial And Time Distribution Of Dairy Cattle Manure In An Intensive Pasture System,
2021
North Carolina State University
Spatial And Time Distribution Of Dairy Cattle Manure In An Intensive Pasture System, S. L. White, S. P. Washburn, L. D. King, R. E. Sheffield, J. T. Green Jr.
IGC Proceedings (1977-2023)
This study determined distribution of feces and urine from dairy cattle managed in a rotationally grazed pasture. Lactating Holsteins (n=18) and Jerseys (n=18) were grazed on a .74 ha endophyte-free fescue (Festuca arundinacea)/white clover (Trifolium repens) pasture. All cows were constantly observed for 24 h 6 times over 12 mo. Cows had access to about 54% of the paddock during the first grazing period (12 h) and had access to the entire paddock during the second grazing period (8 h). Data included: (1) all feces and urine events from eight cows, observed while in the pasture, …
Test Of A Conversion Equation To Increase The Accuracy Of Microhistological Analysis Of Herbivore Diets In The Pantanal,
2021
EMBRAPA, Brazil
Test Of A Conversion Equation To Increase The Accuracy Of Microhistological Analysis Of Herbivore Diets In The Pantanal, S. A. Santos, C. Costa, A. Pott, J. M. Alvarez
IGC Proceedings (1977-2023)
Forty forage species samples were collected in September 1999, including grass, sedges, forbs, shrubs and trees. Seven hand-compounded mixtures of known botanical composition and dry weight were prepared. Five slides of each mixture were made and 20 frequency observations were recorded per slide. Two procedures were used to determine percent composition on a dry weight basis and their values were converted to correct the proportion of the unidentifiable fragments amongst species. Estimated and actual values differed significantly (P < 0.05) in 31.7%, 34.1%, 12.2% and 12.2% of the species for frequency addition (FA), density convertion (DC), frequency addition converted (FAC) and density convertion converted (DCC), respectively. The average similarity values between estimated and observed mixture were 90.2, 86.0, 94.2 and 93.3 for FA, DC, FAC and DCC, respectively. In conclusion, food habits by microscopic analysis may be described using any of the procedures tested because they rank important forage species for herbivores.
Effects Of Herbage Allowance Upon Animal Performance And Grazing Behavior Of Strip-Grazed Heifers,
2021
Universidad Nacional del Centro de la Provincia de Buenos Aires, Argentina
Effects Of Herbage Allowance Upon Animal Performance And Grazing Behavior Of Strip-Grazed Heifers, Claudio F. Machado, F. Di Croce, F. Gonzalez, H. Zeballos, N. J. Auza, M. H. Wade, S. T. Morris, J. Hodgson
IGC Proceedings (1977-2023)
A trial was designed to test the effect of herbage allowance (HA) on live-weight gain (LWG) and grazing behavior of heifers during spring as part of a combined field-modeling research programme. Low HA (L) and high HA (H) of 2.5 and 5.0 kg DM herbage mass 100 kg animal LW-1day-1 were fed respectively. H animals grazed longer and achieved a higher LWG than L (P < 0.05). H animals left a higher residual pasture (P < 0.051) with a significantly (P < 0.05) higher content of green, clover, non-lamina and petiole of a higher digestibility and NSC, with a lower NDF content. The significance of some factors involved in these results on intake and diet selection are discussed in relation to the predictability of animal performance.
Spatial Frameworks For Robust Estimation Of
Yield Gaps,
2021
University of Nebraska at Lincoln
Spatial Frameworks For Robust Estimation Of Yield Gaps, Juan I. Rattalino Edreira, José F. Andrade, Kenneth G. Cassman, Martin K. Ittersum, Marloes P. Van Loon, Patricio Grassini
Department of Agronomy and Horticulture: Faculty Publications
Food security interventions and policies need reliable estimates of crop production and the scope to enhance production on existing cropland. Here we assess the performance of two widely used ‘top-down’ gridded frameworks (Global Agro-ecological Zones and Agricultural Model Intercomparison and Improvement Project) versus an alternative ‘bottom-up’ approach (Global Yield Gap Atlas). The Global Yield Gap Atlas estimates extra production potential locally for a number of sites representing major breadbaskets and then upscales the results to larger spatial scales. We find that estimates from top-down frameworks are alarmingly unlikely, with estimated potential production being lower than current farm production at some …
Factors Influencing The Yield Proportions Of Plantago Lanceolata L. And Taraxacum Officinale Web. In Lolium Perenne L. Swards,
2021
Justus‐Liebig University, Germany
Factors Influencing The Yield Proportions Of Plantago Lanceolata L. And Taraxacum Officinale Web. In Lolium Perenne L. Swards, Harald Laser
IGC Proceedings (1977-2023)
Diaspores of Plantago lanceolata and Taraxacum officinale respectively were sown in established Lolium perenne swards to determine the dynamics of their yield proportions during five years. The experimental factors were forb species, variety of the grass species (= early or late flowering), N-fertilization, and sward density. The amount of nitrogen fertilizer had the most important effect on yield proportions of the forb species and also on the total dry-matter (= DM) yield. The single creation of gaps in grass swards before sowing forbs had a lasting positive effect on the Plantago lanceolata and Taraxacum officinale proportions. Peak proportions of Taraxacum …
Dynamic Of Native Pasture Influenced By Deferment Of Grazing And Fertilization,
2021
EMBRAPA, Brazil
Dynamic Of Native Pasture Influenced By Deferment Of Grazing And Fertilization, K. E. Gomes, G. E. Maraschin, J. Riboldi
IGC Proceedings (1977-2023)
Native pastures of southern Brazil cover 12 million ha and are the main forage feed resource for most domestic livestock. However, their heavy and continuous use has reduced standing biomass and the presence of good forage species, reducing animal performance and jeopardizing the ecosystem sustainability. An alternative for better use of these pastures and their preservation is grazing deferment that allow natural reseeding. The objective of this research was evaluate native pasture dynamic after six years of grazing deferments (GD) periods and soil fertilization effects by point-quadrat method every season. All pasture components were affected by GD, with prostrate grasses …
Evaluation Of Plant Functional Types Response To Grazing And Fertilizer Levels In Natural Grassland,
2021
Fundação Estadual de Pesquisa Agropecuária, Brazil
Evaluation Of Plant Functional Types Response To Grazing And Fertilizer Levels In Natural Grassland, Zélia M. S. Castilhos, V. D. Pillar
IGC Proceedings (1977-2023)
We report a study on a natural grassland experiment with the objective of finding optimal plant functional types (PFTs) for the description of vegetation response to levels of grazing (ungrazed, grazed) and fertilizer (with, without). The experiment was a split-plot design in randomized blocks, with three replications and the grazing levels in the main plots. Vegetation description was based on species composition and on 12 plant morphology attributes (life-form, growth-form, stem tissue type, leaf cross section, leaf texture, leaf dorsal epidermal surface, leaf ventral epidermal surface, spininess, leaf resistance, leaf width, plant height). Cover-abundance of species was visually estimated. By …
Mountain Pastures Structure And Its Relationship With Grazing,
2021
NEIKER, Spain
Mountain Pastures Structure And Its Relationship With Grazing, I. Albizu, S. Mendarte, G. Besga, I. Amezaga, M. Onaindia
IGC Proceedings (1977-2023)
The present work aims toward an approach to mountain pastures as a system of relationships in which it is needed to point out those environmental factors that reflect more clearly their structure and potential productivity. This initial step of pasture tipification is important as a previous activity before the planning and management of protected areas because these areas support an intensive pastoral activity. In order to achieve this objective a field study was conducted in two areas in the Gorbeia Natural Park (Bizkaia): Arraba and Aldamiñape, located at 900-1100 masl. In each pasture four plots were selected according to orientation …
Structure And Function Vegetation Conditions By Grazing Processes In A Humid Pampean Grassland (Argentina),
2021
Universidad Nacional de La Plata, Argentina
Structure And Function Vegetation Conditions By Grazing Processes In A Humid Pampean Grassland (Argentina), O. E. Ansín, Estrella M. Oyhamburu, E. A. Hoffmann, M. A. Eirin
IGC Proceedings (1977-2023)
Expressed changes were evaluated as consequence of the cattle grazing, or their exclusion, in the structure of plant communities of the Flooding Pampa. We center our interest in the species numbers, plant cover, species diversity and forage availability. The treatments were: a) continuous grazing, b) enclosure grazing and c) controlled grazing. The enclosure grazing area was installed two years before starting the measurements. In the continuous grazing St. Augustine grass (Stenotaphrum secundatum Walt.) holds its initial cover of 64 % and dallis grass (Paspalum dilatatum Poir.) the 15 %. In the enclosure grazing S. secundatum decreased its cover …
Nitrogen Dynamics From Decomposing Litter Of Panicum Maximum With Different Nitrogen And Phosphorus Content In Brazilian Alfissol,
2021
EMBRAPA, Brazil
Nitrogen Dynamics From Decomposing Litter Of Panicum Maximum With Different Nitrogen And Phosphorus Content In Brazilian Alfissol, R. M. Schunke, J. C. Kiehl, Valdinei T. Paulino, S. Urquiaga, R. M. Bodey, B. Alves
IGC Proceedings (1977-2023)
The objective of this study was to measure the dynamics (immobilization and release) of N and to evaluate the effect of the initial chemical composition of four Panicum maximum cultivars grown in a Alfisol and fertilized with different levels of nitrogen (0, 80 e 160 kg ha-1 de N) and phosphorus (0 e 200 kg ha-1), on the release of the N from the litter using the litterbags technique. There was an increase in the litter initial concentration of N with time of decomposition. The Aruana and Vencedor cultivars released about 70 and 60% of N; respectively, …
Impact Of Grazing Management Strategies On Carbon Sequestration In A Semi-Arid Rangeland, Usa,
2021
U.S. Department of Agriculture
Impact Of Grazing Management Strategies On Carbon Sequestration In A Semi-Arid Rangeland, Usa, J. D. Reeder, G. E. Schuman, J. A. Morgan, D. R. Lecain, R. H. Hart
IGC Proceedings (1977-2023)
The effects of 12 years of grazing management strategies on carbon (C) distribution and sequestration were assessed on a semi-arid mixed-grass prairie in Wyoming, USA. Five grazing treatments were evaluated: non-grazed exclosures; continuous, season-long grazing at a light (22 steer-days ha-1) stocking rate; and, rotationally-deferred, short-duration rotation, and continuous, season-long grazing, all three at a heavy stocking rate (59 steer-days ha-1). Non-grazed exclosures exhibited a large buildup of dead plant material (72% of total aboveground plant matter) and forb biomass represented a large component (35%) of the plant community. Stocking rate, but not grazing strategy, changed …
Contribution Of Dairy Cow Manure To Soil Fertility And Nutrient Redistribution In Pastures,
2021
Department of Natural Resources and Environment, Australia
Contribution Of Dairy Cow Manure To Soil Fertility And Nutrient Redistribution In Pastures, S. R. Aarons, C. R. O'Connor, M. Hall, C. J. P. Gourley
IGC Proceedings (1977-2023)
The effects of dairy cow manure on soil fertility were investigated at the site of the long-term phosphorus rate by stocking rate farmlet experiment at the Dairy Research Institute, Ellinbank, in Victoria. Manure increased extractable soil P (Olsen) in the 0 - 5 cm layer after 60 days to 61 mg/kg compared with values of 32 mg/kg in the control soils. Extractable soil K (Colwell) almost doubled under manure pads to 5 cm depth from 642 mg/kg in control soils to 1226 mg/kg in manure treated soils. The effects of grazing management on nutrient redistribution and pasture growth within strip-grazed …
Impact Of Increasing Nitrogen Fertilizer Rates Upon An Irrigated Tanzania Grass Pasture. 1. Dry Matter Yield,
2021
Universidade de São Paulo, Brazil
Impact Of Increasing Nitrogen Fertilizer Rates Upon An Irrigated Tanzania Grass Pasture. 1. Dry Matter Yield, F. Queiroz-Neto, G. B. Martha Jr., M. A. Penati, M. Corsi, M. J. T. Menezes
IGC Proceedings (1977-2023)
An experiment was carried out with irrigated Tanzania grass (Panicum maximum, Jacq.) pasture receiving five nitrogen (N) rates of (0, 30, 60, 90 and 120 kg N ha-¹ cut-¹) during the growing season. N application increased dry matter yield and Tanzania growth rate linearly (P < 0.05). Responses to nitrogen applications were higher in the first two cuts of the growing season than in the last two cuts. The N fertilizer conversion into herbage dry matter was also higher in the beginning of the growing season.
Short-Term Study On 13Carbon Discrimination On Irrigated Tropical Pasture,
2021
Universidade de São Paulo, Brazil
Short-Term Study On 13Carbon Discrimination On Irrigated Tropical Pasture, G. B. Martha Jr., M. Corsi, P. C. O. Trivelin, F. Queiroz-Neto
IGC Proceedings (1977-2023)
A better understanding of pasture ecosystem can be obtained through the use of 13C discrimination technique. In this context, an experiment, assigned in a randomized complete block design with four replicates, was conducted to evaluate the Δ 13C (‰) discrimination, nitrogen (N) yield (kg N ha-¹), total nitrogen content (g kg dry matter (DM)-¹) and dry matter yield (kg DM ha-¹) on an irrigated Tanzania grass pasture (Panicum maximum, Jacq.) receiving increasing rates (0, 30, 60, 90 and 120 kg N ha-¹ cut-¹) of N fertilizer during the summer. Dry matter yield, N yield and nitrogen …
Apparent Recovery Of Surface Applied Nitrogen Fertilizer By A Coastcross Pasture,
2021
EMBRAPA, Brazil
Apparent Recovery Of Surface Applied Nitrogen Fertilizer By A Coastcross Pasture, A. C. Primavesi, O. Primavesi, L. A. Corrêa, H. Cantarella, A. G. Silva
IGC Proceedings (1977-2023)
Nitrogen recoveries from five levels of urea and ammonium nitrate surface-applied on coastcross pasture, grown on a dark red latosol (Hapludox), in São Carlos, SP, Brazil, under tropical altitude climate, were estimated. Significant differences occurred within periods (P < 0.05), depending on climatic conditions. Under adequate plant growth conditions, mean N recovery from urea was about 67%, sometimes reaching 80%, of that from ammonium nitrate. Recovery of ammonium nitrate varied from 45 to 68% of applied N.
Soil Ph Correction Affecting N-Use Efficiency Of Urea By Brachiaria Brizantha Cv. Marandu Pastures,
2021
Universidade de São Paulo, Brazil
Soil Ph Correction Affecting N-Use Efficiency Of Urea By Brachiaria Brizantha Cv. Marandu Pastures, P. P. A. Oliveira, P. C. O. Trivelin, W. S. Oliveira, G. M. Teixeira, M. Corsi
IGC Proceedings (1977-2023)
Nitrogen fertilization is one of the largest investment when recovering and intensifying pasture management. Urea nitrogen use efficiency was studied in Brachiaria brizantha pasture under tropical conditions where liming was applied to the soil in two dates ("early" and "late" - March and August, respectively). Lime was broadcasted and urea was either broadcasted or subsurface-band applied. "Early" applied lime caused 16,4% increase in forage dry matter yield in the rainy season. Urea-N recovered in the shoots was higher when subsurface band applied independently from time of lime application.
Development Of A Genomic Prediction Pipeline For Maintaining
Comparable Sample Sizes In Training And Testing Sets
Across Prediction Schemes Accounting For The
Genotype-By-Environment Interaction,
2021
University of Nebraska-Lincoln
Development Of A Genomic Prediction Pipeline For Maintaining Comparable Sample Sizes In Training And Testing Sets Across Prediction Schemes Accounting For The Genotype-By-Environment Interaction, Reyna Persa, Martin Grondona, Diego Jarquin
Department of Agronomy and Horticulture: Faculty Publications
The global growing population is experiencing challenges to satisfy the food chain supply in a world that faces rapid changes in environmental conditions complicating the development of stable cultivars. Emergent methodologies aided by molecular marker information such as marker assisted selection (MAS) and genomic selection (GS) have been widely adopted to assist the development of improved genotypes. In general, the implementation of GS is not straightforward, and it usually requires cross-validation studies to find the optimum set of factors (training set sizes, number of markers, quality control, etc.) to use in real breeding applications. In most cases, these different scenarios …
Evaluation Of “Feeding Intelligence” In Murrah Water Buffaloes Grazing Three Different Tropical Grasses,
2021
Instituto de Zootecnia, Brazil
Evaluation Of “Feeding Intelligence” In Murrah Water Buffaloes Grazing Three Different Tropical Grasses, P. B. Alcântara
IGC Proceedings (1977-2023)
Acceptability and palatability are two terms of large utilization that help to understand animal selection for feed. “Feeding intelligence” is a new theory recently introduced to replace those terms mentioned before. According to most recent research works, the feeding intelligence is acquired and remains for a long period of time in the memory of some animals. The present experiment had the purpose of showing its occurence in water buffaloes aiming, at the same time, to better understand their feeding behaviour. Three tropical grasses were tested: Brachiaria brizantha cv Marandu, Panicum maximum cv Tanzania and Setaria sphacelata var. sericeae cv Kazungula. …
