Weed Science Commons^™

Stability And Purity Of Epichloë Endophyte Infection In New Zealand Ryegrass Pastures, David E. Hume, Grant M. Rennie, W. Mcg. King, A. L. Taylor, Marty J. Faville, D. Luo, Katherine N. Tozer

IGC Proceedings (1997-2023)

Perennial ryegrass (Lolium perenne) in New Zealand pastures is typically infected with the mutualist Epichloë fungal endophyte, which assists the plant in resisting biotic and abiotic stresses. Ryegrass that has naturalised in New Zealand is highly infected with the ‘Standard’ strain of endophyte. This strain provides good protection from a range of invertebrate pests but negatively impacts livestock productivity and health in the warmer seasons of the year. Grass-endophyte associations have been developed between elite perennial ryegrass cultivars and selected endophyte strains to provide protective properties to the host plant and lessen or eliminate the negative effects on …

A Global Perspective Of Epichloë Endophyte Toxicity In Sown Pastures, David E. Hume, S. C. Finch

IGC Proceedings (1997-2023)

The asexual Epichloë fungal endophytes that form mutualistic, obligate, asymptomatic associations with ryegrasses (Lolium spp.) and tall fescue (Festuca arundinacea) are critical components of pastures in the USA, Australia and New Zealand. Research has convincingly demonstrated that these endophytes enhance agronomic performance of their grass hosts, due to protection from biotic and abiotic stresses such as insect pests and drought. However, although beneficial in terms of enhancing forage quantity, the widespread occurrence of ‘common-toxic’ strains of endophyte negatively impacts the quality of forage for livestock. These bioprotective and anti-quality properties are due to endophyte-expressed secondary metabolites. It …

Cytological And Agronomic Evaluation Of Interspecific Hybrids Between Trifolium Repens L And T. Occidentale Coombe, Syed Wajid Hussain, J. L. Ford

IGC Proceedings (1997-2023)

Trifolium occidentale is a diploid wild relative of T. repens with adaptation to dry, saline coastal habitats. Transfer of drought and salt-tolerant adaptive traits from this potential source of germplasm to T. repens could be valuable if interspecific hybridization can be achieved efficiently. To achieve hybridisation, 4x plants of T. occidentale were generated through colchicine chromosome doubling. Interspecific 4x F₁ plants were achieved without embryo rescue. F₂ populations and backcross (BC) hybrids to white clover were also efficiently achieved. Although male and female fertility in primary F₁ and F₂ hybrids were lower than in white clover, …

Root And Aboveground Traits Expressed By Landraces And Interspecific Hybrid Of Alfalfa (Medicago Sativa. Hybr. (Alborea)) With Putative Drought Tolerance In Mediterranean Environments, Luis Inostroza, Nicolás Muñoz, Miguel Garriga, Soledad Espinoza, Viviana Barahona, Carlos Ovalle, Alejandro Del Pozo, Macarena Gerding

IGC Proceedings (1997-2023)

Alfalfa’s drought tolerance has not been a major breeding target until recently, and the extent of genetic variation for this trait and its contributing mechanisms have not been thoroughly elucidated. Eight populations, including four landraces (Alta Sierra, Aragon, APG6567, APG44669), two Australian cultivars (Venus and Genesis), and two interspecific hybrids (AF3448 and AF3347) of alfalfa were selected based on their outstanding breeding values for dry matter production and plant persistence in Mediterranean drought-prone environments. The objective of this work was to evaluate the below and above ground phenotypic expression of these drought-tolerant alfalfa accessions, in order to identify morpho- physiological …

Alfalfa Response To Phosphorus And Potassium Fertility And Harvest Management, M. A. Islam, M. M. Baidoo

IGC Proceedings (1997-2023)

Balanced nutrition of phosphorus (P) and potassium (K) is needed for improving alfalfa (Medicago sativa L.) productivity. Availability and uptake of P and K by alfalfa for yield response can depend on their relative levels with soil calcium (Ca²⁺) and magnesium (Mg²⁺) in combination with harvest management. An experiment was conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center to determine the alfalfa’s response to P and K in association with Ca, Mg, and harvest time. Treatments were 10 selected combinations (kg ha^-1) of three levels of P (0, 34, …

New Insights For Benefit Of Legume Inclusion In Grazing Systems, David M. Jaramillo, José C. B. Dubeux Jr., L. M. D. Queiroz, L. Garcia

IGC Proceedings (1997-2023)

The benefits and challenges of legume inclusion in grazing systems have been well documented over time and across different regions. Recent investigations have provided novel insights into the benefits of legume inclusion in grazing systems. Our objective is not to provide a wide overview of the benefits of legume inclusion but to explore novel insights of recent advancements made from studies evaluating legume inclusion in grazing systems. Efficiency of resource use through legume inclusion in grazing systems can reduce the water footprint associated with beef production through improvements in forage nutritive value and animal performance. These efficiencies also translate into …

Genotype-By-Environment Interaction In Interspecific Urochloa Hybrids Using Factor Analytic Models, R. N. Jauregui, L. M. Hernandez, J. S. Aparicio, L. J. Mazabel, J. A. Cardoso Arango, L. M. Atencio-Solano, S. L. Mejía Kerguelén, V. Castiblanco, M. Peters

IGC Proceedings (1997-2023)

Environmental factors can influence plant phenotypes shaping the expression of pastures. The ability to test genotypes in multiple environments is critical in a breeding program because important traits are heavily influenced by the environment. Nutritional quality is critical in forage breeding because it affects the rate of live weight gain in livestock as well as the quality of end products such as milk and meat. However, there is not much information on the environmental effect on agronomic and nutritional quality traits in tropical forages. For this reason, the objective of the present study was to investigate the genotype-by-environment interaction in …

Comparing Forage Biomass Estimation Between Forager-Mounted Near Infrared Spectroscopy (Nirs) And Rising Plate-Meter (Rpm) Techniques, Andy G. Jones, G. Irisarri, T. Takahashi, M. J. Rivero, P. Harris

IGC Proceedings (1997-2023)

Quantifying the forage mass harvested per paddock is essential for informing late-season management decisions on grazing livestock farms. This information can be used to calculate winter feed budgets and thus support decisions such as area of land to defer for autumn grazing, and head of stock to sell before winter housing. However, there are practical limitations associated with existing measurement methods, which can influence the accuracy of forage biomass estimates. The purpose of the current study was therefore to compare biomass estimation from two alternative precision farming methods — near infrared spectroscopy (NIRS) integrated within-spout of a self-propelled forage harvester, …

Win-Win For Dairy Farms: Heifers Raised On Pasture Reduce Cost And Produce More Milk At First Lactation, Ken F. Kalscheur, C. H. P. Camisa Nova, D. M. Jaramillo, G. E. Brink

IGC Proceedings (1997-2023)

Pastures under good management promote environmental, economic, and animal welfare advantages. However, comparisons of animal performance for pasture-raised dairy heifers versus confinement-raised dairy heifers are scarce. A study was conducted to evaluate the performance of dairy heifers raised on pasture or in confinement. Heifers raised on pasture had similar body weight and age at calving and greater dry matter intake in the end of 2^nd grazing season. Cost of heifers raised on pasture was 26.7% less in the first grazing season and 58.4% less in the second grazing season compared to heifers raised in confinement. Heifers raised on pasture …

Effects Of Fall Dormancy, Cutting Frequency, And K Application Rate On Dry Matter Yield And Nutritive Value Of Alfalfa, Ji Yung Kim, J. S. Choi, M. H. Jo, K. I. Sung

IGC Proceedings (1997-2023)

[Introduction] This study was conducted to determine the effect of the cutting frequency and K application rate on the dry matter yield (DMY) and nutritive value of new alfalfa varieties in Korea.

[Material and Methods] The sowing date and rate were September 21, 2019, and 20 kg/ha, respectively. The treatment was by the split-split plot design, and the main plot was the Fall dormancy (FD) of 3 (Rugged Rancher), 4 (SW4113), and 9 (SW9720), the sub-plot was excess 40 day (LCF), from 31 to 40 days (MCF), and under 30 day (HCF) times of cutting frequency …

What Is The Difference Between Abnormal Climate And Extreme Climate That Cause Yield Damage To Silage Maize (Zea Mays L.)?, Moonju Kim, C. E. Kim, W. S. Lee, J. S. Choi, Ji Yung Kim, B. W. Kim, K. I. Sung

IGC Proceedings (1997-2023)

This study aimed to compare the characteristics by estimating the impacts of abnormal climate and extreme climate on silage maize. In the maize-climate database, the variables were dry matter yield (DMY, kg/ha), mean temperature (MT, °C), lowest temperature (LT, °C), highest temperature (HT, °C), maximum precipitation (MP, mm/hr), accumulated precipitation (AP, mm), maximum wind speed (MW, m/s), mean wind speed (WS, m/s), sunshine duration (SD, hr). To define the abnormal climate, favorable condition was confirmed using the principal component analysis against a normal climate. In order to define the extreme climate, firstly, the median-interquartile method was used instead of the …

Evaluation Of Cenchrus Ciliaris Ecotypes For Seed Yield And Related Traits, E. C. Kirwa, B. K. Kidake

IGC Proceedings (1997-2023)

Cenchrus ciliaris is widely promoted as a choice grass species for reseeding Arid and Semi- arid Lands (ASALs). Due to the high variability in ASAL environments, there is need to evaluate ecotypes of C. ciliaris with potentially higher seed yield and germination that may possibly be selected and promoted for rangeland reseeding initiatives. Nine ecotypes of C. ciliaris collected from selected sites in Kenyan ASALs were evaluated for seed yield and related traits at three KALRO centres (Kiboko, Buchuma and Mtwapa). Buchuma site (208.4 kg ha^-1) had higher (p-1, respectively. Seed yield varied among ecotypes at Mtwapa and …

Conservation Reserve Program Hay Quality From Producer Submissions To A Commercial Laboratory In Central Nebraska, R. J. Kern-Lunbery

IGC Proceedings (1997-2023)

The Conservation Reserve Program (CRP) sets aside hectares to be permanent grassland and keeps those acres out of rotation for agricultural use. In drought conditions, these acres open to emergency haying and grazing. CRP hay is harvested at the end of the primary nesting season, mid to late summer, therefore this is a very mature product for stored forage. Many beef cow producers in the Midwest feed CRP hay in the last third of gestation until cattle can be turned out for spring grazing. Data was obtained from CRP hay samples to evaluate forage nutritive value and supplementation needs relative …

Considerations On Sampling And Statistical Analysis In Grassland Ensiling Trials, B. Kroschewski, Horst Auerbach, K. Weiss

IGC Proceedings (1997-2023)

Critical findings on design, statistical analysis, and interpretation of the results will be addressed based on comparative ensiling trials. For this aim, a lab-scale ensiling trial on biostatistical issues was conducted in 2021. Grass material from a permanent mowing pasture was taken from (i) 10 sampling points, (ii) one sampling point, (iii) a mixture of 10 sampling points. For each sub-trial (based on the sampling design), 3 levels of the fixed treatment factor silage additive were tested with 10 replicates (without additive, chemical silage additive, biological silage additive). The analysis was performed within a linear mixed effects model (LMM) as …

Grazing Corn Produced Under Living Mulch Systems In Tennessee, Renata Laguardia Nave, M. P. Quinby

IGC Proceedings (1997-2023)

The use of living mulch (LM) in the Southeastern U.S. has yet to be assessed for its potential for grazing operations to increase land use efficiency. Therefore, the need to determine the viability of the system is warranted. The objective of this study was to evaluate the benefits of white clover LM and crimson-clover cereal rye annual mulch in corn silage and grain production, and to evaluate the potential of LM grazing before and after the corn growing season in spring and fall. The study was conducted at the Middle Tennessee AgResearch and Education Center (MTREC), University of Tennessee, in …

Efficiency, Yield, And Nutritive Value Of Perennial Warm-Season Grass Under Liquid Fertilizer Applications, Rocky Lemus, J. A. White

IGC Proceedings (1997-2023)

The efficacy of liquid fertilizer formulation in forage production is unclear. This preliminary study compared the impact of liquid fertilizers sources compared to traditional granular fertilizers in forage bahiagrass (Paspalum notatum) production. The experimental design was a randomized complete block replicated three times. Ten N fertilizer treatments were applied to forage systems: a well-established ‘Tifton 9’ bahiagrass. The N fertilizer treatments included a control (C, no nitrogen), two granular fertilizers [urea (U, 46-0-0) and urea ammonium sulfate (UAS, 33-0-0)], and four liquid N fertilizers [ urea ammonium nitrate solution (UAN, 32%), Royal Grow (RG, 30-0-0), Pasture Booster Prime (PBP, 30-0-0), …

Future Scenario Projections Of Livestock Carrying Status Of Grassland Ecosystem In Kazakhstan, Jiahuil Li, L. Huang, W. Cao

IGC Proceedings (1997-2023)

As a country dominated by animal husbandry, the livestock carrying status in Kazakhstan has a prolonged impact on grassland degradation and restoration, and thus on the supply of grassland ecosystem services. Here we predict future conditions of livestock carrying status by modeling change in potential forage supply and consumption from 2020 to 2030, using three alternative scenarios following Representative Concentration Pathways, specifically SSP2 (RCP4.5, MESSAGE), SSP1 (RCP2.6, IMAGE) and SSP3 (RCP7.0, AIM), namely BAU, TSS and SSS respectively. Our future scenarios suggested that from 2020 to 2030, the forage consumption in central and southern regions of Kazakhstan is predicted to …

Effects Of Lactic Acid Bacteria Inoculants And Stage-Increased Storage Temperature On Silage Fermentation Of Oat On The Qinghai–Tibet Plateau, Lin Li, Shiqie Bai, Ping Li

IGC Proceedings (1997-2023)

Ensiling is a simple and effective method of alleviating a shortage of forage for ruminants. This study aimed to investigate the effects of lactic acid bacteria (LAB) inoculants and stage-increased temperature on the fermentation characteristics and chemical composition of oat silage on the Qinghai– Tibet Plateau. The silage was treated with local laboratory inoculant (I) and commercial inoculant (S) and stored at ambient temperature (<10 °C) or stage-increased (5, 10 and 15 days) temperatures of 10 °C and 15 °C for 60 days. The results showed that stage-increased storage temperature can improve silage fermentation. Compared with 10 °C, a stage-increased storage temperature of 15 °C effectively (p < 0.05) promoted the fermentation rate of silage by increasing the dominance of Lactiplantibacillus plantarum, with higher lactic, acetic and propionic acid contents and a lower ammonia-N ratio of the total N and final pH value. Compared with S, treatment with I increased the water-soluble carbohydrate …

Germplasm Evaluation Of An Eurasia Steppe Native Specie--Sheepgrass (Leymus Chinensis), Gongshe Liu, Xiaoxia Li, Dongmei Qi, Liqin Cheng, Shuangyan Chen, Xianjun Peng, Hui Liu

IGC Proceedings (1997-2023)

Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an advantageous perennial native grass in China and other northern Eurasian countries having steppe. As an important forage grass of great value in animal husbandry, sheepgrass is well known for its abundant foliage, high palatability and high nutritive content. Sheepgrass is also valuable in grassland restoration and conservation since it is a perennial grass with a rhizome network to fix the soil and can survive well in stressful environments. Terefore, the collection, evaluation and utilization of sheepgrass are necessary for protecting grassland biodiversity, for establishing artificial pasture, restoring degraded grassland, and the development …

Analysis Of Controlling Genes For Tiller Growth Of Psathyrostachys Juncea Based On Transcriptome Sequencing Technology, Zhen Li, L. Yun, X. M. Ren

IGC Proceedings (1997-2023)

Tillering is an important trait of bunch grass that affects biomass and seed yield. Psathyrostachys juncea is a typical perennial bunch grass, and unraveling the regulatory mechanisms of tillering in P. juncea could be helpful to improve the yield of perennial gramineous forages. Hence, we selected the tiller node of P. juncea for transcriptome sequencing to determine the differentially expressed genes (DEG) between high and low tillering materials. The metabolic pathway was studied，candidate genes were screened, and reference genes stability were evaluated. The results showed that approximately 5466 DEGs were identified between two P. juncea genotypes that significantly differed in …