Agricultural Science Commons^™

Effect Of The Mixed Rates Of Endophyte-Free And -Infected Seed On The Dry Matter Yield And Forage Quality Of Tall Fescue, J. K. Lee, S. H. Yoon, S. Seo, D. A. Kim, Y. W. Rim, G. J. Park, S. K. Lee

IGC Proceedings (1977-2023)

This study was carried out to investigate the effect of the mixed rates of endophyte-free and infected seed on the dry matter yield and forage quality of tall fescue in Korea. In experiment, mixed ratios of endophyte-infected and -free seed were compared under the fourth cutting. Dry matter yield and forage quality of tall fescue were not influenced by mixed rates. The weed contents of botanical composition were slightly increased with high ratios of endophyte-free seed. The results demonstrated that endophyte-free tall fescue did not seem to be greatly weak under bad conditions.

Impact Of Management On Endophyte Free And Endophyte Infected Tall Fescue Cultivars In Ohio, C. D. Penrose, Reuben M. Sulc, J. S. Mccutcheon

IGC Proceedings (1977-2023)

Ten cultivars of tall fescue (Festuca arundinacea, Schreb.) and one cultivar of orchardgrass (Dactylis glomerata L.) were part of a study to determine changes in endophyte levels of fescue under two different styles of forage management: intensive and extensive. Included in the study were two endophyte infected-cultivars of tall fescue to compare interactions with endophyte free and infected cultivars. After three years, the results demonstrate that under high levels of management and non-endophyte infected crops prior to seeding, introduction of the endophyte can be reduced or delayed. Under lower levels of management and a smother crop into …

Grazing Endophyte Infested Tall Fescue And Changes In Bovine Blood Components And Gain, H. A. Fribourg, J. C. Waller, A. E. Schultze, B. W. Rohrbach, J. W. Oliver

IGC Proceedings (1977-2023)

Tall fescue (Festuca arundinacea) is utilized on more than 15 million ha of pasture in the eastern USA and over 80% of the plants in this area are infested with the endophyte Neotyphodium coenophialum. Tall fescue toxicosis results from consumption of the infested (E+) grass host and is an important problem that causes considerable economic loss to producers. However, the agronomic attributes of tall fescue make it an attractive forage because of its ability to withstand cool temperatures, drought, poor soil conditions and intensive defoliation. There is need to understand mechanisms of animal physiology that are affected …

Relationships Between Different Management Practices And Selected Soil Health Indicators, Erika Lambert, Jack Howard, Sammuel Tapp

Scholars Week

Relationships Between Different Management Practices and Selected Soil Health Indicators

Jack Howard, Erika Lambert, Samuel Tapp, Corey Hale, Mallorie Snider, Dr. Brian Parr, and Dr. Iin Handayani

Hutson School of Agriculture, Murray State University

Abstract

Soil health is essential for growing crops productively. Healthy soils help to reduce erosion, improve nutrient cycling, and lower input cost. Understanding how crop rotations and tillage systems affect soil is key to preserving soil while also improving agricultural income and efficiency. This study was conducted in Calloway County, Kentucky to observe the effects of different management practices over nine sites of management on the …

Phylogenetic Grouping By Pcr Analyses Of Sinorhizobium Meliloti Strains Isolated From Eutrophic Soil, W. S. Oliveira, P. P. A. Oliveira, C. M. Bellato, F. R. S. Duarte, S. M. Tsai

IGC Proceedings (1977-2023)

This study evaluated the ability of Sinorhizobium meliloti strains (SEMIA-116, SEMIA- 134 and SEMIA-135) to persist in eutrophic soils after three complete growing cycles of alfalfa. PCR fingerprinting using primers for the nifH, Eric, Rep, RP genes and P25 RAPD-PCR performed the phylogenetic grouping of the three commercial strains and 39 field isolates. These analyzes were sufficiently sensitive to discriminate and group the strains and isolate. Our preliminary studies were based upon Eric primers and RP01 RAPD-PCR.

Achievements And Perspectives In The Breeding Of Temperate Grasses And Legumes, Kenneth H. Quesenberry, M. D. Casler

IGC Proceedings (1977-2023)

This paper will focus on a historical perspective on cool season forage production, plant breeding methods for cool season forages, major cool season forage selection criteria, some examples of significant achievements, and a future perspective. Topics similar to ours have been discussed at recent previous meeting of this Congress (Humphreys, 1997; Van Wijk et al., 1993); however, we will strive to avoid “plowing the same ground twice”. In an attempt to prevent duplication of content with other sections of this Congress, only limited attention will be given to genetic resource acquisition and conservation. Additionally, alfalfa (Medicago sativa L.), one …

Achievements And Perspectives In The Breeding Of Tropical Grasses And Legumes, John W. Miles

IGC Proceedings (1977-2023)

Pasture and forage plant breeding is complicated by the perennial nature of the plants, the diversity of environments in which improved cultivars will be used, and the complex criteria of merit involved, criteria that necessarily include some measure of impact on the efficiency of animal production. While pasture plant breeding in the temperate zone is a demonstrably productive activity, the record of success for the tropical species -- "success" measured by release and adoption of bred cultivars -- is less convincing, in spite of four decades of activity in numerous public sector breeding programs and a large published literature. The …

Tropical Forage Genetic Resources -- Will Any Be Left For Future Generations?, B. L. Maass, B. C. Pengelly

IGC Proceedings (1977-2023)

After very active years of pasture and forage research at major institutes, interest in tropical forage genetic resources has drastically declined. Apparently, the early phases of collecting and evaluation were much more valued than conserving and keeping the germplasm available for future generations. Accumulated data are not easily accessible and, therefore, the knowledge of tropical forage genetic resources is progressively being lost. This worldwide decrease in activity and loss of knowledge is due to declining resources. It is suggested that a global database on tropical forage genetic resources should be established and also that finances be made available to at …

Competition Of 35 Cultivars Of Alfalfa At Sertãozinho-Sp, Ana C. Ruggieri, A. Schmidek, A. R. P. Almeida, L. A. Figueiredo, Alda L. G. Monteiro, M. F. L. Muñoz

IGC Proceedings (1977-2023)

Thirty-five cultivars of alfalfa were evaluated at EE de Zootecnia in Sertãozinho,SP, Brazil. During four years, the plants were harvested to determine dry matter yield on total and individual cuts. A completely randomized block design with three replications was used, and data were analyzed by groups of origin and dormancy degree. There were significant differences (P< 0.05) among the cultivars regarding their dormancy degree, however no differences (P> 0.05) were observed regarding their origin. Cultivars with 8 and 9 dormancy degree showed better performance during the four year trial when compared to 7 degree, although some of the 9 degree cultivars resulted in low yield. The origin of cultivars did not influence …

Adaptability And Stability Of Alfalfa Cultivars, Ana C. Ruggieri, Alda L. G. Monteiro, R. Gualberto

IGC Proceedings (1977-2023)

Yield adaptability and stability of thirty five alfalfa genotypes (Medicago sativa L.) were evaluated at Sertãozinho, SP, Brazil, considering different environments (seasons of year) from 1996 to 1999. A randomized complete block design with three replications was used. Scott-Knott’s test was performed to compare genotypes averages. Adaptability and stability were determined by Eberhart and Russell's procedures. Two diverse groups of genotypes with mean dry matter yield were identified: Araucana, F686, MH4 e BR2 were more responsive under favorable environments, but SW 8210, Alto, Monarca SP, Victoria SP, Florida 77, P5888, MH15, BR1, BR3, SW 9210A presented broad adaptability and …

Effect Of Concentrate Supplementation On Milk Yield Of Crossbred Holstein X Zebu Cows Grazing Elephantgrass, Fermino Deresz, Antonio Carlos Cóser, Rui Da Silva Verneque

IGC Proceedings (1977-2023)

The study was carried out using 12 ha of Elephantgrass (Pennisetum purpureum Schum.) pasture, fertilized with 660 kg/ha/year of 20.05.20 formula, during the rainy season of 1999. It was used eight cows per treatment/site in a completely randomized block design. Blocks were based on milk yield and date of calving. Pasture was managed with 30 days of resting period using a stocking rate of five cows/ha. The objective of the study was to evaluate the effects of feeding concentrate for the first 60 (T60) or 120 days (T120) post-partum on milk yield, in relation to the control-group (T0), fed …

Supplementation Of Dairy Cows Under Alfalfa Grazing Conditions With Ground Corn, A. R. Castillo, L. A. Romero, O. R. Quaino, E. A. Comeron, M. C. Gaggiotti

IGC Proceedings (1977-2023)

Two trials were carried out during the Autumn of 1991 and 1992 to investigate the effects of corn supplementation on lactational performance of dairy cows under alfalfa grazing. Forty two multiparous Holstein cows with 30-60 days in milk were used in a randomized continuous design with covariance analysis. The treatments were 0.0, 3.5 and 7.0 kg.day^-1 of corn grain supplementation (T1, T2 and T3 respectively) in 1991 and 0.0, 3.0, 6.0 and 9.0 kg.day^-1 (T1, T2, T3 and T4 respectively) in 1992. Six cows per treatment were used divided in 3 cows per grazing paddock. Dry matter (DM) …

Animal Production From Tree-Pasture Association Systems In Brazil, João C. Saibro

IGC Proceedings (1977-2023)

Agroforestry systems (AFS) in general and silvipastoral systems (SPS) in particular, have been studied intensively in Brazil since the 1980’s. The majority of the research work has been conducted in the wet tropical Amazon region, in the semi-arid conditions of the Northeast, and under subtropical soil and climatic conditions in the Southeast or in the South. Research emphasis has been placed on interactions between the main components of AFS: tree, pasture, soil and microclimatic elements. Evaluation of animal performance in SPS generally has not been the main objective of experiments. A recent survey of research on SPS using Eucalyptus spp …

Making Agriculture Carbon Neutral Amid A Changing Climate: The Case Of South-Western Australia, Ross Kingwell

Climate Science Research Articles

Making Australian agriculture carbon neutral by 2050 is a goal espoused by several agricultural organisations in Australia. How costly might it be to attain that goal, especially when adverse climate change projections apply to agriculture in southern Australia? This study uses scenario analysis to examine agricultural emissions and their abatement via reforestation in south-western Australia under projected climate change. Most scenarios include the likelihood of agricultural emissions being reduced in the coming decades. However, the impact of projected adverse climate change on tree growth and tree survival means that the cost of achieving agricultural carbon neutrality via reforestation is forecast …

Multi-Strata Silvipastoral Systems For Increasing Productivity And Conservation Of Natural Resources In Central America, Muhammad Ibrahim, Andrea Schlonvoigt, Juan Carlos Camargo, M. Souza

IGC Proceedings (1977-2023)

Conversion of primary forest to pasture is widespread in Central and Latin America and the progressive removal of trees has resulted in environmental degradation and a decline in productivity, simultaneously threatening rural livelihoods and regional biodiversity. Recently there has been keen interest to develop silvipastoral systems for sustainable animal production. Traditional silvipastoral systems are characterised with a diversity of woody perennials that plays an important role in supplying feed to animals in the dry season, production of timber, shade for animals, and in the conservation of natural resources. Improved novel woody perennials such as Morus alba (mulberry) and Trichanthera gigantea …

Transgenesis And Genomics In Molecular Breeding Of Forage Plants, G. Spangenberg, R. Kalla, A. Lidgett, T. Sawbridge, E. K. Ong, U. John

IGC Proceedings (1977-2023)

Forage plant breeding has been largely based on phenotypic selection following sexual recombination of natural genetic variation found between and within ecotypes. Advances in plant genetic manipulation over the last 15 years have provided convincing evidence that these powerful technologies can complement and enhance plant breeding programs. Significant progress in the establishment of the methodologies required for the molecular breeding of forage plants has been made. Examples of current products and approaches for the application of these methodologies to forage grass and legume improvement are outlined. Large-scale genomic analysis of many organisms is under way with human, arabidopsis and rice …

Opportunities In Molecular Biology: Enhancement Of The Nutritional Value Of Forages, K. R. Hancock, M. J. Ulyatt

IGC Proceedings (1977-2023)

Pasture plants, while producing a cost-effective source of feed for grazing ruminants, can frequently be less than optimal in meeting the animals’ nutrient requirements. Over the past half century, there has been a major effort to improve the quantity and nutritional quality of pasture plants using conventional plant breeding. Although considerable progress has been made in improving the quality and agronomic characteristics of our major pasture plants by this means, breeding can only be applied to plants capable of sexual crosses. This poses severe limitations both in terms of speed of progress and in the number of genes available for …

The Role Of Endophytic Fungi In Brachiaria, A Tropical Forage Grass, S. Kelemu, J. F. White, Idupulapati M. Rao

IGC Proceedings (1977-2023)

In temperate zones, endophytic fungi are widely used as biological protection agents for forage and turf grasses. They form nonpathogenic and intercellular associations with grasses and sedges, completing their entire life cycle within the plants’ aerial parts. Our surveys and studies confirmed that various endophytic fungi, including Acremonium spp., also inhabit native savanna grasses and introduced tropical forage grasses. We are now determining the potentially symbiotic relationships between these fungi and C₄ tropical forages, specifically between the endophyte A. implicatum and Brachiaria grasses. We treated half of a group of genetically identical clones of Brachiaria with fungicide to generate …

Advances In Endophyte Research. Progress And Priorities In Temperate Areas, L. R. Fletcher, H. S. Easton

IGC Proceedings (1977-2023)

Fungal endophytes infect a large number of temperate grass species, genera and tribes (Leuchtmann and Clay, 1997). The majority of these systemic endophytes fall into the genus Epichloe or the closely related Neotyphodium genus.

The asexual Neotyphodium endophytes are asymptomatic, never emerge from between the host grass cells, and are only transmitted vertically, via seed of the host plant. They are believed to have derived from the Epichloe endophytes, (Bacon and White, 2000; Schardl and Wilkinson, 2000) which do emerge from their intercellular habitat and form stromata around the emerging seedhead of their host. This is manifested as the choke …

Advances In Rhizobial Research – Progress Priorities In Temperate Areas, Angela Sessitsch

IGC Proceedings (1977-2023)

Rhizobia are well known for their capacity to establish a symbiosis with legumes. During this symbiosis the bacteria inhabit root nodules where they reduce atmospheric nitrogen and make it available to the plant. Biological nitrogen fixation (BNF) is an important source of nitrogen and the various legume crops and pasture species often fix as much as 200-300 kg nitrogen per hectare (Peoples et al., 1995). Globally, symbiotic nitrogen fixation has been estimated to amount to at least 70 million metric tons of nitrogen per year (Brockwell et al., 1995). Furthermore, in many cases nitrogen fertilizers are not efficiently used by …