Agricultural Science Commons^™

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 …

The Legume – Rhizobia Symbiosis. Does It Vary For The Tropics Relative To The Mediterranean Basin?, J. G. Howieson, A. Mcinnes

IGC Proceedings (1977-2023)

Symbiotic N fixation from legumes is one of the most important biological processes on the planet. It currently provides the majority of the N requirement in agriculture, yet will have to double if cereal crop production is to meet world demand by 2020 (Kennedy and Cocking 1997). To effectively harness the value of biological N fixation from legumes we need to more fully understand G² x E; where G refers to the genotypes of both the legume (G_l) and its microsymbiont (rhizobia; G_r), and E refers to the edaphic environment in which the symbiosis is …

Advances In Forage Legumes: Shrub Legumes, M. H. Shelton

IGC Proceedings (1977-2023)

Forage tree legumes benefit agriculture through their multi-purpose contributions to livestock feeding, to productivity of farming systems, and to protection of the environment.

Of the several hundred forage tree legume species regarded as having potential for forage only c. twenty are in common use. These are listed together with their agroecological range and tolerance of adverse environments including acid soils, cool temperatures, low rainfall, poor drainage and high salinity. The value of many species to ruminants is limited due to low nutritive value arising from low protein availability and low acceptability caused principally by high condensed tannin content. Only 10 …

Alfalfa, J. H. Bouton

IGC Proceedings (1977-2023)

Cultivated alfalfa or lucerne (Medicago sativa spp. sativa) is the most important forage legume in the world with approximately 32 million hectares cultivated mainly in the temperate regions of both the northern and southern hemispheres. Intensive research has been conducted on the management and physiology of the crop and a major seed industry has developed world wide. Since insect and disease pests are numerous in alfalfa, development of cultivars with the proper fall dormancy and a broad genetic base for pest resistance has been pursued in order to provide increased adaptation, persistence, and yield. There has been a …

Carbon And Nitrogen Isotopic Discrimination In Alfalfa For High Yield And Quality Forage, W. S. Oliveira, P. P. A. Oliveira, M. Corsi, S. M. Tsai

IGC Proceedings (1977-2023)

Biological nitrogen fixation and assimilation of CO₂ can be indirectly monitored in alfalfa (Medicago sativa L.) through the variation of the stable N and C isotopes in the plant (Δ values). Such measurements result in a simple, non-destructive and reliable method for identification of alfalfa cultivars of high yield and nutritional quality. A program for selection of 12 alfalfa cultivars under field and controlled conditions (lysimeters) included determination of biomass and N accumulation. Under controlled conditions yields ranged from 1.77 to 2.47 ton/ha/month (Pioneer 5312 and WL-605) and N2-fixed varied from 77.43 to 84.01% for total N (Brazilian …

Stolon Growth And Its Morphological Components In White Clover (Trifolium Repens L.) Cultivars, Omar Scheneiter, E. M. Pagano

IGC Proceedings (1977-2023)

A trial was performed to study the seasonal changes in stolon growth and its morphological components in four white clover cultivars, in the north of Buenos Aires Province, in Argentina. Stolons were tagged in four seasonal measurements periods per year, during two consecutive years. Leaf, stolon and flowerheads weights were recorded at regular intervals in each measurement period and total stolon growth was calculated. Differences among cultivars were found in stolon growth and its morphological components in most of the measurement periods. In spring and summer, differences among cultivars in stolon growth were related to flowering quantity and earliness, and …

Dry Matter Production Of Shoots And Root Density Of Two Cultivars Of Lablab Purpureus (L.) Sweet, L. R. De A. Rodrigues, T. J. D. Rodrigues, A. K. B. Ramos, D. G. De Quadros

IGC Proceedings (1977-2023)

This experiment was conducted in green house conditions to evaluate the DM accumulation in the shoots and in the roots of two cultivars of Lablab purpureus (L.) Sweet. A 2x3 factorial (two cultivars and three evaluation dates) was conducted according to a randomized complete block design with four replications, being the cultivars Highworth and Rongai evaluated at 42, 56, and 70 days after seedling emergence (DASE). The results indicated that the cvs. Highworth and Rongai have the same pattern of DM accumulation in the shoots. In the upper layer of the soil (0-0.20 m) it was found 38.83% and 43.64% …

Yellow-Flowered Lucerne (Medicago Falcata L.) - A Potential Forage Legume For The North, T. Mela, H. Ihamäki, M. Matilainen

IGC Proceedings (1977-2023)

The suitability of yellow-flowered lucerne (Medicago falcata L.) for forage production under the northern conditions was studied in a mixture sward with timothy (Phleum pratense L.) in field trials in South Finland for four years from 1995 to 1998. Through the first three winters lucerne stayed unharmed. In June and July lucerne grew vigorously, but in August little. The total seasonal yields were highest in the second and the third year of harvesting, up to 10 t DM ha^-1. In the winter 1997-1998 , winter damages killed 21 to 38 % of lucerne plants, and resulted …

Role Of White Clover In The Improvement Of Economical Efficiency Of Feeds From Grasslands, P. Goliñski

IGC Proceedings (1977-2023)

The aim of the research was to analyse the role played by white clover in the improvement of economical efficiency of feeds obtained from permanent grasslands. The influence of the proportion of white clover in the pasture sward on unit production costs of yield, energy and crude protein and the profit threshold in milk production was analysed taking into account three white clover cultivars, nitrogen fertilisation, irrigation and overdrilling. The investigation procedures employed the author’s own calculation models elaborated in optimisation programs based on production conditions found in dairy farms in the region of Wielkopolska. It was proved that the …

The Use Of Cafeteria Trials For The Selection Of Desmodium Ovalifolium Genotypes, Axel Schmidt, R. Schultze-Kraft, B. L. Maass, C. E. Lascano

IGC Proceedings (1977-2023)

For the selection of tropical legumes which contain anti-nutritive components such as tannins, relative acceptability of genotypes to ruminants is of particular importance, since these plant components may influence selective grazing behaviour and subsequent animal productivity. Plant-animal interactions are not predictable from laboratory analyses. Involving grazing animals through the conduction of relative-acceptability (=cafeteria) trials at early stages of the germplasm selection process might therefore provide a convenient tool to adjust and confirm genotype selection based on laboratory quality analyses data. As part of a multilocational germplasm evaluation project, cafeteria-experiments were conducted at two contrasting environments in Colombia with a core …

Stolon Mass And Classes In White Clover (Trifolium Repens L.) With Two Soil Water Availability Levels, Omar Scheneiter, E. M. Pagano

IGC Proceedings (1977-2023)

Two trials were carried out to study the stolon mass and classes in white clover (Trifolium repens L.) under two soil water availability levels in summer. In each trial, treatments were two white clover cultivars. From December 15^th to February 15^th in 1993/94 and again during the same period the following year, white clover was grown under 30 to 70 % (Forced water uptake) or 85-to100 % (Maximum water uptake) of field capacity. Every two months, throughout two years, total stolon mass, and buried, superficial, and aerial stolons were measured. Differences between cultivars were detected in stolon …

Morphological Description Of Selected Pigeonpea (Cajanus Cajan (L.) Millsp.) Lines, Rodolfo Godoy, F. H. De Souza

IGC Proceedings (1977-2023)

Seventeen pigeonpea pure line accessions selected for desirable forage traits and three commercial cultivars were described according to morphological characters. The following descriptors were used: growth habit, plant height, number of primary and secondary branches, stem color and thickness, leaf shape and hairiness, flower base and second color, pattern of flower streaks, flowering pattern, immature and mature pod color, pod form and hairiness, seed color pattern, base and second seed color, seed eye (region around hilum) color and seed shape and width. Each individual line and cultivar was satisfactorily distinguished from the others by the chosen characters.

Improvement Of Rose Clover Winter Forage Production, Gerald R. Smith, F. M. Rouquette Jr.

IGC Proceedings (1977-2023)

Rose clover (Trifolium hirtum All.) is a winter annual forage legume that has potential for increased use in the U.S. southern region. New cultivars of rose clover are needed with the combination of cold tolerance, winter forage production and full bloom date of late April. Crosses were made between two early flowering cultivars and one late flowering rose clover cultivar. The F₂ and F₃ generations from these crosses were evaluated in northeast Texas for winter growth, cold damage and date of flowering. Fourteen F₃ lines, out of 37 selected F2 parents, showed large increases (>100%) …