Life Sciences Commons^™

Increased Longevity Of Red Clover Through Selection For Persistence And Disease Resistance, R R. Smith

IGC Proceedings (1997-2023)

Red clover (Trifolium pratense L.), an excellent perennial forage legume, has been considered for many years to be a short-lived, two to three years, forage. Selection for resistance to foliar and root rot diseases and for longevity of stand over the past four decades has improved the persistence of the currently available cultivars. The present studies were conducted to evaluate the progress from selection for longevity and disease resistance. Selection for stand longevity and improved disease resistance has reliably extended the production of red clover into the third and fourth year. Selection for healthy plants in 3- or …

Selection For Herbage Yield And Flowering In Ladino White Clover, J A. Garcia

IGC Proceedings (1997-2023)

A geno-phenotypic recurrent selection program is being carried out on ladino white clover (Trifolium repens L.) aiming to combine good DM and seed yields. Selection criteria includes plant density, vigor, winter growth, flowering and diseases resistance. The performance of selections in terms of DM yields and seed production was evaluated in separate trials. Two cycles of selection increased flowering by 36% and seed yield by 59%. Preliminary data on herbage yields shows a very good performance of the selected material and suggests the feasibility of combining high DM and seed yields.

Performance Of Perennial Peanut (Arachis Glabrata Benth) In Cameroon, R M. Njwe, B Awounfouet

IGC Proceedings (1997-2023)

The objective of this study was to assess the yield and chemical composition of perennial peanut (Arachis glabrata) at growth intervals of 30, 45, 45, 60, 75 and 90 days so as to recommend the best interval of cutting. The yield of dry matter increased from 3133 to 3804 kg ha-1 at cutting intervals of 30 and 60 days, respectively, after which it declined to 3445 kg ha-1 at 90 days . The dry matter content increased with cutting interval from 25.6 % at 30 days to 31.6 % at 90 days. After 45 days of regrowth the crude protein …

Forage Production Potential Of Poa Arachnifera Torr In Semi-Arid Climates, J C. Read, M A. Sanderson, G W. Evers, P W. Voigt, J A. Reinert

IGC Proceedings (1997-2023)

This study was undertaken to determine the forage potential of Texas bluegrass (Poa arachnifera Torr). Texas bluegrass is a perennial coolseason grass native to Kansas, Oklahoma, western Arkansas, and the central region of Texas, USA (Gould, 1975). Thirteen different accessions were established in 1988 at the Texas A&M University Centers at Dallas and Stephenville and tested for 2 years. Mean yields at Stephenville and Dallas were 3610 and 6022 kg ha-1. Two synthetic varieties (Syn-1 and Syn-2) were tested from 1990 to 1995 at four locations in Texas. Yields of Syn-1 was greater than Syn-2 whereas Syn- 2 provided …

Participatory Evaluation Of Urochloa (Brachiaria) Grasses In The Cool Highlands Of Central Kenya, Elkana Nyambati, W. Ayako, S. K. Mailu

IGC Proceedings (1997-2023)

Grasslands are increasingly threatened by over exploitation, degradation and climate change that has undermined their productive capacity, leading led to inadequate quantity and quality feed. Urochloa grass, a native of eastern Africa has been widely improved and adapted as livestock forage. A farmer participatory study was conducted to evaluate productivity of eight Urochloa grasses (Urochloa brizantha cv. Marandu, U. brizantha cv. Xareas, U. brizantha cv. Piata, U. brizantha cv. MG4, U. decumbens cv. Basilisk, U. humidicola cv. Humidicola, U. humidicola cv. Llanero and Urochloa hybrid Mulato II) compared to controls of Pennisetum purpureum (Napier grass cv. Kakamega 1 …

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, …

Application Of Fall Nitrogen Increased Spring Tall Fescue Yield, B. L. Hendrix, Christopher D. Teutsch, J. Duckworth

IGC Proceedings (1997-2023)

Late season nitrogen fertilization is a practice that has long been implemented in turfgrass production. This practice involves applying nitrogen from September through December and results in an extended green period in the fall without stimulating excessive shoot growth. The longer green period results in higher levels of carbohydrate reserves and enhanced root growth compared with a spring-summer fertilization program. In addition to these benefits, sods fertilized in late fall have been shown to green up two to six weeks earlier in the spring. Limited research has considered the impact of late fall nitrogen applications on grass growth in hayfields …

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, …

Plant Breeding Perspectives For Alfalfa (Medicago Sativa L.) Success In Warm Climates, Esteban F. Rios, M. Murad Andrade, C. C. Fernandes Filho, P. Sipowicz, A. Biswas, R. Ulbricht, D. Basigalup, E. C. Brummer

IGC Proceedings (1997-2023)

Climate change can have major impacts on adaptation of forage species to agroecosystems around the world. The ability of breeders to select for traits that impart adaptability to climate resilience will be critical for the future of grasslands. Alfalfa (Medicago sativa L.) is the most important perennial forage legume in the world because of its relatively high yield and nutritional value. In Florida, nondormant cultivars were developed for improved adaptation to the state’s subtropical agroecosystem (‘Florida 66’, ‘Florida 77’, and ‘Florida 99’); however, these cultivars are not commercially available. Breeding efforts are underway to develop new nondormant alfalfa adapted …

Growth Components And Yield Of Brachiaria Ruziziensis (Congo Grass) And Centrosema Pascuorum (Centro) Mixtures As Influenced By Mixture Ratios, Phosphorus Levels And Stage Of Harvest, I. Sani, J. T. Amodu, R. J. Tanko, M. R. Hassan, N. Adamu

IGC Proceedings (1997-2023)

This study was conducted during the 2017 and 2018 rainy season at the Crop Production Research farm, Abubakar Tafawa Balewa University, Bauchi to determine the effects of plant mixture ratios in Brachiaria ruziziensis and Centrosema pascuorum (100% Sole B. ruziziensis, 75% B.R: 25% C.P, 50% B.R: 50% C.P, 25% B.R: 75% C.P and 100% Sole C. pascuorum) and phosphorus fertilizer (SSP) levels (0, 100 and 150kg/ha). The experiment was in a split-plot design with 5x3 factorial arrangement in which the mixture ratios constituted the main plots while phosphorus (SSP) levels constituted the sub treatments. Number of plants per …

Cool-Season Perennials And Stability In Year-Round Forage Production Systems, C. D. Teutsch

IGC Proceedings (1997-2023)

Changes in long-term climate normals have resulted in warmer and wetter summers and milder winters in the humid eastern United States. This will likely impact regional forage species adaptation in the long-term and varietal adaptation in the short term. Variety evaluation has been occurring at the University of Kentucky for almost 100 years. There are several considerations for selecting forage species and varieties including regional and local adaptation, productivity, distribution of growth, palatability, nutritive value, anti-quality factors, tolerance to stress, and persistence. Two of the most important criteria are long-term productivity and persistence under grazing, both of which are currently …

Arkansas Wheat Performance Tests 2022-2023, J. F. Carlin, R. B. Mulloy, R. D. Bond

Arkansas Agricultural Experiment Station Research Series

Wheat variety performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program.

The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for small-grain producers. The tests were conducted at the Northeast Research and Extension Center at Keiser, the Vegetable Substation near Kibler, the Lon Mann Cotton Research Station near Marianna, the Pine Tree Research Station near Colt, and the Rohwer Research Station near Rohwer. Specific location and cultural practice information accompany each …

Relationships Between Productivity, Quality And Traits In Seven Co-Occurring Grass Species, L. S. Pontes, Jean-François Soussana, P. Carrère, F. Louault, J. Aufrère, D. Andueza

IGC Proceedings (1997-2023)

The impacts of management options sometimes have dramatic effects on botanical composition which in turn affect yield and nutritive value. A functional analysis of vegetation response may help to understand and predict the impact of changes in grassland management in a more general way screening for plant traits that may control productivity and nutritive value.

Effect Of Adding Moraine Soil Or Shell Sand Into Peat Soil On Soil Properties And Grass Yields In Western Norway, L. S. Sognnes, G. Fystro, S. Øpstad

IGC Proceedings (1997-2023)

Cultivation and utilisation of peat soil leads to problems related to its high water content. The problems have become more pronounced with the increasing weight of agricultural machinery and more frequent harvesting. Increased particle density, reduced porosity and decreased potential plant-available water was found after incorporation of sand to peat in experiments conducted in the north of Norway (Sveistrup & Haraldsen, 1995). Peat soil has a weak soil skeleton, low bearing capacity, poor thermal properties and insufficient soil aeration. The objective of this study was to investigate the impact of added mineral material to peat soil to improve characteristics important …

Yield Progress Of Perennial Ryegrass And Silage Maize - Genetic Gain Or Climate Change?, Antje Herrmann, A. Kornher, Friedhelm Taube

IGC Proceedings (1997-2023)

Gains in annual dry matter yield (DMY) from breeding achieved during the last decades are reported to range between 2.5 and 6% per decade for perennial ryegrass (Wilkins & Humphreys, 2003). In contrast, accelerated progress in improving DMY has been achieved for silage maize, varying between 8 and 13% per decade (Lauer et al., 2001). These gains are mainly attributed to (i) genetic yield potential increase, (ii) improved crop management and (iii) increased stress tolerance. The potential impact of climate change on yield progress, however, is disregarded in most studies. The objective of this study therefore was to quantify …

Herbage Accumulation And Vegetation Structure In Tanzâniagrass (Panicum Maximum, Jacq. Cv Tanzania) Pasture Submitted To Regime Of Intermittent Stocking, Ana C. Ruggieri, Carlos A. M. Gomide, Estella R. Janusckiewicz, E. D. Contato, R. A. Reis

IGC Proceedings (1997-2023)

Knowledge of pasture structure characteristics such as height, tillering density, leaf area index (LAI) and herbage mass (HM), together with growth rates and forage accumulation, can become important tools to indicate improvements to the production system. This experiment evaluated the structural and productive characteristics and persistence of a Tanzaniagrass pasture.

Performance Of Timothy Cultivars In Monoculture Or In Mixtures With Meadow Fescue In Finland, M. Kari, M. Rinne

IGC Proceedings (1997-2023)

Timothy (Phleum pratense) and meadow fescue (Festuca pratensis) are dominating grass species in Nordic countries with severe winters. Dry matter (DM) yield potential, forage quality and winter hardiness are of main interest for commercial cultivars. Further, it is advantageous to take into account the relation between primary growth and regrowth (P/R) DM yield when planning mixtures for different purposes and areas. In the current experiment, three different types of timothy were evaluated: a northern type cv. Jonatan, a southern type cv. Ragnar and an intermediate type cv. Grindstad. In addition, meadow fescue cv. Kasper and mixtures …

First Things First: Widespread Nutrient Deficiencies Limit Yields In Smallholder Oil Palm Fields, Hendra Sugianto, Juan Pablo Monzon, Iput Pradiko, Fatima A. Tenorio, Ya Li Lim, Christopher R. Donough, Sunawan, Suroso Rahutomo, Fahmuddin Agus, James Cock, Joni Amsar, Rana Farrasati, Ridho Iskandar, Juan I. Rattalino Edreira, Shofia Saleh, Heri Santoso, Antonius P. Tito, Nadib Ulfaria, Maja A. Slingerland, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Indonesia is the most important oil palm producing country. Nearly 40% of planted area is managed by smallholders, with yields well below the potential. Efforts to increase productivity have focused on the source of planting material, with little attention paid to plant nutrition.

OBJECTIVE: To assess the degree to which current productivity in smallholder oil palm fields is limited by nutrients in scenarios with distinct sources of planting material.

METHODS: We collected detailed data on leaf nutrient concentration from 30 fields to derive minimum sampling size needed to diagnose nutrient status. Subsequently, we collected data on …

Comparison Of A Biometric Method With Clipping And Weighing Method For Estimating The Yield Of Artemisia Sieberi (Case Study Zarand-E-Save Region), H. Dianati, M. Abedi, E. Shahriary, Hossein Arzani

IGC Proceedings (1997-2023)

Forage production is a most important vegetation attribute in rangeland analysis and evaluation and use in management practices. Artemisia sieberi covered about 47% of the rangeland area in Iran and scientists need to know the best method for analysis and evaluation of this species. Clipping and weighing has high precision, but this method is time-consuming and expensive and alternative methods are required. Russian scientists developed a biometric method based on plant dimensions and suggest this method for rangelands in the Middle East (discussed by Dianati, 2003). In America, Muray (1982) used plant dimensions for yield estimation and regression models for …

Seed Size And Its Relationship With Crop Establishment, Productivity And Nutritive Value In Genotypes Of Maize For Silage, C. Pérez, M. R. Tovar G., G. García, A. Carballo, G. Mendoza, T. Vásquez, F. González, M. Crosby

IGC Proceedings (1997-2023)

For a high dry matter (DM) yield of forage maize an adequate population of plants is required, which is related to germination, vigour, and seed size (Ellis, 1992). The objective of the present study was to investigate seed size and its relationship to establishment, productive and nutritional potential of silage maize, which has not before been reported in the literature.

Forage Yield And Structural Traits Of Tanzaniagrass (Panicum Maximum) At Four Canopy Heights, Carlos A. M. Gomide, Ana C. Ruggieri, R. A. Reis, J. A. Gomide, J. H. De A. Rangel, E. O. Almeida

IGC Proceedings (1997-2023)

Pasture forage production is based on the growth of tillers (Hodgson, 1990). Although the effect of canopy height and structural traits on productivity of temperate grasses are well known e.g. (Bircham & Hodgson,1983; Binnie & Chestnut, 1994) tiller studies on tropical pasture species are scarce.

The Effect Of Cutting Regime And Cultivar On Longevity Of Pure Lucerne Stands In Latvia, Z. Gaile

IGC Proceedings (1997-2023)

Lucerne growing is important for high and excellent quality yields of hay or silage without application of N fertilisers, as well as for increasing crop diversity in crop rotation systems. It is comparatively expensive to establish lucerne stands in Latvia. Different aspects can affect longevity of lucerne stands: suitability of cultivar to specific conditions, soil characteristics, different stress conditions and cutting management, including frequency and height of cutting, and critical rest period in autumn (Sheaffer et al., 1988). The aim of our study was to evaluate the persistence of lucerne stands without renovation while obtaining reasonable yields.

Effect Of Utilisation Date On The Yield And Quality Of A Semi-Natural Grass Stand In Winter, Jiří Skládanka

IGC Proceedings (1997-2023)

Prolongation of the grazing period into the winter season reduces the costs of feedstuffs for dry cows. To enable the use of pastures in winter it is necessary to carry out the last cut or grazing cycle in June or July and to postpone the last grazing until the first week of August. (Opitz von Boberfeld, 1997). The time of the last utilisation in summer influences the yield and quality of herbage during the winter season (Bartholomew et al., 1997). This research studied changes in yield and quality of a semi-natural grass stand in autumn and in winter following …

Hybrids Between Meadow And Smooth Bromegrass: A New Forage Crop For Canada, B. E. Coulman, Y. S. N. Ferdinandez

IGC Proceedings (1997-2023)

Smooth bromegrass (Bromus inermis Leyss.) has been an important hay grass in the agricultural regions of western Canada for approximately 50 years. Meadow bromegrass (B. riparius Rehm.) has become the most important pasture species in this region over the last 15 years. It is possible to produce hybrids between these species, which could lead to the development of a type of bromegrass which would be useful for both hay and pasture purposes.

Breeding White Clover With Improved Tolerance Of Nitrogen Fertiliser, T. A. Williams, M. T. Abberton, P. Olyott

IGC Proceedings (1997-2023)

White clover (Trifolium repens L.) is often considered a forage legume with a primary use in 'low input/ low output' systems. One facet of this is the perception that the persistency of this species is poor when Nitrogen (N) fertiliser is applied. However, new varieties of white clover are able to play a significant role in highly productive systems (Williams et al., 2000) and show consistent yields over ten years at a range of applied N levels (Williams et al., 2003). Germplasm improvement for nitrogen tolerance has been carried out with the aim of not only allowing white …

Evaluation Of A White Clover Variety With Increased Resistance To Stem Nematode (Ditylenchus Dipsaci) Under Sheep Grazing And Cutting, T. A. Williams, M. T. Abberton, K. A. Mizen, P. Olyott, R. Cook

IGC Proceedings (1997-2023)

Stem nematode (Ditylenchus dipsaci (Kühn) Filipjev) is a major pest of white clover (Trifolium repens L.) in UK pastures (Cook et al., 1992a) and in other parts of the world. In a previous trial, resistant and susceptible selections yielded the same in three years in the absence of the nematode but, on infested plots, the susceptible yielded the same as the resistant selection in year 1 but only 68 and 58% in years 2 and 3, as the nematode infestation increased (Cook et al., 1992b). We have now developed varieties with enhanced resistance to this pest …

Evaluation Of Lucerne Cultivars For Dry Matter And Seed Production In Latvia, S. Rancane, M. Sparnina

IGC Proceedings (1997-2023)

Lucerne is highly productivity and has a high quality. Nevertheless, lucerne growing in Latvia is limited, because of a large area of acid soils (pH_KCl<5.8) as well as low and unstable seed yields (Berzins, 2002). In recent years lucerne has taken a more important place in forage production in Latvia, because it is a fast growing crop and in good years gives 3-4 harvests per season. It is important to determine which cultivars of lucerne are more productive and give good seed yields every year in Latvia (Luksa, 2002).

Positive Effect Of Increased Aflp Diversity Among Parental Plants On Yield Of Polycross Progenies In Perennial Ryegrass (Lolium Perenne L.), R. Kölliker, B. Boller, F. Widmer

IGC Proceedings (1997-2023)

In outbreeding forage crops such as perennial ryegrass (Lolium perenne L.), genetic diversity among parental plants may greatly influence the success of a cultivar through mechanisms such as heterosis and inbreeding depression. The aim of this study was to evaluate the use of amplified fragment length polymorphism (AFLP) markers to select polycross parents with contrasting levels of genetic diversity and to analyse genetic diversity and agronomic performance of first and second generation synthetic progenies (Syn1, Syn2).

Predicting Site‑Specific Economic Optimal Nitrogen Rate Using Machine Learning Methods And On‑Farm Precision Experimentation, Alfonso De Lara, Taro Mieno, Joe D. Luck, Laila A. Puntel

Department of Agronomy and Horticulture: Faculty Publications

Applying at the economic optimal nitrogen rate (EONR) has the potential to increase nitrogen (N) fertilization efficiency and profits while reducing negative environmental impacts. On-farm precision experimentation (OFPE) provides the opportunity to collect large amounts of data to estimate the EONR. Machine learning (ML) methods such as generalized additive models (GAM) and random forest (RF) are promising methods for estimating yields and EONR. Twenty OFPE N trials in wheat and barley were conducted and analyzed with soil, terrain and remote-sensed variables to address the following objectives: (1) to quantify the spatial variability of winter crops yield and the yield response …

Genetic Mapping In Tetraploid Alfalfa: Results And Prospects, E. C. Brummer, J. G. Robins, B. Alarcón Zúñiga, D. Luth

IGC Proceedings (1997-2023)

Among the difficulties of improving forages is their perennial nature, which necessarily requires long selection cycles to fully evaluate genotypes. Further, traits of particular importance—yield and winter hardiness—are difficult to assess on single plants, necessitating evaluation of progeny, which is both time consuming and expensive. Because of this, yield of many forages, and particularly alfalfa, has not improved substantially over the past 25 years (Riday and Brummer, 2002). Winter hardiness often has a negative correlation with autumn growth, although some evidence suggests this is not always true (Brummer et al., 2000). One way to overcome some of these limitations …