Agricultural Science Commons^™

Effects Of Lime And Fertilizer On The Establishment Of White Clover In The Falkland Islands, J A. Kerr, Rosie Poultney

IGC Proceedings (1977-2023)

White clover (Trifolium repens L.)-based pastures could improve low pasture and animal production in the Falkland Islands. However, establishment is difficult and expensive. Effects of lime and fertilisers containing nitrogen (N), phosphorus (P) and potassium (K) on white clover dry matter yield and root nodulation were experimentally assessed between 1986-88. Lime at 1 t/ha and 30 kg/ha P as triple superphosphate, separately improved clover yield. Nodulation was improved only by lime. Neither N nor K fertilisers affected on white clover establishment yields,

Complementarity Between Summer-Active Grasses And Cool-Season Annual Legumes In Temperate-Zone Pastures, W H. Johnston

IGC Proceedings (1977-2023)

The effect of mowing and subterranean clover (Trifolium subterraneaum) on plant density; basal area and total dry matter yield of the C perennial grasses Eragrostis curvula complex, cv. Consol and 4 Accession 4660, and Cenchrus ciliaris cv. American, and the c; Pllalaris aquatica cv. Sirocco was studied at Cowra, NSW, Australia between spring 1982 and spring 1987. C. cilaris did not persist. The density and basal area of phalaris was not affected by subterranean clover but declined with mowing, Clover reduced the density, basal area and summer dry matter ·yield of E. curvula while mowing was', advantageous. E. curvula …

Winter Grazing Rough Fescue Grasslands With And Without Preconditioning On Annual Pasture, W D. Willms, L M. Rode, B S. Freeze

IGC Proceedings (1977-2023)

Winter grazing of the fescue prairie is desirable to reduce the cost of feeding preserved forages and to conserving the native prairie. Rough fescue (Festuca campestris Rydb,), the dominant and most productive forage species in the foothills region, is highly sensitive to summer grazing but tolerates grazing while dormant. Since the forage quality declines after senescence, and the energy requirements increase in winter, this study was made to determine the feasibility of winter gmzing pregnant Hereford cows with and without preconditioning on annual pasture. The study, replicated over a 4-year period {n=4), used a 2x2 factorial design representing native …

Interaction Of Drill Type And Herbicide On Pasture Establishment In Semi-Arid Environments, W L. Lowther, R F. Horrell, P D. Johnstone, K D. Trainor

IGC Proceedings (1977-2023)

Results are presented from an overdrilling experiment comparing a conventional triple-disc drill with an' experimental single-pass strip­seeder drill designed to remove competiting vegetation mechanically; Herbicide application markedly increased herbage mass of sown species in the triple-disc treatments. ,However, herbage mass was. higher from the strip-seeder drill than the .triple-disc in both ihe' nbsence and presence of herbicide. The results indicate the potential of the strip-seeder drill technology for cost-effective establishment of pasture species in difficult environments.

Alfalfa Cultivar Selection From 30 Years Of Records In The State Of Illinois, Usa, Don W. Graffis

IGC Proceedings (1977-2023)

Data from alfalfa (Medicago sativa L.) cultivar trials in Illinois, USA from 1963 lo 1992 have been adapted to a computer software spreadsheet for storage and manipulation. The data recorded have been the percentage of check cultivar's yield. The average % of checks for a given cultivar is calculated after each year of recorded yield. The computer spreadsheet enables sorting of resultant yields. The sorting in descending order determines lhe top-performing cultivars. Criteria used lo determine cultivar suggestions for extension clienlele are: (a) a minimum of 3 harvest years in the region of cultivar suggestion, and (b) the cultivar …

Developing Eastern Gamagrass On A Conserved Forage, John A. Dickerson, Paul R. Salon

IGC Proceedings (1977-2023)

Bastern gamagrass (Tripsacum dactyloides L.) is highly regarded as a native forage resource in the prairie region of North America. Recent discovery of a gynomonoecious plant in Kansas has raised expectations that efficient seed production will be possible with the species. A possible use for eastern gamagrass is as a perennial haylage crop for dairy farms, replacing erosion-prone silage corn. Compared with corn silage, eastern gamagrass forage has higher crude protein, slightly lower energy, and higher neutral detergent fibre and acid detergent fibre. Breeding work is underway to develop hardy, high volume forage-producing strains with good seed production capability. …

Rangelands In Dry Mountain Areas, T Boyadgiev

IGC Proceedings (1977-2023)

The extent and characteristics of temperate and mountainous climatic zones, steeply dissected and mountainous areas, permanent meadows and pasture lands, and the trend of land use evolution and aspects of land degradation are presented and discussed. The rangelands improvement strategy in Bulgaria is based on mineral fertilisation of mountainous grasslands leading to an increase in production of dry material, protein, phosphorus and cereals, This reduces sheet erosion. Overgrazing and prolonged dry periods, causing a decrease in the number of species, are also discussed, Measures to improve grassland practices are proposed.

Improvement Strategies In Winter Cold Temperate Rangeland Ecosystems With Particular Reference To Extensive Grazing Lands Of Iran, A Koocheki

IGC Proceedings (1977-2023)

Traditional land use systems in Iran have been divided between crop production and livestock grazing. Grazing land management in most parts is based on pastoral nomadism which operates between plains as winter grazing lands and mountains as summer grazing lands. Mountainous areas are an important source of food and feed production for nomads and their herds. In Iran two main ranges of mountains, Elburz and Zagros, are the summer territory of nomadic pastoralists. At present 1.5% of total population of the country are nomads. They contribute as much as 27% of value added in the animal industry of the country. …

Winter Cold Temperate Rangelands: Improvement Strategies For Intensive Rangeland Ecosystems, B E. Allan, D Scott

IGC Proceedings (1977-2023)

Transfer of developed grassland technologies to rangelands is discussed in terms of environmental gradients and the options and constraints they impose. Winier feed limitation can be overcome through conserved feeds and various in situ systems involving special purpose pastures and feed banks. General animal nutrition can be improved through intensive development, low input systems, better control of range utilisation and, where appropriate, correction of mineral deficiencies. The emphasis in seeking quick and easy solutions to rangeland management problems is questioned, A more informed, environmentally sound and sustainable approach to rangeland fanning atlitudes and management is proposed. A stepwise process to …

Bodine: An Agent-Based Modeling Approach To Studying Localized Coexistence Across Environmental Heterogeneity, Alexandra Campbell

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Designing A Decision-Support Tool For Fertilizer Recommendations In Oil Palm Smallholders, Rana Farrasati

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Oil palm (Elaeis guineensis Jacq.), originally from West Africa, now accounts for 42% of global vegetable oil production and mainly includes key regions cultivated in tropical regions of Southeast Asia, West Africa, South America, and Central America. Despite its economic significance, the oil palm industry faces challenges of stagnant yields and large yield gaps, particularly among independent smallholders. These issues often stem from inadequate nutrient management practices and limited agronomic knowledge. Our objective was to quantify nutrient requirements for mature oil palm plantations as a basis to design a decision support tool (DST) for fertilizer recommendations. To do so, …

Bio-Based Sprayable Mulch For Weed Control In Row Crop Systems, Camila Chiaranda Rodrigues

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Improving current crop productivity levels requires transformative advancements in management, engineering, and science. One of the main challenges is the increasing difficulty of weed management due to herbicide-resistant weeds. There is a growing need for alternative weed management methods to reduce pesticide use and improve environmental safety. An emerging technology that is being developed is spray-on films which could help address these challenges. Spray-on films are liquid solutions that after spraying on the soil will dry and form a physical barrier. The overall objective of this research was to evaluate the effectiveness of a chicken feather bio-based sprayable mulch film …

Assessing The Above- And Belowground Productivity Of Fall-Planted Cover Crop Cultivars In Nebraska's Diverse Ecoregions, Bridget Mckinley

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Cover crops (CC) provide essential ecosystem services including soil conservation, nutrient cycling, and weed suppression, through the accumulation of aboveground (AGB) and belowground (BGB) biomass. While AGB has been widely studied, BGB contributions, particularly root development and distribution, remain less understood. This study evaluated fall-planted CC across three Nebraska ecoregions, assessing AGB productivity, BGB biomass, and correlations between ground cover, plant height, and AGB.

Thirty treatments, including grasses, legumes, brassicas, and mixtures, were evaluated over two fall growing seasons (2022–2023 and 2023–2024) at three UNL research centers in northeast, west central, and west Nebraska. AGB was highest at west site …

Gorse And Its Control, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

Gorse (Ulex europaeus) is a declared pest in Western Australia (WA). This factsheet describes the nature of the plant with links to requirements that landowners/occupiers must adhere to, pest control methods and how to search, detect and report it.

Gorse is a Weed of National Significance (WoNS) present in Australian states and the Australian Capital Territory; it is not present in the Northern Territory. Gorse is a declared pest plant in WA.

Evaluation Of Dual Purpose Canola And Cereals Grazed With Cattle, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

The Department of Primary Industries and Regional Development conducted research to investigate and demonstrate the importance of dual-purpose crops (canola, wheat and barley) to improve the feed availability for cattle (in late autumn to early winter) in mixed farming systems of the high rainfall environment of Western Australia (WA).

The grain yield of a wide range of canola and cereal varieties sown in mid-April were unaffected by the grazing of cattle at a stocking rate of 20 to 22 dry sheep equivalent (DSE) per hectare (ha) for up to 4 weeks at Esperance in 2011.

The grazed crops yielded the …

Water Lettuce And Its Control, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

Water lettuce (Pistia stratiotes) is a declared pest in Western Australia (WA). This factsheet describes the nature of the plant with links to requirements landowners/occupiers must adhere to and pest control methods.

Effect Of Crop Age On Seed Yield Of Arachis Pintoi At Two Sites In Costa Rica, Pedro J. Argel, Alfredo Valerio

IGC Proceedings (1977-2023)

Arachis pintoi is a forage legume well adapted to the humid tropics of Costa Rica. Seed production studies were carried out at two contrasting localities within the country, Gulipiles (very humid tropics) and San Isidro (seasonal evergreen tropical forest). The accessions CIAT 18748, 18744 and 17434 cv. Amarillo of A. pinloi were vegetatively planted at both sites. Seed yields were measured at 8, 12, 16 and 20 months post- planting inGulipiles, and at·8, 16 and 20 months in San Isidro. Mean seed yields among accessions were similar in San Isidro but significantly different in Gulipiles; however, the contrary occurred in …

Efficient Nitrogen Fertilization In Grass Seed Crops With Regard To Soil Mineral Nitrogen Content And Analyzing Grass Tillers In Spring, W Schoberlein, H J. Wahl

IGC Proceedings (1977-2023)

When applying the Nmln method in grass seed crops analogously lo that in cereal crops we proceed from the experience that for a mean level of mineralisation, the sum total of soil-borne Nm1n available to plants at the beginning of the growth period and Nd Input in the form of fertiliser will provide sufficient N to the crop. The total quantity of mineral soil-borne N and fertiliser N is considered as the nominal value. The required N input can be derived from the difference between nominal value and mineral soil-borne N (Nd = nominal value• Nrnin>· For Dactylis glomerata …

Effects Of Aneuploidy On Seed Production In Autopolyploid Forage Crops, A Elgersma

IGC Proceedings (1977-2023)

Between the selection of a population and its commercial use, several generations of multiplication are necessary. The essential feature in variety maintenance is that no genetic changes occur during multiplication. In seed-propagated species, however, during each multiplication cycle natural selection takes place at ihe gamete, zygote, seed and plant level. In induced autopolyploids high frequencies of aneuploids can occur. Aneuploidy not only affects the seed yield level, but also the selection processes that occur during multiplication. It may cause genetic shift and affect variety stability. Species differ in their tolerance to aneuploids. It is not possible to eliminate aneuploidy by …

Effects Of Ratooning And Protection From Diseases And Birds On Seed Production In Guinea Grass, Okoro Oji, F N. Madubuike, F.O C. Ezedinma

IGC Proceedings (1977-2023)

Effects of ratooning and protection from diseases and birds on seed production in guinea grass (Pannicum maximum L.) were assessed in a study from October 1986 to April 1987. Treatments included ratooning and mancozeb application with or without protection from birds (netting). Highest yield occurred with combined netting and mancozeb application. Mancozeb sp,aying without netting gave lower seed yield than netting without fungicide spraying. Seed yield, which generally decreased with ratooning, was lowest among unnetted and unsprayed crops. Prom anthesis to seed maturation lasted, on average, 9 days, and seeds borne on the upper part of the panicle matured …

Potential For Improved Honey Bee Pollination Efficiency From Easy-To-Trip Lucerne, L R. Teuber, E E. Knapp

IGC Proceedings (1977-2023)

The principal pollinator of lucerne (Medicago sativa L.) in California, USA is the honey bee (Apis mellifera L.). However, honey bees are notoriously inefficient pollinators of lucerne because they learn to avoid tripping the floret. Easy-to-trip lucerne florets could reduce this problem. These studies were designed to determine the inheritance of ease of tripping and assess the effect of ease of tripping on the rate of outcrossing. Both additive and digenic variance for ease of tripping were significant, resulting in a heritability of 34.0:1:16.2%. Ease of tripping had no influence on outcrossing rate, which was estimated to average …

Effect Of Final Cutting For Fodder On Seed Yield And Seed Quality In Berseem, S L. Saini, R K. Chowdhury

IGC Proceedings (1977-2023)

The study was conducted to determine the appropriate time of final culling (closing) for fodder to optimise the seed yield and seed quality in berseem (Trifolium alexandrinum L.). Based on 2 years' experimentation, the maximum seed yield was obtained when the final cut for fodder was taken in mid•March and the crop was then closed for seed. Seed yield was reduced drastically when the final cut was delayed to late March•April. The seed quality parameters of standard germination, seed weight and vigour index were also reduced when the final cut for fodder was delayed to late March•early April. Based …

Effect Of Post-Harvest Management Practices On Seed Yields On Fine-Leaf Fescue, Gale A. Gingrich, William C. Young Iii, Thomas B. Silberstein

IGC Proceedings (1977-2023)

Public opposition and legislative actions have restricted the practice of open-field burning of grass seed fields in Western Oregon's Willamette Valley. Finding economically acceptable alternatives to straw residue removal has become a priority for valley grass seed growers. Trials using 4 residue management practices were established on 2 commercial fine fescue (Festuca rubra) seed fields. Seed yields varied significantly between residue management practices. Seed yields from thermal-treated plots were equal or significantly greater than yields from the non-thermal treatments. Fertile tiller number was also greater with thermal treatments. Most fine fescue fields produce 4-6 seed crops before replanting, …

Floret Site Utilization Of White Clover, A H. Marshall, D H. Hides

IGC Proceedings (1977-2023)

Plants of white clover (Trifolium repensL.) cv. Olwen were grown in an open glasshouse at 20°C and ovule growth and development measured. Differences in the rate of growth of ovules within ovaries were observed as early as 2 days after pollination. Ovules reached a maximum size after 8 days, with the smallest only half the size of the largest. After 8 days the smallest ovules became flaccid and shrivelled. Ovule position within the ovary had no effect on the frequency of seed set. Inflorescence position and floret position on the inflorescence had a significant effect on the number …

Influence Of Harvest Date On The Yield And Quality Of Seed Of Phalaris, K Reddy, W R. Scott, R J. Lucas

IGC Proceedings (1977-2023)

Grasslands Maru phalaris (Phalaris aquatica L,) was harvested every third day commencing 12 days after mid-anthesis (DAA) to define the optimum time of harvest for seed yield and quality. Harvesting earlier than 21-24 DAA reduced 1000-seed weight and viability. Delaying harvest until 24 days reduced seed yield due to shattering but had no detrimental effect on seed weight and viability. Heavy seed losses occurred 24 DAA when seed moisture fell below 40%. The results of this experiment suggest that Maru phalaris should be harvested 21-24 DAA when the seed moisture is in the range of 40-42% to reduce the …

Annual Bluegrass And Rat's Tail Fescue Control In Perennial Ryegrass, M E. Mellbye, William C. Young Iii, George W. Mueller-Warrant

IGC Proceedings (1977-2023)

Annual bh1egrass (Poa annua L.) and rat's-tail fescue (Vulpia myruros (L.) C.C. Omel.) are common weed contaminants in seed from perennial ryegrass fields Lolium perenne L. grown in Oregon. A trial was conducted to evaluate post-harvest residue removal methods and herbicides to reduce the level of these impurities. The best weed control was obtained from herbicides following crew-cut management, a comparatively thorough non-thermal nppronch to residue removal. Control was good with sequential herbicide treatments, especially when an effective pre-emergence herbicide such as pendimethalin was used, although no treatment completely eliminated annual bluegrass and rat's-tail fescue from threshed seed samples …

Flowering And Seed Production Of Centrosema Spp. In Relation To Day Length And Temperature, R.J M. Gonzalez, R J. Clements, L R. Humphreys

IGC Proceedings (1977-2023)

The effcc1s of variation in daylength and temperature on the flowering processes leading to seed production were studied in genotypes of 5 Centrosema spp. Short days (11 h) enhanced flowering in accessions of C. virginatum from low latitude but flowering of lines from high latitude was more prolific in 16-h days. A quantitative long-short day response was evident in 2 intermediate latitude accessions. The critical photoperiod for flowering·varied: C. virginianum cross 31 flowered in 13.5 h or less, C. pubescens, C. pascuorum and C. macrocarpum in 12 h or less, and C. schiediam Oowcred only in a 10.5 …

Herbicide Treatments For Non-Thermal Grass-Seed Production, George W. Mueller-Warrant, William C. Young Iii

IGC Proceedings (1977-2023)

Legislation phasing down open-field burning in the Willamette Valley of Oregon is forcing grass seed growers to alter crop production piactices. Adoption of new mechanical means for straw removal has increased reliance on herbicides. Volunteer seedling control and crop tolerance for 15 herbicide treatment sequences were evaluated in established tall fcscue (Festuca arundinacea) and perennial ryegrass (Lolimn perenne) stands during 2 growing seasons using 5 methods of residue removal. Pre-emergence pendimethalin was extremely safe yet fairly effective on volunteer seedlings in both crops. For perennial ryegrass subsequently treated with post-emergence herbicides, pre-emergence metolachlor was slightly more …

A Development Scale For Perennial Ryegrass, Miriam L. Martin, Roger J. Field

IGC Proceedings (1977-2023)

Vernalised plants of perennial ryeg ra ss (Lolium prenne L. cv. Orasslonds Nui) were grown under controlled conditions and apical development followed by regular excision of apices, which were examined by light and scanning electron microscopy. A 12-point scale describing apical development from the vegetative stage to ear emergence has been produced that is presented in 2 forms: a developmental sequence describing organogenesis events at specific stages, and a commentary on easily recognised features of each stage. The developmental scale provides a detailed analysis that is of value as a botanical description and as a practical aid to those involved …

Seed Yield Potential Of White Clover: Characteristics, Components And Compromise, P.T P. Clifford, I J. Baird

IGC Proceedings (1977-2023)

Nd relationship between leaf size and any of the measured variables was found for 63 agronomically superior white clover (Trifolium repens L.) plants of relatively diverse morphological and physiological characteristics, Predominantly crown-flowering plants gave more than double the seed yield of stolon-lip 'flowerers. High seed yields were also associated with delays in peak flowering, harvest date and increased harvest dry matter. Similar associations were evident for inflorescence density. Increased dry matter accumulation was associated with increases in both floret numbers and seeds/ inflorescence.