Agronomy and Crop Sciences Commons^™

Enhancing Crop Resilience: Physiological And Omics Approaches For Drought And Heat Stress Tolerance In Soybean And Peanut, Jyoti Prasad Kakati

All Dissertations

Soybean and peanut are two major crops globally grown for oil and protein. Climate change-associated factors like drought and increased temperature (heat stress) challenge the global production of soybeans and peanuts. Though the United States is the second-largest producer of soybean and the fourth-largest producer of peanuts, it still faces production constraints associated with drought and heat stresses. In the present study, we have examined the responses of soybean and peanut plants to drought and heat stresses during germination and reproductive phases. We conducted field and controlled environmental studies to elucidate the impact of drought stress on germination and seedling …

Use Of Herbicides Coated Onto Fertilizer And Applied Over-The-Top Of Cotton, Summer Linn

Graduate Theses and Dissertations

Cotton (Gossypium hirsutum L.) production faces numerous challenges, many related to weed management. A herbicide application method that focuses on combing resources that producers already have access to, such as herbicide-coated fertilizers, could be a practical approach for addressing late-season control of Palmer amaranth (Amaranthus palmeri S. Wats) and other problematic weed species. Two main factors would potentially impact the efficiency of utilizing this method: cotton tolerance to the application and weed control provided by the herbicide-coated fertilizers. Some considerations could affect the efficacy of these applications, such as when the treatments are applied and when they are activated by …

Evaluation Of A Diflufenican:Metribuzin:Flufenacet Premixture For Soybean Tolerance And Weed Control, Matthew Coleman Woolard

Graduate Theses and Dissertations

Palmer amaranth [Amaranthus palmeri (S.) Wats.] and waterhemp [Amaranthus tuberculatus (Moq.) Sauer] ranks among the most troublesome weeds of soybean [Glycine max (L.) Merr.], having evolved resistance to multiple herbicide sites of action. Bayer CropScience has announced its intentions to launch Convintro™ brand herbicides, one being a three-way premixture for use preplant until 3 d after planting in soybean. The premixture will include diflufenican (WSSA Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15) (DFF-containing premixture), adding a new site of action for use in soybean throughout the United States. In 2022 and 2023, field trials were conducted …

Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King

Graduate Theses and Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats) is the most troublesome and problematic weed in most mid-southern U.S. row crop production systems. With the increased adoption of furrow-irrigated rice (Oryza sativa L.), there is a greater occurrence of Palmer amaranth due to sustained moist conditions allowing continual emergence of the weed throughout the growing season. Palmer amaranth has previously been shown to negatively affect crop yields when left unmanaged. Therefore, there is a high potential for rice yield loss due to the weed’s ability to emerge over an extended period and interfere with crop development. However, there is a lack of …

Evaluation Of A Capsule Suspension Formulation Of S-Metolachlor For Use In Fenclorim-Treated Rice And Wheat, Samuel Charles Noe

Graduate Theses and Dissertations

The continued evolution of herbicide resistance is one of the primary concerns facing Arkansas growers today. Problematic weeds such as barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] have evolved resistance to some of the most used herbicides in rice (Oryza sativa L.) and wheat (Triticum aestivum L.). To counteract this resistance, alternative herbicide sites of action should be explored. S-metolachlor is a very-long-chain fatty acid (VLCFA)-inhibiting herbicide [Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 15] commonly used in U.S. row crops to control grasses and small-seeded broadleaf weeds. …

Assessment Of American Tannin-Free Grain Sorghum As Feedstuff For Poultry: Nutrient Composition, Amino Acid Digestibility And Bird Performance, Santiago Sasia

All Dissertations

Given the rising cost of poultry diets, alternative ingredients like sorghum are crucial for maximizing returns without compromising product quality. Sorghum's drought tolerance and adaptability, along with its nutritional profile, make it a viable corn substitute. This dissertation examines the nutrient composition, amino acid digestibility, and performance of poultry fed with American tannin-free grain sorghum. Chapter II evaluates the impact of sorghum-based diets, with or without phytase superdosing, on broiler performance, including body weight, weight gain, feed intake, and feed conversion ratio. Results indicate that sorghum can replace corn without adverse effects on broiler performance. Chapter III explores the partial …

Using Machine Learning To Combine Genetic And Environmental Data For Maize Grain Yield Predictions Across Multi-Environment Trials, Igor K. Fernandes, Caio C. Vieira, Kaio O.G. Dias, Samuel B. Fernandes

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Complementing phenotypic traits and molecular markers with high-dimensional data such as climate and soil information is becoming a common practice in breeding programs. This study explored new ways to combine non-genetic information in genomic prediction models using machine learning. Using the multi-environment trial data from the Genomes To Fields initiative, different models to predict maize grain yield were adjusted using various inputs: genetic, environmental, or a combination of both, either in an additive (genetic-and-environmental; G+E) or a multiplicative (genotype-by-environment interaction; GEI) manner. When including environmental data, the mean prediction accuracy of machine learning genomic prediction models increased up to 7% …

Economics - The Neglected Dimension Of Pasture Disease R&D, N D. Macleod

IGC Proceedings (1977-2023)

Pasture utilisation underpins a significant contribution of livestock industries to Australia’s economic well-being. Pasture disease represents a direct threat to these enterprises but the economic magnitude of this threat remains largely unknown as the contribution of agricultural economics to pasture disease R&D, management and policy making has been minimal to date. Some insights to explain this apparent neglect are highlighted and a suggestion is made for a multiple disciplinary approach to R&D.

The 'Pendulum Paradigm' - Trends In Nitrogen Fertilizer Use On Temperate Grass/ Clover Pastures, R J. Eckard, F R. Mckenzie, P A. Lane

IGC Proceedings (1977-2023)

Nitrogen fertiliser responses, on perennial ryegrass (Lolium perenne) / white clover (Trifolium repens) dominant pastures, are compared between sub-tropical South Africa and temperate Australia. The data highlight the similarity in inflection point of the response curve, while emphasising the influence of high residual soil N at lower N application rates. The propensity of communities to oscillate between extremes in terms of N fertiliser use on intensive pasture, or the ‘Pendulum Paradigm’ is discussed. Particular reference is made to the dramatic increase in N fertiliser use in dairy pasture of temperate Australia and New Zealand. Emphasis is …

Linking Grassland And Range National Goals With The Grazing Lands Conservation Initiative For National Benefit, David B. Hannaway, Walter F. Wedin, Gerald W. Evers

IGC Proceedings (1977-2023)

Grassland and Range National Goals (GRNGs) were developed to identify national research and education needs for these resources, both public and private. The Grazing Lands Conservation Initiative (GLCI) developed within the NRCS to address the need for technical assistance for the management of privately held grazing lands. These activities are complimentary and, when combined, will address the national need for research, education, and technical assistance leading to better management of grassland and range resources.

The Effect Of Grazing On Etiolated Regrowth In Eight Grass Species, H A. Lardner, S.B M. Wright, R.D H. Cohen

IGC Proceedings (1977-2023)

Grazing by herbivores affects grass species both morphologically and physiologically. A grazing study was conducted on an irrigated pasture near Outlook, Saskatchewan, Canada during the summers of 1991 and 1992 to determine etiolated regrowth after grazing of reed canarygrass (Phalaris arundinacea L.), slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners subsp. trachycaulus), intermediate wheatgrass (Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. intermedium), orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus beibersteinii Roem. & Schult.), smooth bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea (Schreb.) Wimm.) and timothy (Phleum pratense L.) in …

A Vison Of The Future World Food Production And Implications For The Environment And Grasslands, Per Pinstrup Andersen, Rajul Pandya Lorch

IGC Proceedings (1977-2023)

Increases in world population, projected to rise to 8 billion by 2020, and the resultant demand for food places great pressure on our agricultural and aquacultural resources. Anxiety about the future is exacerbated by decreasing grain stocks. Production increases of many commodities are projected to be between 1 and 2% per annum and will generally be higher in developing than in developed countries. Cultivatable land area will increase in some areas of the world but not in others. To cope with these challenges, yield increases will be essential and the application of existing knowledge and technologies will not suffice. Accelerated …

Canada's Forage Resources, D Mccartney, P R. Horton

IGC Proceedings (1977-2023)

Canada is the second largest country in the world and stretches 5,500 km east to west and 4,600 km north to south. About 90% of Canada is uninhabited with 90% percent of the population living within 500 km of the Canadian-American border. About 60% of Canadians live in southern Ontario and Quebec. The grazing industry is located primarily in western Canada with British Columbia, Alberta, Saskatchewan and Manitoba having 84% of the national beef herd. Ontario and Quebec have 73% of the national dairy herd. The majority of harvested forage, dehydrated alfalfa and forage seed crops are grown in western …

Opening Ceremony Address By Chairman Of The Continuing Committee, T Nolan

IGC Proceedings (1977-2023)

Chairman and Vice-Chairman of the Board ofDirectors of the XVIII International Grassland Congress, Your Honour, Lieutenant Governor of the Province of Manitoba, Minister of Agriculture of the Province of Manitoba, Distinguished guests, members of the International Rangeland Congress, members of the International Grassland Congress, ladies and gentlemen. On behalf of the Continuing Committee, I am privileged to welcome you to the XVIII International Grassland Congress. What we will witness is the culmination of about six years of preparatory work by the Canadian Organising Committee and on your behalf! sincerely congratulate them for setting the basis for most interesting scientific and …

Closing Address: A Developing Country Perspective, Walter S. Alhassan

IGC Proceedings (1977-2023)

It is an honour to present this closing address for the XVIII International Grassland Congress and I do it on behalf of colleagues in Africa, Asia and South America. The thirty themes and over 800 papers presented reflect the growing complexity of our grasslands in shaping the general well-being of people on this planet. The XVIX Congress, to be held in Brazil in 2001, will move the frontiers of knowledge concerning sustainable use of grassland resources even further.

This address is being made from the perspective of developing countries that contain the majority of tropical pastures. This region of the …

Closing Address: The View From Outside, Allan Nation

IGC Proceedings (1977-2023)

Closing Address

The Xvii International Grassland Congress And Challenges For The Future Of Tropical Grasslands: A Developing Country Perspective, W S. Alhassan

IGC Proceedings (1977-2023)

All too soon we are to draw down the curtains on the XVIII International Grassland Congress and it is my pleasure and honour to contribute to the closing statements of this historic event, the first of its kind in Canada and one to bring us to the end of the present millennium as we as set the stage for the next. I do this on behalf of my colleagues in Africa, Asia and South America.

The thirty themes and the nearly 2000 technical presentations underscore the growing complexity of the role of our grasslands in shaping the general well-being of …

Congress Highlights From Perspective Of Temperate Regionsr, R J. Wilkins

IGC Proceedings (1977-2023)

This paper commences with brief reference to points made in the concluding paper at the XVI International Grassland Congress in Nice in 1989 (Wilkins, 1989) and then gives consideration in turn to technical advances reported in the Congress and to the future socio­ economic situation and its impact on research priorities. This is inevitably a personal view which does not give justice to the 800 or so papers presented at the Congress.

Forage And Animal Management Systems On Communal Rangelands In Arid And Semi-Arid Regions, Panjab Singh, A N. Ghosh

IGC Proceedings (1977-2023)

Grasslands and savannas, which comprise about 25% of the earth's land surface, are undergoing constant degradation, particularly in ar d and semi-arid regions. The rangeland resource is constantly sinking mainly because of its conversion to crop land, leaving farmer and pastorilist vulnerable to environmental extremes. This Paper presents the existing situation and the herbage and animal Product biomass of these regions. Climate and its impact on the Vegetation are discussed. Prevalent systems of rangeland use by sedentary and nomadic herdsman are considered and the constraints 0 the system are enumerated. Livestock 'rearing has been the most important occupation in these …

Wheat Response To Foliar-Applied Phosphorus Is Determined By Soil Phosphorus Buffering, Raj Malik, Craig Scanlan, Andrew Van Burgel, Balwinder Singh

Grain and Other Field Crops Research Articles

In no-till cropping systems, banding of phosphorus (P) fertiliser at seeding results in low use efficiency due to chemical reactions in soil. Foliar P has the potential to allow grain producers to respond tactically with P application after sowing when P supply from soil and fertiliser is not meeting crop demand. The objective of this study was to evaluate the effectiveness of foliar P on wheat grain yield, grain quality, biomass yield, P uptake and P use efficiency indices. Nine field experiments were conducted to investigate the response of wheat to foliar P. Three rates of P, 0, 2.5 and …

Autumn Grass Growth- The Effect Of Rest Interval, R Neilan, E G. O'Riordan, G Keane

IGC Proceedings (1977-2023)

The effect of closing dates (Experiment 1: August 1, August 14 and September 18) and grass regrowth interval (Experiment 2) on herbage yield in the autumn/winter and in the following spring were investigated on a previously grazed Lolium perenne sward. In Experiment 1, similar yields were obtained for the August 1 and August 14 closing. Yields decreased and the proportion of dead material increased from 0.19 to 0.61 between mid-October and late- December. In Experiment 2, dry matter yield increased linearly (P < 0.05) with rest interval up to 7 wks in swards closed in September. There was no significant yield advantage for rest intervals greater than 5-6 wks. It is concluded that accumulated autumn and spring yields showed increased DM production with the shorter regrowth intervals.

Improving Pasture Composition Increases Wool Returns In Eucalypt Woodlands, T J. Hall, R G. Silcock, J J. Sevil, J R. Van Der Meulen

IGC Proceedings (1977-2023)

A sheep grazing experiment in red earth Eucalypt country on semiarid pastures dominated by either Gayndah buffel grass (Cenchrus ciliaris) or wiregrass (Aristida jerichoensis) quantified liveweight, wool production and quality, and financial returns. Wethers were grazed at 0.32 and 0.6 ha/sheep. In year 1 there was no significant effect of either stocking rate or pasture type on liveweight or wool growth rate. Vegetable fault was greater in the fleeces from the wiregrass. The sheep grazing buffel grew better than those on wiregrass when stocking rates were doubled in year 2, while pasture yields remained high. The …

Responses Of Artemisia Herba-Alba Asso. And Its Associated Species To Grazing Frequency (Midelt, Morocco), M Mejjati Alami, O Berkat, C Bensalem

IGC Proceedings (1977-2023)

The objective of this study (conducted in 1994) was to assess the effects of season and grazing frequency (control, continuous, intermittent during 2 days per week) on vegetation attributes, and animal feeding behavior. Mean standing crop, for which Artemisia herba alba contributed 72%, attained 533 for the control while it was maintained at 394 and 322 Kg DM/ha, for the continuous and the intermittent grazing, respectively. Mean productivity of Artemisia herba alba varied according to treatment and had values of 5.3, 3.0 and 2.5 Kg DM/ha/day, under the ungrazed control, the continuous and the intermittent grazing regimes, respectively. Percent utilization …

Grazing Management Of An Italian Ryegrass Sward With Dairy Sheep In The Mediterranean Environment, M Sitzia, P P. Roggero, N Fois, G Molle

IGC Proceedings (1977-2023)

A grazing experiment was conducted in North-West Sardinia with the aim of testing the sward height as a mean to set up an efficient spring management of Italian ryegrass (Lolium multiflorum Lam.). Three fields were continuously grazed during spring 1992 by three groups of 12 dairy Sarda ewes, at three different sward heights (SH): 30 - 60 - 90 mm. The target sward height was obtained by continuously adjusting the field sizes. The results showed that the different grazing managements influenced the above ground biomass production and partitioning of the Italian ryegrass and the animal performances. During the vegetative …

Estimation Of Herbage Intake Of High Producing Milking Cows Under Intensive Grazing With A Supplementary Feeding Method In Northern Japan, K Ohiai, K Sudo, T Ikeda, T Honma

IGC Proceedings (1977-2023)

The objective of this study was to estimate the herbage intake and to assess a supplementary feeding method for high producing milk cows under intensive grazing. Eight high producing milking cows were grazed rotationally on perennial ryegrass (Lolium perenne L) dominant mixed pasture and on meadow fescue (Festuca elatior L) dominant mixed pasture, changing rotation period and grazing area ccording to seasonal pasture growth rate. Pasture intakes were estimated to be about 2% of body weight by TDN requirements estimation of animals. A supplementary feeding method is examined to be proper for high producing milking cows under …

Palatability Of Grasses And Grazing On Hungarian Grassland, Z Barcsak, I Kertesz, L Szeman

IGC Proceedings (1977-2023)

Grasslands provide the most basic and cheapest forage diet for cattle. The palatability studies were carried out on pure and mixed swards sown in 1990 on the GATE experimental farm. The studies involved the following 12 species: Lolium perenne, Trifolium repens, Festuca arundinacea, Festuca rubra, Poa pratensis, Festuca pratensis, Bromus inermis, Phalaris arundinacea, Lotus corniculatus, Agropyron crystatum, Dactylis glomerata and a mixed sward. During the study the morning and afternoon grazings were investigated with the involvement of 60 Limousin cattle. The following observations were made: 1. On the basis of our ethological observations regarding the bite rates the animals found …

Selective Sheep Grazing In An Heterogeneous Wheatgrass Dominated Pasture Related To Stocking Rate, G L. Siffredi, M A. Brizuela, M S. Cid, C Cangiano

IGC Proceedings (1977-2023)

It has been hypothesized that patch and community selection are driven by forage quality and/or quantity. We assess the relationship between vegetation characteristics and community and patch selection by sheep under continuous grazing at different stocking rates in an heterogeneous pasture. Our results suggest that when communities strongly differed in nutritive value sheep recurrently select the higher quality community in spite of its low biomass. However, sheep do not completely exclude the poorer quality community, generating a patchy vegetation pattern.

Grazing Management Of Elephant-Grass For Milk Production, F Deresz, L L. Matos

IGC Proceedings (1977-2023)

The objectives of these experiments were to study the effects of three resting periods (RP) of elephant-grass pasture on milk production and composition of Holstein-Zebu cows. These trials were carried out during two consecutive rainy seasons (December to May) using 24 cows in each year. They were randomly assigned by blocks according to milk yield and live weight (LW) to four treatments: 30- day RP with no concentrate (30N), 30-day RP with concentrate (30C), 36 and 45-day RP with C (36C and 45C) in the first year. In the second year the treatments were: 30C, 30N, 36N and 45N. Concentrate …

Comparison Of Yield, Forage Quality And Persistence Of 11 Grasses Grown With Irrigation In A Semi-Arid Climate, D E. Glover, G A. Kielly, R H. Cohen, P G. Jefferson

IGC Proceedings (1977-2023)

Nutritive quality of many grass species used for forage in the Northern Great Plains of Canada and the United States is not well documented, especially at different maturity stages. This study compared agronomic and forage quality characteristics of eleven grasses common to Saskatchewan. Botanical separation and quality analysis was undertaken at three growth stages. Meadow Brome (Bromus riparius), Russian Wildrye (Psathyrostachys juceus) and Altai Wildrye (Elymus angustus) were shown to have high leaf to stem ratios which corresponded with high protein levels. Separations showed persistence of Reed Canarygrass (Phalaris arudinaceus), Creeping Foxtail …

The Effect Of Grazing On Leaf Development In Eight Grass Species, H A. Lardner, S.B M. Wright, R H. Cohen

IGC Proceedings (1977-2023)

Grazing by herbivores affects grass species both morphologically and physiologically. A grazing study was conducted on an irrigated pasture near Outlook, Saskatchewan, Canada during the summers of 1991 and 1992 to determine morphological development of regrowth of reed canarygrass (Phalaris arundinacea L.), slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners subsp. trachycaulus), intermediate wheatgrass (Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. intermedium), orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus beibersteinii Roem. & Schult.), smooth bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea (Schreb.) Wimm.) and timothy (Phleum pratense L.) in order to …