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Evaluating Bluebunch Wheatgrass Plant Materials For The Central Great Basin And Range, Mckenna Delton

All Graduate Theses and Dissertations, Fall 2023 to Present

Bluebunch wheatgrass is a perennial grass from North America’s Intermountain West. This area has faced many ecological disturbances, including dryland farming, wildfire, and grazing. These have led to a decline in the populations of native perennial grasses. While bluebunch used to be widespread throughout the region, it often cannot compete with some non-native grasses that are better adapted to these disturbances. Therefore, there is a demand for bluebunch wheatgrass plant materials that have undergone selection for overall better performance in restoration.

Most existing plant materials for bluebunch wheatgrass come from the Columbia Plateau region, but interest is growing in new …

Investigating The Adaptive Potential Of Leaf Variegation In Two Dimorphic Hexastylis Species, Cierra N. Sullivan

All Dissertations

Variegated leaves with disjointed, patterned coloration of the leaf blade are often hypothesized to have decreased photosynthetic capacity in comparison to uniformly colored leaves. Yet, many forest understory plants in tropical, subtropical, and temperate climates possess leaf variegation. Moreover, mixed findings from previous research on the physiological impacts of leaf variegation suggest variegation is adaptative under certain environmental conditions despite decreased photosynthetic tissue area. I take an eco-physiological approach to investigate agents of selection maintaining a leaf variegation polymorphism in Hexastylis, which has both quantitative and qualitative variation in variegation. First, I conduct field surveys of morph frequencies, quantitative …

Factors Influencing Adventitious Root Formation Of Floral Hemp In Propagation, Alexandra Carver

All Theses

Commercial propagators have reported relatively poor propagation success, e.g., <75% rooting, for many hemp (Cannabis sativa) cultivars. These rooting percentages have a significant economic impact due to the wasted labor, space and supplies. Also, the market demands 100% of the propagation cells in a tray to be fully rooted, thus repairing and replacing poorly rooted or unrooted cuttings requires significant labor cost. The goal of this thesis was to evaluate several factors that influence adventitious root formation of hemp stem cuttings.

Chapter 2 describes an experiment conducted to identify rooting hormone treatments that could improve propagation success. Sixteen combinations of indole-3-butyric acid (IBA; 0, …

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 …

Investigating The Etiology, Epidemiology, And Ecology Of Blackberry Yellow Vein Disease In South Carolina, Wanita Dantes

All Dissertations

Blackberry production is growing in popularity in the southeastern U.S. However, blackberry growers in this region report major problems with productivity and longevity due to viruses. First, the state of knowledge on blackberry yellow vein disease (BVYD) complex, associated with mixed infections of a diverse group of viruses, is discussed. Specific viruses associated with symptom types are unknown. Therefore, the etiology of BYVD is not fully understood, which makes BYVD diagnosis challenging. My research focused on improving BYVD diagnosis, etiology, and epidemiology. Second, I developed a farm-level diagnostic protocol to improve virus disease surveillance. High throughput sequencing detected 17 known …

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 …

Developing A Comprehensive Genome-Scale Metabolic Model For The Arabidopsis Thaliana Root System, Lohani Esterhuizen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Arabidopsis thaliana (Arabidopsis) is the most well-established model plant to date. Being the first plant to have its genome mapped, studies on Arabidopsis have provided insurmountable insights into the physiological and biochemical nature of plants. Methods that allow us to computationally study the metabolism of organisms include the use of genome-scale metabolic models (GEMs). Despite its popularity, no GEM currently maps the metabolic activity in the root system of Arabidopsis, which is the first organ to face and respond to stress conditions in the soil. This work aims to develop and implement a comprehensive GEM of the Arabidopsis root system …

The Impact Of Ectopic Expression Of A Plant Elicitor Peptide In Bacillus Subtilis On Nematode Resistance In Soybean Through Seed Treatment, Abeer Alnasrawi

Graduate Theses and Dissertations

Soybean (Glycine max) is the most beneficial legume crop because it is a source of protein as well as oil for humans and livestock. Soybean is the second most planted crop in the United States following corn and it is also the fourth planted crop worldwide. However, the soybean cyst nematode (Heterodera glycines, SCN) is the most damaging pest of soybean in the United States, accounting for more than twice as much yield loss as the following cause of yield loss in soybean. Therefore, there is a pressing need to develop alternative management strategies to control SCN infection in soybeans. …

B.R. Wells Arkansas Rice Research Studies 2023, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading rice producer in the United States. The state represents 49.0% of total U.S. rice production and 49.6% of the total acres planted to rice in 2023. Rice cultural practices vary across the state and across the U.S. However, these practices are also dynamic and continue to evolve in response to changing political, environmental, and economic times. This survey was initiated in 2002 to monitor and record changes in the way Arkansas rice producers approach their livelihood. The survey was conducted by polling county extension agents in each of the counties in Arkansas that produce rice. Questions …

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 …

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 …

Cherry Powdery Mildew In Utah, Marion Murray, Christina Lilligren, Megan Kast

All Current Publications

This fact sheet provides information on powdery mildew, a common problem in commercial tart and sweet cherry orchards in Utah and throughout the western U.S. Hosts, disease biology, symptoms and signs, and management are covered.

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 …

Lure Specificity, Phenology, And Damage Caused By Epiphyas Moths (Lepidoptera: Tortricidae) In Western Australian Apple Orchards, Maryam Yazdani, Elliot T. Howse, Wee Tek Tay, Helen Spafford, Rieks Van Klinken

Horticulture Research Articles

Multiple Epiphyas species inhabit southwestern Western Australia, including Light Brown Apple Moth (LBAM) Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), a globally significant, polyphagous pest. This study evaluated the efficacy and specificity of lures designed for 3 Epiphyas species: E. postvittana, Epiphyas pulla (Turner), and the undescribed Epiphyas sp. (1) (Common). Additionally, the study sought to determine the presence and distribution of Epiphyas species in 3 significant apple-growing localities. Trapping, together with partial sequencing of the mitochondrial COI gene, found LBAM to be restricted to the Perth Hills and E. pulla, to apple orchards near Manjimup and Pemberton. This geographic …

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 …