Agronomy and Crop Sciences Commons^™

The Effects Of Titanium Dioxide Nanoparticles On The Growth And Development Of Sorghum Bicolor (L.) Moenech, Adam Gregory Shoemaker

Graduate Theses/Dissertations

Engineered nanoparticles (ENPs) have seen a drastic increase in their use over the past decade in various consumer products. ENPs will therefore enter terrestrial ecosystems and soils with increasing frequencies, yet research into the effects of ENPs on living organisms and crops is greatly lacking. Currently, there is only one major study reported on the effects of a single ENP, silver quantum dots, on Sorghum bicolor, the 5^th largest crop in the world. I examined the effects of a commonly used metal oxide nanoparticle, titanium dioxide (TiO₂), on the growth and development of sorghum grown in …

Control Of Volunteer Corn In Enlist Corn And Economics Of Herbicide Programs For Weed Control In Conventional And Multiple Herbicide-Resistant Soybean Across Nebraska, Adam Michael Striegel

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

With commercialization of multiple herbicide-resistant corn and soybean cultivars, producers have new management options for controlling herbicide-resistant weeds and volunteer corn. Corn-on-corn production systems are common in irrigated fields in southcentral Nebraska which can create issues with volunteer corn management in corn fields. Enlist corn contains a new multiple herbicide-resistant trait providing resistance to 2,4-D choline, glyphosate, and the aryloxyphenoxypropionate (FOPs). Field experiments were conducted in 2018 and 2019 at South Central Agricultural Laboratory near Clay Center, Nebraska with the objective to evaluate ACCase-inhibiting herbicides and herbicide application timing on volunteer corn control, Enlist corn injury, and yield. Glyphosate/glufosinate-resistant corn …

Buffalograss Diversity Assessment, Jesse Collin Marshall

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

Buffalograss [Buchloë dactylodes (Nutt.) Engelm. syn. Bouteloua dactyloides (Nutt.) Columbus] is a low input alternative turfgrass for the Great Plains region. Buffalograss is a dioecious stoloniferous warm season grass with wide variation of valuable traits and is well adapted for use in minimal maintenance landscapes. The obligate outcrossing nature of the species and wide variation of potentially valuable traits make buffalograss a prime candidate for cultivar improvement and genetic study. Limited information is available regarding buffalograss genetics. In effort to expand genetic resources around buffalograss, we developed buffalograss derived simple sequence repeat markers from previously available transcriptomes of buffalograss …

Impact Of Agricultural Land Use On Stream Nitrate, Phosphorus, And Sediment Concentrations At The Watershed And Field Scale, Brittany A. Kirsch

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

Water quality is directly impacted by the landscape through which it travels. As such, land use, including summer annual and winter annual/perennial agriculture, has dramatic influence on the water quality of downstream aquatic and terrestrial ecosystems. I examined the impact of agricultural land use on water quality through two projects, one at a watershed scale and one at a field scale. In my first project, I investigated the impact of agricultural land use and climate on water quality in 13 HUC10 watersheds across Nebraska using public data from US Geological Survey (USGS), US Department of Agriculture National Agricultural Statistics Service …

The Economics Of On-Farm Rice Drying In Arkansas, Clayton Parker

Agricultural Economics and Agribusiness Undergraduate Honors Theses

Globally, rice producers are faced with the temporal problem of deciding the optimal time to being rice harvest. When harvested, paddy rice is typically at a moisture content (HMC) between 15 and 22%. Upon delivery, the rice is subsequently dried by the mill to a moisture content (MC) of 12.5%. Riceland Foods Inc., the largest miller of rice in the world, uses a stair-step pricing model to charge farmers to dry in price/unit as the MC of grain decreases from a range of +22% to 13.5%. This study estimates an alternative linear relationship in the stair-step model to determine MC …

Resilience To Large, “Catastrophic” Wildfires In North America's Grassland Biome, Victoria M. Donovan, Dirac Twidwell, Daniel R. Uden, Tsegaye Tadesse, Brian D. Wardlow, Christine H. Bielski, Matthew O. Jones, Brady W. Allred, David E. Naugle, Craig R. Allen

Department of Agronomy and Horticulture: Faculty Publications

Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While numerous studies have emphasized the benefits of fire to ecosystems, large wildfires have also been associated with the loss of ecosystem services and shifts in vegetation abundance. The size and number of wildfires are increasing across a number of regions, and yet the outcomes of large wildfire on vegetation at large‐scales are still largely unknown. We introduce an exhaustive analysis of wildfire‐scale vegetation response to large wildfires across North America's grassland biome. We use 18 years of a newly released vegetation data set combined with 1,390 geospatial …

An Evaluation Of Biopesticide Combinations On Yield Performance And Disease/Arthropod Control Of Strawberries Grown In High Tunnel Plasticulture Production Systems In Arkansas., Karlee B. Pruitt

Graduate Theses and Dissertations

This two-year study investigated combinations of biopesticides to determine impacts on strawberry fruit marketable fruit yields, and effectiveness in controlling strawberry pests in a high tunnel production system at the University of Arkansas, Division of Agriculture Research and Extension Center in Fayetteville, Arkansas. Two strawberry cultivars Fragaria × ananassa (Duch.), Camino Real and Sweet Sensation were grown in a high tunnel from early-October to mid-May for two consecutive growing seasons, (2017-18 and 2018-19) with six treatment combinations of biopesticides including an untreated (water) control, nutrient spray and selected biological based fungicides and insecticides, arranged into a split-plot randomized block design. …

Florpyrauxifen-Benzyl Use In Arkansas Rice (Oryza Sativa L.), Hannah Elizabeth Wright

Graduate Theses and Dissertations

Florpyrauxifen-benzyl is a synthetic auxin herbicide which was commercially released in 2018 to combat troublesome grass, broadleaf, and sedge weed species in rice. Many factors may influence cultivar response to a new herbicide; hence, it is important to understand factors contributing to crop sensitivity to an herbicide in order to make appropriate recommendations. Prior to the onset of this study, research had been conducted on florpyrauxifen-benzyl in a flooded environment; however, none had been executed in a non-flooded environment. Experiments were conducted to evaluate the response of a long-grain variety ‘CL111’, a medium-grain variety ‘CL272’, and a long-grain hybrid ‘CLXL745’ …

Comparison Of Soil Sampling Techniques For Alkaline Hydrolyzable-Nitrogen On Clay Soils, Jarom T. Davidson, Trenton L. Roberts, Jarrod T. Hardke, Nathan A. Slaton, Anthony Michael Fulford

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The Nitrogen-Soil Test for Rice (N-STaR) provides a site-specific N rate recommendation by quantifying alkaline hydrolyzable-N (AH-N). A user-friendly method for obtaining a representative N-STaR soil sample is needed, and this study was designed to evaluate the performance of alternative sampling techniques compared with the Dutch auger (DA). The alternative techniques included a Kleen Hole Spade dry (KHS-D), a KHS lubricated with water (KHS-W), a KHS lubricated with WD-40 (KHS-40), and the N-STaR Bucket and Drill (BD). One soil sample was collected with each sampling technique from four blocks and was repeated across 14 sites. Each sample was analyzed for …

Hydroponic And Soilless Culture Systems And Transplant Practices Influence Production Of Basil (Omicum Basilicum L.), Samuel Warren Edward Doty

Graduate Theses and Dissertations

Two controlled-environment greenhouse experiments evaluated (1) plant growth and morphology of basil (Omicum basilicum L.) grown in three different hydroponic and soilless substrate systems and (2) seedling tray cell-count and transplant date into hydroponic culture effects on basil growth and yield at harvest. For the first experiment, four basil cultivars (‘Genovese’, ‘Mrs. Burns Lemon’, ‘Sweet Thai’, and ‘Cinnamon’) were grown in deep flow technique (DFT) hydroponics, nutrient film technique (NFT) hydroponics, and a novel shallow aggregate ebb-and-flood (SAEF) soilless substrate system and were harvested after 21 d. Plant yield and morphological characteristics measured at harvest included shoot fresh mass, shoot …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2019, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Elucidating Basis Of Rice Discoloration And Developing Prevention Strategies, Zeinab Mohammadi Shad

Graduate Theses and Dissertations

Economically, discolored rice kernels have less market value, which can seriously impact farm net profit. The reasons for rice discoloration during storage have not been studied extensively and many questions remain. Therefore, the primary goal of this study was to improve understanding of the role and contributions of storage practices on rice quality degradation and discoloration. In this study, three rice cultivars including XL753 (hybrid), Roy J (pureline), and Titan were assessed for changes in quality and microbial kinetics. The rice samples at a high moisture content (MC) of 21% w.b. and a low MC of 16% were stored at …

Determining Cluster Thinning And Storage Effects On Fruit Quality And Marketability Attributes Of Arkansas Table Grapes Grown Under High Tunnel Systems., Virginia Beasley

Graduate Theses and Dissertations

Table Grapes (Vitus vinifera) are highly valued horticulture crops world-wide. Often, table grape production in the southern United States is restricted due to climate and pest issues. Viticulture production could be expanded to this region by the use of controlled environment growing systems, such as high tunnels (HT). The objective of this project was to evaluate the effectiveness of HT systems for grape cultivation and compare the effects of different cluster thinning treatments on vines. In this two-year study, the cultivars Faith, Gratitude, Hope, and Jupiter were grown in HT systems and assessed for postharvest qualities at harvest and during …

An Evaluation Of Unmanned Aircraft Systems' Ability To Assess Stripe Rust In Large Wheat Breeding Nursies, Jamison T. Murry

Graduate Theses and Dissertations

Stripe Rust (Puccinia striiformis f. sp. tritici) is a foliar disease that significantly impacts global wheat production, and resistant cultivars provide the most efficient method of control. High-throughput phenotyping using unmanned aircraft systems (UAS) offers a potentially more efficient method for field-based phenotyping compared to visual assessment. Here we tested the ability of remote sensing to predict stripe rust severity in a diverse population of 594 soft red winter wheat lines, planted in single-rows, and evaluated them by visually rating stripe rust intensity and remotely using the dark green color index (DGCI), normalized difference vegetation index (NDVI) and blue NDVI. …

Use Of Acetolactate Synthase-Inhibiting Herbicides In Inzen Grain Sorghum (Sorghum Bicolor L. Moench Ssp. Bicolor), Hunter Bowman

Graduate Theses and Dissertations

Grain sorghum is typically grown as a rotational crop in Arkansas because of its many benefits, one being the effective control of Palmer amaranth through the use of atrazine. However, limited options exist for postemergence (POST) control of weedy grasses within the crop. Inzen™ grain sorghum is the result of a nicosulfuron resistant weedy sorghum biotype cross-bred with a commercial line of grain sorghum. Inzen™ allows for safe use of over-the-top applications of nicosulfuron within the crop. Nicosulfuron is an acetolactate synthase (ALS)-inhibiting herbicide, which has historically been used in corn for control of weedy grasses. Experiments were conducted in …

Determination Of Critical Y-Leaf Potassium Concentrations Across Reproductive Growth Stages For Direct-Seeded Delay-Flooded Rice, Chandler Edwin Gruener

Graduate Theses and Dissertations

Rice (Oryza sativa L.) grain yield can be limited by potassium (K) deficiency on soils low in exchangeable K. Visually diagnosing K deficiency during early reproductive growth is not easily done and the interpretation of traditional tissue analysis is limited to select growth-stages. Our primary focus was to define continuous critical Y-leaf-K concentrations during reproductive growth for the production of maximal grain yield. A secondary objective was to examine Y-leaf sap-K concentration, measured using a handheld device, as a rapid in-field method of monitoring rice plant K nutrition. The Y-leaf is defined as the uppermost fully extended leaf with a …

Midseason Nitrogen Sufficiency Guidelines For Corn Production In Arkansas Based On Tissue Analysis And Remote Sensing, Caio Luiz Dos Santos

Graduate Theses and Dissertations

There are a lack of tools to assess midseason nitrogen (N) status in corn (Zea mays L.) production systems and identify the need for additional N fertilization. This study was conducted to determine the ability of leaf N concentration (LN) and the Dark Green Color Index (DGCI) at the 10th collared leaf stage (V10), the 12th collared leaf stage (V12), and tasseling (VT) to predict if midseason N is required to maximize corn grain yield. From 2017 to 2019, eight field studies with 11 N treatments ranging from 0 to 258 kg N ha-1 were conducted on silt loam soils …

The Australian Pastures Genebank, Steve Hughes

IGC Proceedings (1977-2023)

Australian grazing enterprises, including all food and fibre productions, as well as crop rotation, are worth $42 billion per annum to the Australian economy, employing around 693,000 Australian workers. Australia has been a major beneficiary from the introduction and utilization of genetic resources in pasture and forages. Assured access to plant genetic diversity underpins Australia’s ability to maintain agricultural productivity in the face of environmental and economic challenges.

Australia is custodian of potentially the world’s largest and globally significant collection of pasture and forage genetic resources. Much of this is unique and held in state-based collections and represents an invaluable …

The Landscape As A Unit For Rangeland Inventory In Arid And Semi-Arid Regions Of Iran (Case Studies: Touran Biosphere Reserve And Behkadaye Rajinia Development Project), Mansour Mesdaghi

IGC Proceedings (1977-2023)

Severe land fragmentation, degradation, and pollution problems will force us to think about a rural community and research group in Iran to combine our experiences and skills to deal with the challenges of improving land use sustainability (Bosch at el.1995; Mesdaghi, 1993). Planning rangeland inventory requiring recognition of the ecological processes operating at different scales and their particular characteristics (Friedel and Laycock, 1995).

In ancient countries like Persia (Iran), past land use suggests that rangelands exploitation by local herders was co-adapted with natural environments (Nyerges, 1980; Mesdaghi, 1993). Iranian rangelands, however, were nationalized through the land reforming and the …

Livestock Grazing In India: Policy Issues, M. M. Roy

IGC Proceedings (1977-2023)

The grazing/range lands have been very important in India since ancient times when cattle breeding and milk production was regarded as the second most important profession, next only to agriculture. However, during last five decades increasing domestic animal population has placed enormous grazing pressure on such lands, leading to grassland deterioration and desertification especially in arid and semiarid regions (GOI, 2007; Kala, 2009).

Still, grazing based livestock play an important role in rural economy of the as well over 50 per cent of them depend on grazing (of varying degrees) in forests, community lands and other lands in many parts …