Agronomy and Crop Sciences Commons^™

European Corn Borer Management In Field Corn, Igor Sulzbacher Schardong, Francis Reay-Jones

Agronomic Crops

In the past, European Corn Borer (ECB) was considered a billion-dollar pest. Bt corn was first released in 1996 and its widely adoption reduced ECB populations and economic importance. Resistance to some Bt toxins was detected in Canada, representing a possible threat to corn production. In this paper, we reviewed potential management tactics for ECB in corn.

Field Pea (Pisum Sativum L.) Response To Planting Date In South Carolina Organic Cropping Systems, Tristan Lawrence

All Theses

Field peas (Pisum sativum L.) are not widely cultivated in South Carolina, resulting in limited agronomic data to support farmers interested in this crop. However, field peas hold significant promise as a cool season crop for both organic and conventional growers in the region. Most commercially available field pea cultivars are evaluated and bred for the Pacific Northwest, where environmental conditions differ substantially from those in the southeastern United States. Consequently, there is a lack of region-specific recommendations for successful cultivation in South Carolina. To address this gap, a two-year planting date study was conducted during the …

Breeding For Disease Resistance In Melon And Watermelon, Venkata Rao Ganaparthi

All Dissertations

Watermelon and cantaloupe are two widely consumed cucurbits, but their acreage in the United States reduced by nearly 50% in last two decades. Fusarium wilt caused by a soil borne pathogen Fusarium oxysporum f. sp. niveum(Fon) race 2 is a major limiting factor in watermelon production as it reduces yields by 80%. Grafting watermelon plants onto the root stock of wild, disease-resistant varieties like ‘Carolina Strongback’ is the best strategy to manage Fon race 2. Though effective, this approach increases production costs.

Part of this dissertation focused on finding more sustainable, cost-effective solutions to control Fusarium wilt …

Assessing Grafted Triploid Watermelon And Yellow Nutsedge Growth In Saline Agroecosystems, Joseph F. Bazzle

All Theses

In an effort to better understand how saltwater intrusion events will impact watermelon growers a field trial was conducted to study how saline irrigation water will impact weed growth and seedless watermelon productivity at a joint Clemson University and USDA ARS facility. Weed management has always been a hurdle in vegetable crop production systems, requiring extensive labor even in a conventional setup. For organic growers, often the only economical approach is a combination of mechanical weed control techniques, including plastic mulches, tarps, and hand weeding. For watermelon growers, plastic mulch remains the most effective form of organic weed control available. …

The Effects Of Incremental Application Of Chemical Defoliants On Cotton Fiber Quality, Aashish Karki

All Theses

Leaf shedding is a natural process as cotton matures; however, this does not synchronize with harvest timing; therefore, defoliants are used to remove these leaves and improve harvestability of the bolls. A tractor-mounted boom sprayer is typically used to apply defoliants. However, this approach results in low penetration to the bottom canopy, poor defoliation, and, consequently, lower fiber quality. An autonomous robotic spraying system equipped with pulse width modulation technology enables targeted side-spraying of defoliants, overcoming the limitations of conventional over-the-top applications. However, limited information on staggered defoliation timing and its effect on cotton fiber quality is available. Thus, field …

Maximizing Crop Production And Profitability Through Double Cropping Corn And Soybean Systems In South Carolina, Bennett Harrelson

All Dissertations

Profitability is critical for farm sustainability, efficiency, and longevity. Over the last decade, corn and soybean commodity prices have fluctuated considerably, and more recently, extreme increases in input prices have narrowed profit margins. Non-traditional cropping systems that can boost profit are becoming of interest to farmers in South Carolina, specifically double cropping soybean behind corn. In this scenario, corn is harvested at high moisture contents and followed by ultra-late planted soybean. However, prior research related to the agronomic production practices of double cropping corn and soybean is minimal. To develop best management practices for growers interested in double cropping corn …

Identification Of New Germplasm Sources And Traits For Breeding Heat-Tolerant Soybean Varieties, Shelby Hammond

All Theses

The heat-tolerant soybean breeding is constrained by limited genetic diversity for heat tolerance, lack of efficient selection criteria, and incomplete knowledge of heat tolerance mechanisms. The objectives of this study were to characterize the heat tolerance of a soybean recombinant inbred line (RIL) population based on traits defining leaf function, pollen viability and yield, and identify genotypes and traits that can be included in breeding programs for heat tolerance. Field trials were conducted at Pendleton, SC in 2022 and 2023 to test the heat stress responses of 192 RILs [derived from DS 25-1 (heat tolerant) x DT97-4290 (heat-susceptible)], parental lines, …

Anaerobic Soil Disinfestation As A Non-Chemical Management Option Against Fungi And Heterotrophic Bacteria In Organic Sweetpotato Production, Meredith Tucker

All Theses

North Carolina is the largest producer of sweetpotatoes in the United States, with South Carolina increasing farming acreage to 2,501 in 2022 compared to 1,300 in 2017. Growers producing conventional and organic sweetpotatoes are equally challenged with managing fungal pathogens due to fungicide resistance or fungicides being unavailable due to environmental regulations, leading many to shift to growing organic crops. Anaerobic soil disinfestation (ASD) is a non-chemical pre-plant management option that uses a carbon amendment, irrigation, and plasticulture to establish an anaerobic environment in soils, killing soil microbes. A greenhouse study was conducted to assess ASD on fungal pathogens and …

Understanding The Genetic And Metabolic Underpinnings Of Complex Traits In C4 Grasses, Manwinder Singh Brar

All Dissertations

Maize (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) are two important cereal crops cultivated worldwide for food, animal feed, and industrial products. Productivity of these crops is significantly impacted by various biotic and abiotic stresses, such as diseases, insect pests, drought, salinity, and heat. Among factors influencing crop performance under stress, the regulation of leaf longevity plays a critical role in determining yield. Leaf senescence is a highly regulated process essential for nutrient remobilization through the degradation of cellular components in aging leaves, but premature or accelerated senescence reduces photosynthetic efficiency and yield. Staygreen, a phenotype …

Investigate The Use Of Nucleic Acids As Pesticides To Manage Major Pests And Pathogens Of Crops In South Carolina, Prasanna Valavanur Shekar

All Dissertations

The sugarcane aphid (SCA, Melanaphis sorghi), first discovered on grain sorghum in late 2013, has gradually become a major insect pest of sorghum. It inflicts significant damage to the crop year after year, causing millions of dollars in losses throughout the sorghum-producing regions of the United States. Similarly, Armillaria root rot—also referred to as oak root rot—is a major cause of decline in peach (Prunus persica) production in the southeastern United States. This disease is caused by Armillaria mellea and Armillaria tabescens. Current management practices for controlling M. sorghi include the use of synthetic pesticides, resistant varieties, and regular scouting. …

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 …

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 …

Selecting Fertilizer Mixtures For Fertigation, Bhupinder Jatana, Tom Grayson Sanders Iii

Horticulture

Depending upon the physio-chemical properties of the fertilizer solution, many fertilizers, both solid and liquid, are suitable for fertigation (application of fertilizer dissolved in irrigation water). However, some fertilizer materials are incompatible with concentrated solutions, can react with minerals in irrigation water, or with pesticides in tank mixes, and form insoluble compounds and precipitates. Precipitation of fertilizers renders them unavailable for plant uptake and could further clog the micro-irrigation systems. This article talks about fertilizers, fertilizer formulations, fertilizer compatibility, and criteria for selecting fertilizer mixtures for fertigation. This information will be helpful for growers utilizing fertigation as a means to …

Yield And Nutritive Quality Of Fresh And Ensiled Reduced Lignin Alfalfa In Monoculture And Diculture With Novel Tall Fescue, Morgan Boss

All Theses

The objectives of this research were to: (1) evaluate the yield, nutritional value, and digestibility of fresh and ensiled reduced lignin alfalfa (RLA; Medicago sativa L.) in monoculture and when mixed with novel endophyte-infected tall fescue (F; Festuca arundinacea) in comparison to a conventional alfalfa (CA) cultivar; and (2) evaluate ensiled samples under varying DM concentrations; with or without inoculant. A trial was prepared as a randomized complete block design with 4 replicates per treatment. Treatments included reduced lignin alfalfa (RLA), conventional alfalfa (CA) and tall fescue (F) plots as well as RLA/F and CA/F plots. Plots were harvested on …

Cover Crops Integration With Nitrogen Management For Dryland Cotton In Sandy Ultisols, Swabir Alhassan Musah

All Theses

One of the many benefits of cover crops (CCs) is nutrient provision, which can be optimized by synchronizing the nutrient release from residue decomposition with the demand for subsequent cash crops. This study is part of a multistate research (13 states) to measure cotton lint yield in response to cover cropping as a nutrient management strategy. This research-based information will help farmers optimize nitrogen (N) fertilization when integrating CCs into their production systems. A two-year field trial was conducted in 2021 and 2022 with four cover crop treatments (cereal rye, crimson clover, mixtures of cereal rye and crimson clover, and …

Breeding Cotton For Determinate Growth Habit: Increasing Cotton Fiber Yield By Remobilization Of End-Of-Season Perennial Reserves, Salman Naveed

All Dissertations

Cotton (Gossypium spp.) is a major export commodity for the U.S. Despite advances in plant breeding and management practices, the cotton yield gains in the U.S. have stagnated. Therefore, to increase cotton fiber yield, we undertook a novel approach by altering the growth habit of cotton from perennial to annual. In this effort, eight genotypes showing strong expression alleles for five floral induction and meristem identity genes were selected from 44 Upland cotton mini-core collection genotypes and genetically crossed in various combinations to stack the strong expression alleles in a genotype. These efforts have allowed us to develop high-yielding, …

Heat Stress-Induced Lipid Alterations In Peanut, Walker Spivey

All Theses

Peanut (Arachis hypogaea) is a globally important crop cultivated for human consumption and for the production of seed oil. As anthropogenic climate change continues to challenge global crop production with extreme environmental conditions such as high temperatures, the development of heat-tolerant varieties is crucial to meet peanut production demands. At the cellular level, one of the fundamental causes of yield loss at high temperatures (HT) is membrane damage. This work reports the investigations on a subset of a peanut recombinant inbred line population demonstrating that the membrane lipid remodeling occurring at HT is consistent with homeoviscous adaptation to …

Evaluating The Effect Of Biochar Soil Amendments On Belonolaimus Longicaudatus Populations Damaging Bermudagrass In South Carolina, Malone Thomason

All Theses

Belonolaimus longicaudatus Rau, (1958) (sting nematode) is a prevalent plant-parasitic nematode found in association with Cynodon spp. (bermudagrass) in South Carolina (Ye et al., 2012). Due to the persistence of the pest, long-term management strategies are necessary. Applications of biochar and compost amendments have reduced nematodes in various crop systems, but research on turfgrass systems is limited. The objectives of the studies were to determine: (1) The effect of topdressing or soil incorporated biochar amendments on sting nematode populations, and (2) The effect of topdressing or soil incorporated amendments on turf quality. A field study was established to examine topdressings …

Survey And Prevalence Of Palmer Amaranth Herbicide Resistance In South Carolina, Mitchell Williams

All Theses

Palmer amaranth is a troublesome weed for growers to control, not only due to its aggressive growth characteristics that limit row-crop production, but because of its resistance to different herbicide modes of action. The first case of herbicide resistance in Palmer amaranth was detected in 1989 and has since grown to nine different herbicide classes throughout the United States. New herbicide modes of action have not been developed since the 1980s, so proper stewardship of the remaining modes of action is important for effective control of Palmer amaranth. Increased herbicide resistance from states bordering South Carolina have been reported; therefore, …

Winter Cover Crop Performance In The Southern Piedmont Region Of South Carolina, Payton Davis

All Theses

Cover crops (CC) offer in-field and environmental benefits when integrated into cropping systems. Low CC adoption in the southern Piedmont of South Carolina is partially due to the lack of information on CC performance and benefits within the region. To address this, eight winter CC and a fallow/pigweed treatment were investigated for their influence on soil temperature, volumetric water content (VWC), percent cover, biomass, and the occurrence of soil water repellency (SWR). A randomized complete block design experiment was conducted in the fall and winter of 2021-2022 (EXP A) and repeated in 2022-2023 (EXP B). Cover crops minimally influenced soil …

Precision Management Of Inputs In Cotton And Soybean Production In South Carolina, Kyle Smith

All Theses

The adoption of precision agriculture technologies and developing specific product use recommendations in cotton and soybean production could help farmers reduce input costs and optimize overall farm profitability. The objectives of this research were to evaluate whether or not the use of variable rate seeding in cotton could increase profitability and to determine the rainfast interval of commonly used insecticides in cotton and soybean production. The first trial, variable rate seeding in cotton, was implemented at the Edisto Research and Education Center near Blackville, SC across five years to evaluate variable rate seeding in cotton. Results from trials in South …

Influence Of Potassium Fertilizer Application Timing On Cotton Production As Related To Soil Potassium On U.S. Coastal Plain Soils, Shruthy Suresh Kumar

All Theses

Understanding soil K dynamics is highly significant in cotton production owing to its prominent role in cotton fiber quality. About 31 % of cotton production in the U.S. is concentrated in SE states, with coastal plain soils having low innate K availability. Crop fertilizer-K recommendations are primarily made worldwide and across the U.S. using pre-plant STK concentrations. A literature review on cotton K studies suggests that fertilizer-K recommendations based on pre-plant STK concentrations alone need fine-tuning to meet the increasing K demands in modern cultivars, variations in crop K requirement patterns, and varied soil K supplying capacity. Studies have been …

Influence Of Cover Cropping And Nitrogen Fertilization On Soil Properties And Cotton Productivity, Christianah Oladoye

All Dissertations

Conservation practices with cover crops have proven to be effective in nutrient enrichment, increased yield, and environmental stability. Field studies were conducted from 2019 to 2022 to evaluate the short-term effect of No cover crop [NC], RYE, a mix of rye + vetch [R+V], and mix of five species (radish, rye, vetch, clover, and lupin) [5W] on short term soil physical, chemical properties, cotton growth, and lint yield. Cover crops were planted in November and terminated in May of each year. Soil dry and wet aggregate fractions (0-0.05 m) and soil compaction (0-0.4 m depth) were measured at termination. The …

Alfalfa Establishment And Management In South Carolina, Liliane Silva, Michael Mrshall, Jeremy Greene, Matias Aguerre

Livestock and Forages

Alfalfa is a perennial legume with high forage quality that can be used under grazing or hay management. This publication outlines establishment and management recommendations for alfalfa plantings in South Carolina.

Cover Cropping To Improve The Sustainability Of Agronomic Production Systems, Ricardo St Aime

All Dissertations

The adoption rate of cover cropping among farmers in the Southeast is low due to the lack of knowledge regarding the suitable cover crop species and their management practices and the concerns of resource depletion for the subsequent cash crop. To generate information addressing the above knowledge gap, the present research was conducted with the following objectives: (1) to determine the optimal planting method for winter cover crops in the upstate of SC and whether it is influenced by the seeding rates (Project-1); (2) to determine suitable winter cover crops for the region based on biomass production, water use efficiency …

Recapture And Reuse Of Nitrogen And Phosphorus From Rendered Animal Materials To Enhance Nutrient Use Efficiency And Produce Quality In Agricultural Crop, Bhupinder Jatana

All Dissertations

The current fertilizer regime heavily relies on inorganic fertilizers to meet the crop nitrogen (N) and phosphorus (P) demand. However, the United States has a limited N production capacity, with 50% N demand met through imports. On the other hand, the nonrenewable natural reserves of P are being depleted at an unprecedented rate and are expected to be exhausted with in next 100 years. Additionally, high solubility/liability of the field applied inorganic fertilizers often results in lower nutrient use efficiency (NUE;

The MBM led to rapid N mineralization, with 35% of the applied N mineralized within the first five days …

Fungicide Resistance In Botrytis Cinerea From Strawberry - Molecular Mechanisms And Management, Anja Grabke

All Theses

The United States is the largest producer of strawberries worldwide, generating approximately $2.4 billion worth of fruit each year. Strawberry production, however, is often threatened by pathogens. One of the most destructive fungal pathogens is Botrytis cinerea, the causal agent of gray mold disease. The control of gray mold in commercial fields is largely dependent on the application of fungicides, including the dicarboximide iprodione and the hydroxyanilide fenhexamid. Because both fungicides are prone to resistance development, a survey was conducted to determine the occurrence and prevalence of fungicide resistance. Single-spore isolates were collected from strawberry fields in Florida (for …

Glufosinate Tolerance Of Widestrike And Liberty-Link Cotton Varieties And The Recoverability Of Upland Cotton Following Terminal Removal, Jason Sweeney

All Theses

Sweeney, Jason Allen. Glufosinate Tolerance of WideStrike¨ and LibertyLink¨ Cotton Varieties and the Recoverability of Cotton Following Terminal Removal. (Under the direction of Dr. Michael A. Jones).
To evaluate the effects of topical application of glufosinate (Liberty 280SL, 24.5% glufosinate-ammonium salt) on cotton varieties with WideStrike¨ and LibertyLink¨ technologies, two field experiments were conducted in 2011 and 2012 at the Pee Dee Research and Education Center (PDREC) in Florence, SC. In the first experiment, five WideStrike¨ cotton varieties (Phytogen [PHY] 367WRF, PHY 375WRF, PHY 440W, PHY 499WRF, and PHY 565WRF) and three LibertyLink¨ cotton varieties (FiberMax [FM] 1773LLB2, FM 1845LLB2, …

Effects Of Varying Spring Hollow Tine Aerification Size And Timing On Bentgrass Greens, Lewis Hubbard Jr

All Dissertations

The desire to maintain optimal turfgrass and surface properties often leads turfgrass managers to minimize impact from cultural practices like hollow tine aerification (HTA). Comprehensive research is essential to developing aerification programs which allow optimal use of turfgrass surfaces without sacrificing overall turf health.
A two-year field experiment was conducted on a 14-year-old U.S. Golf Association (USGA)-specified Crenshaw creeping bentgrass [Agrostis stolonifera L. var palustris (Huds.)] research putting green in Clemson, SC, to evaluate the effects of varying spring HTA size and timing on turfgrass, surface, organic matter (OM), and soil properties.
Spring HTA treatments included 1.2-cm i.d. tines spaced …

Forage Species Alters Animal Performance, Carcass Quality, And Fatty Acid Composition Of Forage-Finished Beef Produced In Summer Months, Jason Schmidt

All Theses

The objective of this study was to evaluate how forages grazed during the summer months alter live animal performance, carcass quality, consumer acceptability and fatty acid composition in finishing beef cattle. Angus-cross steers (n=60) were finished on alfalfa (AL), bermudagrass (BG), chicory (CH), cowpea (CO), and pearl millet (PM) during this two year trial. Using a complete randomized block design, ten 2-ha paddocks were blocked and assigned to forage species (2 reps per species). Each year, steers (n=3) were randomly assigned to paddocks and grazing began when adequate forage growth for individual species was present. Put and take grazing techniques …