Agricultural Science Commons^™

The Development Of Tools For The Production Of Fusarium Oxysporum Race 4 Resistant Cotton Varieties, Thomas Rylands

All Theses

Fusarium oxysporum race 4 (FOV4) is a fungal pathogen that infects cotton (Gossypium spp.) plants, resulting in fusarium wilt (FW) disease that causes significant wilting, yield loss, and eventually death. Since cotton is such an important crop globally, with tens of millions of bales of fiber produced and sold worldwide each year, it is critical to develop effective strategies to combat this pathogen. This research aims to achieve that goal through two projects: (i) develop an efficient co-culture system to test fungal treatments in vitro, and (ii) develop a computer vision pipeline to more accurately assess plant resistance …

Life Cycle Assessment Of The Cultivation Of Lettuce In A Hydroponic System Using The Nutrient Film Technique, Raquel Jordan

All Theses

Hydroponic systems are an emerging method of soilless crop cultivation typically done inside a greenhouse where nutrients are delivered dissolved in water rather than being supplied from the soil. Potential benefits of hydroponic systems include reduced irrigation requirements, higher crop yield per area, and the ability to grow crops year-round in nontraditional areas such as urban settings, cold climates, and sites with contaminated soil. However, hydroponic systems tend to have high energy requirements for lighting and climate control, which can yield significant environmental impacts. To explore the environmental impacts of cultivating lettuce in a nutrient film technique (NFT) hydroponic system, …

Application Of Artificial Neural Network Algorithms For Irrigation Scheduling, Lisa Umutoni

All Dissertations

Neural networks have been extensively used in predicting soil water tension for improved irrigation scheduling and management. However, their lack of interpretability constrains their efficacy in grasping the nuanced patterns prevalent in soil water tension time series data. The first goal of this research was to develop interpretable deep neural network models for soil water tension prediction across multiple soil depths (0.15m, 0.3m, 0.46m and 0.6m) and prediction horizons (1h, 6h, and 12h). The Neural Hierarchical Interpolation for Time Series (N-HiTS) and Neural Basis Expansion Analysis Time Series (N-BEATS) models were used in this research. Historical soil water tension data …

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 …

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. …

Developing Holistic And Reduced Fertilization Guidelines For Southeastern Peach (Prunus Persica (L.) Batsch) Orchards, Richardson Bien-Aime

All Theses

Peach production in the southeastern United States requires optimizing fertilization practices to balance economic sustainability and environmental health. Current guidelines may overlook rootstock-specific nutrient requirements and fail to align with orchard-specific conditions, often resulting in overfertilization, increased costs, and environmental risks. This study, conducted at Clemson University’s Musser Fruit Research Center during 2023 and 2024, aimed to refine fertilization practices through two complementary experiments. The first experiment investigated how three rootstocks, ’MP-29’, Lovell, and Guardian, influence nutrient dynamics of ‘Carored’ peach trees. Nutrient concentrations were measured in various tree organs, including leaves, pruned wood, thinned fruitlets, and harvested fruits, along …

The Diverse Effects Of Continual Organic Inputs On Soil Biogeochemical Properties And Microbial Communities In Sandy Ultisols Under Organic Production, Zhine Wang

All Dissertations

The objectives of this study were to understand how continual organic amendment inputs improve Nitrogen (N) cycling, microbial diversity and functional traits. Fully crossed factorial experiments were designed to test four cover crop treatments (cereal rye, hairy vetch, mixture of the rye and vetch, and no cover crop fallow) and two levels of manure compost application (with manure application and blank control) in organic vegetable production from 2020 to 2023. Cover crop biomass, soil chemical and biological properties were analyzed for the distribution and availability of soil labile N (Chapter 2), the abundance of N-cycling genes (Chapter 3), the structure …

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 …

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 …

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 …

Development Of New Cotton Defoliation Sprayer Using Unmanned Ground Vehicle And Pulse Width Modulation Technology, Jyoti Neupane

All Theses

Chemical spraying is one of the most important and frequently performed intercultural agriculture operations. It is imperative to utilize appropriate spraying technology as a selection of ineffective one leads to waste of agrochemicals to the non‐target area. Several precision technologies have been developed in the past few decades, such as image processing based on real‐time variable‐rate chemical spraying systems, autonomous chemical sprayers using machine vision and nozzle control, and use of unmanned aerial and ground vehicles. Cotton (Gossypium hirsutum L.) is an important industrial crop. It is a perennial crop with indeterminate growth habit; however, in most parts of the …

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, …

Meta-Analysis Of The Effects Of Endophytes And Their Secondary Metabolites On Herbivory From Insects, Derrick Taylor

All Theses

Endophyte-infected plants have reduced the level of herbivory. The defense to herbivory can vary due to the metabolites in the plant and the method of feeding from the pest. Secondary metabolites produced by the endophytes are mainly alkaloids. The associations between endophytes and some alkaloid groups are studied in greater detail. The lack of research of certain alkaloid groups ultimately means that some alkaloids had more data that could be analyzed. As a result, the alkaloid groups were not evenly represented in the meta-analysis. The meta-analysis analyzed the relative effectiveness of the metabolites or endophytes in each of the articles …

Unmanned Ground Vehicle Proximal Sensing For Forage Biomass Production Estimations, Curtis Erwin

All Theses

A large increase in productivity could be realized by small increases in efficiency and utilization on grasslands due to their large area. Pre-harvest biomass estimations can help forage producers make better informed management decisions. Producers of dry hay and hay silage can better identify plant growth stages and the optimal time to harvest. Grazers can better determine the most efficient number of animals and stocking density. The goal of this study was to create a novel pre-harvest biomass estimation method utilizing compressed height combined with an unmanned ground vehicle (UGV). A compression plate named a “compression ski” was constructed and …

Unveiling The Potential Of Calcium And Natamycin For Botrytis Blight Management On Cut Roses, Melissa Munoz

All Dissertations

Botrytis blight caused by the fungus Botritys cinerea is the most devastating disease of cut roses. The extensive use of fungicides used for Botrytis blight management during cut rose production and postharvest represents a severe threat in terms of fungicide resistance development as has been previously reported. Additionally, health concerns for growers and the environment are growing in recent years making consumers more aware of the fungicides in the products that they consume including ornamentals. This scenario highlights the importance of searching for alternative products to synthetic fungicides. During this research, the use of calcium as an alternative management strategy …

Understanding The Influence Of Excessive Fertilization And Water Relations On Peach (Prunus Persica (L.) Batsch) Skin Bronzing, Sydney Lykins

All Theses

This project evaluated possible causes of peach skin bronzing, a brown-blotchy skin discoloration on mid to late-season peaches that causes drastic decreases to grower incomes in the Southeastern U.S. It is known that there is no bacterial, insectile, viral, or fungal cause of bronzing; thus, these studies focused on potential nutrient imbalances within the peach. On the ‘PF23’ variety, factors of irrigation, potassium fertilization, and transpiration-inhibiting sprays were tested to see the various effects on the incidence and severity of bronzing. The hypothesis was that excessive irrigation and excessive soil potassium concentrations would induce a higher incidence and severity of …

Etiology And Epidemiology Of Mini-Ring In Ultradwarf Bermudagrass Putting Greens, Lukas Dant

All Dissertations

Mini-ring is a disease in ultradwarf bermudagrass (UDBG) [Cynodon dactylon (L.) Pers. × C. transvaalensis (Burtt-Davy)] putting greens caused by Waitea zeae (Voorhees) J.A. Crouch & Cubeta, (formerly Rhizoctonia zeae). Symptoms typically resemble frog-eye patches that are 10 to 40 cm in diameter with a bronze to orange outer ring and green center. In the southeastern United States, mini-ring symptoms appear in late-summer and generally persist until UDBG dormancy in late-fall. Mini-ring is often problematic in UDBG when nitrogen (N) fertility is reduced to manage organic matter production and improve putting green performance and perceived green speed. While …

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.

The Influence Of Water Stress And Rootstocks On Nutrient Uptake And Gas Exchange Of Young Peach Trees, Naif Alshammari

All Theses

Young peach trees are often rainfed in the southeastern U.S. and periods of dry weather can cause tree water deficit that can be detrimental to orchard productivity. There is a lack of understanding of the influence of water regimes and rootstocks on the nutritional status and gas exchange of the peach tree. Most peach growers in Southeastern United States do not irrigate their young peach trees because they do not produce fruit until the third leaf. In this region, peach growers use Guardian as a rootstock, although MP-29 is also interesting for growers with orchards that have Armillaria root rot …

Potassium Level Prediction Of Peach Tree Leaves Using A Hyperspectral Camera And Multivariate Analysis, Megan Io Ariadne Salimbangon Abenina

All Theses

The use of hyperspectral imaging is a valuable piece of technology used in precision agriculture. Hyperspectral imaging system could help farmers and researchers alike in analyzing tissue samples quicker compared to the current way of running a plant tissue analysis on the different nutrient levels that often takes time in generating results. The objective of this research was to measure the potassium level of peach trees using its leaves with a hyperspectral camera. The Senop HSC-2 was used to capture images of peach tree leaves during the fall of 2020 and 2021. The collected data were used to create a …

Sources Of Peanut Digging Losses And Strategies To Reduce Losses During Inversion, Loren Samenko

All Theses

Presented research was conducted at Clemson University’s Edisto Research and Education Center to quantify harvest related losses associated with the effects of peanut digger blade geometry, the effects of the peanut digger inversion assembly, and the effects of vine load on digging and strategies to address vine load. Three studies were performed to determine the potential losses incurred during the digging processes; various harvest metrics were analyzed to quantify the effects of the treatments. Five objectives guided the presented research. Objectives of the effects of peanut digger blade geometry study investigated the impact of blade geometry and blade aggression on …

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 …

Development And Evaluation Of An Automated Linear Move Fertigation System For Cotton Using Active Remote Sensing, Stewart Bell

All Theses

Optimum nitrogen (N) application is essential to the economic and environmental sustainability of cotton production. Variable-rate N fertigation could potentially help farmers optimize N applications, but current overhead irrigation systems normally lack automated site-specific variable-rate fertigation capabilities. The objective of this research was to develop and evaluate an automated variable-rate N fertigation system based on real-time Normalized Difference Vegetation Index (NDVI) measurements from crop sensors integrated with a lateral move irrigation system. For this purpose, NDVI crop sensors and a flow meter were integrated with Arduino microcontrollers and an automated fertigation system was constructed. A computer program was developed to …