Plant Sciences Commons^™

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 …

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 …

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 …

Is There An Economic Advantage To Planting Diverse Summer Annual Forage Mixtures?, Kelly Mercier, Chris Teutsch, Ray Smith, Kenny Burdine, Edwin Ritchey, Eric Vanzant

The Journal of Extension

This study examined economic implications of planting summer annual mixtures of grasses, legumes, and forbs at varying nitrogen rates. No differences in yield occurred between the three mixtures, indicating that mixtures with lowest seed cost will be most economical. Applying N resulted in yield increases of 12.26 lb DM per lb N applied. Although yield responses to N were positive, sensitivity analyses showed that applying N resulted in positive net returns only when hay prices were high and N prices were low. When utilization rates are accounted for, enterprise budgets determined grazing to be 18% cheaper to implement than haying.

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 …

Veganic Agriculture In The United States: Opportunities For Research, Outreach, And Education, Alisha Utter, Mona Seymour

The Journal of Extension

A growing number of farmers are excluding animal inputs from crop production, an approach commonly referred to as veganic or stockfree organic agriculture. This research-based article discusses the soil health and fertility strategies reported by a sample of U.S. veganic farmers. These approaches may be relevant beyond the veganic community to farmers seeking innovative methods for produce safety and nutrient cycling. Agricultural outreach professionals (AOPs), including Extension personnel, play a critical role in supporting veganic practices by serving as cross-pollinators between farmers and research institutions. Thus, the article endeavors to expand AOP familiarity with veganic practices and benefits.

Applying Drone-Based Spatial Mapping To Help Growers Manage Crop Diseases, Qingren Wang, Shouan Zhang

The Journal of Extension

Phytophthora blight (Phytophthora capsici) is one of the major soilborne diseases threatening many vegetable crops including squash. The disease results in severe epidemics and yield losses due to a rapid spread of the pathogen associated with wet weather and soil water-logging. Implementing drone-based spatial mapping with software elevation tools can assist growers in evaluating land levelling for uniform distribution of water to mitigate potential disease incidence. The technology has great advantages: rapid, precise, and labor-cost effective. Our result can implicate Extension professionals with application of spatial mapping to assist growers in managing their land and crops for disease …

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 …

Biology And Ecology Of Wild Radish (Raphanus Raphanistrum), Mayank Malik

All Dissertations

Wild radish ( L.), a facultative winter annual is a troublesome weed in small grain crops of the Southeastern United States. Besides being a weed, it may also be used as a cover crop for weed management due to its production of glucosinolates. Studies were conducted to evaluate the biology and ecology of wild radish as well as its glucosinolate production and its weed management possibilities.
Wild radish emerging in fall months formed a rosette of leaves which aided its winter survival. Plants emerging from December through March that did not form a rosette had minimal survival. Wild radish life …

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 …

Biology And Ecology Of Palmer Amaranth (Amaranthus Palmeri), Prashant Jha

All Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats.) is a troublesome weed of crops in southeastern United States. This research highlights studies on the biology and ecology of Palmer amaranth. Following dispersal in fall, Palmer amaranth seeds require high mean temperatures of 25 to 40 C for germination, which is not likely to occur in South Carolina until the following spring. With dormancy reduction over winter, seeds can germinate at high temperatures (≥25 C) and thermal amplitudes of 15 C during late spring (May) in the presence of light. A majority (>90%) of the non-dormant population in the soil seedbank emerge …

Variable Approaches Investigating Light Quality And Quantity Impacts On Warm- And Cool-Season Turfgrasses, Christian Baldwin

All Dissertations

Bermudagrass (Cynodon ssp.) is the most popular warm-season turfgrass used in warm climatic regions of the world due its recuperative ability, high traffic tolerance, heat tolerance, and relative drought and salt tolerance. However, shade is a microenvironment in which bermudagrass performs poorly. Morphological limitations, such as reduced lateral stem growth and overall reduction of carbohydrate synthesis contribute to bermudagrass, a C4 plant, decline under shade. Therefore, primary objectives of this dissertation were to determine the genetic diversity of bermudagrasses grown in full-sunlight and shade, impacts of shade and cultural practices on bermudagrass spring transition, management recommendations to enhance bermudagrass …

The Molecular Characterization Of The Virus And Virus-Like Agents Present In Ta Tao 5 Germplasm Of Prunus Persica , Diana Marini

All Dissertations

Peach production in the southeastern United States is limited by late spring freezes. Ta Tao 5 germplasm, used either as an interstem or by chip bud inoculation, has been shown to delay bloom and avoid the effects of these late freezes. The growth modification is graft transmissible and the germplasm has been found to be infected with ACLSV, APruV-3, and PLMVd. Using a combination of PCR, cloning, and sequencing techniques, a molecular characterization of the three graft-transmissible agents present in Ta Tao 5 has been completed.

The complete nucleotide sequence of the genome of the isolate of ACLSV (ACLSV-Ta Tao …

Measuring And Modeling Species Specific, Joseph Bowden

All Theses

Differences in transpiration have been reported in tree species over the last several decades; however, few studies have teased out the environmental component with a common garden. Species specific transpiration was measured via sap flow on twenty trees from five deciduous hardwood species, Prunus x yedoensis Matsum., Acer rubrum L. 'Autumn Flame', Acer buergeranum Miq., Prunus serrulata Lindl. 'Kwanzan,' and Platanus x acerifolia (Ait.) Willd., throughout the 2005 growing season in a plantation. In addition, monthly growth and gas exchange measurements were collected for each species and used to parameterize a three dimensional spatially explicit transpiration model, MAESTRA. The model …

Soil Fertility Management In Organic Vegetable Production, Susannah Rauton

All Theses

Organic vegetable production is a rapidly growing sector of agriculture. Due to limitations on synthetic inputs imposed by the USDA National Organic Program (NOP), research is necessary to determine which soil amendments are viable options for organic farmers. Field trials were conducted at the Clemson University Calhoun Fields Laboratory Student Organic Farm. A variety of vegetable crops were grown, including Jericho lettuce in the springs of 2005 and 2006, yellow crookneck squash in the summers of 2005 and 2006, and Early Jersey Wakefield cabbage in the fall of 2005. Soil amendment treatments consisted of combinations of the following: poultry compost, …

The Influence Of Peat And Inorganic Amendments On Physical Properties Of Sand-Based Rootzones, Freddie C. Waltz Jr.

All Dissertations

Many golf course putting greens and athletic fields are constructed with a medium consisting of a high sand content. Peat is the most common amendment to rootzone sand (RZS). However, a trend to replace peat with inorganic soil amendments (IOSA), such as calcined clay (CC) and diatomaceous earth (DE), is occurring. Laboratory studies were conducted to evaluate physical and hydraulic properties of rootzone mixtures and a field study investigated the potential of IOSA as a replacement to peat. In laboratory evaluations, amended RZS reduced the bulk density of all mixtures, while saturated hydraulic conductivity (Ksat) for the RZS and mixtures …