Life Sciences Commons^™

Impact Of Early-Season Postemergence Co-Applications Of Foliar And Residual Herbicides On Crop Injury, Growth, And Yield In 2,4-D- And Dicamba-Tolerant Cotton (Gossypium Hirsutum L.), Logan N. Vallee

LSU Master's Theses

Studies were conducted in 2021 through 2023 at the LSU AgCenter Dean Lee Research and Extension Center near Alexandria, LA to determine the sensitivity of 2,4-D- or dicamba- tolerant cotton (Gossypium hirsutum L.) to an early season application of a Group 15 and foliar-only herbicides. Both studies were randomized complete block designs with a two-factorial arrangement of treatments with four replications. In the dicamba-tolerant cotton study, Factor A consisted of no foliar-herbicide, dicamba alone, glyphosate alone, or dicamba plus glyphosate. Factor B consisted of either no Group 15 residual herbicide, acetochlor, or S-metolachlor. In the 2,4-D- tolerant cotton …

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, …

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 …

Characterization And Management Of Auxin-Resistant Palmer Amaranth In Tennessee, Delaney C. Foster

Doctoral Dissertations

Palmer amaranth has a long history of evolving resistance to herbicides to the point it has become a significant row crop production obstacle. Cotton and soybean growers were offered new technologies in 2016, expanding in-crop herbicide options to include dicamba or 2,4-D. Within three years of commercialization, dicamba use in these crops increased ten-fold and growers began to report Palmer amaranth escapes in west Tennessee auxin-tolerant production systems. A survey of Palmer amaranth escapes in dicamba and 2,4-D-tolerant cotton and soybean fields in Tennessee was conducted in the fall of 2021 with the objective of determining if poor control was …

Improving Water And Plant Growth Regulator (Pgr) Management Practices In Cotton: Cultivar Physiological Responses And Pgr Rates, Kurt Wedegaertner

Masters Theses

Cotton (Gossypium hirsutum L.) is grown in an increasingly unpredictable climate and often under rainfed conditions. Without irrigation to alleviate common drought conditions, cultivar selection becomes a primary tool in mitigating the negative effects of water-deficit stress. Cultivars can differ in water use under water-limited environments, which can affect crop performance. Moreover, cotton management must involve balancing vegetative and reproductive growth through the use of plant growth regulators (PGR) due to the plant’s perennial growth pattern. The efficacy of PGRs are dependent on many variables including environmental conditions, irrigation, and genetics (cultivar). In 2020 and 2021, a series of …

An In Vitro Approach To Identify Sources Of Resistance To Fusarium Wilt Caused By Fusarium Oxysporum F. Sp. Vasinfectum Race 4 In Domesticated Cotton, Stephen Parris

All Theses

Cotton lint produced by the plants Gossypium barbadense L. (pima cotton) and Gossypium hirsutum L. (upland cotton) is the world’s leading source of renewable textiles. The fibers of the cotton plant have been woven so intricately into our society that it would be hard to imagine life without their products. Cotton breeders must then not only continue to work to improve the quality of cotton fibers (fineness, strength, dyability, etc.) but also to improve the resilience of the plant against biotic and abiotic factors. Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) is an aggressive fungal pathogen, which causes Fusarium …

Fungicide Sensitivity Screening Of Corynespora Cassiicola In Us Soybean And Cotton, Tyler Miles Smith

Doctoral Dissertations

Target spot, caused by the fungus Corynespora cassiicola, is a foliar disease of cotton and soybean. Target spot has become a disease of concern in soybean and cotton production systems. Data for fungicide sensitivity and understanding potential impact on yield is lacking for C. cassiicola. Fungicide resistance is also a concern in C. cassiicola with the increase in resistant pathogens in soybean. With the lack of knowledge about baseline fungicide sensitivity and the concern of fungicide resistance the objectives of this study were: (i) to evaluate fungicide products and mixes in small plot soybean and cotton trials, (ii) …

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 …

Sensitivity Of Enlisttm And Roundup Ready Xtend® Technologies To Auxin Herbicides And Comparison Of Resistance To Susceptible Cotton And Soybean Cultivars, James Rose

Graduate Theses and Dissertations

Increases in weed resistance have led to the development of new herbicide-resistant crop technologies, namely the Roundup Ready Xtend® and EnlistTM weed control systems. These new technologies provide resistance to applications of the synthetic auxins dicamba or 2,4-D, respectively, in traited cotton or soybean. It is unknown if there is any resistance to other herbicides within the synthetic auxin group (WSSA Group 4) in these traited crops. Experiments were conducted with auxin herbicides representing all five families within WSSA Group 4. Herbicides were applied either preemergence (PRE) or postemergence (POST) relative to the crop in a single application. Applications were …

Cover Cropping In Soybean-Corn Rotation System: Economic, Agronomic, And Soil Fertility Impact, Jose Rodolfo Mite

LSU Doctoral Dissertations

Planting winter-annual cover crops prevent soil erosion, reduces water runoff, and improves soil structure and soil quality. This research was conducted from 2017 to 2019 to evaluate the nutrient turnover of different species of cover crops in soils under different row crop production systems in Northeast and Central Louisiana. In Northeast Louisiana (Site 1, 2, and 3), treatments (cover crops and no cover crop) were arranged in a strip trial with three replications. At the Ben Hur Research Station, the treatments included three planting dates (September, October, and November) with [7 kg ha^-1 of phosphorus (P) and potassium (K)] …

The Effects Of Seed-Applied Fluopyram On Root Penetration And Development Of Meloidogyne Incognita On Cotton And Soybean, Tracy Hawk

Graduate Theses and Dissertations

Plant-parasitic nematodes are major pests of cotton and soybean in Arkansas, and across the Southern United States. These nematodes cause more than $3 billion worth of crop losses each year, in part due to lack of available control tactics, such as nematicides. Fluopyram has recently been registered as a seed-treatment nematicide in agronomic crops. The toxicity of fluopyram against Meloidogyne incognita infection has been reported, however, information on root protection provided by fluopyram against Meloidogyne incognita is lacking. The first objective of this research was to evaluate the effect seed-applied fluopyram had on nematode development, root galling, and reproduction on …

Exploration Of The Gossypium Raimondii Genome Using Bionano Genomics Physical Mapping Technology, Christopher Jon Hanson

Theses and Dissertations

Cotton is a crop with a large global economic impact as well as a large, complex genome. Most industrial cotton production is from two tetraploid species (Gossypium hirsutum L. and Gossypium barbadense L.) which contain two subgenomes, specifically the AT and DT subgenomes. The DT subgenome is nearly half the size of the AT subgenome in tetraploid cotton and is closely related to an extant D-genome Gossypium species, G. raimondii Ulbr. Characterization of the structural variants present in diploid D-genome should provide greater insight into the evolution of the DT subgenome in the tetraploid cotton. Bionano (BNG) optical mapping uses …

The Genome Sequence Of Gossypium Herbaceum (A1), A Domesticated Diploid Cotton, Alex J. Freeman

Theses and Dissertations

Gossypium herbaceum is a species of cotton native to Africa and Asia. As part of a larger effort to investigate structural variation in assorted diploid and polyploid cotton genomes we have sequenced and assembled the genome of G. herbaceum. Cultivated G. herbaceum is an A1-genome diploid from the Old World (Africa) with a genome size of approximately 1.7 Gb. Long range information is essential in constructing a high-quality assembly, especially when the genome is expected to be highly repetitive. Here we present a quality draft genome of G. herbaceum (cv. Wagad) using a multi-platform sequencing strategy (PacBio RS II, Dovetail …

Distinguishing Isolates Of Rotylenchulus Reniformis Endemic In Louisiana On The Basis Of Root-Associated Females And Egg Masses, Benjamin Mcinnes

LSU Master's Theses

The reniform nematode Rotylenchulus reniformis is a major pathogen of soybean and cotton in Louisiana. Previous studies have shown that populations of reniform nematode throughout the southern United States vary in reproduction and pathogenicity. Limited studies have been conducted to evaluate the reproduction and pathogenicity of populations of R. reniformis endemic in Louisiana. Studies with isolates of the nematode from eight cotton-producing parishes focused solely on reproduction of the root-associated infective and swollen female life stages with and without attached egg masses on the cotton genotypes MT2468 Ren3, M713 Ren5, and Stoneville 4946GLB2 and the soybean genotypes PI 548316, PI …

Spatial Variability Of Seedling Disease Pressure In Cotton Fields, Kyle Douglas Wilson

Graduate Theses and Dissertations

Seedling diseases are important factors in cotton stand establishment, and seedling disease pathogens are widespread in fields in Arkansas. Little is known about the variability of seedling disease pressure within fields. With expanded adoption of site-specific management and other precision agriculture approaches, cotton producers are increasingly interested in predicting seedling disease pressure, particularly in spatially variable fields. The cotton seedling disease pathogens include the soilborne pathogens Thielaviopsis basicola, Rhizoctonia solani, Pythium spp., and Fusarium spp. These pathogens can survive in soil for long periods and, and when the environment is conducive, these pathogens can act individually or in combination to …

Value Of Cover Crops In Suppressing Weeds And Protecting Cotton Yields And Likelihood Of Residual Herbicide Carryover To Cover Crops, Matheus Gabriel Palhano

Graduate Theses and Dissertations

Weed-resistance management has become a topic of concern for modern agriculture. Cost related to herbicide usage has increased greatly due to evolution and proliferation of resistant weeds. Therefore, experiments were conducted to investigate the potential for using cover crops to suppress problematic weeds in cotton as well as chemical options for cover crop dessication, and sensitivity of cover crops to residual herbicides were evaluated. No differences were observed for cereal rye biomass production and consequently weed suppression between broadcast and drilled planting methods. Total amount of cover crop biomass was vital to effectively suppress weeds. Hence, of the cover crops …

Effect Of Potassium Deficiency On Uptake And Partitioning In The Cotton (Gossypium Hirsutum L.) Plant And Detection By A Crop Reflectance Sensor, Taylor Dayne Coomer

Graduate Theses and Dissertations

For cotton (Gossypium hirsutum L.) to grow and develop normally, plants need to uptake the necessary amount of nutrients and use those nutrients in a beneficial fashion. It is recognized that cotton needs a certain tissue concentration of ions to achieve and maintain growth rates (Siddiqi et al., 1987). One of the most essential and abundant nutrients in cotton is potassium (K), second only by mass to nitrogen (N) (Marschner, 1995; Oosterhuis et al., 2013). Potassium exists in the soil in four separate pools and moves through soil to roots mainly through diffusion (Rengel & Damon, 2008; Samal et al., …

Heat Stress Effects On Cotton During Reproductive Development And Subsequent Acclimation Responses, Toby Ryan Fitzsimons

Graduate Theses and Dissertations

High temperature stress is among the most difficult to control abiotic factors affecting crop yields in the Southern United States due to its wide regional influence. Cotton (Gossypium hirsutum L.) though a tropical plant in origin, it is sensitive to the effects of high temperature. This is of particular concern when the warmest temperatures coincide with the most sensitive developmental stage of flowering. Thus, the capacity to improve cotton’s ability to tolerate heat stress has been a significant focus for many decades. Therefore, this research was composed of several different components all designed to investigate heat stress effects. Using a …

Improving Cotton Agronomics With Diverse Genomic Technologies, Aaron Robert Sharp

Theses and Dissertations

Agronomic outcomes are the product of a plant's genotype and its environment. Genomic technologies allow farmers and researchers new avenues to explore the genetic component of agriculture. These technologies can also enhance understanding of environmental effects. With a growing world population, a wide variety of tools will be necessary to increase the agronomic productivity. Here I use massively parallel, deep sequencing of RNA (RNA-Seq) to measure changes in cotton gene expression levels in response to a change in the plant's surroundings caused by conservation tillage. Conservation tillage is an environmentally friendly, agricultural practice characterized by little or no inversion of …

Potential Interaction Between Pre- And Post-Emergence Herbicides And The Efficacy Of Insecticide And Fungicide Seed Treatments In Cotton, Cory Joseph Vineyard

Masters Theses

An apparent reduction in the performance of neonicotinoid seed treatments in controlling thrips, especially in cotton, has been observed, which has coincided with the increased use of both pre- and post-emergence herbicides to control glyphosate-resistant weeds. The objective of this research was to evaluate the potential interactions of both pre- and post-emergence herbicides on the efficacy of insecticide and fungicide seed treatments in cotton

Aldicarb along with imidacloprid and thiamethoxam seed treatments reduced thrips numbers compared with non-treated seed. However, thiamethoxam did not provide effective control. Some pre-emergence herbicide treatments reduced plant health. While there was evidence that thrips injury …

Cotton Injury Due To Soil- Or Foliar-Applied Herbicides: An Assessment Based On The Influences Of Genetic, Agronomic, And Environmental Factors, Brandon William Schrage

Graduate Theses and Dissertations

Increasing populations of glyphosate-resistant weeds, such as Palmer amaranth, have prompted growers to pursue alternative means of weed control in cotton. In many cropping systems, this means the utilization of older chemistries and residual herbicides. The goal of this research was to evaluate and understand the agronomic and environmental factors that affect the inconsistent injury often associated with these herbicides as well as determine the impact of Palmer amaranth emergence date on seed production, biomass, and cotton yield. Experiments were conducted in three counties in Arkansas giving a distinct range of climate and soil texture. Injury, biomass, and number of …

Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson

Masters Theses

Biogeochemical cycling of soil carbon (C) is heavily influenced by conservation agricultural (CA) practices. This study examined SOC stability under three CA practices: reduced nitrogen (N) fertilizer application rate, cover cropping, and zero-tillage implemented for 31 years. Respiration rates measured from a 602-day incubation period were fitted to a double-pool first order exponential model of SOC decomposition. The active [respired] SOC pool showed distinct differences between applications of reduced (34N kg ha^-1 [-1]) and high fertilization rates (101N kg ha^-1) combined with tillage, and suggest that high fertilizer applications with conventional tillage allocated more C into a …

Temperature In The Cotton (Gossypium Hirsutum L.) Canopy And Effects On Cotton Leaf And Boll Growth, Maria Soledad Berlangieri Costa

Graduate Theses and Dissertations

Cotton development and yield are negatively influenced by extremes temperatures, mainly during reproductive stage. Ambient air temperature is used to evaluate temperature stress effect on yield under field conditions; however, there is evidence that actual temperatures in the canopy where bolls develop are different. In terms of cotton responses, there is limited research about the effects of elevated day and night temperatures upon boll carbohydrate content, size, and boll respiration. Field and growth chamber experiments were performed during 2014-2015 using the cotton (Gossypium hirsutum L.) cultivar DP0912B2RF. Field studies for determining temperature gradients through the canopy consisted of two planting …

Use Of Fluridone For Control Of Palmer Amaranth (Amaranthus Palmeri) In Cotton (Gossypium Hirsutum) And On Ditchbanks, Zachary Thornton Hill

Graduate Theses and Dissertations

Since 2006, glyphosate-resistant Palmer amaranth has been considered the most problematic weed in agronomic crops across the Midsouth. As a result of glyphosate resistance, producers began to again utilize a diverse herbicide program for management of this weed, which consists of several soil-residual herbicides most notably diuron, fluometuron, fomesafen, and metolachlor. Fluridone inhibits phytoene desaturase in plants, and is unique in that its mechanism of action (MOA) is not currently registered for use in cotton. Studies were conducted to determine the length of residual that fluridone provides in controlling Palmer amaranth in Arkansas glyphosate- and glufosinate-resistant cotton programs and along …

The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke

Graduate Theses and Dissertations

In cotton production, nitrogen (N) is the most limiting nutrient and the demand is substantial. Foliar-N fertilization is regarded as an effective and environmentally sound method of supplying cotton with N during times of deficiency and high demand. In response to the potential benefits of the foliar-N fertilization of cotton, a myriad of foliar-N based fertilizers have been created; each with their own individual chemical technology and constitution. Experiments were performed with the objectives of examining the effects of the slow-release foliar-N fertilizer, Nitamin® (1) on the growth and development of field-grown cotton, (2) on uptake under various environmental conditions, …

Relationship Between 1,3-Dichloropropene And Nitrogen Fertility In Cotton In The Presence Of Root-Knot And Reniform Nematodes, Amanda Michelle Greer

Graduate Theses and Dissertations

The use of soil fumigation for nematode management in cotton (Gossypium hirsutum) has become increasingly popular in recent years in the absence of effective resistant cultivars. While soil fumigation is relatively expensive, lint yields have consistently been improved to make this practice profitable in fields with severe nematode pressure. Growers in southern Arkansas have observed changes in cotton growth patterns when severely infested fields are fumigated. The most noticeable change has been excessive (rank) growth resulting in an increased need for growth regulators, especially where the nitrogen fertilization exceeds standard recommendations. Field studies were conducted between 2007 and 2010 to …

Study Of Thermotolerance Mechanism In Gossypium Hirsutum Through Identification Of Heat Stress Genes, Jin Zhang

Graduate Theses and Dissertations

ABSTRACT

Heat stress causes major losses to cotton seed and lint yield. Introduction of heat stress tolerance to Arkansas cotton varieties is highly desirable. However, very little is known about the molecular basis of heat stress tolerance in cotton. The present study attempted to identify heat stress tolerance genes in two heat-tolerant cotton cultivars, VH260 and MNH456, originating from Pakistan. Towards this, the expression profile of the cotton orthologs of sevenArabidopsisheat stress tolerance genes was studied in these two cultivars, and compared with the two heat-susceptible cotton cultivars, ST213 and ST4288, originating from Mississippi Delta region. In addition, physiological parameters …

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, …

Resistance Screening And Control Options For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Cotton (Gossypium Hirsutum), Ryan Christopher Doherty

Graduate Theses and Dissertations

In the mid-2000's, glyphosate-resistant Palmer amaranth biotypes began to emerge in many southern states. In 2006, glyphosate-resistant Palmer amaranth was identified in a field in Mississippi County, Arkansas. A greenhouse experiment was conducted in 2008 to screen Palmer amaranth accessions, collected in this survey, for glyphosate resistance. Inflorescence were collected from a total of 276 plants from fields were glyphosate failure occurred, representing 74 accessions in 14 counties, including Clay, Craighead, Crittenden, Greene, Jackson, Jefferson, Lawrence, Lee, Mississippi, Phillips, Poinsett, Randolph, St. Francis, and White Counties. Eight of the 74 accessions did not produce viable seed. In the greenhouse, 32 …