Agronomy and Crop Sciences Commons^™

Letter From The Dean, Deacue Fields

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Letter From The Faculty And Managing Editors, Beth Kegley, Gail Halleck

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Estimation Of Additive And Dominance Effects Of A Mutant Glutathione S-Transferase Gene On Anthocyanin Content In Muscadine Grape (Vitis Rotundifolia), Autumn Brown, Margaret Worthington, Aruna Varanasi, Lacy Nelson, Renee T. Threlfall, Luke R. Howard

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The skin color of muscadine grapes (Vitis rotundifolia) is typically classified as black or bronze. A glutathione S-transferase, VrunGST4, has been identified as a candidate gene for berry skin color in muscadine grapes. A molecular marker was developed within VrunGST4 to distinguish between muscadine genotypes (cultivars and selections) with bronze (T:T), heterozygote black (C:T), and homozygote black (C:C) berries. The objectives of this study were to determine whether there was a correlation between berry skin color and total anthocyanin content and to calculate additive and dominance effects of VrunGST4 in determining total anthocyanins in the berries of two biparental F1 …

Food Accessibility Related To The Double Your Dollar Program, Julia Carlson, Heather Friedrich, Mechelle Bailey, Curt Rom

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The Double Your Dollar (DYD) Program is a program that gives Supplemental Nutrition Assistance Program (SNAP) beneficiaries and Senior Farmers Market Nutrition Program (SFMNP) participants match dollars to spend at local farmers markets. The DYD’s goal is to incentivize healthy eating among individuals of low income and promote spending at farmers markets. Food insecurity affects over 60,000 individuals in Washington and Benton counties in Arkansas. The aim of this study was to assess how the DYD program impacted users’ food accessibility and how the program could be improved for the future. A survey was used to address basic demographics, type, …

The Biofiltration Ability Of Asparagus Densiflorus To Remove Sulfur Dioxide From The Indoor Atmosphere, Rhiannon De La Rosa, Mary Savin

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Sulfur dioxide is an inorganic compound (IC) and air pollutant that causes health risks in humans. The buildup of sulfur dioxide (SO2) in enclosed indoor spaces is, therefore, a concern to human health, especially since the average person spends 90% of his/her time indoors. This study focused on decreasing SO2 concentration in a cost-effective and simple way—by using botanical biofiltration, or the uptake of pollutants by plants. Research in biofiltration has focused mostly on the remediation of volatile organic compounds (VOC). However, research has also shown that plant species that remediate VOC efficiently also have the potential for efficient IC …

The Economics Of On-Farm Rice Drying In Arkansas, Clayton J. Parker, Lanier Nalley

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Globally, rice producers are faced with the temporal problem of deciding the optimal time to harvest rice. When harvested, paddy rice is typically at a harvest moisture content (HMC) between 15% and 22% and 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, which can complicate the timing of harvest as producers try to balance the tradeoff of minimizing drying costs by waiting to harvest at lower HMC vs. maintaining higher rice quality typically observed when …

Decomposition In Pasture Soil Receiving Excreta From Ruminants Fed Alfalfa Forage Diet Supplemented With Increasing Proportions Of Sericea Lespedeza Legume, Yang Kai Tang, Mary C. Savin, Dirk Philipp, Ken Coffey, Jiangchao Zhao

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Healthy soil is fundamental to a productive pasture system as it will decompose labile organic matter and promote retention of carbon to build a stable, resistant pool of organic matter. An easy, standardized approach to measure decomposition and litter stabilization that is gaining popularity in both citizen science and research studies is the use of the Tea Bag Index. The Tea Bag Index is a relatively new method evaluating the loss of organic material in two different kinds of commercial tea bags (green tea and Rooibos tea) after burial in the soil for 90 days. The objective of this experiment …

Corn Response To Wastewater-Recycled Phosphorus Fertilizers, Shane R. Ylagan, Kristofor R. Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4 · 6H2O) is an understudied material that can be created from P- and nitrogen (N)-containing wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple superphosphate (TSP) on corn (Zea mays) response in a greenhouse pot study. …

Letter From Division Of Agriculture Communications, Fred Miller

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Instructions For Authors, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 21 2020, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

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 …

Use Of Aerial Imagery And Novel Experimental Design To Determine The Distribution Of Foliar Diseases On Soybean And Improve Efficiency Of Product Testing, Mckayla Patterson

Graduate Theses and Dissertations

Soybeans are grown on approximately 1.3 million ha in Arkansas generating an estimated $1.7 billion annually. Foliar diseases on soybean can result in economic losses. Growers spend significant time and money on disease scouting via crop consultants and often (subsequent) fungicide applications. Fungicide trials are often arranged in small plots designs. In these scenarios, spatial variability of foliar disease is minimized. While it is advantageous to minimize variance outside of treatment differences, another limitation with many small plot trials is ample disease pressure or having only lower severity. Within a commercial production field, soil types and disease severities vary. Logically, …

Understanding How The Effectors Hopd1 And Hopg1 From The Bacterial Pathogen Pseudomonas Syringae Pv. Tomato Dc3000 Target The Arabidopsis Thaliana Protein Atnhr2b To Cause Disease In Plants, Catalina Maria Rodriguez Puerto

Graduate Theses and Dissertations

The pathogenicity of Pseudomonas syringae is associated with the type III secretion system (T3SS), a complex of proteins assembled in the inner and outer bacterial membranes that traverses the plant cell wall to deliver bacterial proteins into the cytoplasm of plant cells. The effector proteins translocated into the plant cells are called Hops (Hypersensitive response and pathogenicity outer proteins). Bacterial effectors target plant immune proteins to suppress defense responses and enhance bacterial parasitism. The Arabidopsis thaliana nonhost resistance 2B (AtNHR2B), a recently identified immune protein, is degraded after inoculation with the adapted pathogen of Arabidopsis, P. syringae pv tomato DC3000 …

Comparison Of Morphological Traits In Cowpea Pod Length, Seed Number Per Pod, Seed Weight, Seed Color And Seed Density In Usda Germplasm Accessions And Arkansas Breeding Lines, Sora Imamura

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The objective of the study was to compare and correlate the Arkansas cowpea breeding lines to the USDA cowpea germplasm accessions on the following morphological traits: seed color, pod length, number of seeds per pod, 100 seed weight, and seed density. The seed density is defined as the weight of seed in gram per centimeter of pod length. Three hundred seventeen cowpea genotypes were used in this experiment. Out of the 317, 285 germplasm accessions were from the USDA GRIN and 32 lines were from the Arkansas breeding program.

T-test between Arkansas breeding lines and USDA germplasm accessions were done …

Use Of Harvest Weed Seed Control Strategies In Arkansas Soybean, Jeremy Kyle Green

Graduate Theses and Dissertations

Today, most growers use chemical weed management programs; however, a sole reliance on herbicides will place more resistance selection pressure on the weeds to which the herbicide is being applied. As herbicide resistance continues to grow and rob growers of yield, alternative weed control options are being sought to create complex integrated weed management programs to prolong the use of effective herbicides. Harvest weed seed control (HWSC) is a non-chemical practice that has been widely adopted in Australia due to herbicide resistance problems. In most cases, herbicide-resistant weeds that survive applications of herbicides produce viable seed that pass through the …

Phosphorus Runoff Risk Assessment In Karstic Regions Of The United States, Andrew N. Sharpley, Phillip D. Hays, Karl W. Vandevender, Mike B. Daniels

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The Phosphorus (P) Index risk assessment tool has been widely adopted across the United States to identify and rank site vulnerability to P runoff as part of the Natural Resources Conservation Service nutrient management planning (NMP) process. However, limited success has been achieved in addressing the risk of P loss by subsurface flow pathways, despite its relative importance in certain areas of the United States, particularly in those U.S. states dominated by karst terrain. Here we review how states with varying land areas classified as having karst features address the risk of P runoff during the NMP process. Indices adopted …

Cover Crops As An Integrated Approach For Pest Suppression And Pollinator Promotion In Arkansas Watermelon Production Systems, Paige Laurel Hickman

Graduate Theses and Dissertations

Arkansas watermelon growers face a variety of insect pest and disease problems that have the potential to threaten yield. Integrated pest management tactics can provide control over these threats and are intended to cut down on pesticide use and its associated negative impacts like pesticide resistance, non-target effects, and runoff. Cover crops provide an array of benefits and can be useful in integrated pest management. Evidence has shown that certain cover crops can increase beneficial insects and suppress disease in the following cash crop. They can also provide important resources to pollinators. In order to build a better understanding of …

Analyzing Multigene Stacking And Genome Editing Strategies In Rice, Bhuvan Pathak

Graduate Theses and Dissertations

Crop improvement through biotechnology is an integrated effort, incorporating multiple approaches like integration of genes, editing of native genes, and removal of selection marker genes. Before streamlining the protocols, the efficiency and feasibility of the individual approach and their components must be tested. This study evaluated following approaches: 1) stacking an array of genes into a single locus by site-specific integration via Cre-lox recombination in rice, 2) determining the efficiency of I-SceI and the CCR5-ZFN in the targeted excisions of gene fragments in rice and Arabidopsis, and 3) determining the efficiency of CRISPR/Cas9 in generating targeted mutations for genome editing …

Arkansas Soybean Performance Tests 2019, J. F. Carlin, R. D. Bond, J. A. Still

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/or marketing seed within the State, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Genetic Resistance To The Downy Mildew Pathogen And Mapping The Rpf Resistance Loci In Spinach, Gehendra Bhattarai

Graduate Theses and Dissertations

Spinach (Spinacia oleracea) is an important cool-season leafy vegetable crop in the United States (US). Downy mildew, caused by the obligate oomycete Peronospora effusa, is the most economically important disease of spinach. A total of 17 races of P. effusa have been reported on spinach, and many of these races (>10) have emerged in the last three decades. The new races of the pathogen are continually overcoming the genetic resistances used in the newly released cultivars.

A detached leaf inoculation assay was evaluated, standardized, and validated as a new method to differentiate resistant and susceptible spinach genotypes. Disease response …

Arkansas Soybean Research Studies 2018, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading soybean-producing state in the mid-southern United States. Arkansas ranked 11th in soybean production in 2018 when compared to the other soybean-producing states in the U.S. The state represents 3.7% of the total U.S. soybean production and 3.7% of the total acres planted in soybean in 2018. The 2018 state soybean average was 50.5 bushels per acre, half a bushel lower than the state record set in 2017. The top five soybean-producing counties in 2018 were Mississippi, Desha, Phillips, Arkansas, and Poinsett Counties (Table 1). These five counties accounted for 33.7% of soybean production in Arkansas in …

An Evaluation Of Hybrid Traits, Yield, And Major Qtl Effect On Heterosis In Hybrid Soft Red Winter Wheat, Zachary James Winn

Graduate Theses and Dissertations

Wheat (Triticum aestivum L.) is a self-pollinating species that is most often bred as a recombinant inbred line. When two inbred individuals are crossed, they produce progeny which experience heterosis; heterosis is the increased robustness experienced due to the reintroduction of heterozygosity. Hybrid wheat may be produced through the use of chemical hybridization agents, yet the structure of wheat flowers decreases the efficiency of outcrossing. The objectives of this study were to: assess the amount of heterosis experienced by a population of hybrid wheat and observe the effect of major gene loci on yield and yield components, phenotype anthers extruded …

Evaluation Of Topramezone For Use In Rice (Oryza Sativa L.) Production, Matthew Moore

Graduate Theses and Dissertations

The rapid development of resistant weeds, particularly to postemergence-applied herbicides, is a growing concern to rice producers worldwide. Barnyardgrass, one of the most problematic weeds in rice cropping systems, alone has been found to be resistant to four herbicide sites of action (SOA) in certain populations, leaving growers no options for control. This unsettling fact has led to research on other SOAs that have not previously been used in US rice. One SOA that has garnered interest is the 4-hydroxyphenylpyruvate dioxygenase (HPPD)- inhibiting herbicides. The only HPPD-inhibitor that will soon be labeled for use in US rice is benzobicyclon. The …

Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz

Graduate Theses and Dissertations

Soybeans (Glycine max) are one of the major row crops in the United States, particularly in Arkansas. Soybean cyst nematode (SCN, Heterodera glycines) and southern root-knot nematode (RKN, Meloidogyne incognita) are two of the most damaging pests that cause major economic losses in soybeans. Little is known concerning the effects of common and alternative agronomic practices on nematodes in fields with nematode population densities below threshold levels. Therefore, the objective of this study was to evaluate the effects of the combination of tillage (conventional tillage and no-tillage), irrigation (irrigated and non-irrigated), wheat (Triticum aestivum) residue burning (burned and no burned), …

Mitigating Herbicide Impacts To Soybean, Grant Lawson Priess

Graduate Theses and Dissertations

The rapidity in evolution of herbicide-resistant weeds and the resulting cost to U.S. farmers demonstrate the need to responsibly steward the limited number of herbicides available in agricultural systems. To reduce weed emergence and likewise added selection pressures placed on herbicides, early-season crop canopy formation has been promoted. However, impacts to soybean following a potentially injurious herbicide application have not been thoroughly evaluated. Therefore, field experiments were conducted to determine whether: 1) soybean injury from metribuzin or flumioxazin delayed canopy formation or changed the incidence of pathogen colonization; 2) residual herbicides applied preplant reduced the potential for soybean injury and …

Qtl Mapping Of Panicle Architecture And Yield-Related Traits Between Two U.S. Rice Cultivars 'Lagrue' And 'Lemont', Adam D. Rice

Graduate Theses and Dissertations

Grain yield in rice consists of multiple yield components such as number of panicles/plant, number of tillers/plant, and number of seeds/panicle. Panicle architecture is an important yield trait yield as the number of seeds on a panicle greatly contributes to the overall panicle yield. A QTL analysis and mapping study on panicle architecture and yield-related traits was performed to identify major QTL and candidate genes associated with the traits. The first objective of the project was to do a yield study evaluating 15 agronomic traits between each of the four U.S. rice cultivars, ‘LaGrue’, ‘Lemont’, ‘Bengal’, and ‘Mars’, to determine …

Quantification Of Palmer Amaranth Seed Number Using A Computerized Particle Analyzer, Matthew B. Bertucci, Paul C. Bartley Iii, Katherine M. Jennings, David W. Monks, Brian E. Jackson

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

We evaluated the accuracy of a computerized particle analyzer (CPA) for high-throughput counting of Palmer amaranth (Amaranthus palmeri S. Watson) seeds and subsequently used the CPA to verify the accuracy of two subsampling methods for estimation of Palmer amaranth seed production. To determine accuracy of the CPA, 55 hand-counted samples, ranging from 500 to 5000 Palmer amaranth seeds, were drawn from field samples and counted with the CPA. The relationship between hand and CPA seed counts was described by a linear model (R-2 = 0.99) with a slope of 0.987 and a y-intercept of 3.49. Thus, very little discrepancy exists …

Arkansas Corn And Grain Sorghum Performance Tests 2019, J. F. Carlin, R. D. Bond, J. A. Still

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2019 corn performance tests contained 74 hybrids and were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Bell Farming Company near Des Arc, the Rohwer Research Station (RRS) near Rohwer and the Rice Research and Extension Center (RREC) near Stuttgart. The 2019 …