Agronomy and Crop Sciences Commons^™

Arkansas Soybean Performance Tests 2017, R. D. Bond, J. A. Still, D. G. Dombek

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.

Economic Contribution Of The Agricultural Sector To The Arkansas Economy In 2015, Leah English, Jennie Popp, Wayne Miller

Research Reports and Research Bulletins

Agriculture and associated agricultural activities are major contributors to the Arkansas economy. Agriculture is defined as the sum of agricultural production and processing activities, unless otherwise specified, and includes crop and animal production and processing, agricultural support industries, forestry and forest products, and textile goods. Agriculture contributes to the economy through direct agricultural production and value-added processing, and also leads to economic activity in other parts of the economy. This report is the tenth in a series of reports examining agriculture’s economic contribution to the Arkansas economy. The total economic contribution of agriculture (direct, indirect, and induced effects) on value …

Shallow Aggregate Ebb-And-Flow System For Greenhouse Lettuce Production, Joseph Chidiac

Graduate Theses and Dissertations

A novel soilless technique for the production of lettuce was developed and evaluated for its viability for ornamental greenhouse growers adapting their ebb-and-flood irrigation benching systems to diversify into growing lettuce, without having to purchase the conventional nutrient film technique (NFT) or deep flow technique (DFT) hydroponic systems. The experimental design was a three by four factorial, with three treatments for aggregate depth (19, 38, and 57 mm) and four treatments for irrigation frequency (once every 1, 2, 4, or 8 hours), for a total of twelve treatment combinations. Each treatment was replicated three times in a randomized complete block …

New Technologies For Evaluating Putting Green Surface Characteristics, Daniel Patrick O'Brien

Graduate Theses and Dissertations

Golf course putting greens require a high level of inputs predicated on timely, well informed decisions. Putting green quality is ultimately defined by performance of the turfgrass, and this performance encompasses both (i) the health and vitality of the turfgrass plants, and (ii) the ability of the turfgrass to exist as a playing surface, as it interacts with the golf ball. For golf course superintendents, accurately and efficiently assessing moisture levels and nutrient status are critical for guiding maintenance practices. This research sought to examine new ways for measuring each of these parameters, and compared them to ground-truth data and/or …

Evaluation Of Insecticide Seed Treatments To Protect Rice (Oryza Sativa) Against Various Herbicides, Steven Michael Martin

Graduate Theses and Dissertations

The increase in herbicide-resistant weeds in Arkansas crop fields has led to the need for new herbicide modes of action for use in all crops. This need has led to the introduction of technologies that can be devastating to conventional rice crops. Field observation, noted that insecticide seed treatments used in rice could potentially reduce the effects of off-target movement of herbicides onto rice crops and possibly reduce the negative effects of some herbicides applied directly to rice. Research was conducted to determine if insecticide seed treatments could reduce the harmful effects of drift from imazethapyr and glyphosate onto conventional …

Evaluation Of Very-Long-Chain Fatty Acid-Inhibiting Herbicides In Arkansas Rice Production, John Ansley Godwin

Graduate Theses and Dissertations

Because of the evolution of herbicide-resistant weeds, such as barnyardgrass and red rice in rice, there is a need for alternative herbicide sites of action. Very-long-chain fatty acid (VLCFA)-inhibiting herbicides are not labeled for use in U.S. rice production; however, this site of action (SOA) has been used with success in Asian rice. The VLCFA-inhibiting herbicides pethoxamid, pyroxasulfone, acetochlor, and S-metolachlor were evaluated for rice tolerance and control of commonly problematic weeds in Arkansas rice at various rates and application timings. Pyroxasulfone and S-metolachlor were deemed unfit for use in rice production because of negative effects on rice visual injury, …

The Effect Of Preflood Nitrogen And Flood Establishment Timing On Rice Development, Nitrogen Uptake And Grain Yield, Tyler Richmond

Graduate Theses and Dissertations

Urea-N fertilizer is typically applied at the 5-leaf stage to rice (Oryza sativa L.) grown in a dry-seeded, delayed-flood production system. How long the preflood-N can be delayed without adverse effects on yield potential is poorly understood. The research objective was to determine the effects of preflood-N application and flood establishment timing on aboveground-N content, 50% heading, yield components, and grain yield. Trials were established on silt loam soils at the Pine Tree Research Station (PTRS) and Rice Research and Extension Center (RREC) during 2015 and 2016. Urea-N was applied at 0, 45, 90, 135, and 180 kg N ha-1 …

Evaluation Of Provisia Rice In Arkansas Rice Production Systems, Zachary Lancaster

Graduate Theses and Dissertations

With the continued evolution of herbicide resistance, it is becoming more difficult to achieve adequate weed control in Arkansas rice production systems. Thus, new technologies are needed to combat these troublesome weeds. A new non-GMO, herbicide-resistant rice type is under development that is resistant to quizalofop, an acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicide that will allow for selective grass weed control in rice. With the commercialization of this technology by 2018, research was conducted to determine the best fit for quizalofop-resistant rice in current production systems. Experiments included evaluation of off-target movement of quizalofop, determination of plant-back risk from quizalofop …

Characterization Of Glyphosate-Resistant Amaranthus Palmeri (Palmer Amaranth) Tolerance To Als- And Hppd-Inhibiting Herbicides, Shilpa Singh

Graduate Theses and Dissertations

Palmer amaranth is a principal weed problem across the United States and is resistant to several herbicide modes of action. By 2008, Palmer amaranth in Arkansas was reported to be resistant to both ALS- and EPSPS-inhibitors, but the predominant resistance mechanisms are yet to be explored. Herbicide options with different modes of action are needed to provide effective Palmer amaranth control and HPPD-inhibitors (e.g. mesotrione) are among these. The goal of this research was to elucidate the resistance profile of Palmer amaranth in Arkansas to ALS herbicides and glyphosate (EPSPS-inhibitor) as well as evaluate the differential tolerance of Palmer amaranth …

Characterization Of Multiple-Herbicide-Resistant Echinochloa Colona From Arkansas, Christopher Edward Rouse

Graduate Theses and Dissertations

Echinochloa species are highly adaptive weeds that have the potential to impact crops in a variety of environments. This has positioned them as the most problematic weeds in a number of USA cropping systems with some species having the distinction of the 'worst herbicide-resistant weeds' in the world. Recent evidence has positioned Echinochloa colona (junglerice) as the most dominant in Arkansas and throughout the Mid-South, USA, especially in rice (Oryza sativa L.) and soybean (Glycine max L.) production fields. A history of extensive herbicide-use for management and a lack of integrated or diverse approaches to management have led to rampant …

Experimental Simulation Of A Cross-Flow Rice Dryer, Sangeeta Mukhopadhyay

Graduate Theses and Dissertations

After harvest, rough rice is dried, then dehulled and typically milled before consumption. A broad objective of the “rice drying process”, which comprises drying and tempering, is to maximize the yield of “whole, intact milled kernels”, quantified by the “head rice yield” (HRY). Since rough rice is commonly dried using cross-flow (CF) dryers in the United States of America, the aim of this research was to assess the effect of drying and tempering treatments on milling yields when rice was dried in an experimentally-simulated CF drying column. First, because airflow rate was found to be the least-studied “drying variable”, its …

Agronomic Management Practice Effects On Particulate Organic Matter And Infiltration In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Johan Desrochers

Graduate Theses and Dissertations

Improving the understanding of conventional and alternative management practices and their interactions on aggregate-derived particulate organic matter (POM) fractions and soil hydraulic properties, particularly infiltration, is instrumental to soil and groundwater management and long-term sustainability in the Lower Mississippi River Delta (LMRD) region of eastern Arkansas. The objective of this long-term wheat (Triticum aestivum L.)-soybean (Glycine max [L.] Merr.), double-crop (WSDC) field study in a silt-loam soil (Glossaquic Fraglossudalf) in the LMRD region of eastern Arkansas was to evaluate the effects of conventional and alternative management practices, including wheat-residue level, residue burning, tillage and irrigation, on i) POM fractions and …

Arkansas Corn And Grain Sorghum Peformance Tests 2017, R. D. Bond, J. A. Still, D. G. Dombek

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.

Summaries Of Arkansas Cotton Research 2016, Fred Bourland

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Studies In Blackberry: Development And Implementation Of A Phenotyping Protocol For Blackberry Seedling Populations And Impact Of Time Of Day Of Harvest On Red Drupelet Reversion For University Of Arkansas Blackberry Genotypes, Melinda Yin

Graduate Theses and Dissertations

There are two major public blackberry (Rubus L. subgenus rubus Watson) breeding programs in the United States: one at the University of Arkansas (UA) and another at the U.S. Department of Agriculture Agricultural Research Service Horticultural Crops Research Unit (USDA-ARS HCRU) based in Corvallis, OR. The germplasm and breeding objectives of these two breeding programs are diverse, but frequent collaboration necessitated a standardized method of characterizing plant and fruit traits. A phenotyping protocol for blackberry was developed at UA and implemented for two years on UA seedling populations. The protocol included plant traits (health, vigor, estimated crop load, peak bloom …

Evaluation Of Screening Methods To Detect Heat Stress In Diverse Cotton Genotypes, Mathilda M. Van Der Westhuizen

Graduate Theses and Dissertations

Cotton (Gossypium hirsutum L.) is sensitive to heat stress (HS) during reproductive development. The objective of this study was to evaluate different screening methods for identification of heat tolerance in cotton genotypes. Three growth chamber studies and four field trials were conducted from 2014 to 2017 using genotypes Arkot 9704, VH260, DP 210 B2RF and DP393. Measurements were made of membrane leakage (ML), chlorophyll fluorescence (ChlF), glutathione reductase (GR), and sucrose concentration. In the growth chambers, measurements were made at 30 and 40°C and at 2, 4 and 6 hours of HS, as well as 3 and 7 days after …

A Laboratory-Scale Study On The Production Of High-Value Products From Broiler Litter Involving Solid-State Anaerobic Digestion And Mushroom Cultivation, Joe Barrett Carter Iii

Graduate Theses and Dissertations

There is a need to investigate alternate uses and treatments of broiler litter that lessen environmental impacts and decrease costs associated with its disposal. Anaerobic digestion is a biological process in which organic material is converted to a renewable fuel source. However, the substrate for anaerobic digestion often requires some form or pretreatment. Certain types of fungus have been investigated as a pretreatment for anaerobic digestion, one of which is Pleurotis ostreatus or the oyster mushroom, which also produces an edible fruiting body. Thus, this study was performed to investigate the use of broiler litter for oyster mushroom cultivation and …

Application Of X-Ray Imaging As A Technique For Fissure Detection In Rough Rice Kernels, Zephania R. Odek

Graduate Theses and Dissertations

Fissured rice kernels break during milling, leading to head rice yield (HRY) reductions. Conventional fissure detection instruments cannot be used to observe fissures in rough rice kernels, the form in which rice in normally dried and stored. X-rays can penetrate hulls allowing visualization of the internal structure of a rough rice kernel. This study evaluated the capability of X-ray imaging to adequately detect fissures in rough rice and established a correlation between HRY and the fissured kernel percentage (FKP) in a rough rice sample. Fifteen long-grain rice cultivars, harvested in Arkansas in 2015 and 2016 were dried using heated air …

Characterization Of The Relationships Between Soybean Yield, Trifoliolate Leaf Chloride Concentration, And Cultivar Chloride Inclusion/Exclusion Rating, Dillon Cox

Graduate Theses and Dissertations

Chloride toxicity is recognized as yield limiting problem in soybean [Glycine max (L.) Merr.] production. Limited information is available to accurately diagnose and manage Cl toxicity. The only recommendation for Cl toxicity management is to plant an excluder cultivar, however the cultivar Cl sensitivity rating system (excluder, includer, and mixed) does not appear to capture the variability in cultivar Cl tolerance. The objectives of this research were to i) develop critical tissue-Cl concentrations in which yield loss occurs for excluder and includer cultivars and ii) investigate the variability in cultivar Cl ratings. A study was conducted across five site-years using …

Evaluating Methods For Quantifying Evapotranspiration In Arkansas Rice, Colby Reavis

Graduate Theses and Dissertations

The goal of this study was to evaluate different methods for quantifying evapotranspiration (ET) in commercial rice fields using different irrigation regimes. The rice fields were located in south central Arkansas. The different irrigation regimes were alternate wetting and drying (AWD) and continuous flooding (CF). Alternate wetting and drying and conventional flooding estimates of ET were 602 mm and 570 mm, respectively, based on field observations using eddy covariance. Models used to estimate ET estimated values between 498 and 653 mm for the 2015 growing season. The Penman Monteith actual evapotranspiration model (PM AET) performed best when compared to the …

Mushroom Inoculation On Switchgrass Feedstock During Storage: Effects Of Subsequent Pre-Processing For Intended Biofuels Production, Amandeep Singh Turay

Graduate Theses and Dissertations

The objective of this project was to examine the effect of fungal treatment and liquid hot water pretreatment of switchgrass combine in view of increasing glucose release. The fungal treatment consisted of incubating Pleurotus ostreatus in square switchgrass bales, at 50% moisture content for 25 days, 54 days, and 82 days. The digestibility of the switchgrass biomass was subsequently evaluated using Accelerase 1500 enzyme. Lignin is an important barrier to enzymatic hydrolysis, and it was stipulated that incubation with P. ostreatus would disrupt plant cell walls, resulting in enhanced saccharification. Three different concentrations of P. ostreatus were evaluated: 0%, 2%, …

The Cost Of Forward Contracting In Mississippi River Barge Freight And Cif Nola Markets, Bradley John Isbell

Graduate Theses and Dissertations

Grain elevators often use paper markets to mitigate the risk of (or hedge) their cash grain positions, as well as establish a profit margin through basis trading. Typically, merchandisers use futures or forward contracts to perform these transactions. However, in order to liquidate a cash grain position, grain transportation must be arranged in order to deliver the grain to the buyer. For elevators located along the Mississippi River system selling to Gulf export elevators in New Orleans, that mode of grain transportation is most likely river barge. Contracts for barges are bought and sold by grain merchants either directly with …

Arkansas Wheat Cultivar Performance Tests 2016-2017, R. E. Mason, R. G. Miller, D. E. Moon, J. P. Kelley

Arkansas Agricultural Experiment Station Research Series

Wheat cultivar performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers.

B. R. Wells Arkansas Rice Research Studies 2016, R. J. Norman, K.A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Genomic And Physiological Approaches To Improve Drought Tolerance In Soybean, Avjinder Kaler

Graduate Theses and Dissertations

Drought stress is a major global constraint for crop production, and improving crop tolerance to drought is of critical importance. Direct selection of drought tolerance among genotypes for yield is limited because of low heritability, polygenic control, epistasis effects, and genotype by environment interactions. Crop physiology can play a major role for improving drought tolerance through the identification of traits associated with drought tolerance that can be used as indirect selection criteria in a breeding program. Carbon isotope ratio (δ13C, associated with water use efficiency), oxygen isotope ratio (δ18O, associated with transpiration), canopy temperature (CT), canopy wilting, and canopy coverage …

Evaluation Of Safening Effects To Herbicides Conferred Via Insecticide Seed Treatments In Soybean (Glycine Max) And Grain Sorghum (Sorghum Bicolor), Nicholas Robert Steppig

Graduate Theses and Dissertations

Interactions between herbicides and insecticides in crop production have been documented for a number of years. Research has shown that applications of some organophosphate insecticides at planting can reduce cotton injury following applications of the soil-applied herbicide clomazone. Additionally, recent research has shown that, when applied as seed treatments prior to planting, some neonicotinoid insecticides can safen rice to drift from both glyphosate and imazethapyr. Since insecticide seed treatments are commonly used in many crop production systems throughout the Midsouth, exploring their ability to reduce injury from herbicides in other crops besides rice is of great interest. Presently no research …

Efficiency And Competitiveness Of Kosovo Raspberry Producers, Rina Vuciterna

Graduate Theses and Dissertations

Raspberry production is a growing industry in Kosovo. In addition to private investments, this growth has been supported by grants, subsidies, and direct investment from international donor organizations and governmental institutions. At present, most of the commercially produced raspberries in Kosovo are produced on small farms, harvested by farmers and packed manually by collection centers, and then sold in frozen form for the export market. The long-term viability and continued growth of raspberry production in Kosovo depends on the industry being able to compete in export markets and hold its own against production regions in Poland, Serbia, and Russia. Our …

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 …

Characterization Of Candidate Compound For Control Of Barnyardgrass And Other Troublesome Weeds In Rice, Michael Ryan Miller

Graduate Theses and Dissertations

Barnyardgrass remains one of the most difficult weeds to manage in rice. As herbicide resistance in this species, as well as others, continues to increase new control options are needed. Dow AgroSciences recently discovered and is developing a new herbicide for rice which is the primary focus of this research. Experiments were conducted to characterize this new herbicide for its use and effectiveness in midsouthern U.S. rice systems. The research conducted herein covers various aspects of herbicide characterization including: barnyardgrass dose response, accession testing, spectrum of control and tank-mix capability, application optimization, soil carryover and plant back determination, drift onto …

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Graduate Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied …