Horticulture Commons^™

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 …

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 …

Environmental And Climatic Constraints On Large-Scale Camelina Production In Eastern Arkansas, Benjamin Robert Tracy

Graduate Theses and Dissertations

Camelina sativa is a cold weather crop that is typically grown in semi-arid environments in the Western United States, usually as a spring crop, but sometimes during the winter. Research analyzing climate data and soil hydrology is important to better understand the environmental and terrain conditions necessary for Camelina farming wherever it is proposed for large-scale production. This study focused on various conditions and constraints pertaining to the potential for Camelina as a crop biofuel in Eastern Arkansas. Due to interest in the economic potential of crop biofuels in this area, and in particular the low input costs for Camelina, …

Evaluation And Association Analysis Of Cowpea Salt Tolerance, Waltram Second Ravelombola

Graduate Theses and Dissertations

Cowpea [Vigna unguiculata (L.) Walp.] (2n=2x=22) is a leguminous crop providing inexpensive protein for human consumption that can be grown worldwide. Salinity is one of the major threats to cowpea production, particularly in semi-arid regions of Africa. Salinity significantly affects seed germination and decreases pod yield in cowpea. However, little has been done to provide farmers salt-tolerant cowpea cultivars. Knowledge on the genetics of cowpea salt tolerance is very limited. This study aimed to:(1) evaluate cowpea salt tolerance at germination stage, (2) evaluate cowpea salt tolerance at seedling stage, (3) conduct an association study for cowpea salt tolerance at germination …

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 …

Effects Of Cover Crop Treatments On Apple Trees, Jennifer Billig

Graduate Theses and Dissertations

Ground cover management systems affect soil quality and health and thereby orchard growth and productivity. There have been few studies in the southern US on the effects of managed drive-rows using cover crops as part of a sustainable apple orchard management system. A field study used treatments of 1) seasonal legumes (cowpea [Vigna unguiculata] and crimson clover [Trifolium incarnatum]), 2) seasonal grasses (millet [Setaria italic] and annual rye [Lolium multiflorum]), or 3) unmanaged natural vegetation drive row plantings, with mowed vegetation blown into the tree row as mulch (mow/blow) nested variable. The legume crop cycles produced more than twice as …

A Study Of Short-Season Winter Cover Crops For Organic High Tunnel Production Systems, Luke Riley Freeman

Graduate Theses and Dissertations

This two-year study investigated short-season winter cover crops to improve soil quality and growth of subsequent vegetable crops in an organic high tunnel production system. Five winter cover crop treatments including a nontreated control, Austrian winter peas (Pisum arvense), bell beans (Vicia faba), mustard (Brassica juncea cv. Kodiak), and Daikon radish (Raphanus sativus var. longipinnatus) were grown in a high tunnel in a randomized complete block design from mid-November to mid-March, mowed and incorporated into the soil, and followed by a succession of vegetable crops including tomato (Lycopersicon lycopersicum, cv. ‘Plum Dandy’) and broccoli (Brassica oleracea var. italica, cv. ‘Bay …

Quantitative Trait Loci (Qtl) For Salt Tolerance In Soybean And Physiological Response To Salt Stress During Early Growth Stage, Cindy Massiel Lopez Ramirez

Graduate Theses and Dissertations

Soybean is a major cash crop used as a source of high–quality protein and oil. Salt stress is one of the main abiotic stresses causing significant yield losses in soybean, which is considered a moderately salt–sensitive crop. Breeding selection is a promising strategy to improve salt tolerance as soybean germplasm display wide variation in response to salinity stress. However, the physiological and genetic mechanisms for salt tolerance are not quite clear. The discovery of novel QTL/genes associated with salt tolerance facilitates the development of tolerant cultivars through marker-assisted selection (MAS). The objectives of this study were: 1) identify/confirm QTL associated …

Selection Of Drought-Tolerant Soybean Lines Using A Field Screening Method And Identification Of Qtls For Slow Wilting And Nitrogen Fixation Associated With Drought-Tolerance, Mirta Beatriz Dalzotto

Graduate Theses and Dissertations

Drought causes significant yield reductions in soybean. The development of drought-tolerant cultivars is an effective alternative to overcome this abiotic stress. Slow wilting, prolonged nitrogen fixation, and minimal yield reduction under water stress play an important role in evaluating breeding materials. Despite advances in knowledge about plant responses to drought conditions, there is little information on effective methodologies for phenotype screening in the field, and some QTLs have been identified for drought tolerance. Field screenings under drought and irrigated conditions are necessary to detect drought tolerant lines. In addition, QTLs and molecular makers associated with drought tolerance traits will greatly …

Soil And Plant Property Differences Among High-Yield Soybean Areas In Arkansas, Taylor Cass Adams

Graduate Theses and Dissertations

Continued achievement of soybean [Glycine max (L.) Merr.] yields greater than 6719 kg ha-1 (100 bu ac-1) will depend on decreasing the yield gap, which is contingent on gathering more information regarding the soil physical, chemical, and microbiological environment and the main plant factors contributing to high-yield soybean. Therefore, understanding the main factor differences between high- and average-yield areas may provide insight for making management decisions to increase yields. The objectives of this study were i) to evaluate the effects of region and soil depth on soil property differences between high- and average-soybean-yielding areas, ii) to determine which soil properties …

Spinach (Spinacia Oleracea L.) Seed Germination And Whole Plant Growth Response To Heat Stress And Association Mapping Of Bolting, Tallness And Erectness For Use In Spinach Breeding, Jessica Chitwood

Graduate Theses and Dissertations

The effect of temperature on spinach seed germination was evaluated using a total of nine spinach genotypes and seven temperatures: 10, 15, 20, 25, 30, 32, and 35 oC in growth chambers. Genetic variation was observed. ‘Donkey’, ‘Marabu’, and ‘Raccoon’ showed higher seed germination percentage with over 70% at 30 and 32 oC, indicating the three spinach genotypes had heat-tolerance for germination. However, all spinach genotypes except ‘Ozarka II’ had lower germination percentages of less than 30% while ‘Ozarka II’ had 63% at 35 oC, indicating ‘Ozarka II’ may be a source of heat-tolerance for seed germination.

Seed germination may …

Nutrient Management For Growing Dandelion (Taraxacum Officinale L.) In Nutrient Film And Deep Flow Hydroponics, Reetinder Gill

Graduate Theses and Dissertations

This research study was conducted to determine an optimal nutrient strategy for dandelion production in nutrient film technique (NFT) and deep flow technique (DFT) systems of hydroponics. It was achieved by growing dandelion at varying levels of nutrient solution concentration and pH in both NFT and DFT systems. Additionally, an optimal nutrient solution concentration and timing of application for dandelion seedling production was also determined.

Use Of Remote Imagery And Object-Based Image Methods To Count Plants In An Open-Field Container Nursery, Josue Nahun Leiva

Graduate Theses and Dissertations

In general, the nursery industry lacks an automated inventory control system. Object-based image analysis (OBIA) software and aerial images could be used to count plants in nurseries. The objectives of this research were: 1) to evaluate the effect of an unmanned aerial vehicle (UAV) flight altitude and plant canopy separation of container-grown plants on count accuracy using aerial images and 2) to evaluate the effect of plant canopy shape, presence of flowers, and plant status (living and dead) on counting accuracy of container-grown plants using remote sensing images. Images were analyzed using Feature Analyst® (FA) and an algorithm trained using …

Integration Of Herbicide Programs With Cultural And Mechanical Practices For Managing Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Soybean (Glycine Max), Holden Bell

Graduate Theses and Dissertations

Herbicide-resistant Palmer amaranth is the most troublesome weed in Arkansas row crops, causing producers to rely heavily on multiple mechanisms of action to reduce selection pressure for further evolution of herbicide resistance and to successfully produce a profitable crop. It is critical for the sustainability of weed management not only to adequately control this weed but also to reduce the soil seedbank using both non-chemical and chemical practices. Studies were conducted to determine the effect of soybean row spacing, seeding rate, and herbicide program on Palmer amaranth emergence, survival, and seed production in soybean, the effect of drill-seeded soybean population …

Screening Diverse Soybean Germplasm For Water-Logging Tolerance, John Franklin Carlin

Graduate Theses and Dissertations

Water-logging can be detrimental to soybean growth and development; effects range from chlorosis and stunting to yield loss and plant death. Soybean response to, and the effects of, water-logging are dependent on the growth-stage of the plant at the initiation of water-logging. The objectives of this study were to screen a diverse soybean germplasm collection for water-logging tolerance (WLT) at both the V5 and R1 growth stage and to develop a method to screen soybean for WLT in greenhouse. One hundred thirty five genotypes consisting of historical genotypes, PIs, drought and WLT tolerant breeding lines were screened for WLT in …

Nitrogen Management Practices And Colored Plastic Mulch Films Affecting Spider Mites And Aphids On Winter Strawberry In A High Tunnel, Kevin Philip Durden

Graduate Theses and Dissertations

Off season high tunnel strawberry production has the potential to augment income for Arkansas fruit growers during an unproductive time of the year, however management guidelines do not exist. At the University of Arkansas Agricultural Research and Extension Center in Fayetteville, AR studies were conducted to evaluate the effects of four nitrogen (46-0-0 urea fertilizer) fertigation rates (0.75, 0.50, 0.25, 0.0 kg N/day/ha) and red or black colored plastic mulch films on densities of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), numbers of parasitized cotton aphids, and fruit yield weight. Foliar and …

Primocane-Fruiting Blackberry: Optimum N-Fertilization, Jose Carlos Reynoso Campos

Graduate Theses and Dissertations

This study was conducted in 2011 at the University of Arkansas, Fayetteville to determine the optimum rate and time of nitrogen (N) application for `Prime-Ark® 45' primocane-fruiting (PF) blackberries under high tunnel conditions. There were four N treatments: Control (0), 10, 10-split, and 20 kg*ha-1 (Treatments 1, 2, 3, 4, respectively). In a randomized complete block (RCB) design, the following variables were compared: total and marketable yield, fresh weight of plant above ground, and cane diameter. Total fruit yields for Treatments 2 and 3 (2.5 and 2.5 kg, respectively) were highest and significantly different from the other treatments (p< 0.05). Marketable yield had a similar trend as total fruit yield, although not significantly different. Cane diameter and plant fresh weight were not significantly affected by fertilizer treatments. There were not significant differences in N content in leaves among treatments. Results indicated that either a single or split N application of 10 kgN*ha-1 could result in better yields.

Four …

Postharvest Storage And Nutraceutical Evaluation Of Muscadine Grapes (Vitis Rotundifolia Michx.), Derek Barchenger

Graduate Theses and Dissertations

A major limiting factor in muscadine grape (Vitis rotundifolia Michx.) commercialization is deterioration during storage. One solution for extending market seasons and preventing market saturation for fresh muscadines could be the release of new cultivars with improved postharvest storability. Three studies were conducted; Study 1: The effect of fungicide treatments on muscadine genotype postharvest storage and nutraceutical content; Study 2: An evaluation of a diverse range of genotypes for postharvest storage potential and nutraceutical concentrations; and Study 3: The impact of postharvest storage and berry segment on the nutraceutical composition of `Supreme'. Research on table grapes has shown that field …

Spatial Distributions Of Rhizoctonia Species In Soybean Fields Undergoing Annual Rotations With Rice, Terry Neil Spurlock

Graduate Theses and Dissertations

Aerial blight is caused by Rhizoctonia solani AG1-IA. This pathogen also causes sheath blight of rice. In Arkansas, many soybean and rice fields undergo an annual rotation of these two crops which facilitates a continuous source of inoculum from one year to the next. Aerial blight is a two stage disease in that R. solani AG1-IA colonizes the plant during the early vegetative growth stages and then aerial blight develops after the soybean canopy closes in the later reproductive stages of development. As a result of the upper portion of the canopy often being asymptomatic, significant yield loss can occur …

Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays

Graduate Theses and Dissertations

In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same …

Physiological Effects Of Low Mowing Heights, Rolling, And Foot Traffic On Creeping Bentgrass Putting Greens, Joseph Ronald Young

Graduate Theses and Dissertations

Golf course superintendents are managing creeping bentgrass (Agrostis stolonifera L.) putting greens throughout the transition zone where temperatures can exceed optimum levels for consecutive days in the summer. The stress of creeping bentgrass associated with these supraoptimal temperatures has been well documented, but the management practices implemented on putting greens to increase green speeds may exacerbate these environmental stresses. To date, the physiological effects of these management practices in combination have not been evaluated for putting green turf. The objective of this dissertation project was to determine the effect of mowing heights, light-weight rolling, and foot traffic on performance and …

Taxonomy And Dna Barcoding In The Genus Manfreda (Salisb.) Asparagaceae, William David Ritchie

Graduate Theses and Dissertations

The genus Manfreda Salisb. of Asparagaceae is a genus of potential horticultural interest and is currently subject to breeding efforts at the University of Arkansas. A lack of taxonomic clarity however undermines the classification of potential inter - and intrageneric hybrids. The study aims to assess existing species delimitation within the genus Manfreda employing morphology while investigating the potential utility of Consortium for the Barcode of Life Plant (CBOL) DNA Barcodes for identification of specific taxa and an External Transcribed Spacer (ETS) - Internal Transcribed Spacer (ITS) DNA barcode for developed hybridized taxa.

Observation of 855 herbarium specimens facilitated phylogenetic …

Evaluation Of Isothiocyanates And Herbicide Programs As Methyl Bromide Alternatives For Weed Control In Polyethylene-Mulched Tomato And Bell Pepper, Pratap Devkota

Graduate Theses and Dissertations

Methyl bromide (MeBr), a Class I ozone –depleting substance, has been banned for ordinary agricultural uses. In the absence of an effective MeBr alternative, weed control is a major challenge for commercial tomato and bell pepper production. Field trials were conducted at Fayetteville, AR, to compare allyl isothiocyanate (ITC), metam sodium, and herbicide programs with the standard MeBr application (mixture of MeBr plus chloropicrin at 67% plus 33%, respectively, hereafter referred to as MeBr) for crop injury, weed control, viable yellow nutsedge tubers, and marketable yield in low–density polyethylene (LDPE) mulched tomato and bell pepper production. In addition, herbicide programs …

Establishment Method And Cultural Practice Effects On Sports Turf, Josh Anderson

Graduate Theses and Dissertations

The use of soil-based sod on sand-based rootzones for the establishment of sports fields and golf courses is a common occurrence. Furthermore, the use of soil-based sod on sand-based rootzones can lead to potential problems associated with decreased water infiltration, gas exchange, rooting, and turfgrass quality caused by soil layering. Core-aerification and sand topdressing may help alleviate the problems associated with soil layering from the use of soil-based sod on sand-based rootzones. Therefore, the objectives of this research were to evaluate the effects of sod establishment methods and post- establishment cultural practices on the infiltration rate, moisture content, divot resistance, …

Assessing Biodegradable Containers For Growing Long-Term Greenhouse Crops In Subirrigation System, Stephanie A. Beeks

Graduate Theses and Dissertations

The objective for this research was to assess the efficacy of biodegradable containers compared to plastic containers for the production of long-term crops using a subirrigation system. Plastic and various biocontainers were used to grow `Rainier Purple' cyclamen (Cyclamen persicum L.) in ebb-and-flood benches. After 15 weeks, the physical properties of the containers were tested. The used plastic containers had strengths of 23.3, 23.5 and 21.9 g for the bottom, middle and top zones respectively. The peat, dairy manure and wood fiber containers had strengths of less than 2 kg for each zone. The peat, dairy manure, wood fiber and …

Foliar Symptoms Of Acute Ozone Injury And Exposure Response Characteristics Of Select Native Perennials, Susan Denise Frey

Graduate Theses and Dissertations

Twenty seven perennial species native to the Eastern Temperate Forests Level I Ecoregion were exposed to an acute ozone (O3) treatment consisting of a target peak O3 concentration of 2.0 ppm for 30 minutes in a closed chamber environment, during the summer of 2010. Plants were evaluated for visible foliar injury symptoms and symptoms were described and photographically documented. Ten of the 27 species developed visible foliar injury in which interspecific and intraspecific response to O3 was observed. A severity index was used to compare response to acute ozone exposure for the ten species displaying visible foliar injury. Species showing …

Characterization And Molecular Analysis Of University Of Arkansas Peach, Prunus Persica (L.) Batsch, Flesh Types And Development Of A Post-Harvest Evaluation Protocol For Arkansas Peach And Nectarine Genotypes, Paul James Sandefur

Graduate Theses and Dissertations

This study determined the effect of pre-cold storage treatment on P. persica genotypes, developed a protocol for the evaluation of breeding selection and cultivar storage performance, and provided information on post-harvest performance of these individuals. Additionally, characterization of the peach and nectarine flesh types, validation of endopolygalacturonase (endoPG) DNA markers, and investigation of endoPG marker allele combinations associated with the slow-melting-flesh (SMF) trait were done.

Fruit from 30 individuals were harvested at minimum- and well-mature states. After conditioning for 24 h at 20 ◦C, all 2010 fruit were exposed to 2 min of 1 ◦C 100 ppm chlorinated hydro-cooling, a …