Horticulture Commons^™

Investigating Effect Of Seed Source And Developing Germination Protocols To Improve Success In Restoration Of Arkansas Tallgrass Prairies, Rhiannon Spencerosa

Graduate Theses and Dissertations

American tallgrass prairie has faced losses estimated at 87-98% of original land area since European settlement. Native seeds are often used to supplement struggling or extinct plant populations in tallgrass prairie restoration and establishment sites. Two main considerations in restoration and establishment are from where to source seed and how to obtain high germination rates. In order to determine the effect of seed source, a common garden experiment was performed in Fayetteville, Arkansas in 2022 with five prairie species: Andropogon gerardii (big bluestem), Bouteloua curtipendula (sideoats grama), Panicum virgatum (switchgrass), Schizachyrium scoparium (little bluestem), and Sorghastrum nutans (Indiangrass). Seed was …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Phenotypic And Genotypic Studies In The Peach [Prunus Persica (L.) Batsch] And Muscadine Grape (Vitis Rotundifolia Michx.), Jennifer Anne Lewter

Graduate Theses and Dissertations

Peach: Peaches [Prunus persica (L.) Batsch] are routinely chilled to increase shelf-life. Exposure to temperatures of 5° C for two weeks can induce chilling injury (CI) symptoms, including flesh mealiness (or wooliness) and a lack of juiciness. Phenotypic data were collected on seven biparental F1 peach populations maintained at the University of Arkansas Fruit Research Station. A genome wide association study (GWAS) was performed using TASSEL 5 which identified four quantitative trait loci (QTLs) associated with expressible juice, four QTLs for mealiness, five QTLs for soluble solids, and three QTLs for fruit weight. Exploiting these genetic markers could help breeders …

Midseason Nitrogen Sufficiency Guidelines For Corn Production In Arkansas Based On Tissue Analysis And Remote Sensing, Caio Luiz Dos Santos

Graduate Theses and Dissertations

There are a lack of tools to assess midseason nitrogen (N) status in corn (Zea mays L.) production systems and identify the need for additional N fertilization. This study was conducted to determine the ability of leaf N concentration (LN) and the Dark Green Color Index (DGCI) at the 10th collared leaf stage (V10), the 12th collared leaf stage (V12), and tasseling (VT) to predict if midseason N is required to maximize corn grain yield. From 2017 to 2019, eight field studies with 11 N treatments ranging from 0 to 258 kg N ha-1 were conducted on silt loam soils …

Assessment Of Control Of Ppo-Resistant Palmer Amaranth And Salvage Options In Herbicide-Resistant Cotton, Wyatt D. Coffman

Graduate Theses and Dissertations

Palmer amaranth has been the most limiting weed in cotton production in the state of Arkansas for many years. Recently, resistance of Palmer amaranth to the protoporphyrinogen oxidase (PPO)-inhibiting site of action has been discovered at various locations across the cotton-producing region of the state. Cotton varieties have been developed with resistance to synthetic auxin (WSSA Group 4) herbicides. However, research to date has shown PPO-resistant Palmer amaranth to be more difficult to control with herbicides that target alternative sites of action. Herbicide efficacy is also known to vary with weed size, varying spray parameters, and environmental conditions. Preliminary research …

Determining The Light Requirements Of Various Turfgrass Systems And Investigating Techniques To Quantify Photosynthetically Active Radiation, Travis Russell

Graduate Theses and Dissertations

Light is one of the primary growth-limiting factors of turfgrass. Without sufficient quantities of photosynthetically active radiation (PAR; 400-700 nm wavelength), turfgrass quality will decline and could ultimately result in plant death. PAR light can be expressed in a daily quantity known as the daily light integral (DLI) and has been utilized to determine minimum light requirements for turfgrass as well as other plants. With an estimated 25% of all turfgrass being maintained under some level of shaded conditions, it is imperative to define minimum DLI requirements of various turfgrass systems to ensure acceptable turf quality. In addition, it is …

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.