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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 …

Identifying Drought Tolerance Traits In Tennessee Soybean Genotypes: Recovery From Severe Water Deficit Stress, Samuel W. Purdom

Masters Theses

Ninety-four percent of U.S. grown soybeans are produced under rainfed conditions with intermittent droughts occurring late in the season during reproductive growth stages. Due to the temporary nature of drought, the ability of a crop to survive and recover effectively from water deficit stress is important for ensuring yield stability. In 2019 and 2020, two greenhouse experiments and two field studies were conducted to screen eleven soybean genotypes for transpiration response and recovery from water deficit stress and high vapor pressure deficit (VPD). In the first greenhouse study, soybean plants were grown in pots sealed to prevent evaporation and plants …

Rooting Characteristics And Antioxidant Pigment Responses Of Three Hybrid Bermudagrass [Cynodon Dactylon (L.) Pers. × Cynodon Transvaalensis Burtt- Davy] Cultivars Exposed To Drought, Cory Alan Yurisic

Masters Theses

With recent changes in global climate, water use and its conservation have become important topics of discussion. Turfgrasses for lawns, parks, and other recreational areas are often perceived negatively due to the need for irrigation. The identification of turfgrasses possessing an improved ability to withstand water deficit is an important goal in science to curb irrigation requirements in the landscape. Newly released cultivars of hybrid bermudagrass (C. dactylon L. x. C. transvaalensis Burtt-Davy) have demonstrated improved tolerance to stresses such as cold, traffic, and water deficit; however, drought resistance mechanisms of these new cultivars have been largely uninvestigated. Drought …

Physiological Evaluation And Root Morphological Differences Associated With Novel Drought Tolerant Corn (Zea Mays L.) Hybrids, Austin Gentry Scott

Masters Theses

Corn hybrids designated “drought tolerant” (DT) from three commercial seed companies were evaluated in order to determine the benefit of DT technology in a mid-south environment that may receive adequate but often poorly timed rainfall. Field research was conducted in 2014 and 2015 at Milan, TN where hybrid response to stress was evaluated at two planting dates and in non-irrigated and irrigated environments and greenhouse research was conducted in Jackson, TN to evaluate early season drought to plant physiology and root structure.

In 2014 and 2015, the non-irrigated trials received enough rainfall to create a high yielding environment. Since the …