A Comparison of Soybean Leaf Water Potential and Leaf Temperature under Progressive Drought1

Publisher Website
Google Scholar
Abstract
Information is limited on the relationship between leaf water potential (Ψ) and leaf temperature (T) of soybeans [Glycine max (L.) Merr.] grown in the field. Therefore, measurements of Ψ and T were made with a pressure chamber and infrared thermometer, respectively, in five study periods during a field study in 1978. The season was characterized by progressive drought. ‘Forrest’ soybeans were grown at two moisture regimes on a Crowley silt loam (Typic Albaqualf).Linear relationships were found between T and Ψ. Leaf temperature of the nonirrigated soybeans was more sensitive to changes in Ψ than that of the irrigated soybeans and became more sensitive as the drought progressed. The regression equations relating Ψ to T in each of the five study periods were not unique for a given moisture treatment. However, the regression equations expressing the Ψ vs. T relationship for the single linear equation would suffice for describing the Ψ vs. T relationship throughout the season for each moisture treatment, but a different one would be required to express that relationship for a different moisture treatment.