Soybean Response to Foliar Applied Methanol in Humid and Semiarid Environments

Abstract

Recent research from a desert environment in Arizona suggested that foliar application of dilute solutions of methanol substantially increased yield, quality, and water-use efficiency of several C 3 plant species. However, soybean [Glycine max (L.) Merr.], which is one of the major agronomic C 3 crops of the USA, was not included. Therefore, this research was initiated to compare effects of methanol solution concentrations applied to soybean at different reproductive growth stages under field conditions in humid and semiarid environments. The experiment was conducted in 1994 and 1995 at two irrigated (limited and full) locations in semiarid, northwestern Kansas and at one dryland location in humid, southeastern Kansas. Soil moisture was determined for these growing seasons. Each of two methanol concentrations (20 and 40%, v/v) was applied either in a single application at growth stages R1, R3, and R5 or in multiple applications involving all combinations of these three for a total of seven treatments involving stage of growth. One untreated control plot was maintained in each replication. Neither methanol concentration nor time of application affected grain yield, yield components, or seed quality or soil-plant water relations. In addition, no difference was detected between the average responses to methanol application and the untreated control. Thus, we conclude that soybean responses to foliar applications of methanol are not effective under either humid or semiarid conditions typical of those found in Kansas and much of the Great Plains.