Developing functional relationships between temperature and soybean yield and seed quality

Authors: ALSAJRI, FIRAS - Mississippi State University; WIJEWARDANA, CHATHURIKA - Mississippi State University; IRBY, TRENTON - Mississippi State University; Bellaloui, Nacer; KRUTZ, JASON - Mississippi State University; GOLDEN, BOBBY - Mississippi State University; GAO, WEI - Colorado State University; REDDY, RAJA - Mississippi State University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2019
Publication Date: 1/10/2020
Citation: Alsajri, F.A., Wijewardana, C., Irby, T.J., Bellaloui, N., Krutz, J.L., Golden, B., Gao, W., Reddy, R. 2020. Developing functional relationships between temperature and soybean yield and seed quality. Agronomy Journal. 112(1):194-204. https://doi.org/10.1002/agj2.20034.
DOI: https://doi.org/10.1002/agj2.20034

Interpretive Summary: Limited research was done on the effects of high temperature (high heat) on seed composition (protein, oil, fatty acids, and sugars). Therefore, the objective of the current research was to study the effect of temperature on seed composition and yield under controlled environments. Two soybean cultivars AG 5332 and P 5333RY were exposed to the following high/low temperature combinations (Fahrenheit, °F): 69.8/55.4, 77/62.6, 84.2/69.8, 91.4/77, and 98.6/84.2. The results showed that seed protein concentration was slightly higher at the two lower (69.8/55.4 and 77/62.6 °F) and higher (91.4/77 and 98.6/84.2 °F) temperature combinations than at 84.2/69.8 °F. Seed oil concentration increased with temperatures 69.8/55.4 and 77/62.6 °F for both cultivars, and declined at higher temperatures (91.4/77, and 98.6/84.2 °F). Palmitic and stearic acids increased at lower temperatures (69.8/55.4 and 77/62.6 °F), but decreased at higher temperatures (91.4/77 and 98.6/84.2 °F). Oleic acid increased with increasing temperature, while linolenic and linoleic acids declined with increasing temperature. Concentrations of the sugars sucrose, raffinose, and stachyose decreased with the increase of temperature in both cultivars. Yield decreased at higher temperatures (91.4/77 and 98.6/84.2 °F). The current research demonstrated that higher temperatures decreased yield, protein, oil, sugars, and linolenic acid, but increased oleic acid. Thus, seed composition constituents respond differently to temperature. The current research provides the scientific communities with details on the potential effects of temperatures on seed nutritional qualities, and suggests that growers consider changing planting dates to avoid high heat.

Technical Abstract: Temperatures that vary spatially and temporally over the soybean growing areas affect soybean seed yield and quality. Five day/night temperature, 21/13, 25/17, 29/21, 33/25, and 37/29 C, effects on total biomass, yield, and seed quality parameters were investigated on indeterminate (Asgrow AG5332, AG) and determinate (Progeny P5333RY, PR) soybean cultivars. The cultivar × temperature interaction was significant for total biomass, seed yield, protein, oil, palmitic acid, oleic acid, linolenic acid, raffinose, and stachyose. Quadratic functions best described the response of yield to temperature, where the optimum temperature for maximum yield was 26 C for AG, and 23 C for PR. Temperature affected all seed quality parameters in both cultivars. Seed protein concentration was slightly higher at the two lower and higher temperatures than at 29/21 C. Seed oil concentration increased with temperature up to 26 C for AG and 25 C for PR and declined at higher temperatures. Palmitic acids showed quadratic responses to temperature with a significant interaction between cultivars, while stearic acid showed a similar quadratic response in both cultivars. Oleic acid increased with increasing temperature while linolenic and linoleic acids declined linearly with temperature. Sucrose concentration declined with an increase in temperature in both the cultivars. Raffinose and stachyose concentrations in the two cultivars responded differently to temperature and declined with increasing temperature. The effects of temperature on yield and seed quality that are described in this research can be used to improve crop growth models and the management of soybean under climate change.