Effects of alternate wetting and drying irrigation management and air temperature during grainfill on rice grain physicochemical and functionality traits of US inbred varieties

摘要

Background and objectives Declining irrigation resources and warming cropping seasons present challenges to rice production. The alternate wetting and drying (AWD) management system conserve water, but its impact on rice grain quality is not well understood. To determine the effects of AWD irrigation management and varying seasonal temperatures on rice grain quality, a field experiment with two AWD irrigation methods and continuous flood (CF), as a control, was conducted in one year. Two environmental temperatures were observed as a result of two plating dates, one month apart. Findings Results revealed that AWD relative to CF, at either planting date, had minimum effect on grain quality traits of seven US varieties having diverse physicochemical and functional properties. On the other hand, mild warmer air temperatures that occurred during the grainfill period of the first planting were associated with lower head rice yield and higher chalkiness in brown and milled rice of some US varieties. The functional traits of apparent amylose content of low amylose varieties, Tp of a high gelatinization temperature variety, and total carbon were sensitive to air temperature changes during grain development. Conclusions AWD had no significant impact on rice grain quality, while some US varieties were more resilient to warmer temperature during grainfill on milling yield, chalk, and functional traits. Significance and novelty This study demonstrated that rice varieties can withstand moderate soil moisture stress from AWD management with minimum negative effects on grain appearance traits and functional properties.