Estimating crop evapotranspiration under drought stress provides the theoretical foundation for optimizing irrigation schedule and reducing agricultural drought risk. Winter wheat water deficit plot experiments were conducted based on large-scale weighing lysimeters in the Huaibei Plain. The response of evapotranspiration to water deficit during several growth stages was analyzed; four crop coefficients were optimized and then evapotranspiration under drought stress was estimated with the dual crop coefficient method and the genetic algorithm. Drought stress not only reduced evapotranspiration during the current stage, but this influence was also transferred to the following periods. Evapotranspiration could basically return to the normal status after rewatering if the plant did not previously suffer from serious drought stress. Therefore, severe water deficit during continuous wheat growth periods should be avoided, and the deficit intensity during each stage should be controlled. The optimized K_{cb ini}, K_{cb mid}, K_{cb end} and K_{c max} were 0.32, 1.38, 0.33 and 1.39, and the root mean square error, mean absolute error, and mean relative error of the corresponding estimated evapotranspiration under drought stress were 22.83%, 25.36%, and 11.78% less than those using recommended coefficients, respectively. These optimized crop coefficients provide references for the practical application in the Huaibei Plain, this method for estimating crop evapotranspiration under drought stress can be applied to field circumstances and other regions.

In this study, the effect of waterlogging stress at the stem elongation stage on the wheat grain yield, grain traits, and quality of Chinese southern-type steamed bread was investigated in a field experiment using three winter wheat varieties (Aikang 58, Yannong 19, and Huaimai 44). Waterlogging stress significantly (p < 0.001) decreased the grain yields of the three wheat varieties, and Aikang 58 was the most tolerant variety, achieving a 90.8% yield compared with that of the control (normal irrigation). A grain component analysis showed that waterlogging significantly (p < 0.05) decreased the ratios of glutenin to gliadin and amylopectin to amylose in wheat grain. A Mixolab analysis showed that waterlogging significantly (p < 0.05) decreased the dough development time; stability; and C2, C3, C4, and C5 values of the three wheat varieties. A steamed bread-making test showed that steamed bread made from Aikang 58 under waterlogging conditions showed a lighter color, a higher specific volume, and a lower hardness than that made from Yannong 19 and Huaimai 44 under waterlogging conditions. Overall, waterlogging showed different effects on the wheat grain and steamed bread qualities in the three wheat varieties, with Aikang 58 exerting the best performance under waterlogging conditions.