Stress susceptibility index (1-Yd/Yp) / (1-∑Yd/∑Yp) used to determine drought resistance on the field is the alter form of drought resistance coefficient (Yd/Yp) . The correlative coefficient above both is r= -1. Therefore, the former doesn't improve the defect of the latter. Using thirty winter wheat varieties as trial materials, after two years experiments, the concept of drought resistance index in crops was put forward, its expressing equation is. the yield in dryland × drought resistance coefficient... Stress susceptibility index (1-Yd/Yp) / (1-∑Yd/∑Yp) used to determine drought resistance on the field is the alter form of drought resistance coefficient (Yd/Yp) . The correlative coefficient above both is r= -1. Therefore, the former doesn't improve the defect of the latter. Using thirty winter wheat varieties as trial materials, after two years experiments, the concept of drought resistance index in crops was put forward, its expressing equation is. the yield in dryland × drought resistance coefficient / average yield in dryland, it makes the drought resistance coefficient (physical index) correlate well with the yield in dryland (agronomy index) and is suited for breeder. |