Relationship between indices of growth, physiology and reflectivity and yield of winter wheat under water stress

In this study, the correlation between yield reduction rate and the relevant key performance indicators of growth, physiology and canopy hyperspectral reflectivity of winter wheat are established at different drought levels via soil water content control at different growth stages. The results show that dry-matter accumulation rate decreases with increasing drought stress at different growth stages. The correlation between chlorophyll content and soil water condition differs from that for the other parameters. Chlorophyll content is maximum in moderate drought stress and minimum in severe drought stress. Daily variation in photosynthetic rate exhibits two different characteristics, with a higher photosynthetic rate under normal soil water condition than in serious drought stress. Furthermore, an optimal relational model formulated from yield reduction rate with photosynthetic rate and enhanced vegetation index (EVI) can be used to estimate winter wheat yield.