Interacting leaf dynamics and environment to optimize maize sowing date in North China Plain

Leaf growth and its interaction with the growing environment critically affect leaf area, distribution, and function, and ultimately affects grain yield of maize (Zea mays L.). To detect the effects of leaf area dynamics, growth periods, and the environment on maize grain yield, a three-year field experiment was conducted using two maize varieties, medium plant-size variety Zhengdan 958 (ZD958) and large plant-size variety Zhongnongda 4 (ZND4), and three to five sowing dates. The sowing date significantly affected maize yield as a result of changes in leaf area, growth stage, and growing environment. Prior to the 12th leaf stage, significant correlations between leaf area dynamics, environment, and yield were seldom detected. The expansion of leaf area from 12th leaf stage to silking stage was significantly positively correlated with growing degree days (GDD), solar radiation, and grain yield, indicating the importance of leaf area dynamics during this period. After silking, solar radiation played a more important role in inducing leaf senescence than GDD, particularly in the 2nd half of the grain filling stage. Accelerated leaf senescence in late growth period can increase maize yield. The environment affected leaf area dynamics and yield of the large plant-size variety (ZND4) more easily than the medium plant-size variety (ZD958) at the optimum plant density, reflecting the difference in varietal capacity to adapt to the growing environment. This study indicates that optimizing the interaction among leaf area dynamics, growth periods, and environment is a sound strategy to increase maize yield. Favorable interactions are useful to determine the optimal sowing date of a given variety.