The key of maize gain high yield is ensuring plentiful sum grain numbers, enhancing dry matter accumulation after silking stage, increasing rate of grain formed, boosting up source and enlarging sink.

• 高密度下群体源不足是产量提高的主要限制因素，保证一定总粒数，增加吐丝后干物质积累量，提高成粒率，强源促库是玉米高产的关键。