Analysis on the Grain Growing Characters in Wheat under Different Seedling Density

The grain growing processes of winter wheat under different seedling density were analyzed. The results were as follows: The volume and fresh weight of grain after anthesis were fitted "low-high-low " changing tendency, but the change of fresh weight was slightly later than that of volume. Grain water content declined continuously after anthesis. The fast declined time of grain water content was the same as the fast-increasing time of grain dry weight. Logistic equation [Y=K/1 ae-bx] was used to describe the grain filling process under different seedling density. The grain-filling rate of slow increase period and the duration of grain filling mainly influenced the 103grains weight of high yield wheat. Therefore the key of improving grain weight should increase the grain-filling rate, and prolong the duration of slow increase period.