Analysis on Yield Structural Model and Key Factors of Maize High-yield Plots

A total of 41 maize high-yield plots exceeded the yield level of 15 000 kg/ha,and three newhighlights presented in 2008.First,the number and area increased remarkably.Second,most high-yield plots distributed in Inner Mongolian and Loess Plateaus.Third,maize high-yield plot appeared for the first time in Sichuan province which is characterized by higher temperature and less sunlight radiation.The yield structural model of 41 maize high-yield plots was 88 110 ears/ha,530 kernels per ear,the 1 000-kernel weight and the grain weight per ear were 368.3 g and 191.4 g,respectively.The yield level mainly determined on the kernel number and grain weight per ear,and increasing the kernel number was the key to enhance the grain weight per ear.The light and temperature condition,cultivar and planting density were yield determinant factors in maize production.