Grain filling and dehydrating characteristics of maize hybrids with different maturity

Suitable variety arrangement according to the natural ecological conditions, maturity, grain filling and dehydrating characteristics and yield potential of maize hybrid is an important approach for realizing higher maize yield, quality and photothermal resource utilization. Thirteen hybrids widely planted in maize production with three maturity types [medium-early maturity (MEM), medium maturity (MM) and medium-late maturity type (MLM)] were selected to clarify the grain filling and dehydrating characteristics for different maturity hybrids, by investigating the dynamic changes of grain filling and moisture content. The results showed that yield, grain filling and dehydrating characteristics differed significantly between different maturities and hybrids. Average yield level showed MLM (13,813.0 kg hm^–2) > MM (12,970.4 kg hm^–2) > MEM (10,729.0 kg hm^–2), with MLM was 28.7% and 6.5% higher than that of MLM and MM type, respectively. Average grain filling rate showed MEM (0.034 g 100-grain^–1 ℃^–1) > MM (0.031 g 100-grain^–1 ℃^–1) > MLM (0.027 g 100-grain^–1 ℃^–1), average dehydrating rate after physiological maturity (PM) showed MM (0.027% ℃^–1 d^–1) > MEM (0.025% ℃^–1 d^–1) > MLM (0.018% ℃^–1 d^–1). Average grain filling rate and dehydrating rate after PM of MEM representative hybrid Jingnongke 728 were 38.5% and 112.5%, 28.6% and 54.5%, 28.6% and 13.3% higher than those of representative hybrid Zhengdan 958, Xianyu 335 and Nonghua 101 for three maturity type; the yield of Jingke 968 was the highest (14,813.0 kg hm^–2), average grain filling rate and dehydrating rate after PM was7.7% and 18.8% higher than the same maturity hybrid Zhengdan 958. Yield level was significantly or extremely significantly correlated with grain filling period, corresponding accumulated temperature, average grain filling rate and 100-grain weight; grain moisture content at harvest stage was significantly correlated with grain filling period and corresponding accumulated temperature, but negatively significantly correlated with dehydrating rate before and after PM; there were no significant correlation between dehydrating rate before and after PM with average grain filling rate. Maturity, grain filling and dehydrating characteristics were all important factors for higher maize yield, quality and photothermal resource utilization. This study indicated that maize grain filling and dehydrating characteristics differed significantly between different maturity types and hybrids. Maturity, grain filling and dehydrating characteristics should be well considered for variety arrangement in maize production in order to achieve higher maize yield, quality and photothermal resource utilization.