Grain moisture content of maize at harvest is the key factor that affects the grain quality, storage and processing which has been an important issue of technique and economic. The experiment was conducted in the field by setting a shading test throughout the whole growth period. We analyzed the influence of shading on grain moisture content of kernels at maturity. The grain moisture content showed a same tendency, Denghai 618 was the lowest, Xianyu 335 was the second and Zhengdan 958 was the highest under the treatment of CK, S1 and S2, respectively. In addition, the average grain moisture content of Zhengdan 958 was 2.26% and 9.43% higher than Xianyu 335 and Denghai 618; Xianyu 335 was 7.01% higher than that of Denghai 618. Denghai 618 was 4.36% higher than Xianyu 335 under S3 treatment. The grain moisture content increased with increasing levels of shading, the grain moisture content of S1 (85% of natural light), S2 (70% of natural light) and S3 (50% of natural light) was 2.79%, 4.43% and 23.83% higher than that of CK (natural light), respectively. With the planting density increased from 75000 to 120000 plants ha- 1, the grain moisture contents of Denghai 618, Xianyu 335 and Zhengdan 958 increased by 6.63%, 1.62% and 1.53%, respectively. The increase degree of grain moisture content of Denghai 618 was significantly higher than that of Xianyu 335 and Zhengdan 958. The weak light stress by shading delayed the maturity of maize, the maturity of S1, S2 and S3 were delayed by 4.0, 4.0 and 6.5 days comparing with CK, which may be the reason for the increase of grain moisture content. It is suggested that selecting cultivars with earlier maturity and faster kernel dehydration rate will meet the requirement of grain moisture for mechanical grain harvesting in the areas where kernel dehydration rate was slowly caused by frequently rainy and lightless weather.
国家重点研发计划(2016YFD0300110)、国家自然科学基金项目(31871558, 31501266, 31371575)