Research About Spring And Summer Sowing Maize Character Of Grain Yield Formation And The Screening Of Summer-resistant Maize Varieties

In this experiment, chuandan418, zhongdan808, zhenghong6and other10varieties of corn were selected for studying compared spring maize and summer maize in photosynthesis, dry matter accumulation rule, NPK absorption law, the yield and yield components differences, and filter out the appropriate spring and summer sowing maize varieties, in order to spring and summer sowing maize cultivation provide theoretical basis for high quality and high yield.The filed trials were adopted split plot experiment, sowing date processing were the spring sowing (March31) and the summer sowing (May13). The main results of this experiment were as follows:1. Leaf area index of spring sowing and summer sowing maize was insignificant in the jointing stage, but summer sowing maize’s leaf area index higher than spring sowing maize’s in silking stage. And in silking stage maize spring sowing net photosynthetic rate higher than summer sowing, SPAD value, stomatal conductance and transpiration rate of spring maize was significantly higher than that of summer sowing maize. Resistant to summer sowing maize varieties showed that, its leaf area index higher than that of summer sowing maize and there were large difference between them; its net photosynthetic rate slightly lower than the spring sowing, even higher than the spring sowing; its stomatal conductance and transpiration rate was also slightly lower than the spring sowing. So,the gap of yield between spring sowing and summer sowing maize on smaller because the advantages of summer sowing maize’s leaf area index.2. In the early growth of maize, spring sowing maize dry matter accumulation greater than summer maize, but vice versa in the maize growing late. Therefore, in the latter part of the growth of maize, summer maize’s dry matter accumulation rate was significantly higher than spring sowing maize’s. The distribution ratio of jointing and silking summer maize’s dry matter distribution center higher than spring sowing maize, but summer maize’s dry matter transporter weaker than spring sowing maize’s. Therefore, the ear’s dry matter proportion of Mature spring-sowing maize was greater than Mature period of summer sowing maize.It may be the grain yield of summer sowing maize under spring maize. So increase the ability of summer sowing maize’s dry matter transport was an important way to summer sowing maize increased production. 3. Spring sowing and summer sowing maize NPK absorption, accumulation and transport law were similar, but different uptake.100kg of grain per production, spring sowing maize needed to absorb nitrogen2.05kg,0.28kg phosphorus and potassium1.94kg, N:P:K=1:0.14:0.94; summer maize needed to absorb nitrogen2.1kg,0.36kg phosphorous and potassium1.82kg, N:P:K=1:0.17:0.87. Summer sowing maize P demand was greater than the spring maize, and K demand was lower than the spring sowing maize. So summer sowing maize were increasing phosphate fertilizer. In three periods, the phosphorus content and accumulation of summer sowing maize’s leaf and stem were significantly higher than spring sowing corn’s; the potassium content and accumulation of summer sowing corn’s leaf and stem were significantly lower than the spring sowing in the mature period; In corn jointing stage, the nitrogen content of summer sowing maize was higher than spring sowing corn, while silking stage and vice; In maize jointing stage and silking stage, the aerial parts of corn nitrogen content differences were caused by different leaf nitrogen content, and performance for in jointing stage of summer sowing maize nitrogen content was higher than that of spring sowing corn, while in the silking stage and vice.4. Most of the test production of spring sowing were higher than that in summer sowing maize variety, but no significant overall difference. Both in spring and summer sowing, the yield difference between varieties was larger. The highest in spring sowing processing, the yield of Zhong dan808, followed by Chuan dan428,Zheng hong505,Cheng dan30and Zheng hong311. In summer sowing processing, the yield of Zhong dan808and Chuan dan418were the highest, followed by Chuan dan428and Chang yu19. In all tests, spring and summer sowing maize varieties yield differences were relatively large, the yield of spring sowing was higher than that in summer sowing maize varieties were:Zheng hong505,Zheng hong311,Chuan dan428,Cheng dan30; The yield of summer sowing was higher than that in spring maize varieties were:Chuan dan418,Zheng hong6,Zheng hong2and Chang yu19. Showed that different varieties resistant to summer sowing ability difference was relatively large, Chuan dan418summer sowing resistant ability was stronger.