Effects Of Planting Density And Row Spacing On Yield And Canopy Apparent Photosynthesis Of Summer Corn

Maize, an important grain crops and feed crops in china, play an important role inguaranteeing nation grain safety.In order to improve the yield of high-density corn groups andachieve the high-stable yield in high-densities, rational close planting and optimumcultivation patterns will be the necessary means.Study on the effect of different densities andcultivation pattern on yield will produce guidance significance. We set up two kinds ofcultivation patterns,5densities, a total of10treatments in the Yangling corn experimentStation. The main processing is the cultivation mode, include Wide/narrow row alternationand Equal-row spacing cultivation pattern. The assistant processing is different density,respectively45000plants/hm2,60000plants/hm2,75000plants/hm2,90000plants/hm2,10500plants/hm2,there are lots of determination of index: the leaf area, photosyntheticcharacteristics, chlorophyll SPAD in5densities and2cultivation patterns, and the contrasttest is in other5different experimental field are Yijun, Linwei, Chengcheng, Chencang,Huanglong. Further clarify the relationship between corn yield and density or cultivationpatterns, with a view to provides a basis to high yield cultivation theory of maize. The resultsare as follows:1. Compared Wide/narrow row alternation with Equal-row spacing cultivation pattern in45000plants/hm2-10500plants/hm2the yield were increased by1.01%,5.72%,8.94%,13.95%,22.23%, with an average of9.43%, suitable density increase5200plants/hm2. Thegrain number per spike increased an average of0.78%, grain weight increased an average of1.32%, rate of pointless ears, sterile plant rate, rod lodging rate was reduced by an average of10.2%,10.94%,12.36%.And in Chengcheng,Huanglong,Yijun,Chencang,Linwei the yieldincrease18.92%,16.01%,4.82%,2.04%,3.46%,the suitable density and suitable plant spacingis7.5plants/hm2.In Wide/narrow row alternation, increasing yield can be achieved byimproving planting density, it's more suitable for high yield cultivation.2. With increasing density, leaf area index continued to increase; leaf area index ofWide/narrow row alternation in big bell-mouthed stage, silking stage and25days after silkingstage, compared with equal row spacing cultivation pattern respectively increase9.84%,10.65%,8.66%. Leaf area index was5.35is greater than4.62of the conventional cultivation, increase15.30%. With the changes of growth stage, Net assimilation rate ofWide/narrow row alternation decline slowly, crop growth rate in25days after silking stage,mature stage were increased to20%,42%.3. Using the Wide/narrow row alternation, jointing stage, big bell-mouthed stage, silkingstage,25days after silking stage, the ground transmittance reduction of9.26%,8.36%,31.90%,39.33%, and spike transmittance at silking stage,25days after silking were increased15.34%,15.21%. Silking stage,25days after silking stage of the most appropriate groundtransmittance are lower than equal-row spacing cultivation pattern, indicating thatWide/narrow row alternation is more suitable for high planting density, density of about75000plants/hm2,better than the conventional patterns of62000plants/hm2. In silking stageand25days after silking stage, light interception quantity compared with traditionalcultivation pattern increase5.05%and6.04%.The chlorophyll content in Wide/narrow rowalternation decreased slowly during growth period pass,so it still maintains higher level aftersilking stage, and compared with equal row spacing cultivation pattern in silking stage,25days after silking stage, mature stage increasee to6.5%,24.6%,38.6%.The description is thatin Wide/narrow row alternation,the light energy utilization rate of plants are higher.