Effects Of Planting Densities And Spatial Distribution Patterns On Yield And Physiological Characters Of Different Summer Corn Varieties

Increasing planting density is a way to improve maize yield,but too high planting density may lead to mutual restriction between maize plants,decrease growth momentum increasing defensive energy input with the decrease in energy for growth and ultimately reduce yield.So,it is necessary to explore a way of space layout of the plant to weaken the negative effect of too large density.This experiment was conducted in 2013-2014.Different varieties,planting density and space layout was set up to study the effects of different variety,density and spatial layout on yield and physiological characteristics of Tianjin summer corn.Our objective is to determine the suitable planting way for high yields of summer maize and our results may provide the scientific basis for high yield cultivation and breeding of maize in china.In 2013,a two-factor split plot experimental design was used to determine the suitable planting model for ZD 958 in Tianjin area.Four densities(93000,81000,69000,57000 plants/ hm2)were selected as the main processing and three space layout models(equal row spacing with one plant per hole,equal row spacing with three plant per hole and wide-narrow alternate pattern with three plants per hole)were used as the vice processing.The physiological characters such as leaf area,photosynthetic or fluorescence indexes,enzyme activities and yield of ZD 958 were measured and the results indicated that under the density of 81000 plants / hm2 and the space layout of wide-narrow alternate pattern with three plants per hole,the leaf enzymic activity of SOD,POD and CAT,protein content,filling rate in the later growth period,LAI,photosynthesis and fluorescence characteristics were superior to other treatments.Although the yield of ZD 958 under this pattern was not highest,it was still considered that 81000 plants/hm2 and wide-narrow alternate pattern with three plants per hole were suitable for ZD 958 to achieve high and stable yield after comprehensive analysis.Based on the experiment of 2013,a two-factor randomized block experimental design was used in the experiment of 2014 to study the physiological characters and yield of three summer corn varieties under the high planting density of 93000 plants / hm2 and two planting patterns.The varieties were ZD 958,JK25 and JB288.The two planting patterns were three plants per hole and one plant per hole.The results demonstrated that three existed significant differences in plant traits,fluorescence and chlorophyll content among ZD 958,JK25 and JB288,which suggested each corn variety had its own most appropriate cultivation mode.After comprehensive consideration,it was concluded that for ZD 958 and JB288,three plantsper hole might be better under the density of 93000 plants / hm2,while for JK25,the pattern of one plant per hole was probably more suitable.