| This paper aims to study the effect of plant density on yield and related photosyntheticcharacteristics to find the optimal plant density of compact type maize in tianjin region inorder to provide a scientific basis for the Tianjin corn yield cultivation and breeding.In2013,at Tianjin Agricultural College of Agriculture and Environmental Sciencesconducted Specialty Crop,zhengdan958was used for experimental materials, and planted bysix different densities which were2500,3500,4500,5500,6500,7500,8500plant.667m-2.In2014,zhengdan958and denghai618were used for experimental materials.And zhengdan958was planted at Tianjin Agricultural College of Agriculture and Environmental Sciencesconducted Specialty Crop.Denghai618was planted at Tianjin Wuqing District, South Caitown Zhang Xin Zhuang village. And they were planted by seven different densities whichwere2500,3500,4500,5500,6500,7500,8500plant.667m-2. Through the two years of fieldtrials of experimental data for statistics study the effects of planting density on corn yield andits related physiological characteristics index.The main results and conclusions were as fellowed:Under the experimental conditions, the different planting density treatments had significantinfluence on maize yield in the2500-8500plants.667m-2.With the increaseing of plantingdensity, the yield increases.When planting density exceeds a certain range, with the increasein density, the yield decreased. The different maize varieties exist the different reaction in theplant density.Under the5263plants.667m-2,Zhengdan958reaches the maximum yield and themaximum yield is521.8kg.Denghai618reached the highest yield when the density in5667plants.667m-2and the maximum yield is744.2kg.With the increasing of planting density,single panicles per unit area, grain numbers and grain weight showed a decreasing trend inzhengdan958and denghai618.Compared with Zhengdan958,single panicles per unit area ofgrowth is bigger, the redaction of grain number is smaller, grain weight decreased more gentlein denghai618.With the increasing of planting density, bald tip length showed the increasing trend.Withthe increaseing of planting density, the long bald, ear length, ear diameter, rows per ear,kernels per row,single panicle weight and single grain weight decreased.With the increaseingof planting density,the plant height,ear height,empty stalk lodging and disease rates increased.With the increaseing of planting density,stem diameter, double spike,the number ofgreen leaves when harvesting decreased. Plant traits is not conducive to the formation of yieldper plant, so that yield per plant decreased with the increasing of planting density, but groupyield increased within a reasonable range of planting density. Performance, the increasing ofgroup advantage makes up the plant disadvantages. Reasonable increasing planting density isan effective means to achieving high yield of maize.With the increaseing of planting density, net photosynthetic rate, photosynthetic activeradiation, transpiration rate and stomata conductance showed the decreased trend.Thereduction of photosynthesis affect the yield per plant.With the increaseing of planting density,leaf area per plant decreased.But with the increaseing of planting density,groups leaf areaindex and photosynthetic intensity increased.The increasing of source improved the collectiveassimilation, improving maize yield.Through analyzing the output and production value, yield components under the differentplanting density,had the different contribution of yield.In2500-5500plant.667m-2densityrange at zhengdan958,increasing the planting density had the bigger contribution to improveyield.In2500-5500plant.667m-2density range at zhengdan958, increasing grain number andgrain weight had an obvious effect to obtain high yield.In2500-6500plant.667m-2densityrange at denghai618, panicle harvest was an important way to improve the yield.In6500-7500plant.667m-2density range at denghai618,increasing the main spike grain number and grainweight was of great significance to improve yield. Explain the resistance to tightness ofdenghai618is better than zhengdan958. |
