Effect Of Planting Density On Traits Related To Lodging And Yield Of Maize

The experiment was carried out in the agricultural experiment base of Jilin University in 2017.In this study,seven maize varieties（ND222,ND239,Fumin 985,Lishou No.1,Xiangyu 211,Yudan 9953,Zhengdan 958）with high yield,high close planting potential were selected,three planting densities（60 000,75 000,90 000plants/ha）were set up in the field.The purpose of this study was to research the effect of density on stem traits and yield,to explore the relationship between loding,stalk push-down force and stalk traits,to clarify their difference between lodging resistance and high yield potential.In addition,the results are expected to provide scientific basis for stable production and high yield of spring corn.The main results are as follows:1.With the increasing of planting density,the internode diameter,internode dry weigh,dry weight per unit internode length,internode crush strength and stalk bending strength of maize decreased.2.Under the density planting of 60,000-90,000 plants/ha,the lodging rate was significantly negatively correlated with the diameter of 3^rd,4^thh and 6^thh internode,the dry weight of 2^nd,3^rd,4^thh and 6^thh internode,the dry weight per unit internode length of 2ⁿdd to 6^thh internode,the crush strength of 2ⁿdd to 6^thh internode.And the degree of correlation with the lodging rate:dry weight per unit internode length>crush strength>internode dry weight>internode diameter.3.Under the density planting of 60,000-90,000 plants/ha,the stem parameters which were closely related to the bending strength of stem were in turn:dry weight per unit internode length>crush strength>internode dry weight>internode diameter>internode fresh weight>internode length-diameter ratio>internode dry matter percentage.4.Under the density planting of 60,000-90,000 plants/ha,the main parameters for evaluating the resistance of maize were the bending strength of stem,the dry weight per unit internode length,the crush strength,the internode dry weight and the internode diameter.5.Under the density planting of 60,000-90,000 plants/ha,except for 2ⁿdd and 3^rdd internode,the 4^thh internode was also closely related to the maize lodging in the 2ⁿdd to6^thh internode of base of maize stalk.6.Under the density planting of 60,000-90,000 plants/ha,the accumulation of internode dry matter in 2ⁿdd to 4^thh internode of maize stalk was most closely related to the lodging resistance,and the more dry matter accumulation,the stronger the ability to resist lodging.The internode dry matter in the lower part of maize plant is provided by the middle and lower leaves,so it is an important measure to keep the high photosynthetic efficiency of the middle and lower leaves and delay its premature senility.