Effects of Planting Density on Growth and Yield of Xiangnongyu No.13,A New Maize Cultivar

The growth and development and yield formation properties of Xiangnongyu No.13,a new maize cultivar,were comparatively studied under different planting densities in Changsha region.The main results showed that kernel yield of Xiangnongyu No.13 showed a increase-decrease trend when densities changed from 37 500 to 67 500 plant/hm2,and the highest yield was gained under 60 000 plant/hm2.With the planting density increasing,the ear became shorter,the number of kernel per row was significantly decreased,while row number per ear had no significant change.With the density increasing,the LAI increased significantly while the SPAD value had no significant change.The lodging percentage of Xiangnongyu No.13 was over 17% when densities were higher than 52 500 plant/hm2.Therefore,to gain high yield,the suitable planting density of Xiangnongyu No.13 in Changsha was 60 000 plant/hm2,while some measures must be adopted to improve the lodging tolerance.