Study on the Adapted Density of Very Early Maturity Corn Hybrids

The adapted plant density of very early hybrid corn in northern China was studied in 2009-2011, and the proposed method was trials design of split plot,plant density as main plot and variety as sub-plot.The results showed that the adapted plant density with the highest yield was from 22 500-30 000 plant/ha.That means the tolerance to high density was much different in tested varieties.Higher yielding was with higher density,but the highest tolerance to density was not the best hybrid.In these trials,when plant density increase 10 000 plant/ha,the average ear length decrease 0.23-1.13 cm accordingly,then,average tip length of ear increase 0.008-0.367 cm,average ear diameter decrease 0.003-0.103 cm,average cob diameter decrease 0.007-0.063 cm,average kernel length decrease 0-0.023 cm,average percentage of available plants decrease 0-2.20%,average kernel weight each plant decrease 8.4-18.5 g,average number of kernel per row decrease 0.89-2.58.Trials results showed that the adapted plant density of very early hybrid corn range 75 000-105 000 plant/ha,much higher than middle or late maturity hybrid corn such as Xianyu335 and Zhengdan958 in China.