Studies On The Effect Of Different Sowing Date To Maize Growth And Yield Potential

One early-maturing and one late-maturing maize variety were used in this study. Maize growth and kernel potential under different sowing date were studied by crop growth analysis. The effects of ecological factors on maize growth, kernel development and yield potential were studied. The results were shown as following:1. The process of maize growth and development under ecological conditions was significantly different. There were significantly differences for the growth duration among maize varieties and sowing date. Temperature is the major factor affecting maize growth duration. The correlation coefficient for the mean daily temperature and maize growth duration was significant (r luyuio = -0.954**, rnongda108=-0.995**), and the regression model could be shown as yluyu10= 256.9-6.23xt. ynongda 108=336.85-9.1xt. The correlation of the other ecological factors and maize growth duration was not significant.2. The correlation of maize LAI at blossom and grain yield was highly significant (rluyu10=0.8732**, rnongda108=0.9592**).3. The dry material accumulation of maize could be expressed by logistic equation. But there were differences among sowing date and varieties. For the maize sown at April 20 were: yluyu10 = 236.897/(1+228.972e-0.093x), ynongda108 = 314.675/(l+188.990e-0.085x). For the maize sown at June 4 were:Yluyu10 = 373.477/(l+100.645e-0.075x), ynongda108=351.5007(1+61.825e-0.065x). The differences were caused by different temperature and growth rate.4. Sowing date affected maize seed development. Temperature is the major ecological factor affecting maize seed development and filling. The lack of sunshine time and high temperature stress were the major problem for the maize crop inter-planted too early in Shangdong province.5. The coefficients of variation (CV) of the characters of maize ear and seed were related with seed yield. The CV of the maize sowed at June 4 was smaller than the other sowing dates, and its yield was higher. The CV of Nongda 108 was higher than that of Luyu 10, there were big differences among its ears, rows per ear and seed volume, which limited its yield potential.6. The yields of both early and late maize varieties could be high in normal year in Shandong. Late variety has a long filling period and a low filling speed, while early variety has a short filling period and a high filling speed. The yield of the early variety Luyu 10 was high and showed high stability to different environment. Nongda 108 has big ear and high yield potential, but more sensitive to environment. Its yield was low when in the environment of high temperature and deficient light.