Study On Climatic Ecology Of Growth And Yield Formation Of Maize In West Hunan Province

A systematic study on climatic ecology of growth and development and yield formation of maize was conducted with three experiments i.e. adaptability of different varieties in different climatic ecological areas, adaptability of the same variety in different climatic ecological areas and at different sowing dates, adaptability of different varieties at different sowing dates in the same climatic ecological areas in West Hunan Province (mountainous). The results are as follows:(1) Xiangyu-10, a medium maturity variety, which is mainly-grown with an average yield of 6000-6750kg/ha, adapts to be planted in the areas with altitudes of below 500m. Another one, Yunke-5, a medium-late variety, is suitable for the areas with altitudes of between 500~800m, and a top yield of 9295 kg/ha had been achieved.(2) Medium variety Xiangyu-10, had a growth period of 100-120 days in spring, while medium-late variety Yunke-5, had a growth period of 120-140 days. The timely dates for sowing for the two varieties are between later March and earlier April and meddle to later March respectively. Furthermore, the difference of optimum seeding time, according to complex topography in the mountainous areas, would be 2-3 days per 100 meter of altitudegap-(3) Covering with polythene films (CPF) contributed to keep warm and raise temperature, thereby promoted growth of maize. However, the effect was not significant between CPF and the conventional cultivation in the areas with altitudes of below 500m. Therefore, seldom or no films should be used in these areas. In the areas with altitudes of over 500m, CPF took advantages of yield of 525-250 kg/ha and early maturity of 10 days or so over the latter, and...