Study On The Population Structure And Optimized Model Of Density-Fertilizer In Maize In Different Environments In Sichuan

The population structure and the yield of corn arc controlled by both corn's genes and environmental conditions through complicated physiological activities and the processes of biochemical metabolism. This experiment, with the material of Zhenghong 6 and Zhenghong 2, studies the population structure of the corn as well as corn's yield and quality under the conditions of the different density and amount of nitrogen. The conclusions are as follows:1. The yield of corn's grains goes directly along with the accumulation of dry matter after florescence and in mature stage, while it is in the quadratic relation to the accumulation of dry matter in spinning stage, which indicates that the high grain production of the corn depends on a large amount of the population-dry-matter accumulation so that to improve the production, corn colony should not only have high biological production but also be well fertilized and watered in the late stage to accumulate effective dry matter.2. The leave area index (LAI) is an important index to measure the population structure.And both LAI(LAD) and NAR is in complicated relations with the yield, the relation of both LAI and yield is the quadratic relation in the elongation stage and spinning stage, therefore, there are some the most favorable LAI. The experiment shows that in the elongation stage, the most favorable LAI of Zhenghong 6 is about 2.4 and that of Zhenghong 2 is around 2.6; in the silking stage, the former is between 3.9 and 4.5 and the latter between 4.9 and 5.2; in the mature stage, the former around 2.2 and the latter between 2.8 and 2.9. In the whole gestation stage of Zhenghong 6, it is most noticeable that the LAI should be held to a certain level before florescence and so should be the NAR after florescence, and in the same period Zhenghong 2 requires the same as Zhenghong 6 before florescence but after florescence both its LAI and NAR should be insisted.3. The density and nitrogen fertilizer play different effects on the population structure of different breeds of corn in different stages. The density produces a more effective effect on the population structure of Zhenghong 6 during the whole gestation stage than the amount of nitrogen fertilizer does. As to Zhenghong 2 it does so just in the early and late...