Study On The Effects Of Development Of Mazie Ear And Tassel On Yield Under Different Planting Density

Maize yield is decided by three factors of ears per mu,grains per spike and grains weight,and these factors are affected by planting density. Increasing the planting density reasonably could increase LAI and photosynthetic potential and play an important role in increasing the yield of maize hybrid.So,it is very important to determine the planting density scientificly that could reach the super high yield of mazie. It must affect the development of mazie ear and tassel with the changing of planting density.It has both important theoretical significance and application value of mazie super high yield that study the effects on mazie ear and tassel by the different planting density.The study selected two fine varieties, zheng dan 958 and xun dan 20.The differences in development and structures of summer mazie ear and tassel were studied under different planting density conditions. The correlation between structure, density and yield were analysed by the SPSS software. The results are listed as follows:First, the development of tassel was delayed for a period with the increase of the planting density. At high planting density,tassel length and branch number were obviously reduced, anthesis was postponed, and the anther development was slowed down.When anther wall had three layers(endothecium, middle layer and tapetum) at low density, it was only at archesporial cell stage at high planting density. The pollen vitality was gradually declined with the increase of the planting density.Second, the effects of planting density on the ear is obviously. The ear differentiation date was postponed 1 day with the planting density increased. When the proximal floret of ear has differentiated a glume at low planting density,it was only formed plicate glume primordium at high planting density.The filament appearing time was postpone several hours with the increase of the planting density. The total number and size of vascular bundles of rachilla had remarkably negative correlation with the density, but had positive correlation with yield.With the increase of the planting density, vascular bundles xylem vessel diameter was decreased, the phloem area was decreased,and the change of phloem was more obviously than that of xylem.The analysis of data indicated that the size of phloem had remarkably negative correlation with the density, but had positive correlation with the yield.The effect of planting density is more obviously on phloem than that on xylem of the rachilla structures, and the phloem area had negative correlation with the planting density, but had positive correlation with the weight of dry grain per ear ,1000-grain weight and grain numbers per ear.The effects of planting density on the development of floret and kernel of ear was obviously. The numbers of kernel abortion were increased with the increase of the planting density,.