Abstract:

The experiments were conducted to study the effects of planting density on the population growth of fine quality hybrid rice with ‘Yiyou 673’ as experimental material. The results showed that the parabola curve could be used to describe the relationship between rice yield and planting density. The suitable planting densities were 21.43-25 hole/m2. With the increase of planting density, the maximum tillers and panicles per square meter increased, while spike rate and grains per spike declined, and thus, the treatment of suitable planting density formed a larger storage capacity. The seed setting rate and 1000-grain weight showed no significant difference among planting density treatments. With the increase of planting density, the dry matter productivity also increased at different stages after transplanting, and then, the accumulation of structural and storage substances before heading & photosynthetic substance after heading all increased gradually, which provided the material basis on forming a larger storage capacity and maintaining sink-source balance. To improve the crop growth rate (CGR) had to improve the leaf area index (LAI), while the LAI increased at different stages with the increase of planting density. Therefore, the high CGR required rational close planting.