Effect of seeding amount on the population quality and grain yield of direct-seeded rice.

Lingliangyou819 was studied for the effect of different seeding amount on the population quality and yield as early season rice of direct-seeded rice.The result showed that the seeding amount of direct-seeded rice had significant effects on the grain yield and population quality.The seeding amount of 37.5 kg/hm2 had the highest grain yield.The seeding amount of 60 kg/hm2 had the highest dry matter yield.The seeding amount of 45 kg/hm2 had the highest panicle number of a unit area.The harvest index and rate of effective panicles were negatively correlated with seeding amount.Seeding amount had significant effects on the chlorophyll of leaves before heading.The SPAD value of leaves before heading was negatively correlated with seeding amount.The ratio of grains and leaf area decreased with seeding amount.The ratio of grains and leave area and seeding amount were negatively correlated.Hight seeding amount increased nitrogen accumulated before heading,and influenced nitrogen absorption after heading.The dry matter yield of T1 was lower than that of T5,the grain yield of T1 was higher than that of T5,Which was related to population quality.Seeding amount of 35-45 kg/hm2 was suitable to direct-seeded rice.