Effect of planting density on grain yield and quality of rice

Nine planting density treatments(11.2～28.1 hills·m-2) were used to study the density effect on the rice yield, grain fill-ing rate and quality. The results showed that the yield increased when planting density raised and then deceased when the density was oven suitable level. And the suitable planting density was 15.0～18.7 hills·m-2. The order of grain filling rate was superior grains on the up partsuperior grains on the middle partfeeble grains on the up partsuperior grains on the low partfeeble grains on the middle partfeeble grains on the low part of the panicle. Under suitable density condition,protein content increased and amylose content, head rice rate and chalk grain decreased. Raising grain yield could increase protein content, decrease amylose content, head ricerate and chalk grain, and improve the appearance, eating and nutrient qualities.