Abstract:

Rice dry-cultivation is a new technology in paddy rice production. An indica hybrid rice combination, Shanyou 63, was used to investigate the grain yield and quality of rice cultivated with different methods. Three treatments, dry-cultivation mulched with straw (DCMS, the field covered with rice straw before transplanting and not flooded), dry-cultivation mulched with film (DCMF, the field covered with plastic film before transplanting and not flooded), and moist-cultivation (MC, the field kept flooded, control), were established. Grain yield and its components, grain quality, starch profile characters, root dry weight and activity were determined. The results showed that there was no significant difference in the grain yield between DCMS and MC, but the grain yield of DCMS was significantly higher than that of DCMF. Under dry-cultivation, the panicles per square meter were significantly increased, but spikelets per panicle, grain setting percentage and 1 000-grain weight were decreased. More effective panicles by DCMS were produced than by DCMF, which attributed to higher grain yield for the former than the latter. The differences in the milling quality, appearance quality, and cooking and nutrient quality of rice were not significant between DCMS and MC, indicating that DCMS has no bad effect on the grain quality. Grains from DCMF had higher chalkiness, smaller gel consistency and alkali spreading value, when compared with those from MC. Peak viscosity and breakdown value were decreased and setback value of the starch profile of rice endosperm were increased by dry-cultivation, specially by DCMF, suggesting that the eating quality of the rice grown under DCMS is better than that under DCMF. Dry matter accumulation of shoot was reduced, but root dry weight, remobilization of assimilates from stems to grains and harvest index were increased by both DCMS and DCMF. Root activities under both DCMS and DCMF were higher than those under MC at heading and early grain filling stage, but decreased faster during the mid and late grain filling period. In comparison, DCMS exhibited a slower decrease in root activity and leaf senescence than DCMF. The results suggest that the grain yield and quality of rice under DCMS are better than those under DCMF, and all the dry-cultivation of rice do not produce low grain yield and poor rice quality. Reasons for the differences in the formation of grain yield and quality between DCMS and DCMF were discussed in the paper.

Key words: Rice, Dry-cultivation mulched with straw, Dry-cultivation mulched with film, Moist-cultivation, Grain yield, Rice quality