Abstract:

To optimize population development and yield components of direct-seeding rice, explore potential productivity of new varieties and study high quality and high efficiency cultivation technology of rice direct-seeding, a field comparison experiment was conducted using the split plot design. The main plot was two direct-seeding methods, including wet direct-seeding and dry direct-seeding, the subplot was five seeding rates. The effects of direct-seeding methods and seeding rate combinations were studied on population development and yield components of rice. The results showed that dry direct-seeding could improve seedling emergence. For ‘Huashengzaoxiang’ and ‘Zhongzao35’, the effective panicles at the seeding rate of 45~75 kg/hm ² were significantly improved and the peak seedlings were extremely improved with the increase of the seeding rate, but the tillering ability and spike rate in wet direct-seeding was better than that of dry direct-seeding under the same seeding rate. For ‘Huashengzaoxiang’ and ‘Zhongzao35’, the actual yield at the seeding rate of 45~75 kg/hm ²increased with the increase of seeding rate under the 2 kinds of direct-seeding, but wet direct-seeding was more useful to increase the actual yield because the yield increase was mainly associated with the significant increase of the effective panicles under wet direct-seeding, and the effect of full grain number per panicle and 1000-grain weight was not obvious.

Key words: direct-seeding method, seeding rate, population development, yield component, effect