关键词: 直播稻, 播种量, 杂交稻, 千粒重, 产量

Abstract:

In order to clarify the effects of seeding amount on yield formation and characteristics of biomass production of hybrid rice with different thousand grain weight under direct seeding condition, a field experiment was conducted with different seeding amount （7.5, 15.0, 22.5, 30.0 and 37.5 kg/hm2） by artificial broadcasting in Deyang city in 2017, using Ya 5 you 2199（YY2199）with low thousand grain weight and Nei 6 you 103 （NY103）with high thousand grain weight as materials. The results showed that, the effect of seeding amount on the yield of hybrid rice was significant, panicles per m2 and biomass production of hybrid rice showed an increasing tendency with seeding amount increasing, spikelets per panicle of hybrid rice showed a decreasing tendency with seeding amount increasing. The effect of seeding amount on seed setting rate and thousand grain weight were not significantly. The grain yield of YY2199 firstly increased and then decreased with seeding rate increasing, the yield was highest when the seeding amount was 22.5 kg/hm2, which reached to 10.86 t/hm2, the yield was increased by 20.53% compared with the treatment of 7.5 kg/hm2. The yield of NY103 was highest when the seeding amount was 37.5 kg/hm2, which reached to 10.82 t/hm2, the yield was increased by 11.20% compared with the treatment of 7.5 kg/hm2. However, there were no significant difference in grain yield between seeding amount treatment 37.5 kg/hm2 and the other three seeding amount treatment （15.0, 22.5, 30.0 kg/hm2）. There was no significant difference in yield between different thousand grain weight varieties. The optimum seeding amount of hybrid rice with low and high thousand grain weight was 15.0~22.5 kg/hm2 and 22.5~30.0 kg/hm2, respectively, in consideration of both grain yield and seed cost.  

Key words: direct seeding, seeding amount, hybrid rice, thousand grain weight, grain yield