Study on Yield Stability and Dry Matter Characteristics of Super Hybrid Rice

【Objective】The yield stability and dry matter characteristics of super hybrid rice were analyzed under different fertilizer rate conditions at different growing locations. 【Method】 Field experiments with two super hybrid rice cultivars (Zhunliangyou527 and Liangyou293) were conducted in Changsha, Guidong, Hengyang, Nanxian and Yongzhou of Hunan province in 2004 and 2005. According to the ratio of N﹕P2O5﹕K2O as 1﹕0.5﹕1, three fertilizer rate treatments (135, 180, 225 kg N·ha-1) were designed by using random block with four replications. 【Result】 The results showed that the harvest yield of super hybrid rice was highest in Guidong and existed significant differences among five sites, of which the averaged yield of two years and three fertilizer rate treatments ranged from 7 492.3-12 209.2 kg·ha-1 for Zhunliangyou527 and from 6 984.0-11 679.5 kg·ha-1 for Liangyou293. The regional variation of the dry matter accumulation and grain yield components showed the same tendency with the harvest yield. And no significant differences in harvest yield and dry matter production existed among three fertilizer rate treatments at same site. The harvest yield showed significantly positive correlations with productive panicles, seed setting rate and grain weight,and negative correlation with spikelet number per panicle. 【Conclusion】 Super hybrid rice prefers suitable or optimum growing area. The fertilizer rate in the range from 135 kg N·ha-1 to 225 kg N·ha-1 was not the limiting factor for harvest yield performance. Since super hybrid rice has larger sink capability, it is feasible to achieve high yield through increase of grain setting rate and grain weight.