Comparison Study On Optimum Cultivars And Cultural Methods Of Double Cropping Rice Under Cool And Poor Drainage Paddy Field Conditions

To select optimum cultivars and cultural methods of double cropping rice adapted to the cool and poor drainage paddy fields, the field experiments of cultivar-screening were conducted with Lingliangyou211, Luliangyou996, Xiangzaoxian24, Zhongjiazaol7, Zhongjiazao32, Zhuliangyou819as early rice and Fengyou299, Ganxin688, Jinyou299, Liangyou599, Qianyoul, Tianyouhuazhan as late rice in Ningxiang county, Yongxing county and Taoyuan county of Hunan province in2009.At the same time, the field cultural experiments were also conducted with Xiangzao1, Zhuliangyou6, Jinyou297as early rice and Jinyou299, Xiangyou66, Jinyou299as late rice in the three sites, respectively. Each of cultivars and cultural methods whose growth progress, tiller dynamic, dry matter accumulation and N, P, K uptake amount of plants, grain yield and yield components were analyzed. The results were shown as follows:(1)There were significant differences of yield and its components between cultivars, and the highest averaged yield in3locations reached to5.68t/hm2in hybrid Luliangyou-996in early season and5.61t/hm2in Tianyouhuazhan in late season;(2) The significant yield differences existed between different cultural methods. The LongXiang cultural method displayed the highest average yield in3locations, which was5.52t/hm2in early season and5.81t/hm2in late season. On the other hand, traditional cultural method showed the lowest yield, of which4.75t/hm2and5.25t/hm2in early and late season respectively;(3)Under the condition of no fertilizer application, the average yield of tested cultivars in early season was significantly lower than that in late season, but the average yield of tested cultivars was no differences between early season and late one. It is worth to study further in the future whether this was in relation to the low temperature in soils of paddy fields.As above, it is beneficial to have high yielding in cool and poor drainage paddy fields by using both optimum cultivars(Luliangyou996and Tianyouhuazhan) and LongXiang cultural method.