Study on Grain Yields Levels and Suitable Sowing and Transplanting Date of Japonica Rice Varieties in Henan Province Introduced to South

The split block experiment was carried in Hangzhou with two control indica rice varieties,Ⅱyou 838 and Tianyouhuazhan,three tested japonica rice varieties introduced from Henan province,Yujing 6,Xindao 18 and Xindao 20,four sowing and transplanting dates. Grain yields and else main agronomical characters were analyzed and suitable sowing and transplanting dates were discussed. Results showed that under introduced to South condition,the grain yields and biomass,plant height,spike length,total and filled grains per spike of japonica rice varieties were inferior to indica rice varieties,but grain setting percentage and economic coefficients were superior to indica rice varieties. With delaying date of sowing and transplanting,biomass,plant height,spike length,total and filled grains per spike of japonica and indica rice varieties both declined or reduced obviously,heading time deferred,interval from sowing to initial heading and whole growth stage both shortened,grains setting percentage and economic coefficients increased at a certain extent,moreover,grain yields of japonica rice varieties decreased and of indica rice varieties increased with the delay of sowing and transplanting date. The experiment results indicated that introducing japonica rice varieties in Henan to South China is feasible,the key technology is selecting appropriate japonica varieties and scheduling suitable sowing and transplanting.