The yield-increasing mechanism and key high-yield technology of hybrid rice hanyouxiangqing

The rice “Hanyouxiangqing” was introduced into Songjiang District at the end of 1980s,but its yield was not high and stable, and itwas difficult for the large-area yield to be over 550kg/666.7m 2. Between 2001～2002 the rice experiments under different seeding dates, amount of applied fertilizer and application time, planting densities and methods of controlling disease and pest were carried out with the conventional rice“Xiushui 110”used as a control in order to probe the key cultural technique of high-yield and high-quality rice. The yield-increasing mechanism and relations between seeding date, fertilizer, density and yield were analyzed by the experiments and extension.The results showed that the yield-increasing mechanism of Hanyouxiang- qing is well-developed in rootage, strong in absorption ability of nutrient and in tillering ability, high in percentage of ear-bearing tiller, and big in ear size with many seeds. The key technique is early to sow and early to transplant in good time, to adjust application rate and time of fertilizer, to increase phosphorus and potassium fertilizers, to control peak seedlings and raise percentage of ear-bearing tiller as well as to prevent and control false smut of rice.