Impacts Of Agronomic Measures On Canopy Structrue And Its Regulation In Hybrid Mid-Rice

The single factor experiments(nitrogen fertilizer treatment, transplanting density and mode) and multi-factors experiment(secondary regression orthogonal rotary combination designed with four factors which are transplanting density, nitrogen fertilizer, potassium fertilizer, rice seedling tiller number and five levels of each factor) are designed to study the differences of rice canopy structure, yield and quality as honglianyou 6 and liangyoupeijiu materials .The results were as follows:â‘ The experiment on nitrogen fertilizer showed: appropriate leaf area index could be acquaired under middle nitrogen fertilizer level(180kg/hm²,270kg/hm²); net photosynthesis rate was increasing as increased nitrogen fertilzer supplier which was not higher than 270kg N per hm²;higher canopy photosynthesis rate and better light enviroments could be got at the level of 180kg N per hm² at heading stage; nitrogen accumulated amount of rice on the ground was increased as the development of rice, but increased slowlier and slowlier. Nitrogen accumulated amounts of leaves were larger than those of stems and sheaths. Actual yield per hm² was increasing under 180kg N per hm²,harvested yield under 180kg N per hm² treatment reached the largest, which was 8046.0kg/hm²;harvested yield under no nitrogen treatment was the smallest, which was 6292.4kg/hm².Head milled rice rate(HMR) under 180kg N per hm² was higher ,which was 61.6%;Chalkiness was lower ,which was 9.0%;Protein content was higher, which was 8.7%.â‘¡The experiment on different transplanting density and mode showed that appropriate transplanting density(2.7×10⁵ hole/hm²) and mode(wide row spacing and narrow hole spacing) could increase the yield and improve the quality of hybrid rice honglianyou 6. Appropriate density and mode could improve the light environment and raise net photosynthesis rate. it affected rice quality among of which chalky rice, chalky area are reduced greatly.â‘¢The experiment on secondary regression orthogonal rotary combination designed with four factors which are transplanting density,nitrogen fertilizer,potassium fertilizer,rice seedling tiller number and five levels of each factor showed that :high yield of the optimized cultivation mode in practice was that transplanting density, N, K₂O, rice seedling tiller number should be applied at the rate of 2.70-2.85×10⁵ hills/hm², 180kg/hm², 165kg/hm², 3-4 tillers respectively in the medium-level fertilizer soil.