Effect of Direct Sowing Rates on Mid-season "Rice Feng-liang-you-xiang-1"

To study the suitable seeding rate of middle-season rice sown directly in Jianghan Plain, 6 treatments were set up with different seeding rates for hybrid rice Feng-liang-you-xiang-1 which was sown directly: 22.5, 30, 37.5, 45, 52.5, 60 kg/hm 2 , respectively and the optimum seeding rate was selected. Some initiative results were made. The seeding rate influences whole growth period, yield components, yield and relative economic output of Feng-liang-you-xiang-1 significantly. It shows a quadratic curve relationship between seeding rate and whole growth period and when the seeding rates were less than 30 kg/hm 2 or more than 52.5 kg/hm 2 , the whole growth period was obviously shortened compared with that of other seeding rate. Among the yield components, panicles, grains panicles, seed-setting rate and harvest index are effected very significantly by the seeding rate, showing a linear relationship of quadratic curve; while to 1000 seed weight the influence don't reach the level of significant difference. And seeding rate shows in curve relation to yield (y = 2.5248x 2 + 198.89x + 7620.1); when the seeding rate is 39.387 kg/hm 2 , the yield reaches the maximum value of 11536.95 kg/hm 2 .