Research In High-yield Planting Techniques Of The "Three-High And Two-Low" High-efficiency Hybridized Yellow-seed Rapeseed Youyan 9

This test was carried out twice in Guizhou Provincial Rapeseed Research Institute in Tangtou, Sinan from 2002 to 2004, in which the initial study of high-yield planting techniques of the "Three-High and Two-Low" high-efficiency hybridized yellow-seed rapeseed Youyan 9 was launched. Through the test of its seeding time, density and the amount of nitrogenous fertilizer applied, the influence of seeding time, density and the amount of nitrogenous fertilizer applied on the yield and relative correlation of the "Three-High and Two-Low" high-efficiency hybridized yellow-seed rapeseed was discussed, so that the optimum seeding time, density and the amount of nitrogenous fertilizer applied were summarized, which can be applied for its large area production and extending in other similar ecotope.The influence of different seeding time on the rapeseed Youyan 9. There is an extremely significant difference among the average green weights per stem in the whole process of growing of different seeding time. And they have a correlation of quadratic parabolic curve with seeding time. Both of the average green weight per stem and the maximum green weight per stem have an extremely significant positive correlation with the yield. There is no obvious difference among the average green weights of silique per stem in the whole process of growing of different seeding time, but they have a correlation of quadratic parabolic curve with seeding time. The green weights of silique per stem of different phase in different seeding time have a correlation of quadratic parabolic curve with its opening adown with the growing process, which is the same as the result of former scientist. Under the condition of this test, the suitable seeding time for growing seedlings and transplanting, when high yield for Youyan 9 can be obtained, is 4th to 11th of September. If it is in the middle and lower reaches of Changjiang River, the suitable seeding time for growing seedlings and transplanting should be 10 days later.The influence of different direct sowing density and amount of nitrogenous fertilizer applied on the yield of the on the rapeseed Youyan 9.The yield has a correlation of quadratic parabolic curve with density under the condition of direct sowing and has a significant correlation with the amount of nitrogenous fertilizer applied; the yield and colony effective silique number increase following the increase of the amount of nitrogenous fertilizer applied; effective silique number per stem increase following the increase of the amount of nitrogenous fertilizer applied and...