Influences of the Different Sowing Dates on the Agronomic and Yield Characters of Zhongshuang 9

The optimum sowing date of Zhongshuang 9 in Jianghan plain was experimented so as to perfect the matching high-yielding technique.In the field test with random block design,the influences of different sowing dates on the agronomic characters and yield component factors of Zhongshuang 9 were studied.The fresh weight,plant height,stem thickness,total siliques number per plant and grains per pod correspondingly decreased along with the sowing date delaying.The actual yield per plant had some relationship with total available siliques number per plant.There was difference of yields in different sowing dates.The yield per plant had extremely significantly positive correlation with total available siliques number per plant,first branches number,and siliques number on the first branches and plant height,and significantly positive correlation with siliques number on main inflorescence.Total available siliques per plant had significantly positive correlation with the siliques number on main inflorescence,first branches number and siliques number on the first branches.The siliques number on the first branches had significantly positive correlation with plant height,and extremely significant correlation with first branches number.The long vegetative growth stage before spring festival was the key of Zhongshuang 9 for realizing high-yield.The suitable sowing date of Zhongshuang 9 was on about 15th September.