Study On The Effect Of The Evolution And The Density Of Main Soybean Varieties Tiefeng 31 On Agronomic Traits In Liaoning Province

The information is collected between 1980-2006 about the cultivation-area of promoted soybean varieties and agronomic characters in Liao-ning Province. By life-period of varieties , analyze characteristics of the various stages and regulation of evolution of the main soybean varieties in the life cycle in Liaoning Province.After research and field experiments on the density's impact on agronomic traits of soybean-Tiefeng 31. The results as following:1. The traits of different stage of life-period of the number one promotion-area of the mainly soybean varieties in 1980-2006 in Liaoning Province:There is none or short introduction stage of soybean varieties; growing stage (the rapid growth of soybean varieties phase) is basic in 1-2 years,in which,the promotion area of rapid growth to a certain height; maturity stage (the applicatation of soybean varieties) in the peak period is longer,in which,some effective measures can be taken to extend this period; Recession stage (phase-out of soybean varieties) is longer, in which,we should maximize the time out of the market.2. Between 1980-2006 years. Select traits of soybean varieties in Liaoning Province: 100-seeds weight,the number of node of main stem increased;while,stem height and grow period decreased after increased,Podding Habit from limited to limited sub-changing trended.3. Density importantly effect on traits of soybean plant,dry matter accumulation,yield and constitute factors of yield of Teifeng 31.The density between 19.5-22.5×104 stain/hm2 ,we can get the highest yield.