Studies on the Relationship between Yield and Leaf Area Index and Dry Matter Accumulation of Soybean with Different Population

The relationship between yield and leaf area index(LAI)and dry matter accumulation of three soybean varieties(Cangdou No.6,Jidou 16 and Jidou 17) with high yield potential with different planting density were studied.The results showed that the change trend of LAI of three soybean varieties with different planting density approximately followed the quadratic curve.There exited very significant correlation between LAI and yield of Cangdou No.6,while there exited positive correlation between LAI and yield of Jidou 16 and Jidou 17 at R6.The dry matter accumulation of three varieties all existed difference with different planting density.The dry matter accumulation of Cangdou No.6 was very significantly correlated with the yield from R1 to R6.The LAI and dry matter accumulation of Cangdou No.6 were still maintained a high level with high planting density at the late development stage,which was suitable for dense planting.