Effect of Potassium Fertilizer Application on Soluble Sugar Content During Reproductive Stages and Yield in Vegetable Soybean

Soluble sugar content is an important indicator of the evaluation of the eating quality of vegetable soybean,this experiment was going to find out the effect of potassium fertilizer on soluble sugar content in vegetable soybean. Three potassium fertilizer treatments were treated with no potassium fertilizer( K0),120 kg·ha- 1K( K1) at seeding,120 kg·ha- 1K with additional foliar application of 30 kg·ha- 1of K2SO4(K2) at flowering-podding. We discussed the soluble sugar content in leaf,pod shell and seed during reproductive stages and yield in two vegetable soybean genotypes( ‘Zhongkemaodou 1'and ‘Line121') under normal N and P fertilizers application by pot experiment. Potassium application significantly increased the soluble sugar content in each part of vegetable soybean during reproductive stages. Maximum soluble sugar contents were all obtained at K2 treatment. Compared with control,the seed soluble contents of ‘Zhongkemaodou 1'at 7 weeks after flowering,were increased by 29. 2% and 37. 5% in K1 and K2 treatments; while‘Line 121'were increased by 9. 3% and 24. 8% respectively. As to fresh pod yield of vegetable soybean,compared with control,‘Zhongkemaodou 1'increased by 8. 2% and37. 1% in K1 and K2 treatments; while ‘Line 121'increased by 18. 9% and 31. 6%,respectively. Rational application of potassium fertilizer significantly increased soluble sugar content and fresh pod yield of vegetable soybean. The increased seed soluble sugar content by potassium fertilizer application was due to enhanced accumulation of soluble sugar in leaves and pod shells.