Abstract: 【Objective】 To determine the effects of different application methods of uniconazole on the yield and quality of edible sunflowers,in order to solve the problems of the declining in the commodity and quality of edible sunflower seeds in Hetao Irrigation Area. 【Methods】 A random block design was used to examine the effects of different concentrations and application methods of uniconazole on edible sunflower yield,grain apparent traits,and kernel nutritional quality using two ways,seed soaking and foliar spraying with uniconazole. 【Results】 Both seed soaking and foliar spraying with uniconazole increased the 100-grain weight,kernel rate and yield of edible sunflower. The best yield performance was when the concentration of seed soaking treatment was A4（330 mg/L）and the concentration of foliar spraying was B4（400 mg/L）. The yield increased by 15.62% and 16.20% respectively compared with the control. When seed soaking treatment concentration was A2（230 mg/L）and the foliar spraying treatment concentration was B4（400 mg/L）,the grain width increased by 10.42% and 12.50%,respectively,compared with the control. The difference was extremely significant（P<0.01）.When the concentration of seed soaking treatment was A4（330 mg/L）,the crude protein content of seed kernel had the highest increase,which was 9.49% higher than the control. The difference was extremely significant（P<0.01）. When the concentration of foliar spraying treatment was B4（400 mg/L）,the crude fat content of seed kernels had the highest increase,which was 16.18% higher than the control. The difference was extremely significant（P<0.01）. The content of essential amino acids increased when the concentration of seed soaking treatment was A2（230 mg/L）,A3（280 mg/L）,and A4（330 mg/L）.When the foliar spraying treatment was B3（350 mg/L）and B4（400 mg/L）the valine content increased. The methionine content increased at each concentration of the seed soaking treatment and the foliar spraying treatment. And the lysine content increased at the B2（300 mg/L）,B3（350 mg/L）and B4（400 mg/L）treatment. 【Conclusion】 Both seed soaking and foliar spraying with uniconazole increased the yield of edible sunflower and improved the quality of grains. The results showed that seed soaking treatment A4（330 mg/L）and foliar spraying treatment B4（400 mg/L）were the best concentrations in edible sunflower seed appearance,yield,nutrient quality and essential amino acid content.

Key words: Uniconazole, Edible sunflower, Yield, Quality