EFFECT OF POTASSIUM NITRATE AND SULPHATE ON GROWTH,ROOT MORPHOLOGICAL TRAITS,POTASSIUM UPTAKE AND UTILIZATION EFFICIENCY OF TOMATO SEEDLINGS Effects of potassium application rate on yield and potassium use efficiency of summer maize under high yield conditions Effects of potassium fertilizer and potassium use efficiency on early-, mid- and late-season rice in Hubei province, China Effects of grafting on potassium use efficiency of different cotton genotypes Effect of potassium application on crop yields and potassium use efficiencies in a wheat-cotton double cropping system Effects of different potassium fertilizer application periods on the yield and quality of Fuji apple. Effect of Potassium Application Methods on Antioxidant Enzyme Activities, Yield and Potassium Use Efficiency of Cotton