The effects of different potassium(K) fertilizer application rate(0, 75, 150, 225, 300, 375kg/hm~2) on the yield and agronomic traits of Longshu 28 were studied by a single factor randomized block design.The results showed that the stem diameter was determined by the variety characteristics.The appropriate amount of K fertilizer used significantly increased the number of branches, stem length, stem weight, tuberous root weight per plant, and large-and medium-sized tuberous root rate. Application of K fertil...