关键词: 苹果, 叶片, 营养元素, 标准值

Abstract: According to the results of X² test , the distributions of N , P , K, Ca , Mg , B content in leaves conformed to the normal distribution , but those of Cu , Fe , Mn , Zn looked rather like ^X2 distribution. The values of normally distributed characters could be divided into 5 grades by 4 dividing points (standardized probability grading-SPG method) , presented the absence , low value , normal value , high value , excess of standard range of nutritional elements , and the occurrence probability of 1 - 5 grades is 10 % , 20 % , 40 % , 20 % and 10 % respectively. The third grade , which valued from ( X - 0.5246S) to ( X + 0.5246S) , could be the normal value of standard range , rather same to the average value of leaf nutritional elemets in high yield orchards. The values of X² distributed characters graded by SPG method could be corrected by the average value of leaf nutritional elemelnts in high yield orchards. Therefor , proposed the standard range of apple leaf nutritional elements of Shaanxi province ,compared to the others , the characteristics of N , Ca , Mg , Cu are higher , P , Zn , Fe , K are lower , Mn , B are same to.

Key words: Apple, Leaf, Nutritional element, Standard range