Study On The Standard Range And Effective Factors Of Nutritional Elements In Apple Leaves

Through sampling and analyzing the apple leaf samples of Shaanxi Province, the factors of crop level ,cultivars,inter/root-stock,fertilization and grow stage of nutritional element content were discussed, also proposed the proper time of sample leaf and standard range of leaf nutritional element content. The results were as following:1.According to the results ofχ2 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 likeχ2 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 and excess of standard range of nutritional elements, and the occurrence probability of 1~5 grades are 10%, 20%, 40%, 20% and 10% respectively. The third grade, which valued from (-0.5246S) to (+0.5246S), could be the normal value of standard range, rather same to the average value of leaf nutritional elements in high yield orchards. The values ofχ2 distributed characters graded by SPG method could be corrected by the average value of leaf nutritional elements in high yield orchards. Therefore, proposed the standard range of apple leaf nutritional elements of Shaanxi Province, compared to the others, the characteristics of Cu,Mg,Ca ,N are higher, K,Fe,Zn, P are lower, and Mn,B are same to.2.The factors of cultivars,inter/root-stock,fertilization and crop level influence the standard range of apple leaf nutritional elements. The contents of N,K,Ca,Mn,Zn,B are significantly different between 4 apple cultivars Fuji ,Qin Guan ,Starking Delicious and Gold Delicious, but P,Mg,Cu ,Fe are not. The contents of N, Ca, Mn, Cu,Zn are positive relation to the crop level; and P,K are negative relation to the crop level; but B, Fe,Mn are not. The contents of apple leaf nutritional elements are significantly different between M9,M26,M7,MM106 inter-dwarf stock and tall-rootstock, those(except K) of M9 are lower than the others; Zn,Mn,Cu contents of tall-rootstock are lower but Fe is higher than inter-dwarf stock . N,P,K contents in the leaves can be increased 4.51%~25.37% by fertilization.3.The content of apple leaf nutritional element changes with the grow stage, the contents of Ca,Mg,Mn,Zn,Cu increase with the grow stage; the contents of N,P decrease with the grow stage. The proper time of sample leaf is in the 85~90 days after blooming .