| Through the analysis of minerals in Korla fragrant pear leaves with different ages, nutrition diagnosis of leaves was performed using Diagnosis and Recommendation Integrated System (DRIS) method, in order to obtain DRIS parameters and set standard for nutrition diagnosis. The results showed that the overall level of nutrient balance is low for all leaves of different ages for low yield orchards. However, the orders of nutrient requirement are not identical for different kinds of leaves. The 8～10 year old leaf needs more minerals of Zn, Mg, and Fe, the 12～15 year Mg, N, and Fe greatly, the 16～20 year P, N, and Ca greatly, and the 22～25 year K, Mn and Cu. |