Identification of Mineral Deficiencies Associated with Mango Decline by DRIS

Abstract The Diagnostic Recommendation and Integrated System (DRIS) approach was used to identify mineral deficiencies associated with mango decline (a disorder of unknown etiology) of ‘Tommy Atkins’ mango ( Mangifera indica L.) trees in the field. Nutrient deficiencies associated with decline were related to the nutrition of entire orchards and not to the nutrient status of individual trees within an orchard. The nutrient imbalance index (NII) was higher for trees in the orchards with the largest percentage of declined trees compared with the healthy orchard. The most deficient elements in orchards with declining trees according to DRIS were Mn, Fe, or a combination of both elements. The concentration of these elements was below the critical value in two of the three declined orchards sampled. Magnesium concentration was generally higher in declined orchards than in healthy orchards. Phosphorus had the most negative DRIS index, but the concentration was still above the critical value in an orchard that contained no declined trees. DRIS determinations from potted trees showing no mineral deficiency symptoms in a previous study also showed P to have the most negative DRIS index. DRIS, when used along with sufficiency ranges, appears to be a useful approach for identifying nutritional deficiencies involved in a mango decline.