EFFECT OF FOLIAR AND SOIL APPLICATIONS OF ZINC-SULFATE ON ZINC UPTAKE, TREE SIZE, YIELD, AND FRUIT-QUALITY OF MANGO

To compare the effect of methods (foliar and soil) and rate of applica tion of zinc sulphate on zinc and phosphorus uptake, tree size, yield and fruit quality of mango (Mangifera indica L.) cv. Dusheri, zinc sul phate was applied as a foliar spray application (0.25, 0.50, 1.0%) and soil (0.5, 1.0, 2.0 kg tree(-1)) treatments during the second week of October (during flower bud differentiation period). All the zinc sulp hate treatments of soil and foliar spray were effective in increasing the leaf zinc concentrations above recommended adequate level of (grea ter than or equal to 20 mg kg(-1)) whereas control trees maintained lo w leaf zinc concentrations (13.8 to 13.3 mg kg(-1)). The uptake of fol iar-applied zinc was more rapid than that of soil applied zinc. All th e treatments of zinc sulphate except the foliar spray treatment of zin c sulphate (0.25%) significantly increased zinc concentrations in the fruit pulp as compared with those in the control trees. The percent in crease in the stem girth of trees was highest with the soil applicatio n of zinc sulphate (0.5 kg tree(-1)) followed by foliar application of zinc sulphate (1.0%) as compared with all other treatments. The perce nt increase in the tree canopy volume was highest with the foliar appl ication of zinc sulphate (1.0%) followed by soil application of zinc s ulphate (1.0 kg tree(-1)) as compared with control and all other treat ments. There was no significant (P less than or equal to 0.05) increas e in yield, fruit size and weight, pulp or stone weight with any treat ment of zinc sulphate. Total soluble solid (TSS) in the fruit was sign ificantly higher (18.6%) with the treatment of soil application of zin c sulphate (0.5 kg tree(-1)) as compared with all other treatments of zinc sulphate and the control. Acid and sugar content of the fruit was not significantly affected by the foliar or soil application of zinc sulphate.