Nutrient evaluation of 'Sindhri' mango orchards at two growth stages

Abstract

Proper mango nutrition at bud initiation, flowering and fruiting stages is critical for the health of mango trees and may affect the quality and yield of fruit. This study evaluates the nutrient composition in leaf tissue of 'Sindhri' mango orchards in Shaheed Benazirabad district, Sindh, Pakistan, at two growth stages. Two orchards, 25-30 years old, were selected for the experiment. Leaf-tissue samples were collected from 12 mango trees from each orchard twice a year, once at bud initiation during December and then after harvest of mango during July in the following year. About 2030 recently matured leaves (third leaf from the top) were collected from each tree to represent the canopy and combined into a single sample. Soil samples were also collected from around each tree and underneath the canopy at 0-30 cm soil depth and combined for each tree. The soil samples were analysed for texture, electrical conductivity (EC), pH, organic matter, Kjeldahl's N and ABDTPA-P and K contents. The leaf samples were analysed for Kjeldahl's N, and P and K by wet digestion with a nitric acid/perchloric acid (5:1) mixture. This study on NPK nutrition status of 'Sindhri' mango indicated that the N fertilization regime conducted by the mango growers at both sites was adequate for mango nutrition, while P and K nutrition required adjustments to meet mango nutrition requirements. Inherent fertility status also had a bearing on the mango nutrition status, particularly in the after-harvest samples. It is proposed to design further studies focusing not only on NPK but also on micronutrients, particularly B and Zn, which are reported to be deficient in many soils of Sindh province.