Micronutrient imbalance of sapota orchard in table lands of semi arid region of Rajasthan, India

Abstract

Micronutrient status of sapota crop was assessed by analyzing soil and plant samples from table lands ofsouth eastern Rajasthan. Surface and sub surface soil samples were extracted with diethylene triamine pentaacetic acid (DTPA), and plant samples (including leaf and petiole) digested with di-acid mixture for the estimationof available iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn). The DTPA extractable micronutrients in thesoil samples followed the order as Mn> Fe> Zn> Cu. The mean values of surface extractable DTPA Mn, Fe, Znand Cu varied from 15.2 to 8.4, 8 to 3.4, 0.74 to 0.17 and 0.35 to 0.02 mg kg−1 respectively. Total Fe, Mn, Zn and Cuof leaf samples varied from 89.41 to 231.24, 22.2 to 97.61, 0.62 to 48.12 and 4.35 to 19.78 mg kg−1, respectively.Total Fe, Mn, Zn and Cu in petioles varied from 33.52 to 284.51, 11.31 to 69.26, 0.54 to 36 and 2.0 to 18.48 mgkg−1, respectively. Unlike soil micronutrient status, leaf sample analysis showed high Mn and Cu concentration,which resulted in Zn and Fe deficiency, resulting in shortened internodes or rosette disorders in sapota trees.