Variation in the Relationship of Major Nutrients with Micronutrient Absorption in Grape due to Variety and Rootstock

Abstract

A survey of vineyards of Thompson Seedless and Its clone 2A on their own root and Dog Ridge rootstock was conducted with an aim to elucidate the variation in the absorption (ratio of petiole to soil contents) of Fe, Mn, Zn and Cu in relation to major nutrient contents of soil and petioles, and thereby evolve guidelines for major nutrient application for efficient absorption of micronutrients in these stionic combinations. Among the four micronutrients studied, the order of sensitivity to soil and petiole nutrient contents in the four stionic combinations surveyed was Mn>Zn>Cu>Fe. Fe was more sensitive in TS on DR. The sensitivity of Mn was in the order of 2A on DR > TS on DR > 2Aon OR > TS on OR, whereas TS on DR>2A on OR >TS on OR = 2A on DR was the order of sensitivity of Zn. Sensitivity of Cu was in the order of 2A on OR > 2A on DR > TS on OR = TS on DR. Absorption of micronutrients, mainly Mn and Zn was affected most by majority of the major nutrients by Dog Ridge rootstock, particularly in combination with Thompson Seedless and least affected by 2A on own root. Variation in the relationship of major nutrient contents of soil and petioles with the absorption of micronutrients was attributed to the variation in the available soil nutrient contents, rootstock affinity for nutrients and physiological need of varieties. Hence management of micronutrients assumes greater importance in Thompson Seedless on Dog Ridge rootstock. The levels of major nutrients associated with minimum absorption, threshold levels for increasing absorption and the optimum values of major nutrients for maximum absorption of each micro nutrient were identified. The results of the investigation will guide in the application of major nutrients for efficient absorption of Fe, Mn, Zn and Cu in Thomson Seedless and its clone 2A on Dog Ridge rootstock.