Effect of nitrogenous fertilization on the annual variations in nutrients in avocado leaves

Abstract

Three types of leaves were sampled monthly from N‐deficient avocado trees and healthy trees over the course of an entire year: previous year's leaves, leaves from spring flush, and leaves from the second flush (summer). In all three leaf types and throughout the year, N concentration was significantly lower in the N‐deficient trees than in the fertilized ones. A significant difference was found also between the spring leaves and the summer leaves, sampled at the same time. A synergistic relationship was found between N and Ca, Mg, Mn and Cu. Antagonism existed between N and K and possibly also between N and Zn.