Use of Natural Raw Material Mixture and Natural Raw Potassium as Substitute for Chemical Fertilizers in Feeding Washington Navel Orange Trees under Kafr El Sheikh Conditions.

Abstract

This study was done in a private orchard at Kafr El-Sheikh governorate, Egypt, during 2012 and 2013 seasons on 18 years old Washington navel orange trees on sour orange rootstock, to study the effect of fertilization with natural raw material mixture and natural raw material of potassium (feldspar) on growth, leaf NPK contents and productivity of trees. Results show that, natural raw material mixture and natural raw material of potassium (feldspar) applications significantly increased growth and leaf NPK contents as compared to regular mineral fertilizers. Moreover, natural raw material mixture and natural raw material of potassium (feldspar) treatments increased yield and improved fruit quality in terms of fruit weight, fruit size, juice size, TSS, acidity, TSS/acid ratio and vitamin C. The application of 4 kg natural raw material mixture/tree + 3 kg/tree natural raw material of potassium (feldspar) +50 kg (MOM) is considered favorable treatment, which gave the best leaf NPK contents , growth, high yield and improving fruit quality of Washington navel orange trees. This treatment is a good substitute for using chemical fertilizers to avoid their deleterious effects on soil, water and human health.