Influence of various sources of organic nitrogen as a partial substitute for mineral nitrogen fertilizer on yield, fruit quality and leaf mineral contents of Zebda mango trees.
Saad R. I.
Author Affiliation: Department of Tropical and Sub Tropical Fruits, Horticulture Research Institute, Agricultural Research Center, Giza, Egypt.
Bulletin of Faculty of Agriculture, Cairo University 63 : 69-80
Abstract : This investigation was conducted during three seasons (2008/2009, 2009/2010 and 2010/2011) on Zebda mango trees grown in sandy soil under flood irrigation condition. The recommended rate of nitrogen namely 700 gms N/tree/year was added either, completely via mineral source (ammonium sulphate 20.6%) or at various ratios from organic fertilizer (town refuse and cattle manure). The study focused on the effect of these treatments on yield, physical and chemical properties of fruits and leaf mineral contents, to determine the maximum substitution proportion of organic nitrogen source (with best yield and fruit quality) instead of mineral nitrogen fertilizer. The obtained results showed that all the used treatments of various sources of organic nitrogen were effective in improving yield, fruit quality and leaf mineral contents in comparison with mineral N 100% (control). It was also noticed that the positive effect of the superior treatments on yield/tree, fruit weight and diameter, seed/pulp ratio, TSS, TSS/acid ratio, total sugars and fruit carotinoids could be arranged in the descending order with significant differences; mineral N 20%+cattle manure 80%; mineral N 50%+town refuse 50% and mineral N 80%+cattle manure 20%. Moreover, both of mineral N 20%+cattle manure 80% or mineral N 50%+town refuse 50% significantly increased reducing sugars of fruits and leaf P, Mn and Zn than those of other treatments. Hence, it could be concluded that under the condition of this study, using mineral N 20%+cattle manure 80% is very useful for minimizing the use of mineral N fertilizer, reducing environmental pollution and obtaining an economical yield with high quality of Zebda mango fruits and considered a good recommendation for fertilizing mango trees under resembling conditions.