Effect of fertiliser applications to the soil after harvest on leaf nutrient concentrations in mango.
Oosthuyse S. A.
Author Affiliation: HortResearch SA, P.O. Box 3849, Tzaneen 0850, South Africa.
Yearbook - South African Mango Growers' Association 18 : 10-14
Abstract : Mango trees were treated with urea, calcium nitrate, potassium chloride, potassium nitrate, monopotassium phosphate, potassium sulfate, monoammonium phosphate, soluble boron, or calcium hydroxide after harvest in late January 1998. In early May 1998, leaf samples were taken to assess the effect on leaf N, P, K, Ca, Mg, S, Zn, Mn, Cu, B, or Mo concentrations. Leaf nitrogen concentration was increased by potassium nitrate or monoammonium phosphate application. None of the applications significantly affected leaf phosphorus or potassium concentration. Potassium chloride reduced leaf calcium concentration. There was no apparent effect of any of the applications on leaf magnesium concentration. Leaf sulfur concentration was significantly reduced by monoammonium phosphate, and significantly increased by hydrated lime. There were no apparent effects on leaf zinc, manganese or copper concentration. Leaf boron concentration was significantly increased by soluble boron application. Potassium nitrate significantly increased leaf molybdenum concentration. It is concluded that assumptions generally made concerning the effects of fertilizer applications may not necessarily be correct.