Potassium nitrate and urea sprays affect flowering and yields of 'Tommy Atkins' (Mangifera indica) mango in Ethiopia
The effects of leaf applications of potassium nitrate (KNO3), alone and in combination with urea at different concentrations on flowering, fruit set and fruit quality of 'Tommy Atkins' mango grown in the rift valley of Ethiopia were evaluated. The trees were characterised by erratic flowering, continuous and high intensity of vegetative growth as well as irregular bearing. Uniform trees were selected for a randomised complete block design experiment with three replications and three trees per plot. Spraying was conducted initially on the immature post-harvest flushes and then repeated after the flushes had matured and had dark green leaves. Potassium nitrate concentrations especially in combination with urea (5 litre solution of 4% KNO3+0.5 g urea tree-1 and 5 litres of 4% KNO3+1 g urea tree-1) produced better results for most of the flowering and yield parameters. There was a non-significant difference for the qualitative parameters between the treated and non-treated trees. The supplementation of nitrogen through the spraying of KNO3 and urea is believed to be the reason for the observed greater flowering and yield results of the sprayed relative to the unsprayed trees.