Effects of pruning and potassium nitrate spray on floral and vegetative bud break of mango cv. Haden.

A study was undertaken to analize the effect of pruning, potassium nitrate (KNO3) sprays and their combination on the promotion of an early flowering in mango, in order to obtain an early harvest which may guarantee higher prices at the international market. It was established on a 4-year old plantation of cv. Haden/'Criollo', located at 9 degrees 43' NL and 180 m above sea level, in the central region of Venezuela Pruning treatments were: no pruning, pruning on one side of the tree; pruning on top and two sides; and pruning on top and four sides. Pruning was performed on June 12, 1994. KNO3 levels (0 and 6%) were sprayed on single terminal branches (12 per tree), applied in October 21 and December 18, 1994. Pruning, nib-ate levels and time of spray were combined in a 4x2x2 factorial design with 6 replicates and one plant as experimental unit Vegetative bud break was promoted in the three month period following pruning. Flowering was inhibited by pruning and inhibition increased as the intensity of pruning increased KNO3 caused a slight flowering promotion in October aid a heavier one in December, on unpruned trees. The interaction of pruning x KNO3 on flowering was significant, and to a great extent, potassium nitrate compensated the adverse effect of pruning on flowering especially when sprayed on trees pruned either on one side of the tree or on the top and two sides in December.