Effect of paclobutrazol and potassium nitrate on flowering and fruiting of Ewais and Sidik mango trees.
Khattab M. M., Haseeb G. M., Shaban A. E., Arafa M. A.
Author Affiliation: Pomology Department, Faculty of Agriculture, Cairo University, Cairo, Egypt.
Bulletin of Faculty of Agriculture, Cairo University 57 : 107-123
Abstract : Trees of mango cultivars Ewais and Sidik, grown in a private orchard in Giza, Egypt during 2002 and 2003, were treated with KNO3 at 1, 2 and 4% as foliar spray or paclobutrazol (PBZ) at 2.5, 5.0 and 7.5 g/tree as soil drench. Increasing concentrations of both PBZ and KNO3 increased the percentage of flowered shoots and advanced the date of fruit set. Panicle length, initial and final fruit set were increased with increasing KNO3 concentration but decreased with increasing PBZ. Tree yield increased with increasing KNO3 concentration, whereas it decreased with increasing PBZ concentration. A direct relationship was found between PBZ concentration and fruit weight, total soluble solids (TSS) and fruit acidity. Fruit TSS was increased with increasing KNO3 but fruit weight and fruit acidity were decreased. There was a significant increase in TSS/acid ratio of Ewais fruits due to KNO3 application, especially at the highest level. Generally, KNO3 at 4% gave better results of flowering and fruiting than 2 or 1%. Meanwhile, higher concentration of PBZ had adverse effect on panicle length, fruit set and yield.