EFFECT OF PACLOBUTRAZOL CONCENTRATIONS AND TIME OF FOLIAR APPLICATION ON FLOWERING OF ‘NAMDOKMAI-SITONG’ MANGO

Abstract

Paclobutrazol (PBZ) is a growth regulator used to control vegetative growth, stimulating the
reproductive capacity of plants. PBZ has been widely marketed throughout the tropics to stimulate mango
flowering. In the recent years, many reports showed that application of PBZ by soil drenching can cause
permanent stunting of flushes, the vegetative and root growth of mango was reduced. The aim of this work
was to determine the effects of PBZ on flowering of mango by foliar application. The commercial mango
cultivar ‘Namdokmai-sitong’ was used in this study. The experiment was analyzed as a completely
randomized design. There were 4 replications with 10 treatments. Foliar application at 15 days after pruning
with PBZ at 0, 500, 1,000, 1,500 and 2,000 mg./L and repeated at 30 days with 0 and 1,000 mg./L. There was
significant difference on the time to flowering, percentage of flowering shoots and panicle length. The trees
receiving the PBZ at 2,000 mg/L were exhibited stunting of flushes and panicle malformation. This study
suggests that the multiple foliar application of PBZ was effective in promoting flowering in ‘Namdokmaisitong’ mango, can help early flowering and higher percentage of flowering shoots.