Chemical control of tree vigour and the promotion of flowering and fruiting in mango (Mangifera indica L.) using paclobutrazol.
Kulkarni V. J.
Author Affiliation: Fruit Res. Sta., Sangareddy (AP Agric. Univ.), 502 001, India.
Journal of Horticultural Science 63 : 557-566
Abstract : Soil application of paclobutrazol reduced internodal length, shoot length and height increment of 1- to 8-year-old veneer grafted trees of 3 cultivars on seedling rootstocks. Soil applications of the growth retardant caused precocious flowering in young trees and promoted flowering in bearing trees. Axillary flowering and cauliflory were observed in treated trees and flowering was advanced. Soil-treated trees given 10 g a.i./tree flowered 6 to 8 weeks earlier than control trees. In the cv. Banganapalli, early-flowering shoots which failed to set fruits, flowered again at the same time as control trees. It is suggested that post-harvest applications may be more advantageous than a pre-bloom application, with a longer lag time. There was a significant increase in yield per tree which was even more significant when tree vigour was allowed for. Fruit size and quality were not affected by the treatment. An application rate of 10 g a.i./tree gave the desired effects for at least 2 years in 5-year-old bearing trees whereas for 1- and 2-year-old trees, 1.25 and 2.5 g/tree, respectively, were safe and effective. Applications of the growth retardant by foliar spray, on the other hand, had no effect on shoot growth or flowering in any of the experiments.