Paclobutrazol in flowering of some tropical and subtropical fruits

S.K. Mitra
Paclobutrazol (PBZ), a gibberellins inhibitor, has been effectively used to overcome the problems of flowering and tree vigor in a number of tropical and subtropical fruits like mango (Mangifera indica L.), litchi (Litchi chinensis Sonn.), avocado (Persea americana Mill.), citrus (Citrus sp.), etc. Soil application of PBZ on mangoes (1-20 g a.i. tree-1) reportedly reduces internodes length and causes earlier and enhanced flowering in young and old trees. PBZ also reduces the alternate bearing habit of some mango cultivars; however, the effect varies with cultivars, environments and application times. Vegetative flushing in late autumn and early winter is associated with irregular flowering of litchi trees in spring and can result in inconsistent yields. Soil application of PBZ in autumn after maturation of postharvest vegetative flush increases flowering of 'Bengal', 'Kwai May Pink' and 'Tai So' litchi. Spraying of PBZ (2-4%) has been reported to increase yield of 'Hass' avocado in the 'off' year following high yield in the previous 'on' year. The effectiveness of PBZ in promoting flowering in Citrus sp. depends on the crop load as heavy fruit load trees scarcely flowered. In medium to low fruit load trees, PBZ significantly increased the percentage of sprouted buds and floral shoots and depressed vegetative growth. This paper reviews the use of PBZ in overcoming the problems of flowering of some commercial tropical and subtropical fruits.
Mitra, S.K. (2018). Paclobutrazol in flowering of some tropical and subtropical fruits. Acta Hortic. 1206, 27-34
DOI: 10.17660/ActaHortic.2018.1206.4
alternate bearing, mango, litchi, avocado, citrus

Acta Horticulturae