EFFECT OF PACLOBUTRAZOL TREATMENT ON THE GROWTH AND FIRST FLOWERING OF INTACT AND AUTOGRAFTED SEEDLINGS OF MANGO

One-stemmed seedlings that were not grafted or grafted on their own st em (autografted) of mango (Mangifera indica L.) cultivars '13-1' and ' Peach' were grown in containers in a greenhouse. When 2 years old, the plants were pruned and paclobutrazol (PBZ) was applied to the soil at 0, 20, 60 and 240 mg active ingredient (a.i.) per plant. The cumulati ve length of shoots that were produced by autumn following pruning was reduced by PBZ especially in the autografted plants. Flowering occurr ed in spring, 32 months after germination. Autografting did not increa se the rate of flowering. Without PBZ, 25% of the '13-' plants and non e of the 'Peach' plants flowered. Of the '13-1' seedlings, 95-100% flo wered with PBZ treatment regardless of the rate. In 'Peach', the propo rtion of plants flowering was increased by PBZ as the treatment rate i ncreased. At the highest rate, 64% of non-grafted and 31% of autograft ed seedlings flowered. '13-1' seedlings treated with 240 mg PBZ set se edless fruit which did not persist.