Journal of Applied Horticulture. 2000 publ 2001: 2(1): 65-70

Flower induction for producing off-season mango in Thailand

Junthasri, R; Nartvaranant, P; Subhadrabandhu, S; Tongumpai, P

Department of Horticulture, Kasetsart University, Bangkok 10900, Thailand.

The technique in producing off-season mango has been adopted in Thailand since 1986. Paclobutrazol, a plant growth retardant, was used in combination with thiourea for producing as well as breaking of flower buds. The studies on application methods showed that soil drenching of paclobutrazol is more effective for the induction of flowering in mango as compared to foliar spray. The rate of paclobutrazol application depended on the size of tree canopy as well as on mango cultivars. For most cultivars, the rate of paclobutrazol applied is generally determined by multiplying the diameter of tree canopy (expressed in meter) with 1.0-1.5 g of active ingredients of paclobutrazol. At 120 days after the application of paclobutrazol, 0.5% thiourea is usually sprayed to some cultivars for breaking of buds. Using this method, inflorescences are visible within 2.5 to 4 months after the paclobutrazol application depending on cultivar. However, the success in producing off-season mango is also dependent on other factors such as climatic conditions, mango cultivars, orchard management and most importantly the experience of mango growers. Induction of flowering in mango is not the major problem for Thai growers, as we can control the flowering in the 'on-season' and 'off-season' times. The other problems of mango production that need further research are few or none fruit set and pre-harvest fruit drop in both 'on-season' and 'off-season' production.