TEMPERATURE AND GIBBERELIN INHIBITORS IN THE FLOWERING PROCESS OF MANGO CV. ‘ATAULFO’

Abstract

Initiation and floral differentiation is controlled by exogenous, endogenous and hormonal factors. The aim was to determine the effect of paclobutrazol, calcium prohexadione and temperature on floral differentiation of mango (Mangífera indica L.). The study was conducted during 2013-2014 y 2014- 2015 in a mango cv ‘Ataulfo’ commercial orchard eight years old. Treatments were: 1) Three applications of 500 mg L^-1 of P-Ca at 30, 45 and 60 days after pruning (dap); 2) One application of 2500 mg L^-1 of PBZ at 30 (dap) and 3) Control, where water and surfactant were applied. In both cycles, the floral initiation and differentiation was 45 and 30 days earlier in the buds where PBZ and P-Ca were applied, respectively, in regard to the control. The percentage of differentiated buds was higher with the gibberellin inhibitors, 63 % with PBZ and 15 % in control during the cycle 2013-2014 and 73 % - 28 % during the cycle 2014-2015; similar results were obtained in flowering percentage. Bud floral initiation was stimulated by nocturnal temperature near to 15 ºC and the inhibitors of GAs synthesis accelerated the differentiation process.