Delayed inflorescence bud initiation, a clue for the lack of response of the 'Tommy Atkins' mango to promoters of flowering.
Pérez-Barraza M. H., Salazar-García S., Vazquez-Valdivia V.
Author Affiliation: Campo Experimental Santiago Ixcuintla-INIFAP, Apdo. Postal 100, Santiago Ixcuintla, NAY 63300, Mexico.
: 567-572
Abstract : November and December foliar sprays of ammonium nitrate (NH4NO3) promote early flowering of several mango cultivars in Nayarit, Mexico. This treatment has not successfully promoted early flowering in Tommy Atkins. The effect of 3 chemical flowering promoters on the time of inflorescence initiation in apical buds of Tommy Atkins mango was investigated: foliar sprays of NH4NO3 (2%) were applied 3 times (at biweekly intervals) in November or December; ethrel [ethephon] (0, 200, 500, 1000 ppm, or 200 ppm + urea 1%) was sprayed twice in November; and a single soil application of paclobutrazol (PBZ; 0, 10 or 20 g/tree) was done in July. Flower anthesis was 28-35 days earlier in PBZ-treated trees than in controls. PBZ suppressed vegetative flushing during summer and autumn, allowing shoots to mature and initiate apical inflorescences earlier than shoots of control trees which had flushed during autumn. NH4NO3 and ethrel were ineffective at stimulating early flowering of Tommy Atkins; this lack of response could be due to the presence of immature shoots at the time of treatment application.