Article info.

ABSTRACT

Received 08 Aug 2017
Revised 13 Jan 2018

Accepted 20 Jul 2018

This study was aimed to investigate the effect of Uniconazole (UCZ), as a replacement for Paclobutrazol (PBZ), on flowering of ‘Dai Loan’ mango cultivar, and to determine suitable UCZ dosages and the periods for bud break. Experiments were conducted on 7-year-old trees arranged in completely randomized factorial design with two factors, i.e. dosages of bud initiation agents and periods for bud break. The three dosages of UCZ included 1.0, 1.5 and 2.0 g a.i. m^-1 canopy diameter, and a positive control (PBZ at 1.5 g a.i. m^-1 canopy diameter). The second factor comprised three periods for bud break after bud initiation applications, viz. 45, 60, and 75 days (days after bud initiation treatment - DABIT). All treatments were replicated six times, each of which equalled to one tree. The results suggested that UCZ can definitely replace PBZ in regard to its effects on the flowering. Flowering ratio reached the highest, 85.5 - 90.0% when UCZ was applied at 1.5 - 2.0 g a.i. m^-1 canopy diameter and subsequently followed by bud break treatment with KNO₃ 2.5% at 75 DABIT. In addition, inflorescence length was not different between PBZ and UCZ dosages, while UCZ 1.5 and 2.0 g a.i. treatment brought about a high number of hermaphrodite flowers per inflorescence. Furthermore, the application of either PBZ or UCZ at 1.5 g a.i. m^-1 canopy diameter combined with bud breaking treatment at 75 DABIT, resulted in the highest yield, i.e. 40.8 and 50.3 kg/tree, respectively. As for the characteristics and quality of fruit, neither the two investigated factors caused significant impact.

Keywords

Bud break, ‘Dai Loan’ mango, flower bud initiation, Paclobutrazol, Uniconazole

Cited as: Hau, T.V., Ut, P.V., Anh, P.H. and Hieu, T.S., 2018. The effects of uniconazole dosages and suitable periods for bud break on the flowering of ‘Dai Loan’ mango (Mangifera indica L.) grown in Cho Moi district, An Giang province, 2016. Can Tho University Journal of Science. 54(5): 7-15.