Response of mango varieties to paclobutrazol.
Rossetto C. J., Bortoletto N., Castro J. V. de, Carvalho C. R. L., Igue T.
Author Affiliation: Polo Regional do Noroeste Paulista, APTA, C.P. 61, 15500-000, Votuporanga, SP, Brazil.
: 233-237
Abstract : The response of 4 mango cultivars (Haden 2H, Van Dyke, Tommy Atkins and Espada Vermelha) to paclobutrazol (PBZ) combined with ethephon and potassium nitrate was investigated in Votuporanga, São Paulo, Brazil. In the first year, 3 treatments were applied: (1) PBZ+ethephon+potassium nitrate; (2) PBZ+potassium nitrate; and (3) untreated control. PBZ at 2 ml/m of crown diameter was applied as soil treatment on 12 January 1999, in a circular drench 50 cm from the tree trunk, with 5 litres of water per tree. Ethephon at 0.25 ml/litre was applied as spray approximately 60 days after the PBZ application. Potassium nitrate was sprayed approximately 90 days after the PBZ application, using a 4% water solution. In the second year, only the complete treatment (PBZ+ethephon+potassium nitrate) was used in 2 dates: (1) PBZ applied on 13 December 1999, ethephon on 10 February 2000 and potassium nitrate on 15 March 2000; and (2) PBZ on 10 January 2000, ethephon on 15 March 2000 and potassium nitrate on 11 April 2000; and (3) untreated control. PBZ was reduced to 0.75 ml/m of crown diameter. PBZ soil application followed by sprays of ethephon and potassium nitrate was effective for flower induction and harvest anticipation. Ethephon boosted the anticipation effect. The cultivars varied in their responses to PBZ. Espada Vermelha was responsive to 0.75 ml of PBZ/m of crown, and Haden 2H showed no significant response even at 2 ml of PBZ. However, Espada Vermelha had small fruits, and many fruits harvested at the end of August had less than 200 g.