The influence of gibberellic acid (GA3) and water regime was evaluated in the flowering induction and quality of two orchid hybrids belonging to the genera Cattleya (C.) and Brassocattleya (Bc.). The experiment was carried out in the Biotechnology and Orchid Culture Sector of Shunji Nishimura Technology Foundation, Pompéia, São Paulo State, Brazil. Five GA3 concentrations (0, 125, 250, 500 and 1,000 mg L-1) were tested through four consecutive leaf applications in adult plants that had already flowered at least once, besides two water conditions (one and four irrigations per week). Applications were performed in October and November for Bc. Marcella Koss and in January and February for C. Irene Holguin. Flowering could not be induced in the latter by gibberellic acid. In Bc. Marcella Koss, the application of 250 mg L-1 GA3 combined with decreased irrigation frequency induced flowering in around 83% plants. By using the same GA3 concentration but frequent irrigation, only 17% plants were induced to flower. The number and size of flowers increased after application of higher GA3 concentrations. This work allowed developing a commercial technique with the use of gibberellic acid (GA3) to induce flowering in Bc. Marcella Koss hybrid orchid.
Ornamental plants; flowering; quality; pulverization; plant growth regulator; water suppression
