Gibberellic Acid (GA3) on flowering induction and quality of Phalaenopsis orchid

Abstract

The control of flowering is essential in the cultivation of flowers to the rapid commercialization and cost reduction. We evaluated the use of Gibberellic Acid (GA3) on floral induction and quality of flowering of adult plants of Phalaenopsis hybrid. It was test five concentrations of GA3: 0, 125, 250, 500 and 1.000mg L-1 applied twice or four times with seven days of interval. This was made by foliar pulverization in the months of November and December. Promising results for induction of flowering happened at a concentration of 125 mg L-1 GA3, applied for twice in Phalaenopsis plants, and with 83% of flowering plants. The number of flowers increased with increasing doses of GA3, until the concentration of 1.000 mg L-1 applied by twice, and without lost of flowers quality until 500mg L-1. The use of four applications of GA3 and the consequent elevation of concentration of the growth regulator in treated plants, caused reduction of inflorescences and flowers quality.