Regulation of growth and flowering in Polianthes tuberosa L. with gibberellic acid and Ethrel spray

Abstract

Tuberose ‘Single’ plants were sprayed 3 times before spike emergence, first at 40 days after planting and subsequently at fortnightly intervals, with gibberellic acid (GA 3) at 0, 25, 50, 75 or 100 mg l −1 and Ethephon ® (Ethrel ®) at 0, 500, 1000, 1500 or 2000 mg l −1. The plant height was reduced with increasing concentrations of Ethrel spray. The GA 3 spray, in general, increased spike length and floret numbers per spike. The length of the rachis also increased slightly with GA 3 spray at 75 mg l −1. Ethrel spray at higher concentrations reduced spike and rachis length and also floret numbers. Longevity (duration of flowering) of spike in the field improved with 100 mg l −1. Both GA 3 and Ethrel spray inhibited bulb production at all concentrations.