عنوان مقاله [English]
Tuberose (polianthes tuberosa L.) belongs to agavaceae family and is one of the most important cut flowers.
Various factors are affecting it’s flower quality and flowering date. Among the most important factors, effects of growth regulators, in particular gibberlic acid (GA3) is of vital importance. The current research was performed using a completely randomized block design with three replications to evaluate the effects of GA3 on flower quality and flowering date of tuberose. Double variety tuberose bulbs, ranging from 6 to 7 cm in diameter, were considered for this experiment. The gibberlic acid (GA3) solutions tested were 100, 200, 250 and 300 ppm. The bulbs were either soaked before cultivation or soaked and bud sprouts were sprayed with GA3 solutions at two stages of plant development. Although GA3 application had significant effects on most of the assesed characters, but two methods of GA3 application did not show significant diffirances, whereas significat variations were observed between various GA3 concentrations. Comparing the date of flower harvest indicated that the highest number of flowers were picked up in three to four weeks after flowering initiation for both GA3 application procedures. In general, application of 300 ppm GA3 by soaking the bulbs before cultivation increased the numbers of flowering shoots as well as preceded the flowering time, significantly. In conclusion, it is suggested that application of 300 ppm GA3 solution, plantation after soaking bulbs, will provoke flowering time and increase number of flowerig shoots that has advantages for the commercial multiplication of tuberose flower.