effects of gibberellic acid (ga3) and benzyladenine on tuberose quality and quantity

tuberose is one of the most important floral crops in iran. long spikes of fragrant flowers make it excellent for cut flower. due to the beauty and sweet fragrance of flowers, it used in all seasons for flower arrangements. production of high quality flowers and vase life extension is important for competition in world markets. for this reason this research was conducted on polianthes tuberosa var double base on factorial experiment in rcb (randomized complete block design) with three replications. both gibberellic acid (ga3) and benzyl adenine (ba) were sprayed on bulbs and foliage of plants at four concentration levels. results showed that gibberellic acid and benzyl adenine treatments had significant differences in all of the measured indices at one percent level. gibberellic acid increased stem and rachis length in some concentrations and also accelerated flower stalk emerge. benzyl adenine increased stem diameter, floret numbers and vase life and preceded flowering. both of these plant growth regulators improved water uptake by cut flowers and increased diameter of second floret but decreased ethylene production of the flowers. essential oils of flowers were extracted by solvent extraction method. both of the plant growth regulators had negative effects on essential oils of flowers, but in 1000 mg.l-1 of ba essential oils of flowers were higher than other concentrations.