Effects of salicylic acid on growth and flowering of Freesia refracta Klatt

ObjectiveThe present experiment was conducted to analyze effects of salicylic acid on the growth and flowering of Freesia refracta Klatt,in order to provide practical references for using SA to regulate growth,flowering and bulb propagation of F. refracta. MethodPotted F. refracta was treated with the aqueous solutions containing different mass concentrations of SA by soaking bulb,spraying leaf and combining both ways,with those untreated as control(CK). Then vegetative and reproductive growth indexes of F. refracta in all treatments were determined. ResultResults showed that, low concentration of SA(150.0 mg/L) could promote vegetative growth,the bulb development and extend flowering time of F. refracta,high concentration of SA(450.0-600.0 mg/L) could inhibit vegetative and reproductive growth of F. refracta. In soaking treatment group, the best dwarfing effect could achieve by soaking bulbs in 600.0 mg/L SA solution (P<0.05, the same below),plant height was decreased by 16.9% compared with that of CK,scape height decreased by 33.8%,but the leaf was damaged badly and flowering rate declined. After spraying leaf with 300.0 mg/L SA solution ,flowering occured 5 days earlier than other treatments and 150.0 mg/L SA treatment had the best effect on growth of bulbs ,the total weight of bulb increased by 27.3% compared with that of CK. With the method of immersing bulb 300.0 mg/L SA combined with spraying leaf,weight of large bulb decreased remarkably with the increase of SA spraying concentration,and decreased by 11.3%compared with that of CK when spraying leaf of 300.0 mg/L SA ,and when spraying leaf of 450.0 mg/L, plant height and scape height decreased by 13.5%and 10.3%compared with those of CK, respectively,and the leaf growth and flower-ing was good. ConclusionThe method of soaking bulb in 300.0 mg/L SA combined with spraying leaf with 450.0 mg/L SA has best comprehensive effect on growth and flowering of F. refracta,which is applied to regulate plant and flowering of F. refracta and other plants.