Plant Growth Regulators Impact on Vegetative and Reproductive Characteristics of Gladiolus Cut Flowers (Gladiolus hybridus Hort.)

Gladiolus is an important marketable cut flower, especially valued for use in floral arrangements. We assessed the effects of two different methods of application (foliar spray and drench) and various concentrations of gibberellic acid (GA3), salicylic acid (SA), mival (MI) and krizatcin (KR) on vegetative and reproductive features of Gladiolus hybridus. The experiment was planned in a factorial experiment based on a completely randomized design with four replicaties. The results showed that plant growth regulators (PGRs) had significant effect on florets number, leaf area and corm weight and volume. The best treatment to increase the floral stalk length was 50 mg L-1 GA3 spray. Our results indicated that higher GA3 doses significantly increased leaf area more than lower doses. Furthermore, maximum floret diameter was achieved at 100 mg L-1 MI applied as foliar spray. The maximum number of florets (15.87) was obtained in the plants treated with intermediate concentrations of MI in both application methods. Corms drenched with 25 mg L-1MI effectively increased their corm weight and volume. Generally, MI was found to be more effective than other PGRs. Therefore, due to greater efficacy of mival, it is suggested to use this PGR in order to increase the growth of vegetative organs as well as reproductive attributes.