Effect of Foliar Application of Gibberellic Acid and Paclobutrazol on Vegetative and Reproductive Growth of Two Strawberry Cultivars

This study was carried out to evaluate the effects of Gibberellic acid and Paclobutrazol respectively on promote flowering and vegetative growth reduction in strawberry in order to enhance production. Gibberellic acid and paclobutrazol are plant growth regulators. Gibberellic acid can act as a promoter while, paclobutrazol act as an inhibitor. Gibberellic acid at 100 mg/l, 30 and 90 days and paclobutrazol at 150 mg/l, 50 days after transplanting were treated on two strawberry cultivars Diamante and Paros in a split plot design with three replications. Results indicated that foliar spray of gibberellic acid at 30 days after transplanting with paclobutrazol reduced flowering, fruit production and TSS and also significantly increased the runner length up to 127 cm in both cultivars. Application of gibberellic acid at 90 days after transplanting increased flowering to 25 flowers, but didn’t help the plants to produce more fruits. Paclobutrazol strongly reduced runner number with no effect on leaf number and petiole length. The results showed no effect of treatments upon leaf chlorophyll content. The maximum and minimum ftuit weight belonged to diamante cultivar respectively in control treatment (17/8 gr) and two steps gibberellic acid with paclobutrazol treatment (3/8 gr). Generally gibberellic acid treatment didn’t improve production and paclobutrazol treatment was more effective on decreasing the runner number rather than other vegetative growth parameters.