Promoting fruit set and increasing yield of cherry tomatoes with gibberellin

Abstract

Background and Objective: High summer temperatures can reduce cherry tomato yield. Gibberellic acid (GA₃) has been shown to improve fruit sets in some plants. This study aimed to compare the effects of GA₃ on fruit set and yield in two cherry tomato cultivars, ‘Sweet Boy’ and ‘Sweet Girl,’ grown in a greenhouse during the summer months with high temperatures.
Methodology: A 2 × 5 factorial experiment in a randomized complete block design (RCBD) was conducted to assess the responses of the two cherry tomato cultivars to five different GA₃ concentrations (0, 50, 100, 150, and 200 mg/L) (n = 15). Flower inflorescences were sprayed with GA₃ at 0, 2, and 4 days after anthesis (DAA). Data were analyzed to determine means and standard deviations. Statistical analysis was performed using ANOVA, followed by Duncan’s Multiple Range Test at a 95% confidence level.
Main Results: Applying 50 and 100 mg/L GA₃ increased the fruit set of ‘Sweet Boy’ cherry tomato from 72.9 ± 5.9% to 90.6 ± 2.3% and 93.6 ± 2.0%, respectively (P < 0.05), but GA₃ did not affect ‘Sweet Girl’ cherry tomato fruit set, which remained consistently around 91.7 ± 1.9%. The highest yield was obtained by applying 100 mg/L of GA₃ to the ‘Sweet Boy’ cherry tomato, reaching an average of 291.2 ± 113.1 g/cluster. In contrast, the yield of the ‘Sweet Girl’ cherry tomato remained relatively consistent across different GA₃ concentrations at 187.6 ± 17.6 g/cluster.
Conclusions: The application of GA₃ can enhance fruit set and yield in greenhouse-grown cherry tomatoes during the summer when applied at appropriate concentrations. Cultivar responses to GA₃ may differ. In this study, spraying 100 mg/L GA₃ on 0, 2, and 4 DAA significantly increased fruit set and yield in the ‘Sweet Boy’ cherry tomato.