Effect of Ethephon Concentration and Shoot Pruning Time on Flowering and Yield Components of Cucumber (Cucumis sativus L.): Implications for Optimal Production Timing

Background: Cucumber productivity is closely related to floral sex expression because a greater proportion of female flowers can increase fruit formation. Ethephon application and shoot pruning are cultivation practices that may modify flowering and improve yield. Objective: This study aimed to determine the optimal ethephon concentration, shoot pruning time, and their interaction effects on cucumber productivity. Methods: A randomized complete block design (RCBD) with a 3 × 3 factorial arrangement plus one control treatment was used. Ethephon concentrations were 100, 200, and 300 ppm, while shoot pruning was performed at 14, 21, and 28 days after planting (DAP). The experiment consisted of 30 experimental units, each containing 10 plants, with three sample plants per unit. Data were analyzed using analysis of variance (ANOVA), followed by Duncan's multiple range test and orthogonal contrast tests at the 5% significance level. Results: Ethephon at 200 ppm resulted in the earliest flowering, the highest number of female flowers, and the earliest harvest. Pruning at 21 DAP resulted in the highest fruit weight, length, and diameter. The combination of 200 ppm ethephon and pruning at 21 DAP produced the highest number of fruits per plant (8.11), fruit weight per plant (2.71 kg), and yield per hectare (87.91 tons). Conclusion: The 200 ppm ethephon treatment combined with pruning at 21 DAP was the most favorable treatment combination under the experimental conditions. These findings provide practical guidance for improving cucumber yield under tropical lowland conditions in Sleman, Yogyakarta.