Effect of Paclobutrazol and α-naphthaleneacetic acid on Growth and Yield of Zucchini (Cucurbita pepo L.) In Tropical Regions

Zucchini is one of Cucurbitaceae family with a lot of vitamins and benefical for boosting immune system, preventing cancer risk and preventing inflammation. In Indonesia cultivation zucchini less than optimal so that it is necessary to apply cultivation techniques that can increase production zucchini. This Research to study effect of α-naphthaleneacetic acid (NAA) and various concentrations of paclobutrazol (PBZ) on growth and yield zucchini. The Experiments was a factorial experiment using split plot design with two factor, first factor was NAA with 2 treatment levels (with and without apply NAA) and the second factor was the concentration with 5 treatment levels (0, 50, 100, 150, and 200 ppm). The observation data results were analysis of variance (ANOVA) and continued least significant difference (LSD) at 5% error level. The results showed that significant effect of NAA and PBZ on growth and yield of zucchini. There was can inhibit the vegetative organs like plant length, leaf area and stem length. Beside that, there were increasing the generative organs in the parameters number of fruits, fruit length, diameter fruit, fresh fruit weight and fruit weight per plant, harvest index and partition biomass. Effect of PBZ especially at higher concentrations can inhibited plant growth while enhancing fruit quality, where was NAA demonstrated potential in optimizing fruit development through hormonal regulation. In conclusion, the interaction of PBZ and NAA was found to influence not only zucchini fruit morphology but providing into the regulation of growth and quality in horticultural crops.