USE OF PACLOBUTRAZOL IN TOMATO AS AN AUXILIARY STRATEGY IN CULTURAL AND PHYTOSANITARY MANAGEMENT

Abstract

Being a vegetable crop of high economic value, known for its sweet flavor, attractive shape, and versatility in consumption, the grape tomato (Solanum lycopersicum L.) has a growing demand in the market, which is promoting the improvement of agricultural practices, especially in hydroponic systems, which allow greater control over environmental and nutritional conditions. However, the vigorous vegetative growth of indeterminate cultivars requires intense cultural treatments, such as staking and sprouting, increasing operating costs. Paclobutrazol (PBZ), an inhibitor of gibberellin biosynthesis, has been used to control plant growth, reducing the need for labor and facilitating phytosanitary management. This study evaluated the impact of PBZ on the development and yield of grape tomatoes grown in a hydroponic system. The experiment was carried out in the municipality of Parapuã-SP, in protected cultivation, adopting a completely randomized design (DIC), with five treatments (0, 50, 100, 150, and 200 mg L⁻¹ of PBZ) and ten replications. The regulator was applied via foliar spraying 30 days after seedling emergence. The following characteristics were evaluated: average plant height at 45 days, average fruit mass, productivity, root development, and estimated yield per hectare. The data were submitted for analysis of variance and the means were compared by Tukey's test at 5% probability. The results showed a significant reduction in plant height with increasing PBZ dose, confirming its vegetative growth inhibitory effect. The dose of 50 mg L⁻¹ promoted an increase in average fruit mass and yield, while higher concentrations reduced these parameters. Root development did not present statistically significant differences between treatments, although a small increase in the dosage of 50 mg L⁻¹ was observed. The analysis of the yield per hectare indicated a 28% increase in yield for the dose of 50 mg L⁻¹ compared to the control. On the other hand, higher doses resulted in a decline in yield, showing that excessive concentrations of PBZ can compromise crop performance. It is concluded that the use of paclobutrazol in grape tomatoes grown in a hydroponic system can be an efficient strategy to reduce vegetative development and optimize crop management. The dosage of 50 mg L⁻¹ showed the best agronomic characteristics, providing a balance between vegetative and reproductive development.