Exogenous Gibberellin Application in Tomato (Solanum lycopersicum) Recovers Growth Inhibition Caused by Triazole Overuse

Abstract

Tomatoes are widely used worldwide and are an economically important crop. Tomatoes contain important secondary metabolites, as well as lycopene, β-carotene, vitamin C, and flavonoids. The quality of tomato seedlings varies depending on certain environmental factors during the seedling growth season. In Korea, diniconazole (DIN), a triazole-based plant growth regulator (PGR), is widely used to prevent seedling overgrowth. Misapplication of a triazole-based PGR results in excessive growth inhibition. However, little is known about the prevention of side effects such as growth inhibition after a DIN treatment. Therefore, this study sought to determine whether growth inhibition could be resolved by treatment with GA3, a phytohormone, after a DIN treatment. This study compared the survival rates of seedlings after a DIN treatment and analyzed the growth of tomato seedlings treated with GA3 after a DIN treatment. To this end, DIN was diluted to a concentration of 250 mg∙L-1 to be treated at 3 mg per plant, and GA3 was diluted to a concentration of 5 mg∙L-1 and 10 mg∙L-1 to be treated at 2.5 mL per plant. GA3 was administered up to two times per concentration. In the foliar application of GA3 after the DIN treatment, no difference in growth was found between the treatments at different concentrations, but there was a significant difference between plants subjected to the single and double treatments. The results of this study suggest that a GA3 treatment at a higher frequency than a high-concentration treatment can more effectively address the growth inhibition issue associated with a DIN treatment.