INDUÇÃO DE RESISTÊNCIA À MANCHA BACTERIANA UTILIZANDO NEONICOTINOIDES EM TOMATEIRO

Abstract

The use of resistance inducers is a management strategy of bacterial spot in commercial areas. The objective of this study was to evaluate the induction of resistance, using neonicotinoid insecticides to reduce the severity of bacterial spot on tomato. The experiment was conducted in a greenhouse at the Instituto Federal Goiano Campus Morrinhos. Was evaluated the insecticide imidacloprid (IMD) and tiamethoxan (TMT), which were compared with acibenzolar-S-methyl (ASM), a resistance inducer registered for the management of the disease in tomato, and a control treatment, which was applied only water. Two experiments were performed. In the first, taking as a basis the ASM doses, IMD and TMT that provided resistance induction in citrus pathosystem x Xanthomonas citri subsp. citri (0,2; 1,5;. and 0,5 g a.i. plant-1, respectively) are evaluated 100, 10 and 1% of the dose used in this citrus. In this trial, there was phytotoxicity by the use of IMD at concentrations 1,5 and 0.15 g. a.i. plant-1, and the concentration of TMT and 0,5 g. i.a. plant-1. In other concentrations, a reduction of disease severity compared to control treatment, similar to that observed with the use of ASM. In the second assay, we used 10.0; 1.0; and 0.1% of the dose recommended for citrus. There was a reduction of disease severity in these measured doses compared to the control. This result proves that neonicotinoids may induce resistance in tomato against Xanthomonas perforans.