Metabolitos de microrganismos na ativação de defesas em soja à mosca branca

Abstract

The whitefly (Bemisia tabaci) is one of the main insects causing damage to the soybean crop, and most of the time its control is carried out with insecticides. The demand for the reduction of agrochemicals and the search for sustainable production processes is growing. The use of natural products such as metabolites from microorganisms has shown potential to activate defense mechanisms of plants against pathogens, however, this effect is still little explored for the management of insect pests. The objective of the present work is to evaluate the potential of the metabolite of microorganisms, based on glutamic acid (Vorax®) regarding the activation of defense mechanisms of the plant and its relationship with the preference of oviposition of whitefly. The work was developed in a greenhouse and the biochemical analyses were performed in the laboratory of biological controlof the Federal University of Technology - Campus de Dois Vizinhos. Soy plants were grown in pots until the phenological stage V6, then the treatments were applied, being the microorganism metabolite (40ml/100l). After 48 hours of metabolite application, whitefly adults were exposed to the plants and had free choice, being kept up to 96 hours for oviposition. After this period, oviposition and adult preference were evaluated at 144 and 194 hours after 20 days. Plant materials were harvested throughout the experiment at zero, 48, 96, 144 and 192 hours for evaluation of phenolic compounds and total tannins. The application of biofertilizer based on microorganism metabolites (Vorax®) activated metabolic routes of plant defense, increasing the levels of phenoliccompounds and tannins, and made the treated plants less preferred by adult insects.