Eficácia de inseticidas de uso comercial em aplicação foliar no controle do percevejo marrom na cultura de soja

Abstract

Euschistus heros is considered a type of stink bug on a larger scale in soybean crops across the country, causing severe damage, impacting productivity and grain quality. Brazil is considered the second largest soy producer in the world, and the conscientious use of insecticides is essential. The use of insecticides from different groups and molecules is usual and effective for the control of the stink bug complex in soybean crops. The objective of this work was to verify the efficiency of the application of different commercial products in the control of the brown stink bug. The treatments used in the experiment was: Zeta-Cypermethrin + Bifenthrin (T1); Acephate (T2); Bifenthrin + Carbosulfan (T3); Acetamipride + Bifenthrin (T4); Imidacloprid + Bifenthrin (T5); and Control (T0), without application. They are the products respectively of the Pyrethroid, Organophosphate, Pyrethroid + Carbamate groups and the last two insecticides of the Pyrethroid + Neonicotinoid group. The study was conducted in Uberlândia-MG in the 2018/2019 agricultural harvest, in an area cultivated with soybeans. The experimental design was in randomized blocks, with six treatments and four replications, totaling 24 experimental plots. The experimental units consisted of 12 lines of 10 meters in length and spaced 0.50 meters apart, totaling 60 m2 of the area of each plot. The evaluations was performed in the 8 central lines of each plot, eliminating 1.0 meter at the top end and 1.0 meter at the bottom end, totaling 32 m2 the useful area of each experimental unit.The variables analyzed in the experiment was: counting the number of nymphs, counting the number of adults and total (nymphs + adults) of E. heros per beating cloth method. The populations of Euschistus heros, both in nymphal and adult stages, behaved as susceptible to molecules of all evaluated insecticides. All products proved to be effective in reducing insects, with emphasis on Zeta-Cypermethrin + Bifenthrin, Acetamipride + Bifenthrin and Bifenthrin + Carbosulfan, with better efficacy in the control of E. heros. Regarding the amount of adult stink bugs, at the end of the experiment, only Imidacloprid + Bifenthrin showed lower efficacy than other insecticides, being equal to the control plot.