Pontas de pulverização e volumes de calda no controle de Anticarsia gemmatalis Hübner, 1818 e Piezodorus guildinii (Westwood, 1837) na cultura da soja Glycine max

Abstract

The aim of the study were: a) to evaluate the effect of spraying nozzles on two insecticides controlling velvetbean caterpillar, Anticarsia gemmatalis, stink bug, Piezodorus guildinii and b) to evaluate the effect of spray volume in the efficiency of insecticide control velvetbean caterpillar and stink bug in soybean crop. In the experiment of spraying nozzles the experimental design was randomized block with six treatments and five replications. The nozzle used in this study were XR 11002, TXA 8002, AI 11002, TT 11002 and a control without insecticide application, calibrated to of 150 L. ha-1. The spray volumes experiment was in a randomized block design with five replications, in a factorial arrangement (5 x 6). The factor A represented the spray volumes of 50, 100, 150 and 200 L. ha-1 and a check without insecticide application; factor B represented samplings timing. The results showed there was effect of nozzle type on insecticides control of A. gemmatalis and P. guildinii in soybean. For Velvetbean Caterpillar the nozzle XR 11002 promoted the best results for insecticide control, with efficiency ≥ 80 % up to 10 days after application. For P. guildinii control by the insecticides the nozzle TXA 8002 promoted the longest efficient up to 21 day after application. The yield was higher in plots treated with insecticides using the nozzles XR 11002 and TXA 8002. Regarding to spray volume, the control of A. gemmatalis were achieved for up to 10 day after application using volumes of 150 and 200 L. ha-1. Volumes of 50 and 100 L. ha-1 presented no satisfactory result, and did not achieve minimum performance (80%) on the evaluation period. For P. guildinii the sprayer volume of to 50 L. ha-1 did not present satisfactory result in the reduction of the population, since the volumes of 100, 150 and 200 L. ha-1 controlled efficiently until 14 day after application.