Influência do volume de calda na qualidade de aplicação de inseticida na cultura da soja

Abstract

Due to the great global importance of soybeans, studies that enhance the application of pesticides in pest control are becoming increasingly necessary. In this context, this work aimed to evaluate the influence of spray volumes applied to three distinct thirds of soybean plants, targeting the control of the brown stink bug, Euschistus heros (F.) (Hemiptera: Pentatomidae). The experiment was conducted in the field, using two different spray volumes (60 and 120 L ha-1), evaluating the distribution in the three thirds of the plant (lower, middle, and upper). Parameters such as percentage of coverage (%), relative span, volumetric median diameter (VMD), and droplet density (droplets cm-2) were evaluated. Water-sensitive papers placed horizontally on the soybean plants were used for data collection. Increasing the spray volume did not show a significant difference for most of the variables analyzed. However, it indicates how the plant’s thirds affect application efficiency, especially when the plant has a closed canopy. Therefore, increasing the volume alone does not guarantee uniform distribution of the spray solution throughout the canopy; it is necessary to adopt complementary strategies, such as using the correct nozzles, adjusting the working pressure, application speed, and ensuring adequate environmental conditions, among other techniques.