Insecticide spray drift reduction with different adjuvants and spray nozzles/Reducao da deriva de inseticida por diferentes adjuvantes e pontas de pulverizacao

HIGHLIGHTS: AXI and J3D nozzles combined with Oro-solve or Wetcit Gold generated the largest DMVs and the smallest drift at 5 m. The AXI nozzle combined with Oro-solve had the lowest drift at 10 m and at 15 m with the Oro-solve. The JFC nozzle produced droplets with greater homogeneity of size. Insecticide spray drift can lead to reduced control efficiency and loss of product to the environment. Thus, we conducted a study to evaluate the effect of different spray nozzles and the addition of adjuvants in insecticide spray on the resulting droplet spectrum and wind tunnel drift. All experiments were conducted in a completely randomized design with four repetitions using a 5 * 3 factorial scheme. Five spraying solutions were studied; one contained only water and the other four comprised thiamethoxam + lambda-cyhalothrin (no adjuvant, Oro-solve, Wetcit Gold, and Orobor N1), in combination with three spray nozzles (AXI, JFC, and J3D). The droplet spectrum was evaluated through the volumetric median diameter, relative amplitude, and percentage of the droplet volume with diameter [less than or equal to] 100 [micro]m. The drifts were evaluated in a wind tunnel at 5, 10, and 15 m. Data were subjected to analysis of variance and means were compared using the Tukey's test. In addition, a principal component analysis was performed. Application of the insecticide with the adjuvants combined with the different nozzles changed the droplet spectrum and the risk of drift. The AXI nozzle and the J3D associated with the Oro-solve and Wetcit Gold adjuvants resulted in a greater volumetric median diameter of the droplets and drifts were observed at 5 m. Key words: application technology, droplet spectrum, wind tunnel A deriva da pulverizacao de inseticidas pode proporcionar a reducao da eficiencia de controle e perda para o ambiente. Desta forma, foi conduzido um estudo com o objetivo de estudar o efeito de diferentes pontas de pulverizacao e adicao de adjuvantes na calda inseticida, em relacao ao espectro de gotas e deriva em tunel de vento. Os experimentos foram conduzidos no delineamento inteiramente casualizado, com quatro repeticoes, no esquema fatorial 5 * 3, constituido por cinco caldas, uma apenas com agua e outras quatro com inseticida tiametoxam + lambdacialotrina (sem adjuvante, Oro-solve, Wetcit Gold e Orobor N1), combinadas com tres pontas de pulverizacao (AXI, JFC e J3D). Foi avaliado o espectro das gotas, atraves do diametro mediano volumetrico, amplitude relati