INTERACTIONS BETWEEN ADJUVANTS AND THE FUNGICIDE AZOXYSTROBIN+BENZOVINDIFLUPYR IN HYDRAULIC SPRAYING

ABSTRACT Adjuvants are tools to maximize pesticide spray quality. This study aimed to evaluate the interaction effects between adjuvants and the fungicide azoxystrobin + benzovindiflupyr on the physicochemical characteristics, droplet evaporation time, and spray droplet size. The experiment was carried out using a 2×6 factorial scheme, in which the first factor was the absence or presence of the fungicide mixture (water or water + fungicide) and the second factor was the presence of different adjuvants (water and five adjuvants). The parameters evaluated were surface tension, pH, viscosity, electrical conductivity, droplet evaporation time, volume median diameter, percentage of droplets smaller than 100 μm, and relative amplitude of the droplet spectrum. The silicone and propionic acid + soy lecithin adjuvants reduced the pH of the spray solution, and the sodium lauryl ether sulfate, propionic acid + soy lecithin, and orange essential oil adjuvants reduced droplet evaporation when mixed with the fungicide. All tested adjuvants improved spray quality related to the characteristics of the droplet spectrum, reducing the percentage of droplets smaller than 100 μm, and allowing more uniform droplet size. The fungicide azoxystrobin + benzovindiflupyr affected droplet evaporation time.