6 research outputs found
Do combinations of insecticides and acaricides influence spray droplet formation and the interaction with citrus leaves?
In agriculture, the mixing of pesticides in tanks is a common practice. However, it is necessary to previse possible physical-chemical implications of this practice, which may affect
the efficiency of the treatments performed. Therefore, the objective of this study was to
evaluate the effects of the addition of acaricide to insecticidal spray mixtures on the formation of spray droplets and the interaction with citrus leaves. The experimental design was
totally randomized, in a (2 × 3 + 1) factorial scheme for seven treatments. Factor A corresponded to the spray mixture used (isolate or in the mixture). Factor B corresponded to
the insecticides tested (lambda-cyhalothrin + thiamethoxam, phosmet, and imidacloprid)
and the control consisted of a spray mixture with spirodiclofen only. Nine replications were
performed for characterization of the spray droplet size spectrum and four replications for
the analysis of the surface tension and the contact angle. The mixture of pesticides showed
positive results in terms of application safety. The addition of acaricide to insecticide spray
mixtures reduced the surface tension and contact angle of droplets on the adaxial surface
of orange leaves. There was an increment in volume median diameter (VMD), a significant
reduction in the volume of droplets with drift-sensitive size and improvement in the uniformity of droplet size. Therefore, the addition of acaricide to an insecticide spray mixture
positively influenced spray droplet formation and the interaction with citrus leaves providing better coverage and droplet size fractions with an appropriate size for safe and efficient
application