Influência da velocidade de deslocamento na eficiência e qualidade de aplicação de um pulverizador tratorizado

Abstract

The efficiency of applying phytosanitary products depends on the interaction between operational and environmental factors, which directly influence droplet deposition and drift potential. Key factors include sprayer travel speed, weather conditions, and the time of application. This study aimed to evaluate—using generalized linear models and multivariate analysis techniques—the influence of travel speed on the efficiency and quality of application by a tractor-mounted sprayer, relating these effects to the time of application and weather conditions, with a focus on drift potential. The experiment was conducted at the State University of Maranhão’s Teaching Farm using a Completely Randomized Design (CRD) in a 2 × 3 × 2 factorial arrangement. This involved two travel speeds (3.5 and 5.0 km h⁻¹), three analysis distances (1.0, 2.0, and 3.0 m), and two application times (08:00 and 16:00), with four replications; this resulted in 48 collections per time of day, totaling 96 collected samples. The variables evaluated were droplet count, droplet diameter, dispersion, applied volume, droplet density, and surface coverage. Data were subjected to descriptive statistics, assumption testing, generalized linear models (GLM), the Tukey test, and multivariate analysis. The results revealed high experimental variability, a common characteristic in agricultural spraying studies. Collection distance proved to be the primary factor responsible for reduced droplet deposition, causing significant decreases in droplet count, density, applied volume, and coverage as the distance from the boom increased. Travel speed also showed a significant effect, particularly in interaction with distance, influencing droplet distribution and operational spraying efficiency. The time of application also affected dispersion and interacted with the other variables, highlighting the influence of weather conditions on droplet behavior. It is concluded that reducing the distance from the boom, combined with the appropriate choice of application time, constitutes an efficient strategy to minimize drift losses and improve spray quality