Spray Deposition on Watermelon Crop in Aerial and Ground Application

The quality and quantity production of watermelon requires the effective control of pests, diseases, and weeds, which is directly related to spraying techniques. The method of application of phytosanitary products is essential, but, most of the time, emphasis is given mainly to the applied product and little attention to the application technique. The objective of the present study was to characterize the ejected spray in the aerial and terrestrial spraying of watermelon crops, with the use of adjuvants in a liquid solution. The experiment was carried out in two commercial plantations, in an entirely randomized design, employing a 6 × 2 factorial scheme, with six forms of application and two liquid compositions. The droplet spectrum was assessed employing water-sensitive card imaging. Smaller drop sizes and relative amplitudes were produced by aerial applications. In turn, the largest droplet diameters and the lowest percentage of drops smaller than 100 μm were obtained when using air induction flat double-jet nozzles. The adjuvant did not interfere in the numerical and volumetric median diameters, the relative amplitude, or the volume rate of droplets smaller than 100 μm.