AGRICULTURAL SPRAYS: COMPARISON OF EVALUATION METHODS

Abstract

A study was conducted in order to compare two types of artificial collectors (water-sensitive paper and photographic paper) using two software programs (Gotas-PC and CIR1.5) for the assessment of spray applications with two different nozzle types (XR11002VP and TXA8002VK). The evaluated parameters were DV0.5, droplet number density and efficiency, this was compared to the colometric determination with bright blue tracer. The trial was conducted inside a closed facility, under semi-controlled conditions, in absence of wind and on a uniform level ground. Droplet number density did not show significant differences between collectors using Gotas-PC, but differences were found with CIR1.5. For water-sensitive paper, efficiency is overestimated with CIR1.5 software but underestimated with Gotas-PC. However, both software programs underestimate with photographic paper according to the smaller imprints that result in lower values of DV0,5 and efficiency. In applications with smaller droplet population, efficiency is similar with both software programs. The CIR1.5 software is more sensitive for analyzing drops on both collector types and can distinguish a larger number of drops and smaller sizes.