Sprayed liquid loss due to evaporation in different psychrometric conditions

Abstract

Low relative humidity and high air temperature are favorable conditions for droplet evaporation, and this may cause financial losses for the farmer due to poor pest control, and also cause environmental contamination. Thus, the aim of this work was to evaluate the effect of temperature and relative humidity on pesticides spraying, and to estimate the spraying losses by evaporation depending on air psychrometric conditions. The experiment was carried out inside of a climate chamber to control the temperature and relative humidity, and thus to obtain different vapor pressure deficits. This study used the nozzle Lurmark LD11002 operating at the pressure of 300 kPa and the liquid was tap water. The loss by evaporation was studied in a completely randomized design with twenty vapor pressure deficits and three replications. Even obeying the recommendations of climatic conditions for pesticides application, there are losses of liquid due to evaporation. For the nozzle LD 11002 and working pressure of 300 kPa, the loss of pesticides due to evaporation can reach about 27% under weather conditions characterized by low wind velocity, high air temperature and low relative humidity.