Environmental Influences on the Evaporation Rate of Horticultural Disinfestants

Abstract

The evaporation rate of disinfestants when sprayed on production surfaces is expected to vary under different weather conditions, but it is unknown how that affects efficacy. This study was an initial investigation into how the evaporation rates of water and six commercial disinfestants vary under eight weather condition categories. Additionally, an empirical model was developed on the evaporation rate of water in response to air temperature, relative humidity, solar radiation, vapor pressure deficit, and wind speed under the same eight weather condition categories. Isopropyl alcohol lost more weight due to evaporation over 4 h ( P < 0.0001) than all other disinfestant solutions, and no differences ( P = 0.05) existed between the other five disinfestant solutions and water. Isopropyl alcohol had a mean percentage weight loss of 71% under hot and sunny conditions, 43% under cool and cloudy conditions, and 6% under indoor laboratory conditions. Water, hypochlorite, quaternary ammonium, and peroxy disinfestant solutions evaporated at a similar rate over 4 h, with an approximate mean percentage weight loss of 17% under hot and sunny conditions, 6% under cool and cloudy conditions, and 1% under indoor laboratory conditions. The regression model that best explained the influence of weather on evaporation included the variables solar radiation, temperature, and wind speed ( P < 0.0001, R2 = 0.5603). This information will be used further to model the evaporative rate of disinfestants under the same range of weather conditions when applied to multiple types of substrate materials that represent common horticultural plant production surfaces. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2024.