Delta T is an atmospheric moisture parameter whose use in spraying has made its way to North America from Australian operations. Instead, we present Delta T, also known as “wet bulb depression”. But relative humidity (RH) isn’t the best way to measure this effect because the same RH at two different temperatures results in two different water evaporation rates. Low humidity causes droplets to evaporate faster, potentially increasing drift and reducing uptake.
With the average tank of pesticide being 90 to 99.5% water, evaporation plays an important role in both droplet size and active ingredient concentration.
