Atmospheric Effects on Fate of Aerially Applied Agricultural Sprays

Abstract

The deposition and drift of aerially applied crop protection materials is influenced by a numberof factors including equipment setup and operational parameters, spray material, and meteorological conditions. This work focuses on evaluating the meteorological influences on the transport and ultimate fate of aerially applied sprays. There was no single meteorological factor that dominated the downwind transport of the spray treatments replicated in this study. Generally, lower relative humidity decreased downwind deposition and the amount of spray unaccounted for due to evaporative effects. Increasing wind speeds decreased both in-swath deposition and downwind deposition, and increased the amount of mass unaccounted for.
Increases in stability were only moderately correlated to downwind deposition and to flux measurements past 40 m. Though this data set covers a limited range of meteorological conditions, the trends hold from the standpoint of the system physics, and provide applicators with a further understanding of the relationships between spray transport and deposition and local meteorology.