Experimental observations made in eight aerial spray trials on the inter-relationships between physical properties of two spray mixtures, application parameters, meteorological conditions, drop size spectra, ground deposits and foliar concentrations of aminocarb are described in this paper. In 1981, the spray mixtures were applied using a small aircraft (Cessna 188) equipped with four rotary (Micronair® AU3000) atomizers. In 1982, the mixtures were sprayed using a large aircraft (TBM avenger) fitted with 24 hydraulic (1010 Flatfan Teejet®) nozzles. Spray drops were collected at ground level with sampling cards, and ground deposits were assessed using glass plates. Canopy deposits were determined directly on live foliage. Physical properties measured were: viscosity, surface tension and volatility. In the 1981 study, the drop size spectra of both spray mixtures were narrow and contained small drops with a volume median diameter (DV.5) less than 50 μm. In the 1982 study, the drop size spectra were wide and contained large drops with a DV.5 greater than 100 μm. The ground deposits were higher in 1982 than those in 1981. Foliar deposits, on the other hand, were similar in both years. Among the three physical properties studied, viscosity and volatility played significant roles on the drop size spectra and ground deposits obtained in 1981; but no similar relationships could be found in 1982.