FIELD MEASUREMENT OF DROPLET DRIFT FROM GROUND SPRAYERS. I. SAMPLING, ANALYTICAL, AND DATA INTEGRATION TECHNIQUES

Abstract

A procedure for the evaluation of ground deposits and droplet drift characteristics from a typical farm sprayer under actual field conditions is described. It involves sampling both the ground deposits on the swath and the air-borne cloud mass, the latter at various heights and distances downwind from the target area. The system was evaluated with the commonly used 65° flat-fan nozzles operated at 280 kPa which provided an application rate of 0.56 kg/ha of 2,4-D amine (2,4-dichlorophenoxyacetic acid) in 56 ℓ water/ha. The spray solution also contained a fluorescent dye as a tracer. A portable meteorological station, where a number of meteorological parameters can be measured or recorded during the course of a field trial, is also described. Results of four field trials are presented with discussion regarding on-swath deposit density and its distribution over the swath, off-swath drifting cloud mass and its deposition and decay as a function of distance, and mass balance.