Bals (1992) reported that the study of pesticide application
has been almost entirely of spraying practices in
industrialized agriculture, and that such spraying is
based on the hydraulic nozzle spray atomizer. In
industrialized countries spraying is almost totally
mechanized, and spraying equipment is mounted on a
vehicle. The sprayer operator is protected from the
widely dispersed airborne pesticide mist by the vehicle’s
sealed cab. In transferring this technology to developing
countries the hydraulic nozzle has simply been
scaled down for use on knapsack sprayers (the most
widely used type of sprayer in developing countries).
One of the undesirable consequences of this is an
increase in the risk of contamination of the worker,
because the protection afforded to the tractor driver by
the cab is not available to the person carrying the
knapsack sprayer.