Pesticide information box
It is not always appreciated just how inefficient spray operations are in practice. Graham-Bryce  reviewed the efficiency of utilisation of crop protection chemicals in various pest control situations and estimated that:
"Efficiency" of spray application is determined by the complex phenomena that govern droplet transport from the nozzle to the target, which are described in standard texts. As a practical measure, Courshee  coined the term Deposit per Unit Emission (DUE) to describe the amount of pesticide recovered downwind in the target zone, relative to the volume emitted from the spray nozzle (originally in locust control operations). DUE is thus an overall measure of efficiency, permitting valid comparisons of spray recovery. It is usually expressed in units such as ml/m2 (mean quantity recovered in a unit area) per ml/m (liquid emitted over a unit of spray track).
Operationally, a measure
of economic efficiency is:
1. Graham-Bryce, I.J. (1977) Philosophical Transactions Royal Society London B. 281: 163-1792. Courshee, R.J. (1960) Annual Review of Entomology 5: 327-352.