My Subiect is a highly specialised and rather adventurous one—the practice of night spraying of trees and agricultural crops from aircraft.

It may sound hazardous, as it is, and of course it is at present only attempted when biological or climatic factors make spraying by daylight undesirable or ineffective. It is also dependent on a favourable terrain, and the development of better equipment. Where these conditions are fulfilled, in certain cases night spraying may become part of the armoury of a number of spraying contractors, mainly in Africa and America.