The construction of an inexpensive, simple, hand-drawn fumigator for field plots is described. The general principle employed is the injection of liquid nicotine under pressure into the exhaust system of a two-stroke engine, close to the port. The liquid is vaporised by the heat of the exhaust stream and distributed by it below a drag sheet at the rear of the machine.

The machine is of simple and robust construction, utilising standard plumbing fittings, angle iron, strip iron and second-hand motor-cycle parts and can, therefore, be made where only limited facilities are available.

The machine is self-contained and easily transportable as it can be towed behind a car from one locality to another. It is suitable for use on a wide variety of crops since the track is variable between 43 in. and 67 in. and the clearance between 16 in. and 34 in. With the 18 ft. long sheet used it can fumigate, in good conditions, one acre in about five hours. It is pointed out that the use of a lightweight sheet about 54 ft. long would decrease the time required per acre to about if hours and would enable the machine to be drawn by a tractor if desired; these suggestions have not, however, been tried.

The machine has been in use since 1941 for controlling aphis infestation in connection with work on virus yellows of sugar beet and has given most satisfactory results. Tests showed that a kill of 88–99 per cent, of Aphids was obtained.