30 October 1998

Spray drift puzzle

MORE information on the drift potential of modern spray nozzles is urgently needed.

That was a key message from last weeks Association of Applied Biologists conference at Silsoe Research Institute.

Cotswolds farm consultant David Morris pointed out that lower volume treatments help optimise spraying productivity but also increase drift. Recent developments in nozzles and application technology reduce that risk, but there is a pressing need for more information on how they can help.

Nozzle performance is currently assessed using water. But Silsoe work shows adding pesticides and adjuvants alone or in a tank mix alters quoted spray quality.

To help operators make the correct choice a new BCPC nozzle selection guide, incorporating a drift risk rating, is planned. But an attempt to get it agreed at European and international level could slow its introduction.