1 March 2002

Insecticide use on OSR a waste of £s

INSECTICIDE use on oilseed rape may be an unnecessary expense in Scotland, unless pest numbers start climbing sharply.

Even resistant aphids which caused feeding damage last year should not be regarded as a major problem, provided growers switch to alternative insecticides, such as new seed treatment Chinook, says the SACs Andy Evans.

Although around half the Scottish winter rape and more than one-third of the spring crop are sprayed with insecticides, he doubts whether many reached the recognised treatment threshold of 15 pollen beetles/plant or five beetles for backward plants.

Natural predators could suffice, he says. &#42