5 June 1998

Aphid sprays now could pay off in cereals

APHID numbers are rising in crops and could justify the inclusion of an insecticide with ear wash fungicide sprays.

Catches of cereal aphids in Rothamsted Insect Survey traps during warm weather in mid-May confirmed the big migration pressure into this years crops, reports ADAS.

Individual checks

Growers should now check aphid numbers in individual crops as ear emergence starts. If an average of 50% or more tillers are infested an aphicide is worth applying to prevent direct feeding damage, it advises.

As crops move towards early flowering a control threshold of 66% of tillers infested with increasing numbers of aphids is needed to justify spraying. The goal should be to treat clearly rising populations just before thresholds are reached, ADAS advises.