Beetle threat to slow growing oilseed rape crops

The huge area of oilseed rape sitting in very dry ground conditions, waiting for rain in many areas is at particular risk from cabbage stem flea beetle, warns BASF.

"This season much of the increased area of oilseed rape is at a vulnerable stage – that is, when the cotyledons are out and the first true leaves are still developing," says the company's insecticide products manager Dave Marris.

"Damage done at this stage will significantly reduce plant populations, resulting in poor establishment and a thin crop going into the winter."

Mr Marris advises growers to keep a careful lookout for beetles on their oilseed rape crops at this vulnerable stage. "The beetles will be coming out of their summer hibernation about now – they will be hungry and looking to feed on young oilseed rape plants.

His immediate advice is to apply a pyrethroid insecticide to control the beetles as soon as the typical 'shothole' grazing damage is seen on the young leaves, particularly if soil conditions remain dry and establishment growth is retarded.

The product recommended is Contest which has been shown to give good control over an extended period - due mainly to a unique formulation that holds the active ingredient on the leaf surface, therefore exposing pests to the chemical for a longer period