Syngenta introduces new insecticide aimed at pollen beetle in rape

Oilseed rape growers have another option for treating pollen beetle next spring, after an insecticide used in the potato sector gained approval for use in rape.

Plenum contains the active ingredient pymetrozine, which is not a neonicotinoid, making it valuable to growers in helping manage resistance, according to the manufacturer Syngenta.

The firm pointed to results of pollen beetle monitoring which have revealed a dramatic increase in the incidence of pyrethroid resistance in 2010, with resistant beetles now found throughout the south, East Anglia, northern England and into Scotland. In tests, over half of beetle populations showed some resistance to pyrethroids, with up to a third showing complete resistance.

Steve Ellis of ADAS and currently leading an HGCA project to address pollen beetle risk, acknowledges that pyrethroid resistance levels have risen significantly over the past season, and spread far more extensively across the UK. "Any new option that can help growers to manage the risk of resistance more effectively is very welcome," he added.

The Plenum approval is for one application per crop, at the green to yellow bud stage. "We anticipate that most growers will use Plenum as the first option when the crop is at its most vulnerable green to yellow bud stage," said Mr Jobling.

ADAS trials in Kent this year have shown that the product achieved faster control of pollen beetle, compared with either thiacloprid or lambda-cyhalothrin, giving over 80% control after three days and more than 90% after seven days compared with the control. Thiacloprid achieved 20-30% control over the same period.