Farmers returning to oilseed rape this summer are being urged to familiarise themselves with how weed control strategies have evolved in the past three years.

Industry predictions indicate an additional 100,000 hectares could be planted in the UK and Ireland this summer, with the war in Ukraine underpinning sustained high prices of well over £500/tonne.

Faced with pressure from pests such as cabbage stem flea beetle, some arable farmers stopped growing oilseed rape but a significant number are expected to return to the crop this year.

Corteva Agriscience says those growers may not be familiar with recent advances in autumn weed control products which allow them to reduce their establishment risk and be more targeted in their approach to weed control.

Switching from a preventative to reactive autumn strategy allows growers to decide on their herbicide spend after assessing the visible weed pressure plus the impact of pests.

Targeting cleavers, cranesbill, poppy, shepherds purse and fumitory, Belkar® offers an alternative to traditional approaches which rely on pre-emergence control.

“As an industry we have learnt a lot very quickly about how to establish the crop while reducing risks at the same time. This, combined with the attractive price of oilseed rape, will mean a significant number of farmers will return to the crop this year," said Oilseed Rape Herbicides Category Manager, John Sellars.

“Belkar has spearheaded a fundamental change in farmers’ strategies for controlling weeds, paving the way for a much more flexible approach to weed control in their oilseed rape.

Read more: Oilseed rape profit revival?

“Belkar is a post-emergence product which allows growers to see the crop establish before deciding on their herbicide investment. It means they can tackle what is visible, and not spend on herbicides before they know how well the crop is going to emerge.”

Arylex active has been formulated with picloram to create Belkar and the product has a window from either 1 or 15 September (depending on the rate being used) through to 31 December making it the ideal autumn herbicide.

There are three treatment options which Corteva says have performed best in trials. At two true leaves, an application at 0.25l/ha will take out the weeds which have germinated alongside the crop and, in some circumstances, that will be enough broad-leaved control before an application of Astrokerb (propyzamide + aminopyralid) or similar later on.

In high weed pressure situations where a second germination is visible, growers have the option of a second 0.25l/ha spray two-to-four weeks after the first application.

Depending on workloads, growers can wait until six true leaves of the crop – and after 15 September – to tackle bigger weeds at a rate of 0.5l/ha which will take care of the weeds going into the autumn.