A surge in the UK’s pulse crop, coupled with the rapid adoption of Clearfield rape varieties, may increase pressure from volunteers on newly established wheat crops.

In Scotland that means predominantly beans – which have been one of the main beneficiaries of the three-crop rule – while Clearfield varieties now account for up to 15% of the 2017 OSR harvest. “Taken at face value, this suggested that volunteer beans and Clearfield rape volunteers could be much more widespread this autumn,” pointed out Dick Dyason, technical manager for Nufarm UK.

“While they won’t be a problem on every farm, those who’ve had beans or Clearfield varieties in the rotation might consider the value of taking them out now, with an autumn tidy-up, before they compete too much with the growing crop.”

These volunteers can shade young wheat seedlings, compete with them for nutrients and moisture, and damage yield potential. And, for those battling difficult black-grass populations, their shading effect can create spray ‘shadows’, preventing post-emergence contact herbicides from reaching their targets.

Mr Dyason said there’s value in autumn applications of co-formulations such as Cyclops (bromoxynil + DFF) which will also provide control of broad-leaved weed species like groundsel, speedwell, field pansy, common poppy and chickweed.

“As a non-ALS herbicide, Cyclops has a strong advantage in having no sequencing issues,” he added. "This keeps options open for weed control into the spring. It also performs well under the cooler conditions we’ll expect during November.”