Weed Control Advice for Scotland

Cereal growers across Aberdeenshire, Morayshire and the Black Isle are facing a busy spring of fieldwork with some requiring complex strategies to tackle weed and disease pressures.

Autumn residuals applied in dry conditions last autumn have not performed as expected, leaving overwintered broad-leaved weeds in fields across the region. Yellow rust, brown rust and mildew is also evident, according to Colin Bowers, our commercial technical manager in Scotland.

And with some wet weather delaying about one third of the spring drilling growers planned to carry out, operations are already starting to concertina. “Winter cereal growers and their agronomists are walking fields to work out the most effective strategies to control a number of pressures that have materialised,” Colin said. “Some like to get in early and spray off weeds before T0 fungicide applications, but the wet weather has limited opportunities so we’re going to see some complicated tank mixes to address all the issues growers face.

“We’ll be seeing something similar happening in early May on spring-sown crops where mixes might include a herbicide or two, a fungicide, PGRs, trace elements and maybe a graminicide. There is going to be a complex tank mix required to reduce the number of passes as the spring jobs mount up.”

Fumitory is an ever-present threat, and cleavers need attention before they start to affect yield. Large mayweeds should also be taken out to avoid harvesting issues. Colin added that controlling some of those key problem weeds is becoming difficult in some parts of the region.

“Growers will have used a sulfonylurea and CMPP herbicide for maybe 20 years. It’s well established chemistry,” Colin said. “But they want to get away from that if they have suspected or confirmed resistance in chickweed or mayweed.”

A new mode of action for broad-leaved weed control is available to Scottish growers for the first time in well over a decade in the shape of Zypar. Dow’s new broad-leaved herbicide is designed to take out key problem weeds such as fumitory, mayweed, chickweed, cleavers in cold or variable temperatures. “Scottish growers will see this new herbicide as a real benefit because it can handle the variable weather patterns we have.

“Temperatures have been dropping to four degrees at night and rising to 14 degrees during the day, but with a lot of field work ahead of them, growers want to get on with the work.”