Farmer Focus: Herbicide trial shows mixed blackgrass control

All land work and spraying is now complete until February, leaving hedgetrimming and general estate maintenance as the remaining tasks for the season.

Both wheat and oilseed rape crops are looking excellent, with wheat plant counts exceeding 400 plants/sq m and oilseed rape more then 30 plants/sq m.

My ongoing bio-nature nutrition trial in oilseed rape currently shows no visible difference between treated and untreated areas.

See also: Farmer Focus: Prospects for year ahead do not look pretty

However, further applications are scheduled, so results may change.

Interestingly, where I applied 3t/ha of poultry manure, crops are noticeably taller and thicker compared to untreated headlands.

My post-emergence herbicide trials in wheat have delivered promising results.

Initially, I planned to use Cougar (diflufenican + flufenacet) at 0.6 litres/ha.

However, due to persistently high blackgrass numbers, I revised the plan and applied:

• Sovorna (cinmethylin + piclinafen) at 1.25 litres/ha
• Regatta (flufenacet + diflufenican) at 0.3 litres/ha.

Fourteen days after each application, the trial plots drilled on 10 October 2025 showed high blackgrass in the the Bandor (aclonifen) + Cougar (pre-em).

There was low, but still blackgrass present in the Sovorna + Regatta (post-em).

Where Fundatis (bixlozone (isoflex) + beflbutamid) + Cougar (pre-em) was applied pressure was medium.

With the Sovorna + Regatta (post-em), there was very low to no blackgrass present.

The Sovorna + Cougar (pre-em) plot also revealed low grassweed pressure, as did the Regatta (post-em) plot.

The Mateno Star (aclonifen + flufenacet + diflufenican) (pre-em) plot revealved medium pressure and the final plot trial of Sovorna + Regatta (post-em) showed low to none.

Conclusion

From these trials, my conclusion is that Sovorna + Fundatis would have been the ideal pre-em programme, followed by Cougar post-em. 

It’s worth noting that conditions were exceptionally dry after pre-em applications, despite two days of rain following each spray.

Feedback from other farmers suggests that Sovorna, or similar products with actives (cinmethylin + piclinafen), performed well under these dry conditions, making it one of the most reliable options this season.

By contrast, last year’s wet conditions allowed nearly all actives to work effectively.