Autumn Weed Control in Oilseed Rape 2026

Protect crop establishment with effective early grass weed control.

Many of the key grass weeds affecting Winter Oilseed Rape (OSR), including blackgrass, volunteer cereals and annual meadow-grass, emerge during late summer and early autumn, competing with young crops for light, moisture and nutrients at a critical stage of establishment.

Successful OSR establishment relies on effective early-season weed control. Timely  control reduces early competition, helps crops establish evenly and limits the number of weeds that survive to produce a seed return.

Stop blackgrass getting away early this autumn.

Blackgrass remains a key threat to OSR crops with the potential for significant yield reductions and a carry-over of Blackgrass seed to following cereal crops if not controled. Most blackgrass emerges during early autumn (August to October), coinciding with the main drilling and establishment period for oilseed rape.

Without effective control, blackgrass can:

• Reduce crop establishment and yield potential
• Produce large numbers of seeds that Increase weed pressure
• Make long-term resistance management more challenging

To manage the threat, an effective autumn blackgrass strategy should begin with an assessment of field history, weed pressure, cultivation approach and expected emergence patterns andSupport with appropriately timed herbicide applications.

Cereal volunteers, annual and perennial grass weeds in OSR.

Cereal volunteers can also be a significant problem as winter oilseed rape crops start to establish. Left unchecked, they compete aggressively for light, water, and nutrients – leading to yield losses.

Volunteer cereals are usually present in crops grown after a cereal harvest and establish quickly when the oilseed rape plant is still small and uncompetitive. 

Other grass weeds, including annual meadow-grass and ryegrass, can also reduce crop establishment if left untreated.

Early identification and treatment help maintain crop competitiveness while reducing future weed burdens.

Product options that ensure a good, cost-effective start to weed control this autumn. 

Clayton Plant Protection now offers a frontline post-emergence herbicide for use in winter oilseed rape crops this autumn, formulated to a premium quality. 

Clayton Gatso EC™ & Clayton Propose™ | 120 g/L clethodim

• Post-emergence application use up to 5 tillers on weed targets
• Benchmark herbicide for establishing early-season weed control 
• Targets key weed problems, including Blackgrass, annual meadowgrass and volunteer cereals, in a single application

Clayton Satchmo EC™ | 100 g/L Propaquizafop

• Ideal option for cereal volunteer control in OSR crops
• Wide window of post-emergence application use
• Versatile herbicide for controlling Cereal volunteers and Wild oats in OSR crops
• Wide-ranging weed control options, targeting Volunteer wheat, Volunteer barley and Volunteer rye as well as Ryegrass, Common couch and Sterile brome.

Glyphosate: the foundation for early weed control.

Prior to drilling, glyphosate remains an important tool for reducing weed pressure through stale seedbed management. Applying glyphosate before drilling helps remove existing annual and perennial weeds, reducing competition and supporting successful crop establishment.

Available from September…

Clayton Overlord™  & Clayton Trafalgar™  | 360 g/L glyphosate

• Non-selective, systemic herbicide with no residual soil activity.
• Controls a broad spectrum of annual and perennial weeds.
• Effective control of couch grass and other perennial weeds.
• Approved for crop desiccation in certain crops.
• Wide range of agricultural, horticultural, forestry and industrial uses including pre-planting, stubble management and total vegetation control.

Building an effective autumn weed control programme.

Successful weed management starts before drilling and continues throughout crop establishment.

A practical autumn programme should include:

• Assessing field weed pressure before drilling
• Monitoring crops regularly after emergence
• Applying post-emergence herbicides while weeds are small and actively growing
• Using products according to label recommendations and resistance management guidelines