autumn osr

Kerb® Flo 500


Kerb® Flo 500 is the tried and tested herbicide for controlling resistant blackgrass and other grass and broad-leaved weeds in oilseed rape. It still provides outstanding control with no reports of herbicide resistance anywhere in the world.

Kerb Flo 500 can be used in winter oilseed rape and winter field beans enabling the most effective use of a break crop in a combinable crop rotation.


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About Kerb® Flo 500


Excellent blackgrass control

Kerb® Flo 500 gives excellent blackgrass control, with no known resistance

  • controls fop/dim/den/ALS-inhibitor resistant blackgrass
  • gives you a clean start in the following cereal crop, minimising seed return


  • Bean

  • Oilseed Rape

Technical Specifications

Product Registration Number:
MAPP 15586

Active Ingredient:
500 g/litre propyzamide

Pack Size:
10.0 Litres

Suspension concentrate

Maximum Individual Dose:
1.7 L/ha

Maximum Total Dose:
One per crop

Latest Timing:
Before 1st Feb in the year of harvest

Water Volumes:
200 – 1000 L/ha

Spray Quality:
MEDIUM or COARSE as defined by the BCPC


Time of application:

When targeting blackgrass in winter oilseed rape, soil temperatures at or below 10°C at 30 cm depth are recommended to get sufficient activity from propyzamide. Good control is achieved when a lethal concentration is reached in the weed. This is a function of plant size, rate of growth and continuing availability of propyzamide (in the soil) for uptake.

Moisture is a key requirement for activity. Good levels of soil moisture are needed to help the herbicide distribute evenly in the top few cm of the soil, and the soil moisture deficit should be less than 50mm and falling. Soils must not be waterlogged or saturated and care must be taken to avoid any risk of contamination to water and importantly, all aspects of good Stewardship applied.

Depth of germination is an often overlooked factor. The propyzamide in Kerb Flo 500 forms a shallow layer in the soil, about 2.5-5cm. Blackgrass germinating below this will be poorly controlled. High levels of control are achieved where less mixing of the soil takes place (direct drilling etc.). Avoid deep cultivations in a preceding winter wheat crop.



Tank mixes, sequences and programmes:

Wide range of fully supported tank mix partners

  • Centurion Max – do not tank mix – sequence only.
  • Remember only 2 fop/dim applications can be made to an OSR crop. Consider a programmed approach with Kerb® Flo 500 to maximise volunteer cereal and other grass weed control.
  • Kerb® Flo 500 in mixture with PGR fungicides, especially if the crop is under stress, may cause an additive PGR effect.
  • Call Corteva Agriscience Hotline (0800 689 8899) for the latest on tank mix , sequences and programmes involving Kerb® Flo 500.



Do I need a dry leaf for application of Kerb® Flo 500?
The propyzamide active in Kerb®Flo 500 is soil acting so spraying wet weeds at run-off or light rainfall after application is not an issue. All applications should be made with due regard to water stewardship, i.e. do not spray where there is a risk of run-off to adjacent watercourses.

Can I apply Kerb® Flo 500 in a frost?
Kerb® Flo 500 may be applied in frosty conditions but avoid application onto frozen ground where subsequent rainfall could result in run-off into watercourses..

What is the optimum timing for Kerb® Flo 500?
When targeting blackgrass in winter oilseed rape we recommend soil temperatures at or below 10°C to get sufficient activity from propyzamide.

®™Trademarks of Corteva Agriscience and its affiliated companies. Use plant protection products safely. Always read the label and product information before use.