Click to contact us or call 02476 353537

New Years spray opportunity to rid your oilseed rape of black-grass and other weeds


For growers who may have been frozen out of applying herbicides in the unusually cold back end of the year, the dawning of a New Year, and January in particular, offers a potential opportunity to complete the spray applications of the residual herbicide Kerb Flo in winter oilseed rape, providing field conditions allow, says Dow AgroSciences.

Stuart Jackson of Dow AgroSciences points out that after Christmas, oilseed rape growers have a short but ideal weed control window during January. Trials and commercial experience show that effective weed control can be achieved from applications of Kerb Flo right up to the end of January. In fact January applications are particularly effective because grass-weeds develop adventitious roots that are able to pick up sufficient active ingredient. And often at this time the crop canopy has been opened up through winter die-back or pigeon grazing, allowing a more even distribution of the Kerb Flo across the soil surface, which is what is required for good root uptake.

Stuart points out that applications of residual acting propyzamide can take place on the frost or on moist crops but should not take place on snow. Do not use the opportunity to travel on frozen ground where there is any risk of contamination of watercourses as rain falling could cause significant run-off. It is essential that whenever Kerb Flo is applied growers must take every care to avoid contamination of watercourses.

Kerb Flo remains one of the most highly effective herbicides against black-grass and can be applied up to the end of January, even in frosty weather. Applications are best made when soil temperatures are below 10C and falling. Best results are achieved when growth of weeds, especially black-grass and volunteer cereals, is slow but transpiration continues. Lower temperatures means longer persistence, as degradation of the herbicide in the soil is temperature-related, but weed control symptoms will take longer to be seen, explains Stuart.

Kerb Flo can be mixed with a wide selection of tank-mix partners. Mixing or sequencing with contact-acting graminicides such as cycloxydim has been shown to further enhance weed control, particularly if the grass-weed target is larger, as is normally the case at this time of year. The combination of Kerb Flo and a fop/dim type graminicide often results in surprisingly good control, even if the black-grass is known to exhibit fop/dim resistance. There is currently no known strain of black-grass, or any other grass-weed, exhibiting any degree of resistance to propyzamide however.

For further information, please contact Stuart Jackson, Dow AgroSciences on 07976 452466 (mobile) or via the Dow Technical Hotline on 0800 689 8899.


Kerb Flo (400g/L suspension concentrate) is recommended in winter oilseed rape, winter beans and a wide range of other crops for the control of cereal volunteers, annual meadow-grass, black-grass, brome, wild-oats, chickweed, bindweed, fat hen, redshank, small nettle, speedwells and black nightshade. In oilseed rape Kerb Flo has a wide window of application of four months, from the 1st of October through to the end of January. It is recommended at dose rates of 1.25 to 2.1 l/ha depending on weed species and is compatible with a wide range of graminicides, insecticides and fungicides.

Kerb is a registered trade mark of Dow AgroSciences LLC.

Leave a Reply

Your email address will not be published. Required fields are marked * great opportunity to promote your business to our dedicated readership of farmers, landowners, estate managers and associated agricultural professionals.
Contact us today on 02476 353537 and let's work together to drive your business forward.