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

UK - December 20, 2010

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 10°C 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.