Join Roger Moore for a seasonal update as he revisits the Dow AgroSciences’ large scale rotational trial.
With the unseasonably mild weather, soil temperatures (at 30 cms) over the major rape growing areas of the UK continue to be largely static and are still too warm at around 10.0°C-13°C for consistent results to be achieved for blackgrass control.
When applied to “warm” soils it is not only persistence that can be compromised as the propyzamide breaks down relatively quickly, but also the lethal concentration of propyzamide itself in the rooting zone of the blackgrass.
In Yorkshire, soil temperatures are around 8°C-9°C, (nearer to the point where the half-life is relatively longer) and application can be considered if you can travel. Water stewardship needs to be top of mind. Applications must only be made after taking all necessary precautions to avoid contaminating surface waters. More information on water stewardship can be found on the Voluntary Initiative website.
For optimal blackgrass control in oilseed rape, Dow AgroSciences recommend Kerb® Flo 500 and ASTROKerb® applications are made when soil temperatures have got down to 10°C and falling, and there is sufficient soil moisture in the soil for grassweed uptake. Both these criteria are rarely met before November. This advice has been proven in extensive trials over many variable autumns. Similar advice would apply to ASTROKerb. Please note this advice applies to oilseed rape; for winter beans Kerb Flo 500 should be applied within 7 days of drilling but before crop emerges. ASTROKerb is not approved for winter beans.
Data for soil temperatures and moisture-deficits attached. Please note a 30 cms soil temperature reading is less variable than the more commonly used 10 cm reading.
More Kerb Weather Data will be supplied as the season progresses.
Check out application conditions for your local postcode
Click on the My Farm LifeCycle logo to check out forecast conditions for optimizing Kerb Flo 500 and ASTROKerb applications on farm. Simply enter your postcode in the banner and click GO to view the results.
If I wait, won’t the blackgrass roots be too big/too deep for outstanding control?
Propyzamide, the active ingredient for blackgrass in Kerb Flo 500 and ASTROKerb, works mainly by root uptake in the top 5 cms of soil. As long as the oilseed rape has been established using min-till techniques, the majority of the blackgrass will be shallow rooted and even when it develops a more extensive root system, is still likely to have sufficient roots in the Kerb activity zone for uptake.
If severe frosts are experienced before Kerb application, there may be some shear of surface roots. In this situation adventitious roots may subsequently develop, which will take up propyzamide from a later application. In this scenario we have seen excellent results from December/January application.
Download Topic Sheet 16 “Advice for Blackgrass Control in Oilseed Rape” for further advice.
To receive Kerb Weather Data and other newsletters direct to your inbox, click here
Arylex™ active is an exciting, new broad-leaved herbicide active ingredient for cereals.
- The first active from a new family of chemistry
- Broad spectrum, post emergence control of broad-leaved weeds
- Consistent weed control in variable climatic conditions
- Rapid degradation in soil and straw
- Excellent rotational cropping profile without the need for any specific cultivations prior to sowing rotational crops
- Low use rate technology (6g – 10g)
- Favorable toxicological and ecological profile
Clumps of volunteer beans are threatening crop establishment and good grassweed control in autumn-sown cereals, warns Dow AgroSciences cereals herbicide expert Stuart Jackson.
Mr Jackson says: “We’ve noticed a marked increase in volunteers this autumn, which isn’t surprising considering the increased area of beans sown last season. Beans pose a double threat – not only do they shade grassweeds from contact herbicides, but larger clumps can reduce establishment leading to gappy crops.”