Arable farmers could be facing the worst onslaught in 10 years of one of East Anglia’s most problem weeds this autumn, says a crop advisor in the region. According to Chris Bumford who advises farmers across Cambridgeshire, Bedfordshire and Hertfordshire for Cambourne-based agronomy firm, ProCam, Eastern England is already a notorious hotspot for blackgrass. But the problem could be even bigger this coming season, he says. This will be a result of large numbers of blackgrass seeds likely to have been shed by the extremely high populations of the weed present in crops before harvest, he adds.

“Blackgrass populations in the region’s crops last season were clearly very high,” explains Mr Bumford. “With the mild winter, the weed continued growing, so we had some very thick plants, and some herbicides struggled to control them. Added to that, while blackgrass is mainly considered an autumn-germinating weed, we had another big flush of it germinating during the spring.

“The upshot is that the high numbers of blackgrass seeds shed last season will add to the blackgrass seed numbers already in the soil. So farmers will to have to do everything in their power to get on top of the potentially higher populations. In particular, using cultural or non-chemical methods will be even more important this season to underpin the action of herbicides,” he adds.

As an example, Mr Bumford says this could be a key season to delay drilling of autumn cereals, to allow blackgrass to germinate in false or stale seedbeds so that it can be killed off before the next crop is planted.

“Also, don’t forget to consider planting at higher seed rates to establish more competitive crops.

“With blackgrass now increasingly difficult to control due to herbicide resistance it is even more important to consider different methods. That is especially so in autumns like this when growers are facing the prospect of much higher-than-normal blackgrass numbers.”