Annual grass weeds, especially black grass, have become an increasing problem on many arable farms. This is a consequence of an increasing reliance on autumn sown crops (cereals and oilseed rape), earlier drilling (the proportion of the wheat sown in September has increased 10 fold in the last 40 years) and an inability to achieve adequate control due to herbicide resistance. These problems are a direct result of ignoring a critical element of the agroecology of black grass – about 80% of seedling emergence occurs in autumn. Sowing ever earlier means that an increasing proportion of black-grass emerges within the crop, rather than before sowing when it could be more easily killed.
A key element must be to capitalise on the extensive knowledge we have about the agroecology of grass-weeds such as black grass.