A competitive grass-weed with distinctive dark coloured seed heads (hence its common name) and now the most important herbicide-resistant weed of arable crops in Western Europe. More of a problem on heavier clay or silt soils, especially if drilled early and where there is minimum tillage.
A wide range of broad-leaved weeds occur in UK arable fields which have similar management
A group of competitive annual arable grassy weed species with flower heads that droop as they mature
Herbicide resistant weeds:the current situation in the UK
Resistant weeds, especially black-grass (Alopecurus myosuroides), are widespread in the UK. Farmers need to reduce their dependency on herbicides and use more non-chemical methods of weed control.
How competitive are different weed species?
Relative competitive ability of 26 weed species in winter wheat crops
An upright annual grassy weed. Two species of rye-grass commonly occur in the UK: perennial rye-grass (Lolium perenne) and Italian rye-grass (Lolium multiflorum). Perennial rye-grass rarely occurs as a serious weed in UK arable crops, except after rye-grass seed crops, whereas Italian rye-grass is an increasing problem, especially in autumn-sown crops.
5 species: Creeping thistle (Cirsium arvense), Spear thistle (Cirsium vulgare), Smooth sow-thistle (Sonchus oleraceus), Prickly sow-thistle (Sonchus asper) & Perennial sow-thistle (Sonchus arvensis)