Transplanted Brassicas – weed control

Transplanted brassicas (sprouts, calabrese, cauliflower)

These can be relatively slow to come away, increasing the potential for weed competition if weed control programmes are inadequate.  There are on-label recommendations in brussels sprouts, calabrese and cauliflower for a number of products. The following species are NOT controlled: fumitory, hemp (day)-nettle, pennycress, field pansy, knotgrass, fat hen, small nettle, redshank, and corn spurrey are poorly controlled.

Many early sown crops are grown under cover for at least a part of the season.  This can also increase weed growth, and yet there are major limitations to the use of herbicides where covers are used. Residual herbicides all stipulate that they are not to be used on protected crops.  If a crop is covered temporarily some of these residual products can be used once the crop has hardened-off after removal of the cover to kill weeds not yet emerged. But care should be taken, or crop damage may ensue.