Resistant Blackgrass continues to be a problem in cereals.
Bolters and weed beet can become a real problem in sugar beet if not dealt with when they first appear. On average there are 1500 viable seeds per plant. They will harbour pests and diseases, compete for moisture, nutrients and light which will reduce yield by 11% for every bolter/weed beet plant per square metre. If you do nothing within 4-5 rotations you will have to give up growing beet on the field in question.
Hand roguing is the most cost effective method of controlling weed beet and bolters.