Cercospora leaf spot (CLS) has become established as a prevalent foliar disease of sugar beet in the UK over the last few seasons.
The characteristic circular spots or lesions associated with the disease are quite distinct and typically develop in mid-later summer. When more than 5% of foliage is affected, there is an economic loss with root weight, sugars and impurities affected.
Under conditions of high temperature and rainfall, cercospora spreads very rapidly increasing both in incidence and severity of symptoms.