Similar happend with osr when the neonic went. Flea beetle became the scrape goat for every failure and every instance of bad management When some of the time it wasn’t. A couple of years ago a notable nfu media type was stood in a field of apparent csfb ravaged osr, it was drilled in September into a heavily worked seedbed that was about as dry as Death Valley. It was quite obvious it why the rape hadn’t grown and it was certainly not flea beetle!British Sugar/ NFUSugar and BBRO seem to be fixated on Virus Yellows to the point that Cercospora is being overlooked.
searching on the internet this morning North Dakota State University regards it as the most devastating of the foliar diseases of Beet. It adversely impacts the photosynthetic capacity of plants and reduces yield; the disease also results in higher impurities in the juice which reduces sucrose extraction. Now that this disease is very well established we will have the conditions for earlier infection in the next crop, yet as far as I know we do not have one, let alone a choice of fungicides to control it.