A B C D E F G H I J K L M N O P Q R S T V W X Y Z
Ca Ce Ch Ci Cl Co Cr Cu Cy

Cercospora leaf spot (beet)

Cercospora leaf spot is a fungus that affects members of the beet family.

Not to be confused with:
Ramularia beticola, also called leaf spot

recognize Cercospora leaf spot on sugarbeets
Cercospora leaf spot on sugarbeets, photo: Rasbak - CC BY-SA 3.0

Cercospora leaf spot (Cercospora beticola) is a fungus that affects members of the beet family. The fungus causes small grey spots scattered over the leaves, discoloring to brownish-black. As the spots expand, a red border forms around the affected areas. At summer temperatures above 20°C and nights with fog and dew, the fungus becomes active.
The leaf spots caused by Ramularia beticola are larger (4 – 10 mm) and more irregular in shape than the Cercospora spots. In addition, the spots have a dark edge and white dots can be seen in the spots with a magnifying glass.

Where to find

Control

Difficult to control. Once noticed, it is too late to do anything about it.

Prevention

Plant the beets in a not too sheltered place so that the wind has free rein.