Cercospora Leaf Spot of Table Beet

The causal agent is the fungus Cercospora beticola Sacc., which infects leaves, petioles, and stems of the plant. Symptoms do not appear on the roots; however, premature senescence of the foliage impairs post-harvest quality and storage life due to the risk of storage rot development.

Initial symptoms appear on the lower leaves as circular spots ranging from 2–3 mm to 1 cm in diameter, grayish or light brown in color, with a characteristic reddish-brown or purple margin. Under high humidity, a grayish coating of conidial sporulation forms on both sides of the leaf, and as the disease progresses, the tissue in the center of the spots falls out, leading to leaf drying and necrosis.

Resistance of the crop to the pathogen is polygenic and is evaluated by breeders using scoring scales based on the severity of plant infection. No specific resistance genes or intraspecific pathotypes of the fungus have been identified for table beet to date.