Beet cercospora disease

Beet cercospora disease is a disease caused by the fungal pathogen Cercospora beticola. The fungus thrives in warm, humid conditions. It is often caused by diseased seeds or planting materials and promoted by poor air flow, low sunlight, overcrowding, improper soil nutrient and irrigation management and poor soil drainage.

Symptoms
Small leaf spots (4-5mm diameter) with grey necrotic center and red margins. The spots develop and multiply causing severe dehydratation of the lamina starting with the marginal leaves and progressing to the destruction of the entire crop foliage. Black microscopic fructifications occur on the leaf spots on the abaxial surface. The decay of the foliage and the new shoots the plant puts forth in response to the disease cause important loss of weight and sugar quality. The seed crops are also invaded by spots from the base of the plant up to the bracts and seeds.

Treatment
Remove and destroy infected plants.

Prevention
Practice crop rotation. Use diseased-free seeds or use resistant cultivars. Observe proper planting distances and maintain sanitation by removing a disposing of infected plant materials. Avoid working when plants are wet.