The causal agent is particularly prevalent in wetter, cool sites and years. Vigorous new leaf growth and early infection can lead to considerable yield losses and lower sugar content. The beets stay smaller.
Ramularia leaf spot [Ramularia beticola]
Pattern of damage
Brownish-gray spots, which may have dark edges, develop on the leaf blade (Picture 1). The causal agent can be identified by the white stromata, which emerge from the stoma. In the event of a severe infection the leaves tear and desiccate (Picture 2).