Phoma Leaf Spot — Table Beet

The causal agent belongs to the group of hemibiotrophs. In the early stages, the pathogen causes seedling damping-off, leading to thinning of stands and death of sprouts. In the second half of the growing season, necrotic spots up to 2 cm in diameter with concentric zoning appear on the leaves, within which fungal pycnidia eventually form.

Root rot infection often begins at the crown as dark, sunken spots accompanied by tissue cracking; boron deficiency promotes rot development. On seed plants, the pathogen manifests as brown longitudinal necroses on petioles and flowering shoots. In table beet breeding, no specific resistance genes have been identified, so work is focused on developing tolerant varieties based on comprehensive phytopathological screening assessment.