Phoma crown and root rot of celery

The causal agent of Phoma crown and root rot in celery is the fungus Subplenodomus apiicola (synonym Phoma apiicola). It is a serious fungal disease that affects plants throughout their development, starting from the seedling stage and extending through to the storage of harvested produce.

The primary host for this pathogen is celery (root, stalk, and leaf varieties). The fungus attacks the root system, the crown area of the stem, and the root itself, causing severe disruption to nutrient uptake, which ultimately leads to plant death in the field or rapid decay during post-harvest storage.

The hallmark symptoms of the disease include the appearance of brown, slightly sunken lesions on the root tissues and the bases of the petioles. As the infection progresses, the tissue softens and turns dark brown or black, and numerous small black specks, known as pycnidia, form on the affected areas, serving as the fungal reproductive structures.

Disease development is favored by high soil and air moisture, as well as moderate temperatures ranging from +15°C to +20°C. The pathogen persists in the environment via contaminated seeds, infested soil where it can survive for several years, and crop debris that remains on the field after harvest.

Management of Phoma crown and root rot relies on an integrated approach involving both cultural and chemical practices. Key strategies include practicing a 3-to-4-year crop rotation, utilizing high-quality disease-free seeds, removing all infected crop residues, and applying fungicides preventively when conditions are conducive to disease outbreaks.

• Seed treatment to eliminate surface-borne pathogens.
• Maintaining proper irrigation and drainage to reduce humidity.
• Spatial isolation of new celery plantings from previously infected fields.
• Rigorous culling of diseased plants during the harvest and storage process.