How to Manage Pests
UC Pest Management Guidelines
Celery is susceptible to the pink rot fungus at all stages of plant growth (including as transplants in trays), but the disease is most often observed on mature plants when leaf canopies are well developed.
Initial symptoms appear as brown lesions on the petioles that develop at or near the soil line or up in the plant canopy. Lesions rapidly expand into soft, watery, decayed areas. The plant tissue surrounding the lesions may turn pink. In advanced stages of the disease, lesions may contain profuse white mycelia of the pathogen. Hard, black, irregularly shaped resting structures (sclerotia) ranging in size from 0.25 to 0.5 inch long, may develop on diseased tissue. Under favorable conditions, the entire petiole and plant base may collapse.
Leaf infections on newly forming leaves may also occur. Brown leaf lesions rapidly expand into the leaf petiole. As the leaf and petiole collapse, white mycelia and black sclerotia develop.
Sclerotia survive in the soil for prolonged periods without plant hosts. When cool, wet conditions occur, sclerotia germinate and infect nearby plants at or below the soil surface. Alternately, sclerotia may develop spore-producing structures that release windborne spores. These spores may land on susceptible celery tissue and cause a canopy infection. Conditions that promote disease development are periods of prolonged wetness, excess moisture in heavy canopy, and fog.
Because many crops and weeds are hosts of this pathogen, spore releases may occur within and outside celery fields. Pink rot that occurs on celery transplants is caused by spores that blow into transplant facilities.
Organically Acceptable Methods
UC IPM Pest Management Guidelines: Celery