Symptoms and Signs
Symptoms of Fusarium yellows usually begin to appear after plants are well established. Infected plants turn yellow and are stunted. Some of the large roots may have a dark brown, water-soaked appearance. The water-conducting tissue (xylem) in the stem, crown, and root show a characteristic orange-brown discoloration, resulting from infection by this soilborne, vascular pathogen. In the later stages of infection, plants remain severely stunted and yellowed and may collapse. Invasion by secondary rot organisms results in soft rots and hollowed cavities in the plant crowns. Aster yellows also causes similar yellowing and stunting. However, aster yellows usually causes severe petiole twisting and lacks the vascular discoloration caused by Fusarium yellows.
Comments on the Disease
Once introduced into a field, this pathogen can survive for long periods in the soil. The fungus can be moved about in infected plant residues and in infested soil. Symptoms are most severe on the summer celery crops because of warmer soil and air temperatures.
Management
Cultural Control
Use resistant or tolerant celery cultivars, and avoid fields with known histories of the disease. If infested fields must be used, plant resistant/tolerant cultivars only in winter or early spring. Avoid contaminating uninfested fields by preventing introduction of soil/crop residue.
Organically Acceptable Methods
Cultural controls are acceptable for use on organically grown produce.