Addition of chlorine to the wash water helps to reduce the bacterial contamination. Stalks should be thoroughly iced before shipping and stored under cool conditions until sold in the market. Several or more pollutants are responsible for damage to celery in California. Leaves develop a silver or bronze glazing on their lower surfaces and damage to the upper leaf surface occurs when the lower surface is severely damaged. No commercially effective control is known to prevent air pollution damage to celery.
Symptoms are a green to light green mottling and malformation of the leaflets.
Other symptoms are stunting of the plant, shortening of the central younger petioles, and horizontal instead of upright position of the outer petioles, which gives the top of the plant a flattened appearance. As the disease progresses, the older leaves sometimes show rusty or brown, necrotic, sunken areas on the upper surface of the leaves. Western celery mosaic is transmitted by various species of aphids. Celery is the main host of the virus although other plants, such as carrot, have been reported as hosts. Because celery growing in the coastal areas of California is the important host of the virus, celery free periods have been effective for control.