Damping-off is caused by different soil-borne fungi such as Pythium spp., Rhizoctonia solani and others. The disease is recognized by poor emergence and by seedlings that rot at the soil line. The occurrence of this disease is sporadic and is dependent on weather conditions, usually wet weather. The control is based on the use of seed treated with a fungicide by the seedsman, proper seeding depth, and in some cases treating the soil with a multi-purpose soil fumigant.

Wire stem and stem rots are caused by Rhizoctonia solani and soft rot bacteria Erwinia spp. respectively. Wire stem is recognized by the drying up of the stem near the soil; the control is similar to that mentioned under damping-off. Stem rot affects collards and is recognized by a soft, wet, and smelly rot in the pith of the stem. It is favored by hot weather. Because the disease is often associated with burrowing larvae of insects, an effective preventative insecticide program will minimize the disease. Vapam, Vorlex and Chloropicrin soil fumigants may help.