Phymatotrichum Root Rot in Cotton

Identification

• Phymatotrichum root rot, commonly known as cotton root rot or Texas root rot, is caused by the fungus Phymatotrichopsis ominvorum, a fungus that attacks more than 2,300 types of broad leaf plants and makes a home in soil for a long period of time. It is economically damaging to commercial cotton growers and affects ornamental gardeners as well.

Geography

• Phymatotrichum root rot in cotton is an extreme problem in certain geographic locales like the southern and southwestern United States. This root rot is most destructive in high temperatures with plants in limestone soils that are highly alkaline, according to the Oklahoma State University Cooperative Extension Service.

Effects

• The fungus brings on a slight yellowing and then bronzing of leaves with the development of red lesions on the crown of the cotton plant. The condition may result in rapid death of the plant. Management of the problem includes crop rotation, avoiding infested locations, and the planting of non-host and resistant species.