Texas root rot (also known as Phymatotrichopsis root rot, Phymatotrichum root rot, cotton root rot, or, in the older literature, Ozonium root rot) is a disease that is fairly common in Mexico and the southwestern United States resulting in sudden wilt and death of affected plants, usually during the warmer months. It is caused by a soil-borne fungus named Phymatotrichopsis omnivora that attacks the roots of susceptible plants. It was first discovered in 1888 by Pammel and later named by Duggar in 1916.[1][2]