What is phytophthora nicotiana?

Phytophthora nicotiana is a species of water mold that can infect tobacco plants causing a disease known as black shank. It is a soil-borne pathogen that infects the roots and stems of tobacco plants, ultimately causing wilting and death. The disease is a major problem for tobacco growers, particularly in the southeastern United States. The pathogen is known to produce several toxins that contribute to the disease's severity. Management of black shank typically involves the use of resistant varieties, crop rotation, and fungicide applications.