Tobacco is an important economic crop, and the leaves were harvested for use. The quality of tobacco leaf is the main factor that affects cigarette industry. Tobacco diseases and pests have seriously affected the leaf quality, especially bacterial wilt. They has spread from south area of tobacco production to north area. The bacterial wilt can cause tobacoo plants death when it is very seriously. Wide range of incidence and severe diseases restrict the development of tobacco production in our countr...