北卡罗来那州是美国最集中的烤烟产区,产量占全美总产的65.78％。 威胁北卡州烟草生产的病害约有20种,按其严重程度来分:①青枯病,为最严重病害,1981年减产率1％,占病害减产比重的20％,②普通烟草花叶病,为主要病害之一,减产率1.03％。③黑胫病,④根结线虫病及其 North Carolina is the United States the largest concentration of flue-cured tobacco production, accounting for 65.78% of total production in the United States. There are about 20 kinds of diseases threatening tobacco production in North Carolina. According to their severity, ① bacterial wilt is the most serious disease. The rate of decrease in 1981 is 1%, accounting for 20% of the total amount of disease reduction. ② The average tobacco mosaic Disease, one of the main diseases, the yield reduction rate of 1.03%. ③ black shank disease, ④ root knot nematode disease and its