Occurrence and pathogen isolation of tobacco fusarium root rot in main tobacco production regions of Shandong province

Tobacco fusarium root rot as a new disease was founded in Shandong tobacco growing regions. In 2010, a survey of tobacco root rot caused by fusarium sp. was made in main tobacco growing-area of Shandong province. The results indicated that this disease was an important tobacco root and stem disease, incidence about 8.0%. Expect Yishui country, some isolates were separated from tobacco plants with typical root rot symptoms in 18 fields. The separation rate was 40%. Fusarium sp. and phytophthora. were both isolated from part tobacco plants with typical root rot symptoms, the proportion was 31.3% of total diseased. Through pathogenicity tests, 10 strains possessed pathogenicity. Among these, 5 strains had stronger pathogenicity.