Catch cropping method for preventing and controlling black shank of flue-cured tobacco

The invention discloses a catch cropping method for preventing and controlling black shank of flue-cured tobacco. The catch cropping method is characterized in that garlic is cropped in the planting idle time of the flue-cured tobacco, and the specific method comprises the steps that the seeding time of the garlic is early October after the flue-cured tobacco is picked; the harvesting time of garlic bolts is mid-March of the next year; the flue-cured tobacco is cropped by a conventional cropping method after the garlic bolts are harvested; the line spacing of the garlic cropped in a catch cropping manner is 10-20cm, and the row spacing is 5-10cm. According to the catch cropping method disclosed by the invention, by utilizing the killing function of root exudates of the garlic on fungal pathogens of plants, the black shank of the flue-cured tobacco is prevented and controlled by adopting the catch cropping method for the garlic for the first time. Compared with the existing method for preventing and controlling the black shank of the flue-cured tobacco, the catch cropping method disclosed by the invention has the beneficial effects that (1) the garlic is cropped in the catch cropping manner in the idle time in the crop rotation mode of the flue-cured tobacco, so that the attack rate of the black shank of the flue-cured tobacco is reduced by 66.0-77.1 percent, the effect of preventing and controlling the black shank of the flue-cured tobacco reaches 83.1-85.2 percent, and the farmland combination yield is obviously increased; (2) chemical pesticide, such as metalaxyl, is prevented from being applied, so that the application amount of the pesticide is reduced, the pesticide residues of the tobacco is reduced, and the safety of the tobacco is enhanced.