Five flue-cured tobacco varieties were grown in rotations on a black shank-infested soil. In the 1-year rotation, losses from black shank increased rapidly in succeeding tobacco crops, while in the 3-year rotation losses decreased. The difference in black shank losses between the 3- and 1-year rotations was significant in 1956 and 1957. The black shank pathogen was not eliminated from the soil by a 3-year rotation or a 4-year period between tobacco crops.

(Full article published with kind permission from "Tobacco International")