Plow under cover crops and manure in plenty of time to ensure complete decomposition before transplanting. If the cover crop and manure are plowed under 6 weeks before transplanting, regardless of height, the toxic period passes in most years before the tobacco is set. All manure, and part or all of the fertilizer, should be turned under so the fertilizer, especially nitrogen, can help the organic matter decompose. In cases where lush cover crops are turned late, removing the top grow as feed or even clipping it and allowed it to decompose on the surface can aid decomposition and reduce root rots. Allow the soil pH to drop during the rotation period escalates decline of the fungus population, but maintain it about 6.0-6.4. while tobacco is in the field will aid in control where varieties with limited resistance are used.
Excess lime appears to increase the incidence of black root rot.
These relative ratings are based on the assumption that soil pH is at the recommended range for high yield of the rotational crop. In A Range of Varieties. If black root rot has infested a field, the best method to reduce the severity is the use of resistant varieties on a rotation basis. Thus, practice crop rotation to reduce the effect of black root rot and other root diseases. If crop rotation is not feasible, then use varieties with high resistance to black root rot, but expect other root diseases to increase, such as tobacco stunt, black shank, nematodes, etc.