How Do I Manage Soil-borne Diseases and Nematodes?

Producing a good tobacco crop depends on what you do to control diseases and nematodes. To prevent and diminish losses from nematodes, experts recommend growers follow the "Big Three" management protocols. 
  • - Regular crop rotation
  • - Use of resistant varieties
  • - Use of a multipurpose fumigant, such as Telone® C-17 soil fumigant and nematicide

Rotation
Selection of rotation crops is very important, as it provides many agronomic benefits. Studies have shown that tobacco rotations are increasingly effective when used along with Telone C-17.

  • Length
    Significant disease and nematode problems are usually found in fields continuously planted with tobacco. Because crop rotation removes a suitable host for the disease-causing agent, the longer the rotation, the more beneficial it may be. Thus, a four-year rotation is more effective than a two- or three-year rotation. Where tobacco is grown continuously, growers are "feeding" populations of pests, thereby contributing to their buildup and the probability of severe disease problems in the future. 
  • Crops
    Grasses such as bahiagrass, bermudagrass, millet and sorghum are among the most effective crops in reducing soil populations of root-knot nematodes and should be grown at least one year before planting tobacco. Small grains, fescue, corn and sorghum also may be used for rotation with root-knot nematodes.

    Studies have shown that root-knot nematodes with tobacco rotations are increasingly effective when used along with Telone C-17.

    For tobacco-cyst nematodes, most crops - except for tomato, pepper and potato - are recommended for rotation.
Resistant Varieties
Resistant varieties are useful for control of some tobacco diseases, including nematodes.

Growers should not rely on the same variety for disease control year after year. Changing varieties is a good idea and should slow down the development of new problems.

Root-knot nematode resistant tobacco varieties are available for only the southern root-knot nematode. Tobacco varieties without this resistance should not be planted in fields where root-knot nematode damage is likely. Root-knot-resistant tobacco varieties should be expected to assist and not replace other root-knot nematode damage management practices.
 
Chemical Controls
Using a soil fumigant is highly recommended, combined with crop rotation and planting resistance varieties of tobacco.

Telone C-17 is a preplant soil fumigant that controls all major species of nematodes and has been proven effective for helping manage diseases such as Granville wilt and black shank.

Here are some of the secondary benefits of Telone C-17:
  • Crop grows off quicker
  • More uniform crop
  • Crop holds longer in the field
  • Healthier root system that can tolerate wet or dry conditions better

For more information on disease management, read the North Carolina Cooperative Extension Service's Flue-Cured Tobacco Guide.