What to Watch For: Soil Insects in Organic Tobacco
Organic tobacco acreage has increased throughout the southeast for 2015, and along with this increase has come more questions about insect management. To help answer these questions, our lab will be conducting several projects focused on both chemical and biological insect management in organic tobacco this summer.
As with many organic crops, we have fewer insecticide options in organic tobacco. Where available, organically acceptable tools are identified in the North Carolina Agricultural Chemicals Manual. However, for some insect pests, there are no effective organic insecticides for use in tobacco. This includes soil insect pests. Wireworms and white fringed beetles are among the more common soil insect pests in tobacco. In conventional tobacco, these insects are managed two ways–through crop rotation and, when populations are high, with pretransplant insecticides.
Knowing which fields to apply insecticides to pretransplant for soil insects requires an understanding of field history–both which crops were planted before and the incidence of soil insect damage. Most fields that have been in regular production will not require treatment for soil insects prior to tobacco transplant.
However, many new organic tobacco growers are also planting fields that have not previously been in tobacco production (or any crop production). We do not know what the potential is for soil insect damage in these fields, but organic tobacco growers should be aware of potential risk. In particular, fields that have previously been planted in grasses or pasture may foster higher wireworm populations. Because there are no effective organic insecticides to manage soil insects, pretransplant treatment is not recommended. Instead, organic growers planting into recent grass or pasture land should be aware of potential damage and be prepared to fill in plants if necessary to ensure a good stand. In other words, if you’re setting into a risky field for soil insects, plan to have some extra plants on hand in case you them!