Root-knot nematodes
scouted Oct. 2, 2026
- Scientific Name
- Meloidogyne sp.
- Background
- A tobacco field in Lee County was being scouted, and it was observed that 15% of the field was affected by spots in patches throughout the field, with some galling on plant roots, suspected to be a nematode issue. Brown spot and target spot were observed in the field, with the grower finding some angular spot as well. A sample was submitted to the PDIC for diagnosis.
- Conclusion
- The issue was identified as root-knot nematodes (Meloidogyne spp.), which are microscopic roundworms that affect a wide range of plant hosts, including tobacco. These nematodes complete their life cycle in the soil and roots, where juveniles infect roots and establish feeding sites that cause characteristic galling. Aboveground symptoms often appear in patches across the field and include chlorosis, stunting, and wilting. Symptoms are frequently more severe under drought conditions due to reduced water and nutrient uptake and increased susceptibility to secondary root pathogens. Management of root-knot nematodes is challenging because of their broad host range, and effective control relies on integrated management practices, including routine soil sampling to assess nematode presence and population levels.
- Resources