Root-knot nematodes
scouted Aug. 31, 2026
- Scientific Name
- Meloidogyne sp.
- Background
- A tobacco field in Randolph County was being scouted, and it was observed that 45% of the field was affected by widespread leaf spot. Suspected Frog eye leaf spot, target spot, and root knot nematode. Grower did not treat land as this is organically grown tobacco. 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