Related Experiment Video
Updated: Jul 19, 2026
Bioassays for Monitoring Insecticide Resistance
Published on: December 30, 2010
Sensitivity of Meloidogyne enterolobii and M. incognita to fluorinated nematicides
1Department of Plant Pathology and Crop Physiology, LSU AgCenter, Baton Rouge, LA, USA.
Background:
Meloidogyne enterolobii (Yang and Eisenback) was recently introduced into Louisiana on contaminated sweetpotato planting material. Given the known variation in sensitivity to nematicides within the genus Meloidogyne, there is question as to whether fluorinated nematicides will be as efficacious toward M. enterolobii as they are with M. incognita (Chitwood). Using a series of in vitro and growth cabinet experiments, this study compared the sensitivity of M. enterolobii and M. incognita to four synthetic non-fumigant nematicides (fluopyram, fluensulfone, fluazaindolizine, and oxamyl).
Results:
Meloidogyne enterolobii had lower sensitivity to nematicides than M. incognita in the majority of the in vitro exposure assays. Similar levels of reduction in root infectivity were observed after nematicide exposure among both nematode species. Fluopyram showed high hatching inhibition for both Meloidogyne species at low concentrations [median effective concentration (EC50 ) values of 0.273 to 0.018 mg L-1 ], whereas fluensulfone showed high root penetration inhibition at low concentrations (EC50 values of 0.151 to 0.065 mg L-1 ) relative to that of other evaluated nematicides. For both Meloidogyne species, each of the four non-fumigant nematicides reduced root galling (58-96% reduction for M. enterolobii, 71-100% reduction for M. incognita) and egg production (63-99% reduction for M. enterolobii, 58-96% reduction for M. incognita) on sweetpotato when applied at the label recommended rate.
Conclusion:
Fluorinated nematicides and oxamyl show capacity to suppress M. enterolobii on sweetpotato. © 2021 Society of Chemical Industry.
Insights
Meloidogyne enterolobii, a new sweetpotato pest in Louisiana, showed reduced sensitivity to some nematicides compared to Meloidogyne incognita. However, fluopyram, fluensulfone, and other tested nematicides effectively suppressed root galling and egg production in both species.
Area of Science:
- Plant Nematology
- Agricultural Entomology
- Pesticide Science
Background:
- Meloidogyne enterolobii, a root-knot nematode, has been introduced to Louisiana via contaminated sweetpotato planting material.
- The efficacy of synthetic nematicides against M. enterolobii is uncertain due to known variations in nematicide sensitivity within the Meloidogyne genus.
Purpose of the Study:
- To compare the sensitivity of M. enterolobii and M. incognita to four synthetic non-fumigant nematicides.
- To evaluate the efficacy of fluopyram, fluensulfone, fluazaindolizine, and oxamyl against M. enterolobii and M. incognita.
Main Methods:
- In vitro exposure assays were conducted to determine nematicide sensitivity.
- Growth cabinet experiments assessed the impact of nematicides on root infectivity, galling, and egg production in sweetpotato.
Main Results:
- Meloidogyne enterolobii exhibited lower sensitivity to nematicides than M. incognita in most in vitro assays.
- Fluopyram demonstrated high hatching inhibition, while fluensulfone showed high root penetration inhibition at low concentrations for both species.
- All four nematicides significantly reduced root galling and egg production in sweetpotato for both M. enterolobii and M. incognita at label rates.
Conclusions:
- Fluorinated nematicides and oxamyl are capable of suppressing M. enterolobii populations on sweetpotato.
- Despite lower sensitivity in some assays, these nematicides remain effective tools for managing M. enterolobii in sweetpotato production.
