Fluopyram or Resistant Cultivars Manage Meloidogyne arenaria Infestation in Virginia-Type Peanut Production

Meloidogyne arenaria (peanut root-knot nematode, PRKN) is an important pest in peanut (Arachis hypogea) production in the United States, including specialty Virginia-type peanuts. Cultivars resistant to PRKN and nematicide application are two available methods for managing PRKN. The objectives of this study were to determine the impacts of resistant Virginia-type peanut cultivars (Georgia-19HP and TifJumbo) on (1) management of PRKN abundances and damage and (2) total free-living nematode soil abundances. A common susceptible cultivar (Bailey II) with or without in-furrow fluopyram nematicide was compared to the resistant cultivars without nematicide in field trials in Florida (2022 and 2023). Resistant cultivars reduced midseason PRKN abundances from roots by 92-98% and final PRKN soil abundances by 81-93% relative to the untreated susceptible cultivar. Fluopyram reduced midseason PRKN root abundances by 65-74% and final PRKN soil abundances by 42-51% relative to untreated susceptible. Although PRKN reproduced on peanuts, no damage symptoms were observed, yield did not vary by treatment in 2022, and yield was significantly greater for fluopyram than either resistant cultivar in 2023. Impacts on total free-living nematode soil abundances were inconsistent. In summary, either fluopyram or resistant cultivars are effective tools for managing PRKN abundances in Virginia-type peanuts.