Resistant peanut cultivars reduce peanut root‐knot nematode infestation in field production

Meloidogyne arenaria (peanut root‐knot nematode [PRKN]) is the most important plant–parasitic nematode on peanut ( Arachis hypogea ) in the United States. Some PRKN‐resistant cultivars are available, but comparisons among these cultivars in the field are needed. The objective of this study was to evaluate cultivars designated as resistant for their influence on PRKN and agronomic performance in fields with PRKN. The resistant cultivars TifNV‐HighO/L, TifNV‐HG, Georgia‐14N, Georgia‐22MPR, and ACI N104 were tested without nematicides. These were compared to a susceptible cultivar, Georgia‐06G, with or without in‐furrow fluopyram nematicide. Field trials were conducted in northwestern Florida (West Florida Research and Education Center [WFREC]) in 2023 and 2024 as well as north‐central Florida (North Florida Research and Education Center [NFREC]) in 2024. PRKN indicators were low and unaffected by cultivars at harvest at WFREC in 2023 and midseason at NFREC. For all other seasons and sites, TifNV‐HighO/L, TifNV‐HG, Georgia‐14N, and Georgia‐22MPR substantially reduced PRKN abundances from roots at midseason and in soil at harvest as well as root and pod galling at harvest relative to Georgia‐06G. ACI N104 typically supported greater PRKN abundances than other resistant cultivars, but generally reduced galling relative to the susceptible cultivar. In‐furrow fluopyram with Georgia‐06G was not effective at reducing PRKN abundances or improving yield. TifNV‐HG was consistently a high‐yielding cultivar, Georgia‐06G was generally a low‐yielding cultivar, and the other cultivars varied by site‐year. In summary, cultivars highly resistant to PRKN are available, but even when PRKN is present, yield benefits of resistant relative to susceptible cultivars can vary based on environmental conditions.