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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #420560

Research Project: Integrated Management of Nematodes in Southeastern Field Crops

Location: Crop Genetics and Breeding Research

Title: Effect of non-fumigant nematicides on reproduction of recently detected Meloidogyne species in Georgia under greenhouse conditions in tomato

Author
item POUDEL, NABIN - University Of Georgia
item TORRES, LUIS - University Of Georgia
item Davis, Richard
item JAGDALE, GANPATI - University Of Georgia
item MCAVOY, THEODORE - University Of Georgia
item CHOWDHURY, INTIAZ - University Of Georgia

Submitted to: Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/31/2024
Publication Date: 1/3/2025
Citation: Poudel, N., Torres, L., Davis, R.F., Jagdale, G., Mcavoy, T., Chowdhury, I.A. 2025. Effect of non-fumigant nematicides on reproduction of recently detected Meloidogyne species in Georgia under greenhouse conditions in tomato. Horticulturae. 11(1):36. https://doi.org/10.3390/horticulturae11010036.
DOI: https://doi.org/10.3390/horticulturae11010036

Interpretive Summary: Root-knot nematodes (Meloidogyne spp.; RKN) are among the most devastating soil-borne pathogens affecting tomato production. In recent years, aggressive RKN species, including M. floridensis (the peach root-knot nematode), M. haplanaria, and M. enterolobii (the guava root-knot nematode), have been detected in multiple tomato fields across the southern United States. Host resistance, which is effective against the commonly encountered M. incognita, has proven ineffective against these new species, making chemical nematicides the primary management strategy. The objective of this study was to evaluate the effect of the non-fumigant nematicides Salibro (fluazaindolizine), Nimitz (fluensulfone), Velum Prime (fluopyram), and Vydate (oxamyl) on the reproduction of these emerging RKN species along with the commonly detected M. incognita. Nimitz provided the most consistent results, suppressing nematode reproduction by over 90% across all species. Other nematicides exhibited variable efficacy depending on the RKN species. Velum Prime reduced nematode reproduction by over 50% in most species but achieved only 24% suppression in M. enterolobii. Similarly, Salibro suppressed egg counts by more than 50% across all species, except M. enterolobii, where it reduced egg counts by 41%. Vydate effectively suppressed egg counts in M. floridensis and M. incognita by more than 50%, but its efficacy was lower against M. haplanaria and M. enterolobii, with reductions of 39% and 23%, respectively. These differences highlight potential variations in sensitivity among RKN species to non-fumigant nematicides. Although Nimitz consistently reduced egg counts, it also negatively affected root and shoot biomass in most experiments. In contrast, Velum Prime showed a consistent increase in both root and shoot biomass across all experiments. Overall, our study suggests that non-fumigant nematicides hold promise as alternatives for managing these newly detected, aggressive RKN species. Further field studies are necessary to validate their consistency and assess their impact on tomato growth and yield.

Technical Abstract: Root-knot nematodes (Meloidogyne spp.; RKN) are among the most devastating soil-borne pathogens affecting tomato production. In recent years, aggressive RKN species, including M. floridensis, M. haplanaria, and M. enterolobii, have been detected in multiple tomato fields across the southern United States. Host resistance, which is effective against the commonly encountered M. incognita, has proven ineffective against these new species, making chemical nematicides the primary management strategy. The objective of this study was to evaluate the efficacy of the non-fumigant nematicides fluazaindolizine, fluensulfone, fluopyram, and oxamyl on the reproduction of these emerging RKN species along with the commonly detected M. incognita. Fluensulfone provided the most consistent results, suppressing nematode reproduction by over 90% across all species. Other nematicides exhibited variable efficacy depending on the RKN species. Fluopyram reduced nematode reproduction by over 50% in most species but achieved only 24% suppression in M. enterolobii. Similarly, fluazaindolizine suppressed egg counts by more than 50% across all species, except M. enterolobii, where it reduced egg counts by 41%. Oxamyl effectively suppressed egg counts in M. floridensis and M. incognita by more than 50%, but its efficacy was lower against M. haplanaria and M. enterolobii, with reductions of 39% and 23%, respectively. These differences highlight potential variations in sensitivity among RKN species to non-fumigant nematicides. Although fluensulfone consistently reduced egg counts, it also negatively affected root and shoot biomass in most experiments. In contrast, fluopyram showed a consistent increase in both root and shoot biomass across all experiments. Overall, our study suggests that non-fumigant nematicides hold promise as alternatives for managing these newly detected, aggressive RKN species. Further field studies are necessary to validate their consistency and assess their impact on tomato growth and yield.