Comparative reproduction potential of Meloidogyne enterolobii, M. floridensis, and M. incognita on major vegetable crops in Georgia, USA

Authors: POUDEL, NABIN - University Of Georgia; Davis, Richard; MCAVOY, THEODORE - University Of Georgia; DUTTA, BHABESH - University Of Georgia; CHOWDHURY, INTAIZ - University Of Georgia

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2026
Publication Date: 4/9/2026
Citation: Poudel, N., Davis, R.F., Mcavoy, T., Dutta, B., Chowdhury, I.A. 2026. Comparative reproduction potential of Meloidogyne enterolobii, M. floridensis, and M. incognita on major vegetable crops in Georgia, USA. Plant Disease. https://doi.org/10.1094/PDIS-09-25-1919-RE.
DOI: https://doi.org/10.1094/PDIS-09-25-1919-RE

Interpretive Summary: Georgia ranks among the top vegetable-producing states in the U.S., and vegetables in Georgia incur losses from diseases and pests, including root-knot nematodes (RKN; Meloidogyne spp.). In a recent statewide survey in Georgia, two RKN species—guava root-knot nematode (M. enterolobii) and peach root-knot nematode (M. floridensis)—were detected for the first time in addition to the commonly occurring southern root-knot nematode, M. incognita. No comparative studies have evaluated the reproductive potential of these species on key vegetable crops. This study assessed the relative reproduction potential of M. enterolobii, M. floridensis, and M. incognita on seven economically important vegetables in Georgia: beet, cantaloupe, carrot, snap bean, squash, pepper, and tomato. Three independent greenhouse trials for each vegetable crop were conducted during the summer and fall of 2023 and 2024. Each plant was inoculated with 3,000 nematodes of a particular Meloidogyne species. Ten weeks after inoculation, the reproduction factor (Rf = final nematode population/initial nematode inoculum) for each nematode species in each vegetable crop was calculated. In one trial, no significant differences in Rf were observed among the species for any crop. However, in two of the three trials, M. enterolobii had significantly higher Rf values than M. incognita and M. floridensis on beet, carrot, pepper, snap bean, cantaloupe. For tomato and squash, all three species reproduced at similar levels. These results demonstrate the high reproductive potential of M. enterolobii on multiple vegetable crops. Also, we hypothesize that when more than one RKN species occurs in the same field, M. enterolobii may outcompete M. incognita and M. floridensis to become the dominant species.

Technical Abstract: Georgia ranks among the top vegetable-producing states in the U.S., and vegetables in Georgia incur losses from diseases and pests, including root-knot nematodes (RKN; Meloidogyne spp.). In a recent statewide survey in Georgia, two RKN species—guava root-knot nematode (M. enterolobii) and peach root-knot nematode (M. floridensis)—were detected for the first time in addition to the commonly occurring southern root-knot nematode, M. incognita. No comparative studies have evaluated the reproductive potential of these species on key vegetable crops. This study assessed the relative reproduction potential of M. enterolobii, M. floridensis, and M. incognita on seven economically important vegetables in Georgia: beet, cantaloupe, carrot, snap bean, squash, pepper, and tomato. Three independent greenhouse trials for each vegetable crop were conducted during the summer and fall of 2023 and 2024. Each plant was inoculated with 3,000 second-stage juveniles (J2) of a particular Meloidogyne species. Ten weeks post inoculation, plants were harvested to determine the reproduction factor (Rf = final nematode population/initial nematode inoculum) for each Meloidogyne species in each vegetable crop. In one trial, no significant differences in Rf were observed among species for any crop. However, in two of the three trials, M. enterolobii had significantly higher Rf values than M. incognita and M. floridensis on beet, carrot, pepper, snap bean, cantaloupe. For tomato and squash, all three species reproduced at similar levels. These results demonstrate the high reproductive potential of M. enterolobii on multiple vegetable hosts. Also, we hypothesize that in a mixed population in vegetable fields, M. enterolobii may outcompete M. incognita and M. floridensis to become the dominant species.