Prevalence, spatial distribution, and population density of plant-parasitic nematodes in vegetable fields of North Carolina, South Carolina, and Tennessee counties

Abstract

Plant-parasitic nematodes are a diverse group of soilborne plant pathogens that limit the yield of numerous vegetable crops globally. Few studies have investigated nematode populations affecting vegetable crops in Tennessee and North and South Carolinas. Between December 2020 and October 2022, vegetable fields in selected counties of these states were sampled for plant-parasitic nematodes. Data on the prevalence, spatial distribution, and population density of seven genera of plant-parasitic nematodes, identified via morphology, were collected. Root-knot nematodes were identified in 60% of the total fields sampled, with population densities ranging from 10 to 10,400 nematodes per 500 cc soil. Detection rates of other genera as percentage of total fields sampled were as follows: spiral (42%), stubby root (32%), stunt (21%), ring (13%), and lesion (8%) nematodes. Out of eight crops sampled, fields either currently or formerly planted to tomato or pepper were the most frequently sampled in the survey (77% of total fields). This is the first survey to collect data on populations of plant-parasitic nematodes in this region, and results highlight the need for continued surveillance and study of their impact in vegetable production.