Soil Census of Kentucky High Tunnels Reveals Statewide Distribution of Two Meloidogyne Species

Abstract

High tunnels are passively heated and cooled structures used for specialty crop production that can increase marketable yields, extend the growing season, and protect crops from harsh weather. Kentucky has more than 1,500 high tunnels and although there are many benefits, production still has several challenges. High soil temperatures, lack of rotation and sanitation, and intensive and continuous cropping make high tunnels hospitable environments for root-knot nematode (RKN; Meloidogyne spp.). This plant-parasite infects roots, causing chlorosis, wilting, stunting, and yield loss. Determining the presence, population density, and species of RKN is important to inform management strategies. To our knowledge, this is the first research aimed at determining the presence and distribution of RKN across Kentucky. From 2019 to 2022, we sampled the soil in 175 high tunnels in 62 counties. The characteristics of production system, soil type, crop rotation, and high tunnel age were collected to analyze with RKN presence, species, and soil population density. Of the soil samples collected, 45% had no presence of RKN. Out of 55% of total samples that had RKN identified, 55% were identified as M. incognita, 39% M. hapla, and 4% M. arenaria. Root-knot nematode presence was dependent on production system and crop rotation, whereas, RKN species was dependent on production system and soil type. With over half of the sampled high tunnels infested with RKN, this project justifies further research for management strategies for RKN, especially those that are sustainable species-specific options and appropriate for commercial high tunnels.