Field Survey and Ecological Evaluation of Nematode-Trapping Fungi for Suppression of Meloidogyne incognita in Pumpkin

Plant-parasitic nematodes, particularly the root-knot nematode Meloidogyne incognita, severely threaten agricultural production in tropical and subtropical regions. Although nematode-trapping fungi have been considered environmentally friendly alternatives to chemical nematicides, their field performance often remains inconsistent due to limited ecological adaptation. This study combined a field survey of crop-associated nematode communities with laboratory and greenhouse evaluation of selected nematode-trapping fungal isolates under subtropical conditions. Field surveys across multiple crops identified M. incognita as the dominant plant-parasitic nematode species. Five fungal isolates with different trapping mechanisms were compared for growth under contrasting nutrient conditions and nematode-trapping efficiency. Among them, Drechslerella brochopaga (NTF2), which forms constricting rings, showed superior growth stability under nutrient-limited conditions and the highest nematode mortality in vitro. In greenhouse experiments, NTF2 reduced root gall formation in two of three independent trials, indicating potential but variable suppression of M. incognita on pumpkin. These findings highlight the importance of ecological adaptation and trapping strategy in determining the effectiveness of nematode-trapping fungi for sustainable nematode management.