Evaluation of nematicidal and plant growth promotion properties of some soil nematophagous fungi against root-knot nematode Meloidogyne incognita: in vitro and greenhouse studies

The root-knot nematode Meloidogyne incognita infects tomato plants, significantly reducing tomato yield. Using pesticides to manage crop diseases impacts crop yield quality, environmental pollution, and people's health. In this study natural enemies such as soil fungi are used in biological management methods to combat nematodes, offering a potential substitute for chemical nematicides. All fungal treatments dramatically reduced the number of hatching juveniles and increased mortality. Spore suspension (SS) of Aspergillus terreus and A. niger produced the fewest hatched juveniles and the most significant number of dead juveniles. The A. niger showed the highest phosphate solubilization (207.1 µg ml-1), and the production of IAA was produced in the absence and presence of tryptophan in A. terreus. Trichoderma longibrachiatum gave the highest siderophore. The greenhouse experiment showed that T. longibrachiatum_SS produced the longest plants (36.3 cm) and the highest fresh weight (8.9 g). The female number decreased by 93.8% compared to nematode treatment when T. longibrachiatum, A. niger, and A. terreus_SS was used. In soil, A. niger and A. terreus_SS had the highest nematode reduction percentage (75%). The number of eggs was significantly reduced in A. terreus_SS (55, 82.1%). A. niger and T. longibrachiatum_SS significantly reduced the number of galls (94.1%) and eggs (94.7%) for both fungi. A. niger_SS enhanced the production of the pigment. At the same time, T. longibrachiatum_SS significantly increased the peroxidase and polyphenol oxidase.