Abstract

Crop failure due to root-knot nematode (Meloidogyne hapla) infestations in tomato plants can reach as high as 29%. Considering the long-term environmental repercussions of chemical interventions, the exploration of biocontrol agents, particularly nematophagous fungi, presents itself as a viable alternative to mitigate challenges associated with M. hapla. This study was designed to assess the potential of Trichoderma yunnanense J2 isolated from Lake Toba and Arthrobotrys thaumasius (LKTS1) from Lau Kawar, Indonesia in inhibiting nematode growth in vitro and reducing M. hapla infestation on tomato plants in vivo. Employing a completely randomized design, both the fungal isolates were inoculated to control nematode, with observations made at 12, 24, 36 and 72 h. In the bioassay test, six treatments (M. hapla as a positive control, negative control without M. hapla, pesticide control using carbofuran, nematophagous treatments using T. yunnanense J2, A. thaumasius LKTS1, and a fungal consortium consisted of J2 and LKTS1, were designed and evaluated at 7, 14, 21 and 30 days, with each evaluation performed in quadruplicate. Recorded parameters included the number of vermiform nematodes, root swellings, root knots, plant height, crown height, root height, crown fresh weight, crown dry weight, root fresh weight, and root dry weight. In the in vitro test, J2 exhibited a 99% reduction in nematode survival, while LKTS1 displayed a remarkable 100% reduction. The most effective treatment in suppressing root cavities was the combination of J2 + LKTS1, exhibiting a notable 98% reduction. Furthermore, when administered individually, both J2 and LKTS1 achieved a 98.1% inhibition. These findings showed the potential of these indigenous isolates as promising biocontrol agents against M. hapla infestations, providing valuable insights for sustainable and eco-friendly pest management strategies in the future.