Ganoderma, a fungal pathogen, is the causal agent for basal stem rot disease in oil palms, which has led to significant losses in palm oil production. The fungal production of lignocellulosic enzymes is crucial for successful infection, hence the disease severity could be significantly reduced by inhibiting these enzymes. The current study investigated the impact of integrated factors on inhibiting these enzymes and promoting Trichoderma virens spore production using response surface methodology. The identified optimal conditions of temperature (27.5–36.5 °C), boron (0.07–0.30 mg/mL), potassium (3.5 mg/mL), and mancozeb (1.0 mg/mL) can lead to the production of ≥5.0✕105 spores/mL of T. virens, while minimizing the laccase, cellulase, and xylanase activities to ≤0.08, 0.0, and 0.0 U/mL, respectively. The model's prediction accuracy was 81.25 %. In a greenhouse application, soil temperature was increased to 43.7 °C by solarization before applying the optimal concentration of boron, potassium, mancozeb, and T. virens. The results demonstrated the inhibition of lignocellulosic enzymes in G. boninense, as indicated by 69.0 % and 68.7 % lignocellulose contents in Trichoderma-treated and Ganoderma + Trichoderma-treated oil palm roots, respectively, which were higher than that in Ganoderma-treated roots (58.1 %). This highlights the practical relevance of our findings. Therefore, these results will help the oil palm growers to develop disease management strategies to control basal stem rot.
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