Silicon Soil Amendment and Arbuscular Mycorrhizae Inoculation Enhance Eggplant Defense Against Rhizoctonia solani by Promoting Growth and Mitigating Root Rot Stress.

Eggplant, an important global crop, faces severe threats from Rhizoctonia solani, causing damping-off, root rot, and stem canker. Conventional control methods are often ineffective, necessitating sustainable alternatives. This study investigates the synergistic potential of arbuscular mycorrhizal fungi (AMF) and silicon (Si) to enhance eggplant resistance against R. solani. In vitro assay demonstrated potassium silicate (PSi) inhibited fungal growth by 100% at 200 ppm, inducing hyphal malformation. Greenhouse trials using AMF and PSi (200 ppm) in pathogen-infested soil revealed reduced disease severity (32% vs. 75% in controls) and improved growth metrics (shoot height, root length, biomass). Combined AMF + PSi treatment elevated lignin deposition, phenolic content, and defense enzymes (peroxidase, polyphenol oxidase), while enhancing silicon uptake and macronutrient (N, P, K) levels. AMF colonization remained robust (55-56%) under pathogen stress. These findings highlight the efficacy of AMF-Si integration in bolstering plant immunity, promoting beneficial plant-microbe interactions in the rhizosphere, and reducing agrochemical reliance, offering a sustainable strategy for managing soil-borne pathogens in Solanaceae crops. This AMF-Si synergy offers a scalable, ecofriendly solution for soil-borne disease management in Solanaceae crops, aligning with global sustainable agriculture goals.