Integrated assessment of wood-rotting fungi and sustainable protection of tropical timbers using invasive weed extracts and Trichoderma harzianum

Wood-decay fungi cause substantial timber deterioration, but comparative data linking fungal decay with timber-specific mass loss, chemical and anatomical changes, and biological protection remain limited for tropical timbers of the Western Ghats, Karnataka, India. This study compared the decay susceptibility of Artocarpus heterophyllus, Pterocarpus marsupium, Tectona grandis, and Dalbergia latifolia, characterised fungal-induced changes, evaluated Trichoderma harzianum and selected invasive-weed extracts for wood protection. Five wood-rotting fungi and the brown-rot fungi Rhodonia placenta were tested for 120 days using mass loss, chemical analysis, FTIR spectroscopy, and anatomical observations. A. heterophyllus showed the highest mass loss (62%), whereas D. latifolia showed the lowest (30%). Cellulose loss was highest in A. heterophyllus (14.3%) and lowest in D. latifolia (8.4%). T. harzianum suppressed fungal growth by up to 98%, while Parthenium hysterophorus and Hyptis suaveolens extracts showed 95–98% inhibition at 0.40% (w/v). Extracts of Croton bonplandianus, H. suaveolens, and Lantana camara provided up to 98% wood protection. Overall, A. heterophyllus was the most susceptible and D. latifolia the most resistant, while T. harzianum and selected plant extracts showed promising laboratory-scale potential for the sustainable management of fungal timber deterioration.