Novel Fungicide from Waste Oil Palm Fruit Bunch for Sustainable Management of Tomato Wilt Disease Caused by Fusarium oxysporum - experimental and in silico studies

Abstract

Tomato wilt, a widespread and persistent disease caused by the fungus Fusarium oxysporum, can be effectively controlled through biological approaches, promoting ecosystem sustainability and enhancing agricultural productivity and quality. This study explored the use of empty oil palm fruit bunch (EOPFB) waste as a natural fungicide to control tomato Fusarium wilt disease through in vitro, pilot scale, and molecular docking experiments. EOPFB aqueous extract showed the highest mycelium growth inhibition of 68.3 %, with the commercial fungicide Mancozeb exhibiting a moderate 42.30 % inhibition, and sterile distilled water having a negligible effect of 0.24 %. The inhibition rate varied with concentration, peaking at 72.63 % at 0.15 g/mL and dropping to 54.80 % at 0.01 g/mL. In terms of wilt disease incidence and severity, EOPFB performed best, recording the lowest incidence of 47.20 % and severity of 15.58 %. Mancozeb followed closely, with an incidence of 46.30 % and severity of 26.23 %. Sterile distilled water, on the other hand, showed the highest incidence of 76.28 % and severity of 56.17 %. Molecular docking simulations corroborated the experimental results, validating the potency of EOPFB as an inhibitor of trypsin from F. oxysporum, and identifying 2-amino-5,6-dimethyl-3 H-pyrimidine-4-one as the primary active compound responsible for the fungicidal activity. This phytochemical, abundant in the crude ethanolic extract of EOPFB, was found to have a higher binding affinity (6.1 kcal/mol) than Mancozeb (4.8 kcal/mol), at the trypsin target. These findings demonstrate the potential of EOPFB, an agricultural waste product, as a sustainable and eco-friendly solution for managing tomato Fusarium wilt disease, contributing to increased tomato production. It also highlights the potential of 2-amino-5,6-dimethyl-3 H-pyrimidine-4-one as a lead compound for the development of novel, natural fungicides, and underscores the value of EOPFB as a rich source of bioactive compounds with agricultural and biotechnological applications.