Inhibitory activity of an ethanolic extract from Azadirachta indica (Neem) on Fusarium sp.

The intensive use of synthetic fungicides for the control of Fusarium has raised concerns regarding environmental impact and pathogen resistance. As a sustainable alternative, plant-derived extracts are gaining attention due to their bioactive properties. The objective of this research was to identify the mineral and phytochemical composition of an ethanolic extract from Azadirachta indica and to evaluate its in vitro fungicidal activity against Fusarium sp. The extract was obtained using ultrasound/microwave-assisted extraction with 70 % ethanol. Phytochemical profiling was conducted through high-performance liquid chromatography (HPLC) and Fourier-transform infrared spectroscopy (FTIR), while mineral content was assessed by X-ray fluorescence (XRF). The antifungal effect was evaluated using the poisoned medium technique, with extract concentrations of 0 (control), 1, 2, 3, 4 and 5 mL/200 mL of medium. Mycelial growth inhibition and conidia production were recorded. Data were analyzed using ANOVA (analysis of variance) and Tukey’s test (p = 0.05). Potassium was the predominant mineral (4 %) and eight major phytochemicals were identified, including caffeic acid 4-O-glucoside, (+)-catechin, secoisolariciresinol, quercetin 3-O-xylosyl-glucuronide, quercetin 3-O-glucoside, caffeoyl glucose, p-coumaric acid 4-O-glucoside and pcoumaroyl glucose. Extract concentrations between 2 and 5 mL/200 mL reduced mycelial growth by up to 35 %, while doses of 2 and 5 mL/200 mL treatments significantly reduced conidia count to 173500 and 155500, respectively. These results suggest that A. indica extract exhibits fungicidal properties against Fusarium sp., highlighting its potential as a natural alternative to synthetic fungicides.