Medicinal plants hold significant value for researchers engaged in the study of plant and animal disease management.The objective of the study was to evaluate the chemical composition and antifungal activities of Garcinia kola (bitter kola) leaf extracts on cucumber fruit rot fungal pathogens.Garcinia kola leaf methanol extract at 5, 10, 15, 20, and 25mg/ml concentration was employed to assess the fungal inhibition, while the extract diluted with 1 mL of potato dextrose agar broth at 100, 50, 25, 20, 20, 15, 15, 10, and 5 mg/Ml, was utilised to assess thein-vitro minimum inhibitory concentration (MIC). Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the compounds present in the G. kola leaves. The study found Botryodiploidiatheobromae, Fusariumoxysporium, and Aspergillus flavus in diseased cucumber fruits.As extract concentrations decreased, fungal mycelial growth inhibition decreased linearly. Synthetic fungicide, Mancozeb had the highest inhibition, having a specific inhibition value of23.0 mmon Aspergillus flavus, 26.23 on Fusariumoxysporium, and 26.70 on Botryodiploidiatheobromae, this was followed by 25mg/mlof the extract,having inhibition zone of 19.567 on Aspergillus flavus, 20.57 on Fusariumoxysporium, and19.01mmon Botryodiploidiatheobromae. Garcinia kola extract with lowest MIC was 100 mg/Ml, having a specific MIC value of 7.40 for Aspergillus flavus, 9.40 for Fusariumoxysporium, and 6.40 for Botryodiploidiatheobromae. However, 5 mg/mL of Garcinia kola extract had the highest MIC. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis, revealed the presence of 30 bioactive compounds with a variety of pharmacological activities. The predominant compounds include 2,5-Methanofuro[3,2-b]pyridine, octahydro- (21.416%), 5-Amino-2-methoxy phenol (17.539%), 2,5-Methanofuro[3,2-b]pyridine, oc (17.465%), and 8-Azabicyclo[5.1.0]octane (22.035%). Hence, the inhibitory effects of bitter cola leaf on Cucumber fruit rot fungal pathogens may be attributed to the presence of these compounds, suggesting their potential as a viable substitute for synthetic fungicides.
