Antifungal Potential of Three Plant Extracts in the Control of Some Major Fungi Associated with Cashew Seeds (Anacardium occidentale L.)

Abstract

Cashew (Anacardium occidentale L.), is an economically export oriented crop that could plays an important role in the Cameroonian economy. Owing to its importance, a study was carried out to evaluate the potential antifungal activities of three plants extracts against three major fungal pathogens associated to its seeds. To achieve this objective, cashew seeds samples were collected from Cameroon and Chad, and fungal pathogens isolated on Potato Dextrose Agar (PDA) culture medium. In vitro antifungal activities of Callistemon viminalis, Cupressus lusitanica and Lantana camara were assessed on three major fungi; Cercospora sp., Colletotrichum gloeosporioides and Pestalotia heterocornis. Results showed that cashew seeds harbour a diversity of fungal species; the most frequent are Cercospora sp. (26%), followed by Aspergillus niger (17.78%) and P. heterocornis (15.6%). Aqueous extracts at 28 mg/ml and ethanolic extracts at 16 mg/ml of C. lusitanica and L. camara, inhibited at 100%, the radial growth and sporulation of all tested fungi. This preliminary work has opened up a possibility of the use of these extracts in the treatment of seed-borne fungi of cashew nuts. However further studies are still on-going under in vivo field conditions to practically evaluate on their potential in cashew seeds disease management.