Evaluation of Plant Leaf Extracts for Inhibition of Mycelial Growth of Fusarium oxysporum Associated with Guava Wilt

Abstract

Guava (Psidium guajava L.) is an important fruit crop cultivated widely in tropical and subtropical regions and is severely affected by guava wilt disease caused mainly by Fusarium oxysporum f. sp. psidii. The present study was conducted to evaluate the antifungal efficacy of selected plant leaf extracts against the pathogen under in vitro conditions. Ten plant leaf extracts viz., Satyanashi (Argemone mexicana), Madar (Calotropis procera), Neem (Azadirachta indica), Datura (Datura metel), Moringa (Moringa oleifera), Devdaru (Polyalthia longifolia), Lantana (Lantana camara), Carrot grass (Parthenium hysterophorus), Nilgiri (Eucalyptus globulus) and Makoy (Solanum nigrum) were evaluated at 10% concentration using the poisoned food technique. All plant extracts significantly inhibited the radial growth of F. oxysporum compared to the control. Among the tested extracts, Nilgiri leaf extract exhibited the highest inhibition of mycelial growth on the 3rd, 5th and 7th day after inoculation, followed by Lantana, Datura, Madar and Neem. The least inhibition was observed in Satyanashi leaf extract. The mycelial growth in the control treatment was recorded as 26.21 mm, 48.21 mm and 75.33 mm on the 3rd, 5th and 7th day after inoculation, respectively. The results indicate that plant extracts may serve as effective and eco-friendly alternatives for the management of guava wilt disease and may help reduce dependence on synthetic fungicides. However, further studies under field conditions are required to validate these findings.