In-vitro and in-vivo evaluation of different fungicides against leaf blight causing fungus Alternaria cucumerina in bitter gourd

Bitter gourd (Momordica charantia L.) belongs to family Cucurbitaceae, and is a popular vegetable crop in the tropical and sub-tropical countries. It is an annually grown herbaceous vine that requires warm climate for growth. The leaves, stem and roots of bitter gourd contains a lot of bio-active components having nutritional and medicinal importance. Alternaria leaf blight (Alternaria cucumerina Ellis & Everh.) is a fungus which causes leaf blight on bitter gourd and leads to significant crop damage. The present study investigated the efficacy of five different fungicides against Alternaria leaf blight (ALB) of bitter gourd under in vivo and in vitro conditions. The single hyphal tip method was used to isolate and purify the fungal pathogen from the ALB infected leaves of bitter gourd. Five commercially available fungicides (1. Melody duo 66.8% WP, 2. Polyram DF 70%, 3. Score 250 EC, 4. Tilt 250 EC, 5. Flumax 60% EC) were evaluated at concentrations of 50 ppm and 100 ppm for effective ALB diseased control. Among tested fungicides, maximum inhibition (90 %) of fungal growth was given by Melody duo @ 100 ppm concentration followed by Polyram (81 %), Score (77 %) and Tilt (70 %), whereas Flumax resulted in minimum (45 %) fungal inhibition under in vivo. Melody duo revealed minimum disease incidence (15.67 %) compared to disease incidence recorded in polyram (17.83 %), Score (20.50 %) and Tilt (22.33 %) treated crop. Flumax was not tested in vitro because it gave minimum disease control in in vitro experiments. The control plants showed high disease incidence (56%).