In Vitro Evaluation of Fungicides, Botanicals and Bio-control agents against Stagonosporopsis cucurbitacearum Causing Gummy Stem Blight

Abstract

Gummy Stem Blight (GSB), caused by Stagonosporopsis cucurbitacearum, is a highly destructive disease of cucurbitaceous crops such as cucumber, melon, bitter gourd and ridge gourd, leading to substantial yield losses under favorable conditions. The present investigation was carried out at Horticultural Research Station, Anantharajupeta, YSR Kadapa district, Andhra Pradesh, during 2020-21. The study aimed to evaluate the in vitro efficacy of selected synthetic fungicides, plant-based botanicals and bioagents against Stagonosporopsis cucurbitacearum. Seven fungicides were tested at concentrations ranging from 50 to 750 ppm using the poisoned food technique. Mancozeb recorded the highest mean mycelial growth inhibition (77.17%) and complete inhibition at 500 and 750 ppm respectively. Among six botanicals evaluated at 5%, 10% and 15% concentrations, Azadirachta indica (neem) exhibited the greatest antifungal activity, with 93.70% inhibition at 15%. In dual culture assays, Trichoderma harzianum demonstrated the strongest antagonism against the pathogen (98.05%), followed by T. viride (93.33%). The findings underscore the potential of integrating chemical, botanical and biological components into an Integrated Disease Management (IDM) framework for sustainable and environmentally sound control of GSB in cucurbit crops.