In vitro evaluation of fungicides, botanicals and bioagents against Colletotrichum truncatum causing soybean anthracnose

Five fungicides viz., carbendazim 50 WP, chlorothalonil 75 WP, difenconazole 25 EC, hexaconazole 5 EC and propiconazole 25 EC were evaluated @ 100, 150 and 200 ppm each. Five botanicals viz., neem (Azadirachta indica), mehandi (Lawsonia innermis), Eucalyptus (Eucalyptus globules), Bogunveilia (Bogunveilia sp.) and Parthenium (Parthenium hysterophorus), each @ 10 and 15% and ready made formulations of two bioagents viz., T. viride (Tricho-Action, 100% w/w) and V. lecanii (Viro-Action, 100 w/w) were evaluated in vitro against C. truncatum, an incitant of anthracnose/pod blight in soybean following poisoned food technique. All the test fungicides, botanicals/plant leaf extracts and bioagents tested were found fungistatic and significantly inhibited mycelial growth of the test pathogen over untreated control. Among the fungicides, carbendazim recorded highest mean inhibition (90.59%) of mycelial growth, followed by propiconazole (87.95%), hexaconazole (86.15%), difenconazole (84.71%) and chlorothalonil (70.23%). Among botanicals, neem recorded highest mean inhibition (72.56%) of mycelial growth followed by Parthenium (61.31%), mehandi (46.03%) and Bogunveilia (28.98%). Bioagents, T. viride and V. lecanii recorded mean mycelial growth inhibition of 41.79 and 23.75 per cent, respectively.