In vitro Evaluation of Fungicides against Alternaria brassicae, Causing Alternaria blight of Mustard

Foliage/leaf blight caused by Alternaria brassicae (Berk.) Sacc. is one of the major destructive disease of Mustard (Brassica juncea L.) crop grown in the sate of Maharashtra. In the present study, bio-efficacy of ten fungicides was evaluated in vitro against Alternaria brassicae. All the fungicides tested were found fungistatic/fungicidal against the test pathogen and significantly inhibited mycelial growth of the test pathogen over untreated control. The percentage mycelial growth inhibition of the test pathogen was increased with increase in concentrations of the test fungicides. However, Iprodione 50 WP was found most effective and recorded significantly highest mean mycelial growth inhibition (100.00%). The second and third best fungicides found were Mancozeb 75WP and Carbendazim 50 WPwhich recorded mean growth inhibition, respectively of 90.29 and 88.58 per cent. This was followed by the fungicides, viz., Chlorothalonil 75 WP (inhibition: 86.70%), Copperoxy chloride 50 WP (inhibition: 86.60%), Difenconazole 25 EC (inhibition: 78.37%), Hexaconazole 5 EC (inhibition: 75.65%) and Penconazole 25 EC (inhibition: 72.18%). Thus, in the present study those fungicides found effective could be exploited under field conditions for effective management of Alternaria blight of mustard.