Sensitivity of Alternaria blight pathogen (Alternaria brassicicola) to fungicides and its effects on yield contributing parameters of mustard

Alternaria leaf blight (also called black leaf spot) caused by Alternaria brassicicola is an important disease of mustard in Bangladesh. Twelve commercial fungicides were assessed against Alternaria brassicicola Bangladeshi isolate PMIL-5 in poison food technique. Among these fungicides, three fungicides viz. Contaf 5EC (Hexaconazol 50%), Rovral 50 WP (Iprodione 50%) and Autostin 50WP (Carbendazim 50%) inhibited the total mycelial growth of A. brassicicola isolates PMIL-5 at the lowest concentration 0.0125% in in vitro condition.Contaf 5EC@ 0.1% concentration showed better results in minimizing disease occurrence and frequency of Alternaria leaf blight disease as well as a significant positive impact on the yield parameters of mustard variety BARI Sharisha 14 in the field.