Chemical management of Helminthosporium vignicola: The incitant of cowpea target leaf spot

The target leaf spot disease of cowpea incited by Helminthosporium vignicola is a new emerging threat to all the cowpea growers of Odisha. Coastal districts of Odisha are mainly inflicted by this leaf spot disease. An in-vitro experiment was conducted at the Plant Pathology Laboratory of College of Agriculture, OUAT, Bhubaneswar to test the effect of some fungicides on radial growth inhibition of H. vignicola. The efficacy of ten fungicides viz. Hexaconazole 5%EC, Zineb 75% WP, Hexaconazole 68% + Zineb 4%WP, Azoxystrobin 23% EC, Tebuconazole 250EC, Azoxystrobin 11%+ Tebuconazole 18.3%SC, Mancozeb 75%WP, Azoxystrobin8.3%+ Mancozeb 66.7% WG, Cymoxanil 8% + Mancozeb 64%WP and Difenoconazole 250SC were carried out against H. vignicola by poison food technique. All the fungicides notably reduced the growth of fungus included under investigation. Among all the fungicides Azoxystrobin11%+Tebuconazole 18.3%SC recorded maximum fungal growth inhibition (98.7%) followed by Tebuconazole 250EC (95.1%) and Difenoconazole 250 SC (89.0%).