Management of Alternaria blight (Alternaria alternata) of tomato through novel combined formulations of fungicides

Abstract

Abstract The present investigation aimed to find the most efficient and novel combined formulation of fungicides belonging to triazole and strobilurin groups for managing Alternaria blight (Alternaria alternata) of tomato under open field conditions. Efficacy of seven fungicides like propineb, hexaconazole, propiconazole, azoxystrobin, mancozeb, tebuconazole + trifloxystrobin and carbendazim + mancozeb was evaluated in vitro and in vivo. In vitro study was carried out through poisoned food technique, while field experiment was conducted for two consecutive years (2017 and 2018) at Jobner (Jaipur), India. Two foliar sprays were applied at 45 and 60 days after transplanting (DAT), and disease intensity was recorded at 75 DAT. Hexaconazole (@ 300 and 500 ppm) completely inhibited mycelial growth, followed by tebuconazole + trifloxystrobin (@ 500 ppm). In field conditions, two foliar sprays of hexaconazole (@ 0.2%) at 15 days intervals provided maximum disease reduction (79.74%) with increased fruit yield (88.51%) over control, followed by tebuconazole + trifloxystrobin (76.33% and 82.35%, respectively). Alternaria blight is one of the significant biotic stresses that limit crop productivity and grower's prosperity. Systemic fungicides, particularly triazoles, play a substantial role in preventing infection by Alternaria sp. Thus, two foliar sprays of hexaconazole (0.2%) at 15 days intervals reduced disease intensity effectively with increased fruit yield and profitability.