In vitro evaluation of fungicides, bio agents and natural plant extracts against early blight caused by A. solani

Abstract

Early blight (Alternaria solani) of tomato is most destructive disease in tropical and subtropical countries. It is a potential disease of tomato that reduces its production globally both in conventional and tunnel cultivations. In present study, fungicides, bio agents and botanicals were screened against early blight disease causing pathogen A. solani on tomato. Among all the tested fungicides, contact fungicide Mancozeb @ 1000 ppm, systemic fungicide, Hexaconazole @ 1000 ppm and the combi fungicide Carbendazim 12 % + Mancozeb 63 % @ 0.2% recorded the maximum inhibition of 88.42 %, 90.58 % 88.07 % mycelial growth respectively. Among the bio agents tested Trichoderma harzianum (UAHS 1) found effective in inhibiting the mycelial growth (80.36 %) followed by T. harzianum (UAHS 2) (78.33 %). Among the nine plant extracts evaluated, Pongamia leaf extract @ 10 per cent was found to be effective in inhibiting the mycelial growth of A. solani (54.76 %). The efficacy of fungicides, bio agents and botanicals can be further evaluated in combinations of spray options under field conditions.