Isolation and in vitro evaluation of biocontrol agents, fungicides and essential oils against stem blight of tomato caused by Sclerotium rolfsii (Curzi) C.C Tu & Kimber

Abstract

Tomato is subjected to several diseases at all the stages of its development from nursery to the consumption of tomatoes. Among all the diseases infecting tomato, the stem blight of tomato is the most severe threat for the tomato industry and also for foreign exchange earnings. This disease is incited by the number of pathogens but the major causal organism is Sclerotium rolfsii (Curzi) C.C Tu & Kimber. Three antagonistic fungi of Trichoderma species were tested against Sclerotium rolfsii under in vitro conditions by using the dual culture method the results revealed that Trichoderma harzianum has most promising antagonist against S.rolfsii. In vitro evaluation of fungicides were tested hexaconazole and mancozeb was the most efficacious fungicide to inhibiting the mycelial growth of Sclerotium rolfsii, while essential oils i.e palmarosa (Cymbopogon martini oil) and thyme (Thymus vulgaris) oils were provided significantly high inhibitory responses against Sclerotium rolfsii.