Evaluation of biocontrol agents, fungicides and organic amendments against sclerotium wilt (Sclerotium rolfsii Sacc) of jasmine (Jasminum sambac (L.) Aiton)

Abstract

Sclerotium wilt of Jasmine is an important fungal disease known to cause serious yield loss in Tamil Nadu. Twelve isolates of S. rolfsii collected from various areas of Coimbatore and Erode districts were studied for the cultural, morphological and biochemical variability. The colony characteristics, mycelial and sclerotial characters and oxalic acid production were investigated in all the twelve isolates. Significant variations were observed in the mycelial type, number of sclerotia and production of oxalic acid. The virulence of the isolates were positively correlated with oxalic acid production. Twelve bacterial and fungal isolates were screened in vitro for their antagonism against S. rolfsii. Among the various isolates tested, Bacillus subtilis (EPCo8) and Trichoderma viride1 inhibited the mycelial growth of S. rolfsii to an extent of 42.22 per cent and 73.33 per cent respectively. In vitro screening of various fungicides and organic amendments indicated that 100 per cent inhibition of the pathogen with Trifloxystrobin+Tebuconazole 0.15% and Mahua oilcake extract showed 83.07 per cent inhibition.