Efficacy of new generation fungicides against Corynespora leaf fall disease of rubber (Hevea brasiliensis)

Abstract

Corynespora leaf fall disease of rubber caused by Corynespora cassiicola a minor disease once became a major threat to the rubber cultivation especially in South Karnataka in late nineties. Recently it was found severe in some pockets of Kerala and also in nurseries. In this direction a study was conducted to identify some of the new fungicides for the control of this disease. In vitro studies showed that the fungicides viz., thiophanate methyl, iprodione + carbendazim, pyraclostrobin+metiram and the recommended fungicide carbendazim exhibited high level of efficacy both in arresting the mycelial growth and inhibiting the germination of the spores. Based on in vitro studies eight fungicides were selected and were evaluated in nursery against corynespora leaf fall disease. Among eight fungicides, the fungicides fungicides pyraclostrobin+metiram, iprodione + carbendazim were effective followed by the fungicides thiophanate methyl and mancozeb.