TS No. 52: Determination of 50% Lethal Concentration (LC50) of Fungicides Against Pathogenic Ganoderma

Fungicides are used to control plant diseases. New compounds with novel modes of action have been developed from the 1990s – strobilurins, phenylpyrroles, anilinopyrimidines, phenoxyquinolines and compounds that trigger the plant defence system. There are now 113 compounds registered worldwide as fungicides (Knight et al., 1997). However, none of them are effective against Ganoderma basal stem rot (BSR) in oil palm, either in vitro or in vivo, or even in slowing down the disease progress in infected palms although some have shown promise (Geogre et al., 1996; Idris et al., 2004). With the new fungicides differing fundamentally from the chemicals of old in their modes of action, it may be worthwhile to test them against Ganoderma. However, testing is expensive, and it would be ideal if a screening test can fi rst be run to eliminate the chemicals unlikely to be successful. This article describes an in vitro screening test to determine the 50% effective concentration (EC50) of fungicides against Ganoderma pathogenic to oil palm.

Main Research:  Dr Idris Abu Seman