Biological Activity of Carpropamid (KTU 3616)

A New Fungicide for Rice Blast Disease

Abstract

Carpropamid ({(1R*, 3S*)-2, 2-dichloro-N-[1-(4-chlorophenyl)ethyl]-1-ethyl-3-methylcyclo-propane-carboxamide}) was found to be an effective rice blast fungicide with systemic properties. The basic activities of the compound were studied in vitro and in vivo. The compound did not inhibit mycelial growth of various plant pathogenic fungi tested except Oomycetes spp. In addition, carpropamid did not show direct activity on the mycelial growth, the spore germination and the appressorium formation of rice blast fungus. Inhibition of fungal melanin biosynthesis was observed, however, in the mycelial growth test with many fungi and in appressorium cells of rice blast fungus. The compound showed strong penetration inhibition into rice epidermal cells at very low concentrations but was less effective once the appressorial penetration had started.