Sources of peach brown rot caused by Monilinia fructicola in Okayama Prefecture

Abstract

In Okayama Prefecture, apothecia of the fungus causing brown rot of peach (Monilinia fructicola) were found for the first time in the western part of Japan in 1990. Maturity of the apothecium coincided with flowering of peach in early April. M. fructicola produced numerous conidia on the leaves and twigs with leaf curl, mainly from mid May to late June. Isolates of M. fructicola from ascospores produced on mummified fruits were pathogenic on peach flowers. These results show that the primary inoculum source, the ascospores of apothecium of M. fructicola, and the secondary inoculum source, conidia on leaves with leaf curl are infection sources for peach brown rot in Okayama Prefecture.