A Study of Some Biological Aspects of Monilinia laxa, the Causal Agent of Cherry Brown Rot in Guilan Province

In order to study the primary inoculum source, apothecium production, as well as overwintering of Monilinia laxa, the causal agent of sweet cherry brown rot, this study was carried out in Guilan Province during 2005-2006. Apothecium production by the fungus was investigated under natural and laboratory conditions. The mummified fruits collected in early October didnt produce apothecia under either natural field or laboratory conditions, but the mummified cherry fruits remaining on the trees produced many sporodochia following overwintering. Conidia recovered from sporodochia exhibited considerable viability. Mummified cherries on orchard floor were rotted with either no sporodochia or apothecia produced on their surfaces during the following year. M. laxa were observed only in one case and from peach twig canker in natural conditions and another one case on cherry opening bud in laboratory conditions. Therefore, it seems that the asexual form of last year mummified fruits is the most important source of overwintering and dispersal of the pathogen in Guilan Province.