Aggressiveness of Monilinia spp. towards detached plum fruit

Abstract

Stone fruit species are by far the most important for total fruit production in Serbia, with plumbeing the most important. Over the last five years, total annual plum production amounted toover 500,000 tons, placing Serbia among the three top producers in the world and the first inEurope. However, plum is severely affected by brown rot disease that occurs every year, resultingin significant losses. Monilinia laxa and Monilinia fructigena are widely distributed brown rot causalagents, with first reports of their presence and significance in Serbia originating from the middle ofthe 20th century. Monilinia fructicola, the most destructive pathogen of Monilinia spp., has recentlybeen introduced into Serbia. Its spreading in stone fruit orchards has already been observed. Theaim of this research was to compare aggressiveness of newly introduced M. fructicola with well-established M. laxa and M. fructigena species towards plum fruit, in order to assess the potential ofM. fructicola to repress and replace the other two species in Serbian plum orchards. Unwoundedand wounded fruits of two plum cultivars at three developmental stages were inoculated with M.fructicola, M. laxa, and M. fructigena. Seven days after inoculation, the fruits were visually examinedfor symptoms of brown rot. A CART model, describing the probability of infection establishmentwas constructed. The results showed that wounding of fruits, developmental stage of fruits andspecies of the pathogen had significant effects on the incidence of brown rot, while the effect ofcultivar was not significant.