Early and Late-Season Susceptibility of Peach Fruits to Monilinia fructicola. A. R. Biggs, Agriculture Canada, Research Station, Vineland Station, Ontario, Canada, L0R 2E0. J. Northover, Agriculture Canada, Research Station, Vineland Station, Ontario, Canada, L0R 2E0. Plant Dis. 72:1070-1074. Accepted for publication 2 August 1988. Copyright 1988 Department of Agriculture, Government of Canada. DOI: 10.1094/PD-72-1070.

Peach fruits of the cultivars Redhaven and Loring were harvested weekly beginning in early June and continuing to full ripeness, and were inoculated under controlled conditions with Monilinia fructicola at a range of 10³–10⁶ conidia/ml. In both years of the study, fruits were susceptible to infection at all inoculum concentrations for 2 to 3 wk in June. At pit hardening they became resistant to infection at all the inoculum concentrations. Fruits again became increasingly susceptible to infection approximately 2 wk before full ripeness.