Epidemiology of Anthracnose Caused by Colletotrichum lindemuthianum on White Bean (Phaseolus vulgaris) in Southern Ontario: Survival of the Pathogen. J. C. Tu, Research Station, Research Branch, Agriculture Canada, Harrow, Ontario N0R 1G0. Plant Dis. 67:402-404. Accepted for publication 12 September 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-402.

Longevity of Colletotrichum lindemuthianum varied greatly depending on environmental conditions. Moisture had a profound effect on its longevity. The fungus survived at least 5 yr in infected pods and seeds of Phaseolus vulgaris that were air-dried and kept in storage at 4 C or in dry infected plant materials left in the field in sealed polyethylene envelopes that had no contact with water. In infected materials placed in nylon-mesh pouches and buried in the field in November, C. lindemuthianum could not be isolated after mid-May. Laboratory tests showed that an alternating wet-dry cycle was detrimental to survival of the fungus. The fungus in the infected pod segments lost viability after three cycles of 72 hr wet and 72 hr dry. In the field, there was no sign of anthracnose throughout the 1979 and 1980 growing seasons in plots on sites with heavily infected crops the previous year. The degree of transmission by seeds increased with increasing severity of infection and density of conidia in the infested seeds.