Mycoflora of strawberry in Ontario

Abstract

Mycelial fungi associated with leaves, flowers, and fruits of strawberry (Fragaria × ananassa Duchesne) were monitored in a field plot from August 1986 to July 1987. The principal fungi found on leaves of various developmental stages were Alternaria alternata, Botrytis cinerea, Cladosporium spp., Colletotrichum dematium, Coniella fragariae, Epicoccum purpurascens, Gliocladium roseum, Gloeosporium sp., Gnomonia comari, Penicillium spp., Trichothecium roseum, and Verticillium spp. A majority of the fungi were observed more frequently on leaves that were washed and then plated on agar media than on leaves that were plated without washing. Trichothecium roseum, however, was found mainly on the unwashed leaves. Principal fungi on calyces, petals, and fruits were A. alternata, B. cinerea, Gloeosporium sp., Pencillium spp., T. roseum, and Verticillium spp. Other fungi variously found on the flowers and fruits included Rhizopus stolonifer, Paecilomyces spp., C. dematium, and Fusarium spp. Many of the fungi found frequently on the strawberry plants were present at most or all stages of development and decline of the various plant organs. The mycofloral observations are discussed in relation to the biocontrol of strawberry diseases. Key words: strawberry, mycoflora, Botrytis cinerea, population dynamics.