COLLETOTRICHUM ACUTATUM: SURVIVAL IN PLANT DEBRIS AND INFECTION OF SOME WEEDS AND CULTIVATED PLANTS

Colletotrichum acutatum can survive in strawberry residues in nordic conditions over one winter, maybe even for almost two years. When annual and perennial weed species common on strawberry fields were inoculated in greenhouse, the fungus sporulated on old leaves of all the artificially infected weed species but not on the young leaves and tops of all the respective species. Old leaves of Tripleurospermum, Chenopodium, Lapsana, Plantago, Capsella, Viola, Epilobium and Rumex were heavily infected while the fungus was not recovered on young parts of Epilobium, Viola, Senecio and Lapsana. Young leaves of fallow plants Phacelia tanacetifolia and Brassica juncea had infection, but C. acutatum was recovered only old leaves of Helianthus annuus and Lupinus sp. Infection in young leaves could be superficial, but in old leaves the fungus easily colonized senescent tissues. C. acutatum caused necrotic lesions on some plant species like Plantago major and P. tanacetifolia. The fungus was able to survive in infected debris of some weeds on soil surface over one summer.