Impact of coniferous trees bark extract formulations on growth of phytopathogenic fungi Botrytis cinerea and Colletotrichum acutatum on strawberry leaves

Abstract: Damage caused by phytopathogenic fungi on strawberries (Fragaria × ananassa) results in considerable economic losses in strawberry production. Plant extracts with fungistatic and/or fungicidal properties possess the potential for their use as biofungicide. The aim of this study was to evaluate impact of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) bark ethanol extract formulations on phytopathogenic fungi Colletotrichum acutatum and Botrytis cinerea mycelial growth in vitro on strawberry leaves. In vitro phytotoxicity test of pine and spruce bark ethanol extracts at various concentrations on detached strawberry leaves were carried out. No phytotoxic effect from coniferous bark extracts on strawberry leaves was observed. Pine and spruce ethanol extracts and their preparations reduced the growth of Colletotrichum acutatum mycelium on strawberry leaves. However, these differences were not statistically significant, except for the variant of 10 g/l extracts. Pine and spruce extracts possess fungistatic properties, but further investigations are needed to identify active substances and evaluate way of action for perspective antifungal agents usable for the control of strawberry fungal pathogens.