Alternative products against anthracnose affect selected primary and secondary metabolites in strawberry fruit

Introduction. Anthracnose disease causes severe economic losses in strawberry ( Fragaria × ananassa ) production. Plant response to the pathogen attack is closely linked to its content and composition of polyphenols. In order to reduce the damage caused by pathogens, organic and inorganic fungicides are applied. The aim was to determine the influence of selected fungicides on various metabolites in strawberry fruit. Materials and methods. The efficiency of potassium bicarbonate (PBC) and acetic acid (AA) was compared with the control and a fungicide treatment in the strawberry cv. Elsanta. To examine the possible effects of these fungicides, artificial inoculation was performed in all treatments except for the control. The percentage of infected fruits and the content of selected primary and secondary metabolites in non-infected and infected fruits were determined. Results and discussion. Both analyzed inorganic fungicides proved effective against anthracnose. AA treated fruits were the least infected (only 4%), followed by PBC, fungicide and control. The highest percentage (9.26%) of infected fruits was determined following artificial infection treatment. Total sugar content decreased for 32% in infected control and AA treated fruits. PBC treatment exhibited a positive effect on the organic acid content in comparison with other treatments. The content of phenolic compounds was higher in PBC treated fruits and did not change significantly after infection. Infection increased the total flavonol content of the fruit. Conclusion. The use of PBC and AA potentially present a prospective protection in the strawberry orchards especially for controlling anthracnose in organic fruit crops.