Assessment of applying an integrated pest management strategy to control the raspberry leaf and bud mite, Phyllocoptes gracilis (Nal.) and its effect on the raspberry leaf metabolites

Abstract

In the years 2018‒2020, the effectiveness of three synthetic active substances (acequinocyl, fenpyroximate, spirodiclofen), one substance derived from Streptomyces spp. (abamectin), a plant extract (orange oil) and silicone polymers in controlling Phyllocoptes gracilis in two Polish raspberry plantations (v. ‘Glen Ample’) was assessed. All the substances showed high and comparable efficacy against the tested pest, significantly reducing its population. However, their effects occurred at different times after the application. The strongest immediate control was shown by silicone polymers, followed by abamectin and spirodiclofen. The full effect of fenpyroximate application was visible after approx. 2 weeks, while acequinocyl was effective 3‒4 weeks after the application. Moreover, the content of phenolic compounds, sterols and triterpenoids was determined in leaves of plants treated with spirodiclofen, orange oil and silicone polymers. The observed increase in the content of salicylic acid and changes in the content of triterpenoids in leaves may indicate a stimulating effect of the substances to the natural defense processes of plants.