1Department of Agrotechnology, Plant protection and Economics on Crops, Institute of Agriculture, Agricultural Academy, Sofiysko shosse 1, 2500 Kyustendil, Bulgaria
(Manuscript received 20 May 2022; accepted for publication 15 July 2023)
Abstract. The investigation was conducted in the experimental plum orchard with cultivar ‘Stanley’ (European Plum) during the period 2019–2021 at the Institute of Agriculture – Kyustendil, Bulgaria. The aim of the study was to establish suitable bioinsecticides to control the economically important pest of the plum Cydia funebrana. Plant protection products Madex Twin and Naturalis were used to control the plum fruit moth in organic plum production. Madex Twin is a biological insecticide, based on the Cydia pomonella granulovirus virus and Naturalis is a bioinsecticide based on the living conidiospores of Beauveria bassiana strain ATCC 74040. During the study period, both bioinsecticides yielded satisfactory results. The damages were in the range of 1.67% to 6.0% for Madex Twin, 1.78% to 5.0% for Naturalis, and 3.0% to 10.0% for untreated control.