Application of vermicompost extract to improve the phytochemical composition of berry fruits

The growing market demand for environmentally friendly products for plant nutrition has led to the development of new fertilizers, particularly liquid compost-based products such as teas, extracts, and leachates. The aim of this research was to compare the effect of chemical fertilization (CF) and its combination with liquid fertilizer based on vermicompost and beneficial microorganisms (CF + VP) on the phytochemical profile of strawberry (Senga Sengana), blackberry (Čačanska Bestrna) and blueberry (Aurora). The results showed that CF + VP positively affected fruit weight (8.8 g), soluble solids (8.9°Bx), total sugars (65.5 g/kg FW), and the sum of all phenolic groups (275.12 g/kg FW) in blackberry fruits. Significantly higher fruit weight (15.5 g), total sugars (62.4 g/kg FW), organic acids (9.6 g/kg FW), and flavanones (20.06 mg/100 g FW) content in strawberry fruits were confirmed in CF + VP. The same treatment exhibited the highest effectiveness in terms of organic acids (17.3 g/kg FW) and anthocyanins (153.26 g/kg FW) in blueberry. The application of CF + VP improved all components of fruit quality in the examined species compared to CF, and the positive impact was particularly pronounced in the phenolic composition of blackberries. Taking into account the stimulating effects on the sensory and nutritional value of the fruit of the studied berry species, the usa of VP as a supplement to CF can be regarded as a sustainable practice for enhancing growing technology aimed at obtaining biologically valuable fruits.