Alternative Plant Protection Strategies Using Bacteria and Thyme to Improve Strawberry (cv. Elsanta) Yield and Quality.

Alternative plant protection methods should be promoted to mitigate the dangers and consequences of using chemical pesticides, ensuring a safe environment and protecting human health (Directive 2009/128/EC). One of the objectives of the EU organic production action plan is to provide substitutes for plant protection methods, decrease the adverse effects on the environment, and promote the diversity of living organisms. The use of synthetic and non-organic chemicals has significantly expanded, damaging human health and the environment. This study aimed to evaluate alternative plant protection solutions for the improvement of the strawberry cv. Elsanta plant's generative development, yield, fruit quality, and biochemical composition. The two-year strawberry experiment conducted in a tunnel greenhouse included chemical and biological means (Bacteria and Thyme preparations). The experiment randomised a block design with four replicates and 32 plants per replicate. The treatments were conducted at the 10% flowering state (BBCH 61-65), every 7-10 days (a total of four times): (1) Control, (2) Chemical, (3) Bacteria, and (4) Thyme. We evaluated the yield, fruit weight, size, number of leaves, crowns, flowers, inflorescences, fruit firmness, soluble solids, and Vitamin C. The highest fruit weight at the first picking was in the Bacteria treatment. The number of rotten fruits was similar after all treatments. Additionally, they were firmer and bigger in size but had a smaller soluble solids content. The strawberry ascorbic acid and soluble solids content (Brix %) showed significant variation. The highest ascorbic acid concentration in the fruit was after the Thyme application (45.06%). Our study showed that alternative plant protection measures can reduce the use of chemical fungicides and maintain proper fruit quality.