Genotype-dependent productivity and quality responses of strawberry to Tetranychus urticae stress under contrasting pesticide treatments

This study aimed to investigate the genotype-specific responses of five strawberry genotypes, two commercial cultivars (Festival, Rubygem), and three advanced breeding lines (Genotypes 36, 61, and 112), to two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) infestations under the contrasting pesticide regimes. Pest mite suppression significantly enhanced fruit yield from 289 to 702 g per plant, accompanied by increased fruit weight (14.6 to 18.5 g) and number (19.8 to 38.1 berries). Genotype 61 displayed consistently high levels of glucose (4.04 g/100 g FW), malic acid (2.34 g/kg FW), catechin (58.5 mg/kg), and ellagic acid (26.1 mg/kg) under untreated conditions, reflecting strong basal metabolic defense involving osmoprotective sugars, malic acid-driven respiratory flux for energy and antioxidant phenolics aiding redox homeostasis. Festival, maintained high anthocyanin (403 mg C3G/kg) and antioxidant capacity (1473 µmol/100 g FW) even after pest removal, indicating robust and sustained secondary metabolism regardless of stress presence. PCA confirmed genotype × treatment interactions, revealing a trade-off between yield-related traits and metabolites, where genotypes achieving higher productivity tended to exhibit downregulation of antioxidant and quality-related compounds. Results obtained emphasize the necessity of breeding metabolically resilient genotypes that can balance yield performance and quality-related metabolism for sustainable strawberry production under increasing pest pressure, which may be further influenced by changing environmental conditions.