Salinity is a major abiotic constraint limiting strawberry (Fragaria × ananassa) productivity by disrupting water relations, nutrient uptake, and photosynthetic processes. Biopolymer-based biostimulants have emerged as a sustainable strategy to enhance crop performance under stress conditions. The objective of this study was to evaluate the effect of a chitosan–maltodextrin (CHTMD) formulation on growth, physiological response, and fruit quality in strawberry plants under saline conditions at the Universidad Autonoma Agraria Antonio Narro in Saltillo, Mexico. A randomized complete block design with a 2 × 4 factorial arrangement was established, including two salinity levels (0 and 45 mM NaCl) and four CHTMD concentrations (0, 250, 500, and 1000 mg L−1). The application of CHTMD significantly mitigated the adverse effects of salinity and improved plant growth, biomass accumulation, gas exchange, yield, and fruit quality. Under saline conditions, 250 mg L−1 increased total fresh weight by 148.5% compared with the saline control, while root length increased by up to 58.5% under non-saline conditions. Yield was enhanced by 87.3% and 71.4% with 250 and 1000 mg L−1, respectively, whereas fruit number increased by up to 63.8% under salinity. Photosynthetic rate increased from 12.58 to 16.19 μmol CO2 m−2 s−1 and stomatal conductance from 0.235 to 0.325 mol H2O m−2 s−1. Fruit quality was also enhanced, with soluble solids increasing from 5.9 to 7.1 °Brix, vitamin C from 50.58 to 115.42 mg 100 g−1 FW, and total anthocyanins from 65.7 to 106.2 C3G 100 g−1 FW, indicating a substantial enhancement to the fruit’s nutraceutical quality, particularly at 500 mg L−1 and 1000 mg L−1. These findings demonstrate that the CHTMD system is an effective biostimulant capable of improving tolerance to salt stress by modulating key physiological and biochemical responses, as well as enhancing the functional quality of the fruit. This approach represents a promising and sustainable strategy for strawberry production in agricultural systems affected by salinity.
Cruz et al. (Fri,) studied this question.