The Impact of Chitosan Nanoparticles on Stimulation of the Lupinus albus L. Growth, Productivity and Phyto-Components Content

Nanotechnology represents a promising approach for advancing sustainable agriculture by mitigating global issues such as climate stress, crop diseases, and nutrient deficiency. Among nanomaterials, chitosan nanoparticles (ChNPs) are of particular interest due to their biodegradability, environmental safety, and multifunctional roles as biostimulants and elicitors of plant defense. White lupin (Lupinus albus L.) is an important leguminous crop valued for its high protein content and nutritional and health benefits. So, the aim of this investigation is to evaluate the impact of ChNPs foliar-applied at concentrations of 0, 30, 60, 90, and 120 mg/L, applied once or twice, on enhancing vegetative growth, productivity, secondary metabolite accumulation, and antioxidant activity of lupin. Most concentrations stimulated growth parameters. ChNPs at 90 mg/L with twice implementation, significantly increasing plant height (150.67 ± 4.16 cm), plant weight (257.83 ± 13.4 g), branch number/plant (7.00 ± 1.7), pods number/plant (57.33 ± 17.6), and number of seeds/pod (5.67 ± 0.5) compared to control plants. Moreover, total phenolic content was maximized with increasing ChNPs concentrations, especially at 90 mg/L in both one and two doses (17 and 19 mg PGAE/mg extract, respectively). Notably, ChNPs at 60 mg/L enhanced antioxidant activity by 77.5%, which was indicated by a significant reduction in IC50 273.48 mg/ml compared to non-treated plants. These findings indicate that foliar application of ChNPs, particularly at moderate concentrations, can effectively stimulate growth and enhance bioactive metabolite production in L. albus. Further eco-toxicological assessments are recommended to validate the long-term environmental safety of ChNP in sustainable crop production systems.