Chitosan nanoparticles modulate plant growth, and yield, as well as thrips infestation in Capsicum spp.

The objective of this study was to investigate the physiological and biochemical effects of Chitosan nanoparticles
on Capsicum annuum plants. The particle size, polydispersity index, composition, and structure of the synthesized
chitosan-based nanoparticles (Chitosan (CS), Chitosan-Silver (CSAg), and Chitosan-Copper (CSCu) NPs) were
determined by analyzing the zeta potential, FTIR, TEM, and XRD. The seedlings showed improved physiological
and biochemical characteristics when 1, 10, and 20 ppm concentrations of nanoparticles (CS, CSAg, and CSCu)
were used for 24-h seed priming. The application of nanoparticles in different concentrations (0, 20, 40, 60, 80,
and 100 ppm) on the leaves of Capsicum spp. plants resulted in improved physiological traits and protection
against thrips by 70–85 %. Furthermore, it enhanced the content of chlorophyll (20–75 %), carotenoids (20–30
%), total phenolics (20–45 %), total flavonoids (40–125 %), reducing sugars (15–40 %), total antioxidant activity
(10–82 %), FRAP (10–100 %), DPPH (76-83 mg mL