Thrips infestation is the prime limiting factor for the quality of the fruit and its yield in chili ( Capsicum annuum L.). In the present study, Rhizopus-elicitor (RE)-mediated silver nitrate (SN) and silver thiosulfate nanoparticles (R-Ag, R-STS) were synthesized, exhibiting a transition of colour from pale yellow to brown, having absorption peaks at 425 and 432 nm. Synthesized silver nanoparticles were found in the 18–35 nm size range. The nanoparticles were examined against thrips infestation in chili plants. Under greenhouse conditions, seed priming was performed using various nanoparticles (RE, R-Ag, R-STS, SN) at 1, 10, and 20 mg L⁻¹ . Seed priming enhanced the seed germination (96–100%), seedling vigour index, seedling length, biomass, total phenolic content (TPC), total flavonoid content (TFC), carotenoids, and chlorophyll of 45-day-old seedlings. The foliar spray of the nanoparticles at ranging from 20 to 100 mg L minimized thrips populations by 85–94% considerably compared to the control. The foliar spray enhanced chlorophyll, carotenoids, TPC, TFC, reducing sugars, TAA, and FRAP activity, and DPPH (IC 50 100–47 mg mL⁻¹) was found. Additionally, nanoparticle application resulted in a 277% increase in capsaicinoids, making them a suitable option for economically significant chili plants. The findings suggest that the use of biosynthesized nanoparticles could also be an effective bionano-pesticide for preventing thrips infestation and promoting sustainable agronomic improvement.
Nandini et al. (Sat,) studied this question.