Tomato plants are prone to various biotic and abiotic stresses. Fusarium wilt is one of the most devasting diseases of tomatoes caused by Fusarium oxysporum f. sp. lycopersici, causing high yield and economic losses annually. Magnetite nanoparticles (Fe₃O₄ NPs) are one of the potent candidates to inhibit fungal infection by improving plant growth parameters. Spinach has been used as a starting material to synthesize green-synthesized iron oxide nanoparticles (IONPs). Various extracts, i.e., pomegranate juice, white vinegar, pomegranate peel, black coffee (BC), aloe vera peel, and aspirin, had been used as reducing/stabilizing agents to tune the properties of the Fe₃O₄ NPs. After utilizing spinach as a precursor and BC as a reducing agent, the X-ray diffraction (XRD) pattern showed cubic magnetite (Fe₃O₄) phase. Spherical-shaped nanoparticles (∼20 nm) with superparamagnetic nature indicated by scanning electron microscopy (SEM) monographs, whereas energy-dispersive X-ray gives good elemental composition in Fe₃O₄ NPs. A characteristic band of Fe-O at ∼ 561 cm^-1 was exhibited by the Fourier transform infrared (FTIR) spectrum. X-ray photoelectron spectroscopy (XPS) results confirmed the binding energies of Fe 2p_3/2 (∼710.9 eV) and Fe 2p_1/2 (∼724.5 eV) while, Raman bands at ∼310 cm^-1 (T₂ _g ), ∼550 cm^-1 (T₂ _g ), and 670 cm^-1 (A₁ _g ) indicated the formation of Fe₃O₄ NPs synthesized using BC extract. The in vitro activity of BC-Fe₃O₄ NPs significantly inhibited the mycelial growth of F. oxysporum both at the third and seventh day after incubation, in a dose-dependent manner. In vivo studies also exhibited a substantial reduction in disease severity and incidence by improving plant growth parameters after treatment with different concentrations of BC-Fe₃O₄ NPs. The increasing tendency in enzymatic activities had been measured after treatment with different concentrations of NPs both in roots and shoot of tomato plants as compared to the control. Correspondingly, the upregulation of PR-proteins and defense genes are in line with the results of the enzymatic activities. The outcome of the present findings suggests that Fe₃O₄ NPs has the potential to control wilt infection by enhancing plant growth. Hence, Fe₃O₄ NPs, being non-phytotoxic, have impending scope in the agriculture sector to attain higher yield by managing plant diseases.

	Year	Citations

About