Fungicidal activities of chitosan-stabilized copper nanoparticles on Magnaporthe oryzae, Rhizoctonia solani, and Phytophthora capsica

Pathogenic fungi are the most common causes of economic loss in crop production. Until now, synthetic fungicides are the most effective tools for management in agriculture, but they cause a severe impact on the environment as well as several side effects for human health. The use of synthetic fungicides is prohibited in organic agriculture; however, sulfur and copper fungicides are still permitted in organic farming. In this study, chitosan-stabilized copper chitosan nanoparticles (CS-CuNPs) were synthesized and characterized via UV-Vis analysis and scanning electron microscopy (SEM). Moreover, fungicidal activities of CS-CuNPs in the range of concentrations (00, 500, and 1000 mg/L) against several plant pathogenic fungi, including Magnaporthe oryzae, Rhizoctonia solani, and Phytophthora capsici, have been assessed via filamentous fugal growth inhibition. The results indicated that the size of CS-CuNPs ranged from 70 to 74 nm with the plasmon absorption peak at 600 nm, which implied the CS-CuNPs were successfully synthesized. Furthermore, CS-CuNPs effectively inhibited the growth of all three fungi at a concentration 1000 mg/L. Among the three species, Rhizoctonia solani was the most susceptible to CS-CuNPs, with the growth inhibitory effect at 100 mg/L. In conclusion, CS-CuNPs demonstrated a strong potential for the elimination of plant pathogenic fungi and further applications in agriculture.