Management of Phytophthora parasitica causing gummosis in citrus using biogenic copper oxide nanoparticles

The main aim of the present study was to develop nanotechnology-based solutions for the management of a fungus, Phytophthora parasitica causing gummosis in citrus.

Biogenic copper nanoparticles (CuONPs) were synthesized using two different biocontrol agents, Pseudomonas fluorescens and Trichoderma viride and characterized using different analytical techniques. Furthermore, in vitro (at the concentrations of 10, 15, 30, 50, 70, 100 and 150 mg/L) and in vivo (at the concentration of 100 mg/L) activities of these nanoparticles were evaluated for their antifungal efficacy against P. parasitica. The results obtained confirmed the synthesis of irregular-shaped CuONPs having a size in the range 40-100 nm in case of P. fluorescens, whereas, spherical CuONPs in the size range 20-80 were recorded in case of T. viride. As far as the in vitro antifungal efficacies of both these CuONPs is concerned, the maximum percent growth inhibition was observed in case of CuONPs synthesized from T. viride compared to CuONPs from P. fluorescens. However, in case of in vivo antifungal efficacies, CuONPs synthesized from T. viride showed the activity significantly higher than the conventionally used Bordeaux mixture.

It can be concluded that biosynthesized CuONPs can be effectively used as a potential fungicide against P. parasitica.

The application of nanoparticles having antifungal activities can be used as alternative fungicides to the conventional chemical fungicides. It has the potential to revolutionize the existing management strategies available for plant pathogenic fungi.