EVALUATION OF MYCOSILVER NANOFUNGICIDES AS POTENTIAL CONTROL AGENT AGAINST Phytophthora infestans

Potato (Solanum tuberosum L.) is one of the most important vegetable crops across world and India is second largest producer of this crop across the world. Late blight disease has been the most serious threat to world’s potato production, resulting in 80-100 % yield loss. The causal agent of late blight is fungi, Phytophthora infestans. The present investigation was carried out to evaluate the efficacy of mycogenic silver nanoparticles as an antifungal agent against P. infestans. The silver nanoparticles were synthesized biologically by using Aspergillus niger biomass and characterization of silver nanoparticles (AgNPs) was done by UV-Vis Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray (EDX), Dynamic Light Scattering (DLS) and Fourier Transform Infra Red (FTIR). The inhibition percentage of P. infestans caused by silver nanoparticles treatment was established in vitro. Field experiment was conducted to compare the efficiency of silver nanoparticles and chemical fungicide at the parameters of disease severity, tuber number and tuber weight. The data were analysed by SPSS software for descriptive statistics and analysis of variance (ANOVA) including least significance difference (LSD). The development of mustard yellow colour in the reaction mixture preliminary confirmed the synthesis of AgNPs. The UV-Vis Spectral report showed peaks corresponding to AgNPs at 420, 430, 440 and 460 nm. The FESEM images confirmed synthesis of roughly spherical nano-sized particles and the elemental composition of the same was confirmed to be silver by EDX analysis report. DLS analysis depicted the average size of nanoparticles as 37.2 nm. The FTIR spectral report provided information about the molecular interactions between AgNPs and surrounding chemical functional groups. The AgNPs showed 75% inhibition percentage during in vitro analysis. The average disease severity was found to be significantly higher in control plants as compared to AgNPs and chemical fungicide treated plants. Also, AgNPs and chemical fungicide treated plants showed significantly higher average tuber production as compared to control as tested at 0.05 significance levels. There was no significant difference between AgNPs and chemical fungicide treated plants at all the parameters taken under consideration. It may be concluded by the study that AgNPs may be proved to be potential fungicides in near future and it is an excellent alternative to chemical fungicides.