Journal of Plant Pathology & Microbiology

Abstract

Chitosan and Silver Nanoparticles as Control Agents of Some Faba Bean Spot Diseases

Ahmed IS Ahmed

Faba bean (Vicia fabae L.) is one of the most economic legume crops in Egypt. The antifungal effects of different concentrations of Chitosan and silver nanoparticles (20 ppm, 40 ppm, 60 ppm, 80 ppm and 100 ppm) were studied against aggressive isolates of Botrytis fabae and Alternaria alternata causing chocolate spot disease and Alternaria leaf spot disease respectively. Under laboratory conditions, the application of five concentrations of Chitosan nanoparticles and silver nanoparticles to the cultures of B. fabae and A. alternata showed significant inhibition of mycelial growth. Number of spores/ml decreased with increasing of nanoparticle concentration. Mycelial weight of fungal pathogens also decreased. The lesion growth was suppressed by increasing in the concentration of nanoparticles with significantly different relative to control using detached leaf test. Under greenhouse conditions, chitosan and silver nanoparticles were sprayed in concentrations 60 ppm, 80 ppm, and 100 ppm on faba bean plants. The tested nanoparticles showed significant effect against B. fabae and A. alternata relative to control. The obtained results indicated that the highest reduction of chocolate spot severity was obtained with treatment by 100 ppm of silver nanoparticles (52.94%) followed by chitosan nanoparticles 80 ppm (50.59%). While the application of 100 ppm of chitosan nanoparticles was highly efficient against Alternaria leaf spot where the reduction in disease severity (67.13%) followed by 100 ppm silver nanoparticles which caused reduction rate (61.5%). The obtained results indicated the possibility of using chitosan and silver nanoparticles as a substance in the manufacturing of fungicides to minimize the impact of chocolate spot and Alternaria leaf spot diseases in faba bean. However, further experimental trials under field conditions and safety evaluation studies are needed before the nanoparticles types and concentrations can be used as potential antifungal agents.