RESUMEN
Fungal pathogen "Neoscytalidium novaehollandiae" is the causal agent of trunk canker in mulberry trees. Mulberry is considered as most valuable tree for landscaping in Tehran. Here in, for the first time, chitosan nanoparticles (CSNPs) were used to inhibit canker disease causal agent of mulberry. For this purpose, CSNPs were synthesized with a yield of 86%, and after characterization of the synthesized nanoparticles, the growth inhibition rate of fungus (GI%) was evaluated. The results of in vitro assays showed that the concentration of 1500 ppm significantly (P ≤ 0.05) decreased the radial growth of the fungus in comparison with control. For in vivo experiments, 2-year-old branches from healthy randomly selected mulberry trees in the landscape, were inoculated artificially in the laboratory with mycelial plugs from a 7-day-old culture of fungus. The infected branches were then treated with 500, 1000, and 1500 ppm of CSNPs. The results indicated that the disease severity (DS%) in all the treatments and the control plants increased over time. However, the slope of the changes in DS was less in CSNPs treated compared to control. This effect was concentration dependent so that no disease progress was observed at 1500 ppm of CSNPs. The findings indicate the effectiveness of CSNPs in control of canker disease of mulberry caused by N. novaehollandiae.
