Investigation on the control effects of green copper oxide (CuO) nanoparticles on the tomato gray mold disease caused by Botrytis cinerea

Tomato gray mold disease, caused by Botrytis cinerea, is one of the most important tomato diseases. In recent years, the application of nanoparticles for the control of plant diseases has been given special attention. In this research, the effect of copper oxide nanoparticles biosynthesized by plant extract of eucalyptus was investigated. Three experiments were conducted in order to control the severity of gray mold disease under different growth conditions. In the first experiment, the effects of nanoparticles at concentrations of 100, 200, 400 and 600 ppm were investigated. In the second experiment, two more concentrated extracts i.e. 800 and 1200 were investigated. In the third experiment, the effect of three concentrations of 400, 600 and 800 ppm of copper oxide nanoparticles on the severity of mildew disease on detached leaves was investigated. The results of all three experiments indicated that 1) Copper oxide nanoparticles can control the growth of B. cinerea and gray mildew disease in both in vitro and in vitro conditions. 2) The relationship between the concentration of copper oxide nanoparticles and the inhibitory effect on fungal growth and disease control was invertible and significant at 1% probability level (P≤1%). In fact, the most effective concentrations were obtained at 400 and 600 ppm, 800 and 1200 ppm, and 600 and 800 ppm under in vitro, in vivo,and detached leaf assay, respectively. Accordingly, with increasing concentrations of copper oxide nanoparticles, the rate of growth of the fungus colony decreased and the severity of the disease decreased. Based on these results, the application of green synthesized copper oxide nanoparticles was recommended in controlling of gray mold disease caused by Botrytis cinerea.