The inhibitory effect of five plant extracts on the pathogen of mulberry dieback disease (Sclorotinia sclerotiorum) in laboratory conditions

The dieback disease of mulberry tree caused by Sclerotinia sclerotiorum is one of the important diseases of mulberry trees in the world and Iran. The aim of this research was to prepare a suitable extract to combat the disease-causing fungus with the least side effects for silkworms. The effect of the extract of five plants (garlic, thymus, peppermint, tea and neem) in three solvents (water, ethanol and methanol) was studied by mixing method in culture medium during 2018-20. The extracts were tested in three concentrations: 1000ppm, 100ppm, and 10ppm. Among the aqueous extract, garlic extract showed the highest inhibitory effect with more than 80% on the disease-causing fungus. In the second group, tea and peppermint showed the highest retention with 54.16% and 66.66%, respectively. Among the methanolic and ethanolic extracts, tea and neem showed the highest inhibition rates, (48.91% and 61.5%) and (56.32% and 51.5%) respectively. As the concentration of the extract decreased, the inhibitory rate decreased. The inhibitory rate of extracts depends on various factors such as solvent, concentration and mushroom type.