The present invention provides a method of treating wheat fungal pathogens, comprising applying an electrolyzed water composition to a wheat crop affected with pathogens or area containing a wheat crop affected with pathogens. The electrolyzed water composition is prepared by a method comprising: preparing an electrolyte solution comprising water, at least one carbonate salt selected from anhydrous alkali metal carbonate salts, and at least one chloride salt selected from: alkali metal chloride salts； introducing the aqueous electrolyte solution into an electrolytic cell comprising a plurality of boron-doped diamond electrodes； and operating a power supply to apply a predetermined voltage to the electrolyte solution to produce an electrolyzed water biocidal composition comprising a plurality of active molecular and ionic species having biocidal activity, in which the mixture of at least two salts of the electrolyte are selected such that the dissolved O
