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 O3 concentration is in the range of from 0.1 to 1,000 ppm.
