Disclosed is an anti-pathogen concentrate which is produced by adding about 35 parts of bromo-chlorodimethyl hydantoin (BCDMH) and about 1 part silica drier to about 100 parts diacetone alcohol. Further disclosed is a method for the removal of pathogens from crops being grown and intended for human consumption comprising application to a crop, prior to harvest, of irrigation water which contains an anti-pathogen concentrate produced by adding bromo-chlorodimethyl hydantoin (BCDMH) and silica drier to a solvent whose residue is non-toxic and is selected from the group consisting of glycol alcohols, glycol ethers and diacetone alcohol, wherein the BCDMH is used as 5 to 100 ppm as chlorine.