Fungal diseases and resulting mycotoxins are reduced or eliminated from plant tissues during crop growth or post-harvest during storage by treatment with an aqueous spray solution prepared from a fungicide composition of a bicarbonate salt containing a surfactant system to reduce the surface tension and contact angle of the spray solution on the plant surface thereby controlling the crystal size of the bicarbonate and re-distribution and adherence of the crystals to the crop vegetation and/or grains.
