Disclosed is a method for treating a plant having, or susceptible to, a plant disease, the method comprising effecting systemic uptake of a composition comprising an amount of silver dihydrogen citrate (SDC) and an organic acid such as citric acid effective to at least reduce a level of disease or reduce susceptibility to disease by said plant, wherein said systemic uptake is effected by contacting said composition with at least a portion of an external surface of the plant, or wherein the said systemic uptake is effected by contacting said composition with at least one of: a root of the plant, a portion of soil and/or groundwater proximal to the plant, or any combination thereof.
