Abstract: A method for control of horticulture diseases and decontamination of plant tissue which includes applying a solution of hydrogen peroxide to plant tissue, said hydrogen peroxide being a solution having a concentration of between 0.05 to 3.00%. In some cases the hydrogen peroxide solution has a concentration of between 0.05 and 1.5%. Some forms of the invention may utilize a hydrogen peroxide solution that further includes an acid selected from the group consisting of acetic acid and phosphoric acid. Various structures are used for applying the hydrogen peroxide solution such as hydraulic spraying, misting, fogging, or injecting the hydrogen peroxide into a commercial cooling system. In other cases the hydrogen peroxide solution is injected into a recirculating subirrigation nutrient system solution to control microbial growth in the irrigation water. In some cases the hydrogen peroxide solution is applied to the plant tissue at a variety of stages in the plant production cycle.