Chitosan, the active ingredient in WarHammer, is a compound naturally extracted from crustacean shells and fungal cell walls. When applied, chitosan acts to fight diseases in several ways: 1) Activates the plant’s natural defense system 2) Disrupts the cell wall of certain fungi and 3) stimulates the beneficial microbes present in the soil. Diseases suppressed include Pythium, Phytophthora, Rhizoctonia, Fusarium, Pseudomonas, Xanthomonas, Powdery and Downy Mildew, Botrytis and much more. WarHammer can also suppress harmful nematodes including root knot, sting and citrus as well as others.