RootShield WP Biofungicide - 1lb RootShield biological fungicide formulated as wettable powder for drench or dip. RootShield grows on roots, shielding them against fungi. One application protects for up to 12 weeks. REI: 0 Hrs Active Ingredient: Trichoderma harzianum Rifai strain T-22 Signal Word: Caution Rate: Varies depending on application method. See label. Controls: Soilborne plant pathogens and root diseases.