Vismax technology contains a peptide that directly activates the plant’s immune system, providing broad-spectrum prevention and suppression of a wide range of fungal and bacterial diseases, including Citrus Greening/Huanglongbing (HLB). The objective of the 2-year project is to determine whether Vismax treatment promotes resistance to other major citrus diseases, specifically citrus canker and phytophthora root rot in greenhouse assays. In year 1 of the project, Vismax treated orange trees were significantly more resistant to citrus canker, causative agent Xanthomonas citri, when the formulated peptide was applied as a dilute foliar spray or soil drench, 7 days prior to leaf inoculation. In year 2 of the project, inoculated greenhouse assays further probed Vismax-activated defenses, with greenhouse testing conducted by Dr. Megan Dewdney (U. Florida IFAS CREC). The results of canker trial #5 indicated that Vismax foliar applications gave statistically significant reductions in canker severity both in the presence and absence of surfactant, and that commercially available surfactants were compatible with Vismax. A repeat inoculation of the trial on a subset of the same plants showed that the canker protection does not persist, and the treatment must be reapplied to effectively provide canker protection. Currently, a phytophthora root rot trial is underway, evaluating rates of drench-applied Vismax in combination with and comparison to Foliar-applied Vismax for their ability to promote resistance to phytophthora root rot in susceptible orange seedlings by comparing dry root mass and scoring roots and leaves for symptoms of phytophthora rot.