In this reporting period, nine different variants were included for the optimization of T-SOL with agriculture-grade chemicals. These variants involved three different Zn chelating agents and three different concentrations of a plant surface permeability enhancer (with respect to metallic Zn). Interaction of metal chelating agents with Zn was characterized by UV-Vis and FT-IR spectroscopy suggested binding of metal ions with the chelate functional groups (such as carboxyls, hydroxyls and amines) which resembles the data collected with lab-grade chemicals. Microplate Alamar blue assay was used to determine the minimal inhibitory concentration (MIC) of the different variants of the T-SOL. Antimicrobial properties of the newly made T-SOL samples (from agri-grade chemicals) were assessed by running a Minimal Inhibitory concentration (MIC) assay as delineated by Clinical Laboratory and Standards Institute. The MIC values of the three variants of T-SOL containing chelating agent- (1, 0.5 and 0.1) were 75 ppm against Escherichia coli, whereas the MIC values for the T-SOL variants containing chelating agents 2 and 3 was 150 ppm for E. coli. But, the MIC values for all the nine variants were 75 ppm when treated against Xanthomonas alfalfae, values similar to the reagent grade chemicals. Phytotoxicity study was conducted with citrus plants (Sp. Cleo) at a field spray (800ppm) rate with different T-SOL variants. No toxicity was observed for all the treated variants. TSOL materials were tested for their efficacy in protecting a citrus variety in the Vero Beach, Indian River County area of Florida. Six different materials were tested using 3 different capping agents and with /without a surface modifying agent. Materials were sprayed on 8 yr.-old ‘Ray Ruby’ grapefruit trees at an application rate of 0.5 lbs/ acre (750-800 ppm) every 21 days from April to September. Materials were compared against standard Cu and/or (Cu+Zn) commercial products. The untreated control displayed a total infection incidence of 60 % while T-SOL materials reduced the infection incidence to 17-24 %. T-SOL materials performed better to commercial products which displayed comparable protection. The two best performing T-SOL variants will be delivered this month for canker and HLB field trial. In the coming reporting period, plant uptake studies will be conducted to determine the uptake and translocation of TSOL inside different plant tissue which can help further to select the most effective T-SOL variant prepared with agri-grade chemicals that can be later used in green house and field trial studies.