1. Please state project objectives and what work was done this quarter to address them:Objective 1: Using callose inhibitors to improve systemic uptake and reduce HLB symptoms.We repeated the field experiment on sweet orange ~8 years old (Citrus x sinensis) trees. We selected and labeled 48 trees according to 4 different treatments: (1) injected control (water), (2) Oxytetracycline (2 g per tree), (3) DDG (0.1mM) + Oxytetracycline (2 g per tree), (4) 3AB (0.1mM) + Oxytetracycline (2 g per tree). Then we located and designed the appropriate map for the experiment. Before applying treatments, baseline stomatal conductance data and data related to trunk diameter, canopy volume and canopy density was collected, and CLas titer and quantify callose level of each tree were measured in September 29th 2023. The trunk injection was employed (as described in Vincent et al. 2022) in October 3rd 2023. Following to the scheduled date, we collected eight mature leaf samples per tree to measure the CLas titer and quantify callose level of each tree 10-day (October 13th 2023) and 1-month (November 1st 2023) and 3-month (January 3rd 2023) after treatments. Furthermore, we collected stomata conductance data to assess the treatment impact on leaf health, and also measured the canopy volume and density in pretreatment (April 20th 2023) and 1st measurement (October 24th 2023). In order to minimize the variation and difference on applying each treatment, the injection flow rates of each four treatment (see above) were also measured on another extra 24 trees with 4 directional sites (a) north, (b) west, (c) east, and (d) south in October 31st 2023. Objective 2: Maintaining water-saturated injection site: Sealed trunk injection ports that stay functional by avoiding woundresponses.Field experiments for this objective are ongoing, testing the potential duration of single injection sites. We expect to have results next quarter. Objective 3: Targeted root delivery.Experiment began in January and is ongoing. 2. Please state what work is anticipated for next quarter:We had a serious problem with the health of the tree we are using. Those trees, while on UF propoerty, were not maintained well. We had some good p[reliminary results with the 3AB callose inhibitor, and we decided to make new injections in healthier trees, using 3AB and OTC. We will evaluate the trees for callose level and CLas titre bi-monthly starting in May 2024 (5-month after treatment) to evaluate the effect of the callose inhibitor on tree health and CLas infection. We will also measure the fruit drops via monthly data collection and the canopy volume and density via 6-month measurement to determine the effect of injections on tree health.3. Please state budget status (underspend or overspend, and why):Underspend- since it took some time to initiate the work proparly.4. Please show all potential commercialization products resulting from this research, and the status of each:We are still evaluating the effect of the callose inhibitor in the field trials