1. Please state project objectives and what work was done this quarter to address them: The objectives of this project are: 1, To study the effect of Brs on priming immunity on young, newly planted trees. This will allow to know for how long immune response will last after Br application, so we can adjust timing (number of applications). We have continued treatments and samplings. We do see a very strong induction of immunity-related gene expression around 5 days after brassinosteroid treatment (x119 fold for ICS, a salycilic acid precursor, and x150 fold for PR5, a downstream salicylic acid gene related with resistance to disease). After 6 months (with a monthly application), 80% of these trees are still HLB-negative and with a denser foliage, in part due to a more abundant flushing in May than the control-infected trees.2, To determine the best time of application (frequency) to achieve maximum protection against pests and disease in newly planted trees. We have started the assesment of treatments after May flush, and we are collecting data on psyllid population, egg deposition and bacteria titer. This will be related to the gene expression levels we see in objective 1, so when those levels start to decline and we see increase in psyllid infestation and/or bacteria titer, that will mark when to apply a new treatment. 3, To determine the effect of Br application on advancing fruit maturation in both Valencia and Hamlin. Applications in Valencia started in early January 2023. In non-treated control trees we found a decrease in Brix in mid-February as we expected (from 8.07 to 7.63) that was coincident with new bloom and fruit set. Brix levels recovered later.In contrast, Brix in brassinosteroid treated fruit increased to 8.70. By harvesting, in March, Brix in controls was 8.5, whereas in Brassinosteroid-treated fruit was 9.4. This is an encouraging increase, but unfortunately, harvesting was performed earlier than expected, which prevented us to continue with the treatments and gathering data on the effects of brassinosteroids on late maturation. Yield at harvest was between 9% and 29% higher than in controls, depending on the time of application. Higher yields were obtained when brassinosteroids were applied closer to harvesting.As stated in my last report, we have been working on the analysis of juice samples from Hamlin to assess any possible effects of brassinosteroid treatments on organic acids and sugars. Our initial data show a significant increase in fructose content after brassinosteroid treatment, 160 mg/L as compared to 110 mg/L in controls. 2. Please state what work is anticipated for next quarter: For objectives 1 and 2 we will continue treatments, samplings and molecular analysis to determine the best timing for treatments to achieve the most protection against psyllid infestation. For objective 3, we will start in August treatments on Hamlin. We will also continue analyzing juice samples from Hamlin and start analysis on juice samples from Valencia. 3. Please state budget status (underspend or overspend, and why): Spending is on track