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 to confirm what we have previously reported. We do see again a very strong induction of immunity-related gene expression around 5 days after brassinosteroid treatment. After 9 months (with a monthly application), 60% 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. Interestingly, we do see more synchronous flushing in trees treated with Brs as compared to controls. Trees treated with Brs had a massive flushing in June, whereas control trees had a more spread flushing in June and July. We are following this flushing dynamics in fall to confirm that Brs can synchronize flushing.2, To determine the best time of application (frequency) to achieve maximum protection against pests and disease in newly planted trees. We started the assesment of treatments after May flush, and we collected data on psyllid population, egg deposition and bacteria titer. We do see less psyllids and eggs per tree. We are now analyzing bacteria titer in samples collected through the first year. 3, To determine the effect of Br application on advancing fruit maturation in both Valencia and Hamlin. We have continued juice analysis of samples collected through the year. Treatments are planned to start in September for Hamlin and January in Valencia. We have prepared the experimental area in Duda, flagged the trees and collected baseline data (canopy, fruit set, tree height) as we are using the same trees than last year, so we can also assess any cummulative effects of treatment over time. Outreach:-Alferez, F., Shahid, M. (2023). Can brassinosteroids help citrus to cope with disease and extreme weather events? Citrus Industry, 104, 4 April 2023.-Alferez, F. Use of Auxins and Brassinosteroid in citrus to improve fruit growth and development. In Service Training Use of plant growth regulators in Florida horticulture industry. Daytona Beach, FL. June 13, 2023. 2. Please state what work is anticipated for next quarter: Treatments will start in Hamlin. 3. Please state budget status (underspend or overspend, and why): Spending is on track