1. Please state project objectives and what work was done this quarter to address them: Specific objectives are: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 confirmed in field conditions that Br application activates SAR gene expression for at least 6 weeks in young citrus plants. We have also found that in greenhouse-controlled conditions, trees maintained in cages and exposed to hot psyllids that were added, % of trees infected in non-treated controls is 60% after 4 months. Strikingly, no plants treated with Br are infected in the same conditions of heavy psyllid pressure, and eggs and nimphs are not present or significantly in lower numbers. There exists the possibility of an altered volatile profile in leaves after Br treatment taht may repel the insects, and we will explore this possibility in next quarters.2, To determine the best time of application (frequency) to achieve maximum protection against pests and disease in newly planted trees. We are ready to assay this both in the field and in controlled conditions in cages. For this we have pruned young plants in cages to allow new flushes before treatments and introduction of hot psyllids. We are waiting for the spring flush in the field to perform treatments in field conditions and to assess psyllid population dynamics after Br treatment.3, To determine the effect of Br application on advancing fruit maturation in both Valencia and Hamlin.We finished Br applications at Duda farm by the end of November in Hamlin. These applications started at the end of August 2022. In non-treated control trees we found a decrease in Brix between Oct 31 and Nov 15 (from 8.45 to 7.9) that was coincident with fruit set from off blooms in early October. Brix levels recovered later. Interestingly, that decrease was not found in Br treated trees, were the Brix remained stable at around 8.4-8.5. The most striking finding, though, was that acidity dropped faster after Br treatment as compared to controls and this led to increased ratios earlier in the season. This ratios were higher in Br treatment thereafter and at the end of the season, at harvest. In controls sugar/acid ratio was stable around 9 from September to December 1st. It only increased to 11 by the time of harvest in January 5. With Br treatment, values of 12 were achieved in early December, 1 month in advance, and by January 5th ratio was 14. We have collected juice samples throughout the maturation process and we will be analyzing them for organic acid composition and sugar profiles, to tdetect any possible differences. We are partnering with Prof Yu Wang at CREC for this. Outreach:- F Alferez, Combining IPCs and brasinosteroids in citrus & increasing yield by using Zinc. An update. Citrus Production School, February 9, 2023 in Arcadia. 2. Please state what work is anticipated for next quarter:For objectives 1 and 2, treatments and samplings will continue.For objective 3, we will continue treatments on Valencia, that started in early January. We will assess maturity periodically. 3. Please state budget status (underspend or overspend, and why):Spending is now on track.