1. Please state project objectives and what work was done this quarter to address them: Objectives: 1) Test the efficacy of different injection devices, 2) Determine the most effective formulation of OTC, 3) Determine the best month of injection and most appropriate OTC concentration based on tree size. Trial 1: SW FL(Duda) – 8-year-old Valencia/Carrizo.** Trial 2: SW FL (Graves Bros) – 8-year-old Valencia/Kuharske. Trial 3: East coast (Graves Bros) – 9-year-old Valencia/sour orange. Trial 4: East coast (Graves Bros) – 4-year-old Valencia/x639. Trial 5: Central ridge (King Ranch) – 4 year-old OLL8/x630**The grower collaborator for trial 1 stopped tree care after our year 2 injections, and trees have been declining rapidly. We have therefore terminated our evaluations in this trial. Harvests and fruit quality analyses were completed for trials 3 and 4. In trial 3, we found significant increases in yield and juice quality after OTC injection. Depending on the OTC dose and the method by which it was administerd, yields were increased by 74-131% (control: 31 lbs. fruit/tree, injected: 54-72 lbs fruit /tree) and Brix was increased by 11-20% (control: 9.7, injected: 10.8-11.6). Also improved by OTC injections were the juice color, acid, and the Brix/acid ratio. Both methods (Chemjet injection+Arbor-OTC and Flexinject injection+ReMedium) produced similar results. The best juice quality was obtained injecting ReMedium with the Flexinject injector at the high rate (1.1 g OTC/tree), but at the lower rate (0.55 g OTC/tree) two-sided injection using the chemjets produced slightly higher yields than one-sided Flexinject injections. In trial 4 we found significant differences among the different treatments. Overall, most treatments improved fruit yield and juice quality, with higher OTC doses producing better results. The highest dose (0.75 g/tree) resulted in 52 lbs of fruit/tree compared to 20-22 lbs for the non-injected and OTC-foliar spray controls. OTC was delivered double-sided either using the Treecise system (dose: 0.18g and 0.38 g/tree) or the chemjet injectors (dose: 0.38 g and 0.75 g/tree). Best results for the juice quality were obtained when OTC was injected in August and at the high rate (0.75 g/tree) – Brix was 11.3 compared to 8.7 for the controls.The same rate injected in May produced a Brix of only 9.6, but May injection resulted in larger fruit than August injection. The same trend was observed in the previous year. Some of the data from this project were presented at the Citrus Institute, the Citrus OJ Break, the Florida Citrus Industry Annual Conference, and other venues. 2. Please state what work is anticipated for next quarter: We are still waiting for some of the results from the OTC residue analyses (performed by the NSL lab). PCR analyses will still need to be completed as will wounding evaluations. Data will be included for presentation at the Citrus Expo and in an upcoming Citrus Industry magazine article. 3. Please state budget status (underspend or overspend, and why):Everything is on track.