1. Please state project objectives and what work was done this quarter to address them: Objective 1: To compare different rates and annual use patterns of trunk-injected OTC on late-season (Valencia) and early-season (Hamlin) sweet orange tree and their effects on health, yield, and fruit quality over a period of 3 years in a commercial citrus production environment.Trees were harvested and fruit quality was assed in December 2023. We measured less fruit drop and increased yields (18-32%) for injected trees compared with non-injected trees, but yield differences were only significant at p = 0.12. In general, the highest OTC rate (1.65 g/tree) and the 75% rate (0.825 g/tree) resulted in the highest yield (32% increase). The highest pound solids and percent juice were measured for the trees that received the highest rate (p < 0.001). Please note that the highest rate (1.65 g/tree) was administerd by split-injections (0.825 g each on two opposite sides of the trunk). Fruit size and juice color were also improved by the injections. A subset of fruits was collected and processed for OTC residue analysis by the National Science Lab in Gastonia.Leaves were collected for CLas analysis (in progress) and tree ratings were performed. Trees that received the highest OTC rate are the densest and show the least foliar HLB symptoms compared with the controls. Obective 2: To compare spring with late summer injections in Valencia orange trees to determine if OTC effects on yield can be enhanced, and the harvest window extended, through timing of injections.Canopy ratings were performed and fruit drop was monitored. Injected trees look denser; trees that received the highest OTC rate are the densest and healthiest looking trees. 2. Please state what work is anticipated for next quarter: The Valencia trial will be harvested, fruit will be collected for fruit quality assessment and OTC residue analysis. Tentative harvest time is March 2024. 3. Please state budget status (underspend or overspend, and why):The budget is as expected.