The purpose of the project is to develop new guidelines for restoring root health and improving overall tree nutrition in Florida oranges and grapefruit. The objectives of the project are to:1. Determine optimal nutrient concentrations in roots and leaves for multiple grapefruit and orange varieties.2. Compare and contrast fertigation, soil, and foliar fertilization to identify best application method for uptake of nutrients into both underground and aboveground components.3. Investigate the relationship between root and leaf nutrient contents to tree health, yield, and fruit quality as well as bacteria titer.4. Generate updated and new guidelines for optimal nutrient contents for roots and leaves for HLB-affected trees.� Progress to date:The project is being implemented at three sites at Citrus Research and Education Center (CREC), Southern Gardens Citrus near Clewiston, FL and Indian River Research and Education Center (IRREC). Preliminary data collection (on yield, canopy size, HLB and other disease ratings, soil characteristics and tree and root health and nutrition) is underway and will be reported in the next quarter. Nutritional treatments will be applied starting in spring 2019. One graduate student (CREC), 5 agricultural assistants (IRREC and CREC) have been recruited to work on the project. A search for another graduate student (IRREC) has been completed and the person will start in Fall 2019. Co-PIs (Drs. Kadyampakeni, Rossi, Ferrarezi and Johnson) on the project presented some of their on-going work at the Citrus Show in Fort Pierce, FL and indicated that results from this project will be used to refine current citrus nutrition guidelines. Updates and data will be presented in future extension meetings after about a year or two of data collection and validation of results to get feedback from growers and the citrus industry.�Plans for Next QuarterThe team will continue with data collection and reporting on the progress of the project.���