Progress report for the second quarter of the 2019/2020 project yearThe purpose of the project is to develop new guidelines for restoring root health and improving overall tree nutrition for 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 conducted at three sites: Citrus Research and Education Center (CREC), Southern Gardens Citrus near Clewiston, FL and Indian River Research and Education Center (IRREC). Data collection continued in the second quarter of 2019/2020, focused particularly on soil, root and leaf nutrient concentrations, HLB disease ratings, tree physiological characteristics, and root growth and longevity. We also collected second fruit yield and juice quality data on the research site near CREC, and first year fruit yield and juice quality data at the IRREC. Data collection continues, and analyses will be done as more data are collected. Root measurements, soil characterization, and canopy size determinations are completed every 6 months. Data analysis and comparison of early trends continues. We will provide further updates on the outlook of results for the orange and grapefruit trees in the next quarter. We will continue to monitor the trends over the coming months and report any observations accordingly. Root image tracing is almost up to date and preliminary quantification should be completed soon. One set-back during this quarter affected one deliverable on the project. The project could not collect harvest and fruit quality data for the Clewiston site due to COVID-19. Nevertheless, the yield and fruit quality data collected near Lake Alfred and at IRREC will provide the updates for this year. Plans for Next QuarterThe team will continue with fertilizer treatments and data collection including HLB rating assessments, canopy size and root growth measurements and reporting on the progress of the project. Preliminary root longevity analysis will be done on the traced root images from Lake Alfred and Southern Gardens sites comparing lifespans of root flush cohorts in response to fertilizer treatment.