Seasonal root sampling continues in two field sites for root density and root growth. We have completed a second year of root growth data from Hamlin/Swingle and are continuing to collect a second year of root growth data on Valencia/Swingle. Results continue to emphasize the need to use treatments that improve root longevity as the main method of managing HLB root loss. Additional root growth appears to occur at the expense of older roots and is unlikely to provide sustained improvement in root density. Root tube images taken with the root scanner to assess root growth, lifespan, and death continue to be collected monthly. Visual observation shows that the method is working well, but data analysis has been delayed due to an unexpected software glitch, a new version has been released and we are working through a backlog of images. Only one rootstock tested to date has shown a significant difference in response to HLB. It remains the only rootstock with significantly better root density (increased) when infected by HLB. Root loss has not been observed yet in this rootstock. Fruit drop data has been collected to determine if the increased root density is associated with reduced fruit drop. We continue to monitor the most promising rootstocks identified in the field trial to HLB using rhizotrons in the greenhouse. The second set of rootstocks has been grafted with Hamlin scion or left ungrafted to monitor the effects of the scion rootstock interaction on the rootstock response. Phytohormone analysis has been completed on roots, but no clear consistent change has been observed in old roots or new root tips. Microscopy of the root samples to identify the mechansim of root dieback is awaiting the arrival of a new confocal microscope.