HLB is known to make citrus roots more susceptible to Phytophthora root rot. It also reduces the efficacy of chemical management of Phytophthora root rot, creating a difficult management scenario. Current Phytophthora management recommendations are based on pre-HLB work done in the 1980s. These three conditions raise the question of whether yield improvement from Phytophthora management is enough to pay for the management costs themselves. The goal of this project is to develop new soil propagule density managment thresholds and recommendations for chemical management of Phytophthora root rot based on ecomonic analysis of yield responses in different soil conditions. Finding and getting to sites during the research ramp-up has proven more difficult than predicted. We are still looking for suitable grower sites with Phytophthora pressure. Meanwhile we are planning an additional greenhouse Phytophthora and HLB experiment to determine if the newly labeled chemistries have the same limitation on HLB-affected plants as fosetyl-Al and mefanoxam have shown.