The objectives of this study are to identify optimal pH range for root function and minimize root turnover on HLB-affected rootstocks and how uneven pH levels in the root zone (e.g. irrigated vs. row middle portions of root system) affect the overall health of the tree.� This is being done in a split root system in the greenhouse where pH of different parts of the root system can be controlled an maintained.�Enough split root rhizotrons for the experiment are currently being constructed and plant material is being prepared.� The Masters student has been recruited and begun planning work for project setup and execution.� We expect all materials to be prepared to initiate treatments in April or May, depending on the timing of the spring flush in the greenhouse trees.