1. Please state project objectives and what work was done this quarter to address them:
Objective 1: Determine effects of lowered soil pH on CLas populations and root physiology including internal root apoplast and vascular tissue pH.
We got our experiment in rhizotrons under way on March 28, 2023 using HLB free trees due to challenges with CLas inoculation and are evluating varying pH levels from 5.5, 6.5, 7.5 and 8.5 in rhizotrons under greenhoiuse conditions. All protocols are developed and pretesting for the study is finalized.
This quarter we measured physiological responses, root growth variables and apoplastic pH changes and are still completing micropscopy work and desdtrctive sampling through the next quarter. The portion CLas impacts will be conducted on selected and periodic field root samples from CLas infected trees. Early results of the greenhouse work were shared at the Florida State Horticultural Society (FSHS) annual meeting and a scientific note was published.
Objective 2: Field test multiple acidification materials including organic acids for tree response CLas suppression, nutrient uptake, and root and vascular pH changes.
In this quarter, we continued root sampling and soil pH determinations. We also completed fruit harvesting and juice quality determinations in the Lake Alfred site in April 2023.
2. Please state what work is anticipated for next quarter:
The greenhouse and field work portions on objective 1 will be completed in August 2023. Once the greenhouse and field work portion of objective one is done, we will prepare a journal manuscript and possibly a cittrus industry magazine article to share the results with other researchers and the citrus industry.
A poster on Objective 1 will be presented at the American Society of Horticultural Science in Orlando, in August 2023.
3. Please state budget status (underspend or overspend, and why):
The budget is on track and meeting the project milestones. However, we plan to request a no-cost extension so as to collect a fourth harvest in 2024 and also owing to some delays we had in executing the greenhouse portion of the project due to changes in project leadership.