1. 303
Status Of Huanglongbing (HLB)(Citrus Greening) Multi Agency Coordination (MAC) Projects on Thermal Treatment of Citrus Trees with Citrus Greening
D.A. Komm (1), R. Ehsani (2), P. Ravenna (3)
(1) USDA APHIS PPQ, S&T, CPHST AQI Raleigh, NC, USA; (2) University of Florida, lake Alfred, FL, USDA (3) AG Harvesters, Au Gres, Michigan, USA
Field Trials- U of Florida
Project- Ag Harvester
Introduction
Citrus trees infected with ‘C. Liberibacter asiaticus’, subjected to steam heat treatments, have shown an improvement in citrus yields and vigor (Fan et al., 2013). Thermal treatment equipment for all sizes of Floridian citrus trees is being developed and improved for citrus trees infected with ‘C. Liberibacter asiaticus’. Two MAC projects are contributing to the development and improvement of thermal steam treatment equipment for all sizes of citrus infected with ‘C. Liberibacter asiaticus’. The status of the two projects is described in poster.
Treated Trees
Treatment-131°F for 30 seconds
Prototype treated trees
Improved system treated trees
Total (May, 2016) 7695 treated trees
Treatment Timing ( preliminary results)
Spring & Summer- Optimal
Winter Months
Decrease in cold tolerance
Inefficient heating
Fail to reach treatment temperature
Title: AG Harvesters Citrus Steam Machine ( CA)
Principle Investigator: Peter Ravenna
Objective (1) Determine best way to hold an consistent temperature in canopy of tree for continuous thermal therapy for large citrus trees (18’ high x 20’diamter)
Built structure for tent and tunnel
Engineered and fabricated a self-contained boiler skid & trailer with a factory test tent tunnel
Successful tests of tent and tunnel
Issues resolved with SF-50 Boiler by Sioux Corporation
Resolved steam supply hoses and boiler skid issues
Determined the amount of steam required
Project –University of Florida
Title: A Compact, Mobile, and Improved Tree Steaming for Thermal Therapy of Individual Medium-sized Citrus Trees ( CA)
Principal Investigator: Dr. Reza Ehsani
Objective: (1) Improve on the design and effectiveness of the existing steamer prototype. Test performance and operation of modified system by treating up to 10,000 trees. The ‘Improved system” has several benefits over the prototype system which met the objectives of MAC project.
Objective (2); Assembly all parts for field trails.
Modified AG Harvester tomato harvester with diese4l motor, rubber tracks & hydraulic power supply
20’ wide by 15’ long x 18’ tall steam tunnel with Herculite canopy
50 BHP Sioux Corp SF50 diesel powered boiler with tank and 1725 lb./hr. steam capacity
525 gal supply water tank and pump
9600 watt electrical generator
Towed support trailer
Objective (3): Field Trails
Recommend modifications to the center of gravity & drive mechanism
Maneuvers within the grove but needs periodic direction change
Proper route planning is required
Modifications to include boiler and water supply; eliminates the trailer
The tunnel is planned to be open at both ends but colder winter temperatures required closing the ends
Tree Evaluation- U of Florida
Redesign Prototype- U of Florida
Evaluate trees before and after treatment.
Collect: tree age, scion, rootstock, root density, leaves for PCR, soil type, soil pH, cultural practices, fertility programs pest control, yield and fruit quality etc.
Pre & Post treatment- Tree canopy decline index (DI) score
Data collection on-going
Optimized positioning of the tree enclosure
Larger square tree enclosure for trees up to 10 feet tall
Increased the number of steam nozzles in tree enclosure to improve steam distribution
Controls for monitoring and operation consolidated into a single control panel
A street-legal mounting platform in order to transport system on roads
A larger steam generator, doubling capacity of the previous system
Addition of two axial fans in the tree enclosure to improve steam circulation
All systems will be compared to one another to provide growers with multiple options for thermotherapy
Thermotherapy- Three Videos
1.Open QR code reader 2. Hold device over QR code 3. automatic or push button 4. Open.
Operation of Thermal Systems
Ag Harvester- Full sized mature tree prior to HLB thermal therapy
Reference
Fan,G., Xia,Y., Lin, X., Cai, Z., Hu, H., Wang, X., Ruan, C., Lu, L., Sequeira, R., & Liu, B. (2013) Evaluation of thermotherapy against Huanglongbing (citrus greening) under laboratory condition. Proceedings of the 3rd International Research Conference on HLB, Abstract no. 7.23P. Orlando, Florida.
Ag Harvester
Canopy Opening
Ag Harvester
Continuous Steaming
Prototype
Improved System