3. Huanglongbing (HLB) background
• The disease has been around since the 19th century
• 1927: Psyllids were first linked to HLB and are the known vector
for the disease
• 1998: Asian citrus psyllid was discovered in Florida
• 2005: HLB was confirmed in Florida
• 2010: HLB was confirmed in all citrus-producing counties in Florida
• The level of HLB infection varies widely in the state
3
4. The Challenges of HLB
• Among most significant challenges to citrus worldwide
• Few solutions available from beyond Florida
• Significant research questions unanswered
• HLB impacts are immediate
• Clearly beyond the scope of the industry’s basal facility to
organize, prioritize and fund (2005)
5. Greening Effects on Citrus Production
• Overall tree decline, eventual tree death
6. Greening Effects on Citrus Production
• Bitter-tasting, lopsided fruit, small in size
• May not color properly with portions
remaining green
7. Production Costs for a 10+-Year-Old Southwest Florida
Processed Orange Grove
Source: R.P. Muraro, UF, IFAS
2002-03 2009-10 2009-10
Without HLB- Without HLB & With HLB &
Greening Black Spot Black Spot
$/Acre % $/Acre % $/Acre %
Weed Control & Herbicide 183.13 23.3 185.72 17.2 185.72 11.3
Spray-Pesticide 137.18 17.4 169.10 15.6 482.93 29.4
Fertilizer & Lime-Calcium 152.56 19.4 303.04 28.0 303.04 18.5
Pruning/Topping 28.03 3.6 32.08 3.0 32.088 2.0
Tree Removal/Resets 102.44 13.0 136.72 12.6 276.08 16.8
Irrigation & Ditch Maintenance 184.16 23.3 224.77 20.8 243.17 13.7
HLB Scouting Management
& Canker Decontamination 0.00 0.0 29.85 2.8 137.09 8.4
Total Production Costs 787.50 1,081.28 1,641.72
9. ASIAN CITRUS PSYLLID
Adults
• 3-4 mm in length
• may live 30-60+ days
• prefer to feed on new leaf flush
when present
• can survive long periods feeding
on undersides of mature leaves
• adults infected with HLB bacteria
spread pathogen to healthy trees
Eggs
Psyllid nymphs
• 0.3 mm in length
• 5 nymphal (immature) stages
• laid within unfurled leaves
• range in size from 0.3 – 1.6 mm in length
• use hand lens to observe
• develop exclusively on young tender flush
• eggs hatch within 3-5 days
• nymphs are easily observed when populations are
increasing during periods of abundant new flush
10. Citrus Greening: The Pathogen
Candidatus Liberibacter asiaticus
• Phloem-limited bacterium
• Transmitted by psyllids
• Graft transmissible
• Not currently cultured
11. Hlb management guidelines
• Guidelines are rigorous psyllid control & inoculum removal
• What does it mean for the growers?
– Routinely scouting for psyllids
– Continuously scouting for symptoms of HLB
– Pesticidal suppression of psyllids
– Immediately removing trees confirmed to be infected
11
28. What We Know Today with HLB
Management
Growers must Maintain Low Incidence
Rates
• Inspection
• Tree Removal
• Psyllid Control
• Clean Nursery Stock
No Science to support any other practice
3/23/2012 28
29. HLB Management
Positive Trees
• Positive HLB Trees Identified 2006 – 2011 = 598,000
• Positive HLB Trees Removed 2006-2011 = 429,000
• Southern Grove
– 350,000 HLB Positive Trees Identified
– 169,000 HLB Positive Trees Removed (Grove Sold to SFWMD)
• Dunwody/Alcoma & Devil’s Garden Groves
– 248,000 Positive HLB Trees Identified
– 248,000 HLB Positive Trees Removed
• Cumulative Infection Rate
– All Groves = 24%
– Dunwody/Alcoma & Devil’s Garden Groves = 23%
3/23/2012 29
30. Why the urgency?
Assumptions: Starting production 150M boxes/yr Starting trees 60 million Nursery capacity 3.5 M/yr
Production loss 5%/year Starting infection 18% % of Nursery reached 55%
Infection rate 1.25X per year
3/23/2012 30
31. Why the urgency?
Assumptions: Starting production 150M boxes/yr Starting trees 60 million Nursery capacity 3.5 M/yr
Production loss 5%/year Starting infection 18% % of Nursery reached 55%
Infection rate 1.25X per year
3/23/2012 31
43. Increased Production Cost Due to HLB
PSYLLID CONTROL Cost Per Acre
Admire Injections 6 @ $15 $90.00
Additional Ground
Sprays 2 @ $32 $64.00
Arial Sprays 5 @ $23 $115.00
Additional
Insecticides 4 @ $10 $40.00
TREE HEALTH
Nutritionals $250 - $500 $375.00
ROOT HEALTH
Ridomil
Applications 2 @ $45 $90.00
HLB CONTROL
Surveys 3 @ $25 $75.00
Tree Removal 3 @ $10 $30.00
SUBTOTAL $879.00
Loss of Income Due to HLB
Tree Loss 5% $150.00
Fruit Loss 2% $60.00
SUBTOTAL $210.00
Reduction of Income Per Acre
Due to HLB
$1,089.00
