What is in this article?:
- Recent finds of citrus greening disease in Texas' Rio Grand Valley have the California and Arizona citrus industries on high alert.
- HLB could already be in the Los Angeles basin but not yet detected.
- A top concern for the spread of HLB is the most common paths travelled by the psyllid — along major transportation corridors and U.S.-Mexico border crossings.
RESEARCHERS CHECK yellow sticky traps for the Asian citrus psyllid in a backyard citrus tree.
There is no cure for HLB — the most deadly citrus disease in the world. Host plants for the disease include, grapefruit, orange, lemon, tangerine, and orange jasmine.
Polek concurs with other Western citrus leaders: It is a matter of when — not if — HLB is found in California and Arizona.
“My hope is researchers will find solutions before HLB gains a grip in California citrus,” Polek said. “It is a race now. We are at the final few laps. It’s getting a little tense.”
Polek says ongoing HLB-psyllid research is short- and long-term based. In late January, citrus and pest scientists from across the U.S. submitted a five-year, $10 million grant request to USDA to study potential solutions.
HLB is found worldwide in various climates. States known to have the disease include Florida, Georgia, Louisiana, South Carolina, and now Texas. So far, California and Arizona are, by the book, disease free but both have multiple psyllid finds.
In 2005, Florida officials detected HLB in the Sunshine State; the first HLB find in the U.S. The first psyllid arrived in Florida in 1998.
The University of Florida reports HLB has reduced Florida revenues by about $3.63 billion and eliminated 6,611 jobs by reducing orange juice production since —all since 2006.
According to the National Agricultural Statistics Service, Florida is the nation’s largest citrus producer with 503,000 bearing acres during the 2010-2011 crop year with an economic value of $1.57 billion. California follows with 267,400 acres — a $1.3 billion value. Texas ranks third at 27,300 acres worth $70 million; followed by Arizona with 13,500 acres and a $38 million value.
HLB was found in Mexico several years ago and has quickly spread across the country. Mexican HLB finds are within several hundred miles of California and Arizona.
Of Arizona’s 13 psyllid finds, one was trapped in commercial citrus in Yuma County. The others were in residential citrus. Arizona’s first find was in San Luis in Yuma County in the fall of 2009. A psyllid was captured last year in a trap just north of the Nogales port of entry (Santa Cruz County). The latest find was in Pima County last December near I-19 near Continental.
Polek’s first concern is the most common path travelled by the psyllid — along major transportation corridors and at U.S.-Mexico border crossings. In addition, budget cuts by states have made psyllid control more difficult.
“We are very concerned as funding for border inspections to check for the psyllid and other pests and diseases has been cut in California, Arizona, and Texas,” Polek said.
In California, the CRB has increased trapping efforts especially along the routes near packinghouses. The CDFA has increased the collection of plant tissue samples to check for HLB; up from 1,000 total samples last year to more than 2,000 samples in the first two weeks of January.
The CRB Diagnostic Lab in Riverside, Calif., has agreed to assist CDFA in analyzing psyllid and plant samples for the presence of HLB-associated bacteria. Lab costs are paid by a commercial citrus grower assessment on field boxes of fruit through the Citrus Pest and Disease Prevention Program.
On close watch for HLB-ACP in Arizona is Glenn Wright, University of Arizona citrus specialist, Yuma, Ariz. About 75 percent of Arizona citrus is grown in Yuma County; about 75 percent are lemons.
Wright says Florida’s HLB experience allowed Texas to better prepare for HLB. California and Arizona will learn valuable lessons from Texas’ psyllid-HLB experiences. “So far it looks like the Texans have done a good job as they had time to plan following the finds in Florida.”