Texas working with APHIS, California on citrus disease - The Packer

Texas working with APHIS, California on citrus disease

03/15/2012 09:31:00 AM
Don Schrack

Texas is joining California in committing itself to stopping huanglongbing.

The Texas Department of Agriculture, which discovered the state’s first infected trees in December, has joined forces with the Animal and Plant Health Inspection Service of the U.S. Department of Agriculture, said Ray Prewett, president of Mission-based Texas Citrus Mutual.

Prewett also said in mid-March one of his staff members was headed to California to see how that state’s successful pest education and public outreach programs could be replicated in Texas.

“After taking a tremendous number of samples before and since the find, we have only a fairly small number of positives,” he said.

The infected trees — about 35 of them — have been pulled from the two San Juan area groves about six miles from Mexico, Prewett said. All of the infected trees were within a few rows of one another, not sprinkled throughout the groves, he said.

“Time will tell,” Prewett said. “We may have found it (the disease) relatively early. We certainly hope so.”

Among the biggest fans of California’s psyllid/HLB assault plan is the state’s Citrus Pest and Disease Prevention Committee, formed shortly after psyllids were discovered near San Diego in 2008.

“Everyone on the committee is extremely pleased with the aggressiveness of Sec. Ross and her decision to make sure that if HLB is found that tree removal will be immediate regardless where the tree is located, urban or rural,” said Nick Hill, a citrus grower-shipper who chairs the committee.

The California Department of Agriculture, headed by Sec. Karen Ross, revealed March 8 that it is putting into effect a plan that includes mandatory spraying if psyllids carrying the disease are discovered and mandatory removal of any trees found to have HLB.

Also known as citrus greening or HLB, the disease is carried by the Asian citrus psyllid, an aphid-sized pest that was discovered several years ago in Texas and more recently in Southern California.

California protocols are still in development, Hill said, but will include a quarantine be established around any tree found to be infected and every tree in the zone tested for the disease.

As Florida and Brazil have already discovered, symptoms of HLB are often not obvious until a few years after a tree is infected. That is not the only challenge, Hill said. The disease takes its time infecting an entire tree, so that a sample could return a negative result if taken from a still healthy section of a diseased tree, he said.

“There has to be very systematic sampling process to ensure whether the tree is infected,” Hill said.

Organic fruit groves pose a particular challenge for the California citrus industry. Research entomologist Beth Grafton-Cardwell, director of the University of California Lindcove Research and Extension Center, has begun working on protocols in the event a psyllid infestation is found in an organic grove, Hill said.

The state and the committee have held discussions with leading organic grower-shippers and have proposed to the USDA a limited one year loss of certification if nonorganic chemicals must be used to eradicate the psyllids, he said. Organic certification in California requires a three year, nonchemical waiting period.

“Organic growers have been extremely cooperative,” Hill said. “They get it ... We’re planning to be here 20 years from now. We’re convinced we can beat this thing.”

Joel Nelsen, president of Exeter-based California Citrus Mutual, is getting similar feedback from organic grower-shippers.

“There’s a commitment from them to do what’s necessary to save the industry to the extent that they can and save their organic certification,” he said.

There are materials organic growers can use on the psyllids, but they are not as effective as the sprays available to conventional growers, Nelsen said.

“As a result, their spray program will be more frequent and more intensive — and more expensive,” he said.

Porterville-based Homegrown Organic Farms has joined the rest of organic grower-shippers in wholeheartedly supporting the efforts to rid the state of the psyllid and the potential for HLB, said Scott Mabs, director of marketing.

“We’re working with all of the stakeholders to work toward a solution,” he said.

That California has been able to confine psyllid infestations to Southern California for nearly four years is due in large measure to the industry’s self-imposed assessments of more than $15 million annually. The funds are used to match USDA dollars for trapping costs, to augment some treatment costs and for public education, Nelsen said.

“We have had greater than 99% cooperation from homeowners in Southern California,” said Robert Leavitt, acting director of the CDFA’s Plant Health and Pest Prevention Service.

Texas also is coughing up big dollars to protect the future of the industry.

“The growers and the industry just committed $440,000 to protect budwood sources to keep them clean, to keep commercial nursery stock clean,” Prewett said.

“We may be playing catch up, but we’re trying to get there as quickly as we can.”

More than 85% of California’s citrus crops are headed for the fresh domestic and export markets. Because it has no domestic citrus crops, Canada, the state’s No. 1 export customer, is not directly affected by the HLB scare, Nelsen said, but some countries such as Australia have expressed concern.

“We have to do a comprehensive trapping program for some of our overseas customers, so that they know where the psyllids are and that we’re ensuring the pests are not on the fruit,” he said.

The millions of dollars the industry is providing to fight the pest and HLB signal the belief California citrus will be available long term, Hill said.



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