Plan to stop Asian citrus psyllid laid out

Growers were told of the resolve of ag officials to stop the spread of what they call the most dangerous pest to the orange industry. Growers were also resolved to what they will need to do, even though it will mean costly adjustments to how many do business.

Tuesday’s meeting was to update growers, packers, nurseries and shippers of what the consequences are from the discovery of two of the tiny pests that can carry the tree bacterial disease Huanglongbing (HLB), also known as citrus greening, that has already caused great devastation to the citrus industry in Florida and parts of Texas. The disease does not affect the fruit, but can kill trees in less than five years. There is no cure for the disease.

Ted Batkin, president of the Citrus Research Board, said the meeting was not about the psyllid. “It’s about the trees and about the bacteria that’s vectored by the psyllid,” he opened the meeting.

“Once the bacteria get in your trees, it does not go away,” he stressed.

“What we’re trying to do is prevent that bacteria from moving into the citrus growing region.”

Batkin said HLB has caused both China and Brazil to move their citrus growing regions and the disease is infesting trees in Florida at a pace of 15% a year, a comment that drew a response from the approximately 350 growers at the meeting.

So far, the disease, which is spreading in Mexico, has only been found in one tree in Southern California and only one psyllid in the state has been found with the disease. The psyllid is spreading in southern California.

Officials have discovered three psyllids in Tulare County. The first, found last December, was considered a hitch hiker and did not prompt any action. The second and third finds, both found in traps picked up in October — in the Strathmore area and the other south of Terra Bella — have led state ag officials to declare two 5-mile-radius restricted areas around each find, and treatment areas of an 800-meter radius around each find.

The two areas are similar to quarantine areas that were considered. Those areas would have been 20-mile radiuses around the finds.

In both the quarantined or restricted areas, no green waste or untreated fruit can be moved outside of the zone. If a grower’s packing house is within the zone, and several packing houses are within the 163-square mile restricted zones, then their is no impact on a grower.

However, fruit within the zones has to be cleaned and stripped of all foliage, including stems, before it can move outside of the zone.

Fruit that has been packed can move freely.

One concern expressed is what is termed “gunny sackers.” Those are pickers not affiliated with any packing houses who pick a few bags of fruit for flea markets or markets in Southern California. Officials said they are working on how to regulate them to ensure that they are not taking green waste with them

Green waste is the only way the psyllid can travel and why, officials said, it is so important to limit its movement. That means cleaning green waste from bins and equipment, including sprayers, tractors and those large trimmers used to trim trees.

Treatments Begin

Much of Tuesday’s meeting focused on spraying.

Dr. Beth Crafton-Cardwell with UC Riverside called on the growers to work together to treat their groves. Growers were told, “If we can work together we can get control of the bug.”

While spraying is voluntary in the restricted and outside the restricted areas, it is mandatory within the eradication zones — the 800 meters around the finds.

Dr. Robert Leavitt with the California Department of Food and Agriculture said if a grower does not treat their grove, the grove could be “declared a public nuisance” and the agricultural commissioner would have the power to abate the land and treat it.

“We expect people to treat for ACP,” he said.

He also explained that if more psyllids are found, then they would likely go to the standard 20-mile radius quarantine zones. “The default would be the entire county, but it could be smaller,” he said of the zones.

He also said that even organic groves would be treated if they are in the eradication zones.

That would mean that crop could not be called organic this season, but the grove would remain certified as organic and next year’s crop, if not sprayed, could be sold as organic.

Cardwell said during the winter months only adult psyllids are found, while the larva and eggs are found on new growth on the trees in spring. She said that would be the best time for spraying, but agreed that can cause problems with pollination and bees.

Cardwell also said if weather makes it impossible for growers to apply the mild pesticides by ground, then aerial applications may be used.

Some growers would have liked the entire county included in the quarantine, which would have made movement of fruit much easier. Bob Blakley, director of grower operations for California Citrus Mutual, disagreed.

“Whole county concept at this point would be counter productive,” he said, explaining that allowing more movement could spread the bug faster if there are breeding populations.

So far, officials have found just the three psyllids, leaving many to hope they simply “hitch hiked” to the Orange Belt from one of the infested areas of Southern California. Leavitt said hundreds of traps have been put out and they are being monitored weekly right now and will be monitored at least every two weeks in the future.

“So far, we don’t think we have the HLB infected Asian citrus psyllid here in California,” he said.

There was some encouraging news out of the meeting.

- Backyard citrus can be moved freely outside of the quarantined area if it is cleaned of green foliage.

- Officials will evaluate the restricted zones in six months and may even end the restrictions if no more psyllids are discovered. Originally, officials had said the restrictions are in place for two years.

Citrus is a $750 million industry in Tulare County and harvesting of the 2012-13 crop has just begun.

Residents who believe they have seen evidence of HLB in local citrus trees, should call CDFA’s toll-free pest hotline at 1-800-491-1899.