A California Department of Agriculture (CDFA) quarantine area will be established in eastern Tulare County following the recent discoveries of six Asian citrus psyllids (ACP) in the Porterville area.

About 450 people filled a meeting room at the International Agri-Center in Tulare, Calif., July 30 to hear state regulators explain the quarantine process and, more importantly, the impacts the quarantine will have on growing and packing operations in one of California’s richest citrus regions.

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According to the CDFA, the quarantine prohibits movement of host nursery stock from a 178-square-mile quarantine area. It requires citrus fruit be cleaned of leaves and stems prior to movement outside the quarantine zone, which was a provision under the regulatory restrictions placed on Tulare County after the first ACP finds last fall. An exception can be made for nursery stock and budwood grown in USDA-approved facilities designed to exclude the Asian citrus psyllid.

Included in the quarantine zone are about a dozen packing sheds and one commercial nursery. Shipment of about 70,000 citrus trees from the nursery was put on hold by the quarantine, according to Marilyn Kinoshita, Tulare County Agricultural Commissioner.

A map of the quarantine area can be found online at: http://www.cdfa.ca.gov/plant/acp/maps/quarantine/3435ACP_Tulare_20130730.pdf. Important to note is that any commercial orchard operation or packing facility within the zone is either all-in, or all-out of the quarantine area. No single facility or operation is split by the quarantine boundary.

A pre-harvest spray treatment provision that was in place under the regulatory restrictions program has not been decided by regulators, according to Kinoshita.

The quarantine comes just weeks after Tulare County officials received good news. The absence of ACP discoveries in Tulare County since three were discovered in traps last fall led state officials to lift regulatory restrictions on the shipment of citrus within a small zone in Tulare County.

This news was followed within weeks by the discovery of six additional psyllids on three traps in roughly the same area of Tulare County, leading to the tougher regulatory action.

Official quarantine designation includes regulatory oversight by the U.S. Department of Agriculture (USDA).

Spraying begins

The quarantine also will include urban spraying operations by the State of California in and around the City of Porterville, which is the nearest urban center to the recent ACP finds.

State officials appear pleased that citizens living in and around the affected area are receptive to state spraying operations.

“Residents support this program,” said John Hooper, CDFA environmental program manager with the pest detection emergency program. “They want this pest eradicated.”

Urban spraying will begin immediately and will include a dual insecticide approach, Hooper says.

Growers will pay for sprays in commercial citrus.

A website for growers and homeowners on ACP is located at http://ucanr.edu/sites/ACP/. It includes guidelines and steps to help growers control the ACP insect.

Providing a Florida perspective on the ACP was Ken Keck, a third-generation Florida citrus grower and the new president of the California Citrus Research Board. Keck previously served as the general counsel and executive director of the Florida Department of Citrus from 2006-2012.

Given Florida’s early lackluster efforts to address the ACP, Florida’s citrus industry has been decimated by Huanglongbing (HLB). HLB is caused by a bacteria vectored by the ACP. There is no known cure for HLB. The disease makes fruit unmarketable. Every infected tree eventually dies.

“In Florida, we had the psyllid and thought of it just as another pest that was around in the new flush,” Keck said. “It will be a crime if you don’t take this seriously.”

Keck advised growers to set aside the natural inclination of independence for a more coordinated and area-wide effort to aggressively address the issue.

Keck urged growers and citrus representatives to take an aggressive approach to address ACP and HLB.

“If institutions don’t respond appropriately, write emails and make the phone calls,” he said.

Trapping and sampling

San Joaquin Valley citrus growers are urged to contact their local California Citrus Pest and Disease Prevention Program  (CPDPP) grower liaison for more information and assistance; Kern County – Judy Zaninovich - (559) 730-8691; Tulare County – Bob Wagner - (559) 730-1200; and Fresno/Madera counties – Sylvie Robillard - (559) 730-8690.

Additional information and the ACP and HLB can be found online at: www.citrusinsider.org, http://californiacitrusthreat.org, and www.cdfa.ca.gov/plant/acp/index.html

Several sampling and treatment strategies were recommended by Beth Grafton-Cardwell, IPM specialist and research entomologist with the University of California, Riverside. These include:

  • Aggressive sampling for ACP;
  • Do not rely on yellow sticky cards alone;
  • Use tap and visual sampling to check orchards at the edge of orchard blocks and in the middle of the block. Sample at least 10 trees;
  • If an adult ACP is found, place it them in 90 percent alcohol for HLB testing. Report it to the county ag commissioner;
  • For immature ACP stages, flag the tree, Contact the county ag commissioner to collect it;
  • When ACP is found, treat the area quickly;
  • Treat over a wide area; and,
  • Use effective insecticides.

According to several officials in the room, Tulare County still has the opportunity to eradicate the pest from commercial orange groves and urban citrus trees since the number of ACP finds remains quite small.

In areas where the ACP is established (Southern California for example), pest management with the goal to slow HLB spread into commercial groves is a more realistic option until research can find cures for the disease.

California has a single confirmed case of HLB, found in a single tree in the Hacienda Heights neighborhood in Los Angeles County. The tree was destroyed.

In related news, CDFA extended the CPDPP, the funding mechanism approved by citrus growers to protect against citrus threats including ACP and HLB. Based on state projections, CPDPP producer assessments are expected this year to generate $15 million.

The CPDPP and its related committee were created by legislation in 2009 in response to widespread discoveries of the ACP. The 17-member committee of citrus growers advises the CDFA Secretary and the agricultural industry about efforts to combat serious pest and diseases which threaten the state’s citrus crop.

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