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Posts Tagged: Beth Grafton-Cardwell

Three old trees might save the citrus industry

Three citrus trees that produce inedible fruit at the UC Lindcove Research and Extension Center in Visalia may be a game-changer for the citrus industry, reported Ezra David Romero on Valley Public Radio.

The trees are thought to be resistant to huanglongbing, a severe disease of citrus that has devastated the Florida industry and could become a serious problem in California. The citrus-saving potential of the three 34-year-old trees was outlined in an article by UC Agriculture and Natural Resources writer Hazel White in the most recent issue of California Agriculture journal.

UC Riverside citrus breeder Mikeal Roose collected seed from the trees and will test seedlings as soon as they are large enough. 

"So what (breeders) have to do is cross this with some edible varieties and eventually create something that has the gene for resistance, but also the genes for good fruit," said Beth Grafton-Cardwell, Lindcove director and research entomologist.

Huanglongbing disease has cut citrus production in Florida by more than half. It's been found in residential citrus trees in Southern California, but hasn't reached the state's vast commercial orchards yet. Grafton-Cardwell said she expects the disease will arrive in 4 or 5 years.

Eremocitrus crosses at Lindcove REC are potentially promising in the pursuit of a genetic source of resistance to HLB. The fruit is golfball size and inedible.
Posted on Friday, February 24, 2017 at 1:35 PM

Community enjoyed 100s of citrus fruit at UC's Lindcove REC

Mandarins, oranges, pomelos, citrons, lemons, limes and other citrus were on display - more than 100 different varieties - at the UC Lindcove Research and Extension Center on Dec. 10, reported Calley Cederlof in the Visalia Times-Delta.

“We're trying to expose homeowners to the fact that there are more than five varieties of citrus,” said Elizabeth Grafton-Cardwell, UC Cooperative Extension citrus entomology specialist and director of the Lindcove REC. “We also like to let them know we exist.”

The public came out in droves to taste the fruit and take home some of their favorites. The event came on the heels of a similar citrus tasting for industry representatives and farmers on Dec. 9.

More than 400 varieties of citrus are on display annually at the UC Lindcove REC citrus tasting events.

“People are shocked at how many varieties there are,” Grafton-Cardwell said. “Everything related to citrus happens here.”

The Lindcove REC also hosted a mock citrus judging for local FFA students during the tasting event. The students observed citrus with 47 different types of damage and were asked to judge them. The team typically learns about different possible citrus damage through textbooks, one student said.

“To see them in person is actually really helpful,” he added. “It's a good experience.”

Lindcove REC hopes to work more with local schools in the future, Grafton-Cardwell said. She and her team are currently in the early stages of creating a teaching garden where students can learn more about the citrus industry.

A fundraiser is in the works and donations can be made on the research center's website,

Posted on Monday, December 12, 2016 at 3:19 PM

Citrus trees sprayed for Asian citrus psyllid in Highland

Beth Grafton-Cardwell.
Backyard citrus trees in Highland, Calif., were sprayed with a pesticide to kill Asian citrus psyllids, reported Jim Steinberg in the San Bernardino Sun. The invasive pests pose a threat because they can carry huanglongbing disease, which is incurable. The California Department of Food and Agriculture is treating trees that have ACP to keep the pest number in California low.

“What they are really doing is buying time until disease resistant trees become available, or there is some treatment for the (huanglongbing) disease,” said Matt Daugherty, a UC Cooperative Extension entomology specialist based at UC Riverside.

The reporter also spoke to Beth Grafton-Cardwell, who is a UCCE entomology specialist at UC Riverside and director of the UC Lindcove Research and Extension Center in Tulare County. She said that it is unlikely huanglongbing was completely wiped out in the Southern California areas where infected trees have been found, even though CDFA destroyed the infected trees.

A tree can be infected for a year before it shows symptoms, she said. 

Grafton-Cardwell asks homeowners to monitor backyard trees for signs of Asian citrus psyllid and report any finds to CDFA or their county agricultural commissioner's office. For more information, see the video below.

Posted on Tuesday, May 3, 2016 at 1:29 PM

Californians are checking new growth on citrus for Asian citrus psyllid

Beth Grafton-Cardwell speaks with ABC30 reporter Dale Yurong, left, and cameraman Sam Gill at the UC Lindcove Research and Extension Center.
The Asian citrus psyllid is public enemy No. 1 at the UC Lindcove Research and Extension Center in Exeter, reported Dale Yurong on ABC30 Action News in Fresno. Yurong visited Lindcove to interview UC Cooperative Extension citrus entomology specialist Beth Grafton-Cardwell, who along with other UC ANR experts is calling on Californians to join the fight against the pest.

"Basically, you just look really closely (at new growth) with any kind of magnifying device you have to see if you can find any insects on there," Grafton-Cardwell said.

If tiny yellow eggs, sesame seed-sized nymphs, or ACP adults are found, take action. Maps, treatment protocols and other information that detail what to do when ACP is present are available at

Since ACP can spread the devastating citrus disease huanglongbing (HLB), controlling the insect population will buy time for researchers working around the world to find a way to grow healthy and delicious citrus fruit in the presence of HLB.

Yurong reported that the disease has been found in a dozen Southern California trees. Grafton-Cardwell figures Valley trees will ultimately get infected.

Dale Yurong poses with a giant mock-up of Asian citrus psyllid.
"HLB is going to come. We fully expect it to come up here because it rides in the bodies of the psyllids," she said.

Reed Fujii of the Stockton Record interviewed Karey Windbiel-Rojas, a UCCE advisor for home and garden integrated pest management, for a story on Asian citrus pysllid.

“It's really important to detect Asian citrus psyllid in backyard trees because one psyllid can carry the disease from tree to tree in a residential landscape,” Windbiel-Rojas. “Citrus growers, they treat all their fields, but home gardeners don't necessarily treat or monitor their backyard trees so it can spread a lot faster in backyards than in managed citrus orchards.”

Stories about the call to check trees this spring for Asian citrus psyllid also appeared in:

View a four-minute video about Asian citrus psyllid here:

Posted on Wednesday, March 9, 2016 at 8:27 AM

Arroyo Grande psyllid has caused a big stir

One sign of potential Asian citrus psyllid infestation is waxy tubules on new growth. (Photo: M.E. Rogers)
The discovery last month of one Asian citrus psyllid on a sticky trap perched in an Arroyo Grande lemon tree has the citrus industry and agricultural commissioner on guard, reported Jono Kinkade in the San Luis Obispo New Times.

They've established a quarantine zone within a five-mile radius of the ACP find and monitoring has been stepped up in the area. Officials are concerned because of the psyllid's ability to spread huanglongbing disease, should the disease make its way into California. (So far, only one backyard tree has been found in California infected with huanglongbing.)

“If you don't have a vector like a psyllid, no big deal, but when you have a vector alive and moving around, then you have a big problem,” said Beth Grafton-Cardwell, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside.

The psyllid is established in some areas of Southern California and has been found in commercial orchards in the San Joaquin Valley, where an eradication plan is underway. In San Luis Obispo County, the main focus is on residential areas.

“It's so tiny that people don't even know they have it,” Grafton-Cardwell said. “It's very difficult to completely eradicate it because 60 percent of California [residences] have a citrus tree in their yard, so it can hop, skip, and jump.”

Comprehensive information about Asian citrus psyllid and huanglongbing disease is available on the UC ACP/HLB Distribution and Management website.

Posted on Thursday, April 10, 2014 at 2:05 PM

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