No more psyllid finds in county

Citrus growers, packers and sellers continue to keep their fingers crossed as no more Asian citrus psyllids have been discovered in Tulare County.

Late last year, two psyllids were discovered in commercial groves in the county — one northeast of Strathmore and the other south of Terra Bella. The two discoveries led ag officials to impose two five-mile-radius quarantine zones around the discoveries in an attempt to contain the pest. The insect poses a serious threat to the $750 million dollar industry in Tulare County.

“We haven’t found any more,” said Bob Blakley of California Citrus Mutual. The programs seem to be working well and growers are cooperating, he said.

Blakley said spraying for the tiny pest — the psyllid is smaller than an aphid — has been completed in the quarantine areas, including spraying of backyard trees in those areas.

The psyllid can carry Huanglongbing, also known as citrus greening disease, a bacterial infection that is severely threatening citrus production worldwide.

The disease has wiped out thousands of acres of commercial citrus groves in Florida. Once a tree is infected, there is no cure. The only thing that can be done is to destroy the trees.

While no more psyllids have been found in Tulare County, Blakely said there have been several new discovers in Southern California where the pest has been found in several counties.

Citrus industry stepping up detection research

Research has been ongoing on several fronts, and just this week the California Citrus Research Board signed two new contracts with Applied Nanotech Holdings to increase instrument development and testing for HLB disease in trees in Texas, Florida and California, with a focus on early detection.

The two contacts are worth over $490,000, reported Nanotech. The research board is funded by growers.

Blakley agreed early detection of the disease is important, since the disease spreads from tree to tree, and removal of infected trees has proven to be an effective method to eradicate and contain the disease.

Greening disease and other pathogens cause more than $1 billion in lost revenue to citrus growers annually. Early detection and monitoring cannot only save billions of dollars but also millions of trees while keeping fruit and juice prices from skyrocketing.

The first contract is for the continued development and refinement of point of analysis agricultural pathogen detection systems. This contract includes further development of the EZKnowz pathogen detection systems for the detection and monitoring of HLB disease.

In addition to the portable pathogen detection units, the company will provide testing services, training and technical support services for the CRB over the next few months. This novel point of analysis agriculture pathology system will be used to boost research and understanding into detection and monitoring of citrus HLB disease.

Field evaluation of new technology ongoing

The second contract is to continue field testing and evaluating the EZKnowz agriculture pathology sensor system, developed with help from CRB funds by Cristina Davis at the University of California, Davis and APNT. This field testing will take place in Texas to determine just how early the disease can be detected asymptomatically.

“This system and technology will offer great flexibility in meeting both CRB’s and the citrus industries Point of Analysis HLB early disease detection and monitoring needs in preventing the disease to take over the citrus industry,” said Alan Jernigan, CEO of EZDiagnostix. “They can be utilized to provide near instantaneous information for detecting the HLB bacteria asymptomatically, as well as, provide tools for the growers to get ahead of the spread of the disease.”

“The advancement of this technology fills a critical need for the continued production of citrus worldwide,” reported Ted Batkin, president of the Citrus Research Board. “HLB has caused severe damage to citrus production regions in Asia, South America, Mexico and the United States. The ability to detect the disease early in its life cycle will allow the industry to develop management strategies to prevent spread and maintain financial viability.”

Research is first move toward early detection

Batkin said the new contract is to take the next step in developing an early detection system.

“This is the first phase of moving it from research stage to development stage,” he said, adding it is part of a long-term strategy to detect the disease as early as possible. Right now, the disease can go undetected for as long as five years.

“These new contracts are important to accelerating commercial development of our technology and will be important in combating a growing problem in the citrus industry. We are pleased that the CRB has recognized the importance of our technology and our leadership role in this area,” continued Jernigan.

Blakley said there is other research under way, including development of disease resistant trees and ways to modify the bug “to where it can’t transmit the disease,” he said.

There has also been a wasp introduced in Southern California that lays its eggs in the psyllid nymphs, killing them.

Batkin said, however, that disease resistant trees in commercial groves are probably 20-30 years away.

Blakley added that about 40 percent of the current navel orange crop has now been harvested.