Since China closed the door to citrus coming out of Tulare County, Calif. in April, citrus industry officials paired with university experts and the U.S. Department of Agriculture with one goal: reopen citrus exports to China.
The market loss is significant as about half of the state’s total orange exports to China come from Tulare County, according to James Cranney, president of the California Citrus Quality Council.
While negotiations between the Chinese and U.S. officials continue, citrus growers and packers are being informed what changes they need to make to resume exports to China.
Chinese officials reported that a total of 12 shipments of citrus from Tulare County tested positive this season for two strains of Phytophthora fungus – P. syringae and P. hibernalis. The suspension affects all citrus to China, grown or packed in Tulare County.
Exports to other countries have not been impacted.
Subsequent investigations by U.S. officials of Tulare County operations revealed shortcomings in mitigation measures that are known to control the fungal disease, commonly called brown rot.
John Loyd, trade specialist with the USDA Animal and Plant Health Inspection Service (APHIS) in Fresno, said there were a number of instances where growers and packing house officials did not fully comply with requirements put in place about a year ago to control Phytophthora. He said those missteps are partially to blame for the violations.
Loyd spoke to more than 100 citrus growers and packinghouse representatives during a mandatory meeting in Tulare on the topic.
While Loyd agreed compliance lapses occurred at the farm level, he also pointed to a number of factors outside of growers control that could have exacerbated brown rot. Those include the West Coast ports strike, which allegedly saw shipping containers not shipped in a timely manner. Loyd said there were also issues with the broken cold chain.
It didn’t help that heavy December rains just ahead of fruit harvest to meet Chinese New Year demand complicated disease management.
Brown rot infections are primarily caused by splashing soil borne spores onto fruit by heavy rain.
Trade requirements with China stipulate various cultural practices to mitigate the likelihood of brown rot making its way onto the fruit. These include skirt-pruning trees so fruit does not hang close to the ground and well-timed copper and other treatments.
Packinghouses are also required to monitor groves for brown rot before harvest and to document those visits.
Addressing these and other issues will be necessary for China to open its market to Tulare County citrus.
Growers and packers must also satisfy Chinese officials regarding pre-harvest spray records, evidence that packinghouses are screening fruit in the orchard before it is picked, inspection logs, and detailed reports that identify fruit by lots and farm location.
Jim Adaskaveg, a plant pathologist with University of California, Riverside, addressed the biological causes of the fungal disease with growers, saying the disease is spread by water. Rain and irrigation practices can have the same effect on fruit. The chances of developing brown rot can be effectively reduced through a host of good cultural practices, he said.
Adaskaveg is a recognized university expert which USDA has used during trade negotiations with China.
Detailed spray records will be important going forward for growers shipping to China as the timing and frequency of those applications are part of the trade agreement, Loyd says. Growers should inform packers on the timing of any chemical treatments.
Harvest crews will also need to be trained on how to handle fruit, particularly since export requirements will not allpow any fruit to be harvested for China that is growing lower than 50 centimeters (20 inches) from the ground.
The fruit growing closer to the ground can be harvested, but not shipped to China. Therefore, packinghouses need to design a system to segregate lower hanging fruit so it is not shipped to China. Because other countries do not have the same requirements for such practices as China, citrus can still be shipped that does not meet the Chinese standards, Loyd says.
Growers can find more information on brown rot grove management at the University of California’s Pest Management Guidelines Website at http://www.ipm.ucdavis.edu/PMG/r107100711.html
For more information on the Chinese protocols, contact Jim Cranney at the California Citrus Quality Council at (530) 885-1894. Information is also online at http://calcitrusquality.org/export-issues/