Saving the citrus industry

The 500,000 backyard citrus trees in the Rio Grande Valley represent the biggest problem facing the Rio Grande Valley’s citrus industry as it tackles the devastating disease known as citrus greening. The annual farm-gate value of the Valley’s citrus crop is $72 million. Associated businesses — packers, shippers, implement and crop care suppliers — bring the industry’s overall economic contribution to the region to $134 million

Dale Murden of the research facility Rio Farms and Mary Palm of the USDA talked to citrus growers and researchers about developments in the critical battle against citrus greening, which has already decreased Florida's citrus production by 4% per year. — Dale Murden of the research facility Rio Farms and Mary Palm of the USDA talked to citrus growers and researchers about developments in the critical battle against citrus greening, which has already decreased Florida’s citrus production by 4% per year.

“If we go by Florida’s experience since 2004, 100% of their citrus has been infected” with citrus greening, said Texas AgriLife economist Luis Ribera. Production there is down by 40% for several reasons. The projected reduction in Valley production of 4% a year “could have a huge economic impact here.”

The Asian citrus pysllid insect, which carries the bacterial disease known as HLB or citrus greening, has been found primarily in the Valley’s residential citrus trees from Mission and Edinburg on the west and north to Harlingen on the east. While commercial groves have conscientious plans that cover watering, fertilizing and general tree health, backdoor trees across the community rarely do. That makes them more vulnerable hosts for the pyslid. Infected trees produce misshapen, sour fruit. Most commercial groves border residential areas filled with backyard citrus. And pysllid in Mexico’s citrus trees are only a strong south wind away.

Last summer, citrus industry leaders from California, Florida and Texas requested a greater sense of urgency in the fight against HLB. The USDA in December formed a multi-agency coordinating group (MAC). With the future of the citrus industry at stake, citrus growers and researchers met this spring in Weslaco, home of TAMU-Kingsville’s Citrus Center and TAMU AgriLife Research Center, to discuss ongoing efforts to deter, delay and, in the long term, recover from the fatal disease.

Erik Mirkov of TAMU AgriLife Research has been working on a transgenic citrus rootstock which is resistant to citrus greening. New rootstock will most likely be needed to replace citrus trees killed by the HLB bacteria carried by the Asian psyllid.

Currently the USDA has $125 million allocated to fight citrus greening over the next five years. “This is unprecedented, that so much has been designated for one particular disease of one particular crop,” said Mary Palm, MAC leader and assistant director for USDA-APHIS Plant Protection and Quarantine. The initial financial support is being directed at the most promising and close-to-field-ready solutions to combat HLB. “Everybody is so totally motivated to try to find promising ideas that would help move efforts forward,” she said. “Working together is what is going to make the industry sustainable.”

The emphasis is on applied research and a common sense approach to the problem, said Dale Murden of the agricultural research facility Rio Farms and chairman of the Citrus Disease and Pest Management Corporation. He likened the local, grower-driven industry self-help program to the boll weevil eradication program. “We are buying time until we have a solution.”

Among the tools gaining ground in Texas is bio-control. Small projects with tree owners are under way using a tiny parasitic wasp that lays its eggs in the pysllid. AgriLife Extension, in fact, has enlisted volunteers, including participants in its Master Gardeners program, to run bio-control projects that tent infected backyard trees and release the predator wasp. They have seen success in reducing the pysllid population. The short-term goal is to grow and release 500,000 wasps per month. Ninety RV parks have been surveyed for the insects.

To read more on this story by Eileen Mattei, pick up a copy of the May 2014 edition of Valley Business Report or click on this site’s “Current & Past Issues” tab.

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