USDA funds citrus research

Rio Grande Valley citrus researchers hope to get their hands on a portion of $22 million in grant funding being made available by the U.S. Department of Agriculture for the fight against Huanglongbing or citrus greening, the world’s most serious citrus disease.

U.S. Rep. Filemon Vela’s office announced the funding Tuesday. He is co-chairman of the Congressional Citrus Caucus.

Huanglongbing has inflicted major damage on citrus production in Florida since it was detected there in 2005 and threatens to devastate the Valley’s citrus industry as well if a solution isn’t found.

The disease, spread by a small insect called the Asian citrus psyllid, was first confirmed in the Valley in 2012 in San Juan. HLB also is threatening California’s industry, which grows about 80 percent of the nation’s fresh citrus.

On the home front the news is mixed, according to Dr. John da Graca, director of the Texas A&M-Kingsville Citrus Center in Weslaco. Most new infected trees being reported are in the mid-Valley, where the disease is concentrated, though more reports are coming in from the Upper Valley and Lower Valley, he said.

In the face of the threat, growers are going the extra mile in maintaining their orchards in terms of fertilization and aggressive spraying for the psyllid and other pests, da Graca said. So far at least, the disease hasn’t spread as rapidly in the Valley as it has in Florida, he said.

“We’re not seeing the decline that they saw in Florida,” da Graca said. “It may still happen, but certainly the disease progression is a lot slower than we’ve seen elsewhere. We still need to be concerned and try and stay on top of it. We can’t relax.”

He knows of one orchard with HBL that, nevertheless, has seen its best production yet, he said.

“What will happen next year or the year after, I’m not going to try to predict,” da Graca said.

Meanwhile, the Citrus Center continues to collaborate with partners including the USDA, the citrus industry and the Texas Citrus Disease and Pest Management Corporation, which is mapping psyllid infestations.

The most promising research so far is that of Dr. Erik Mirkov, a plant pathologist with the Texas A&M AgriLife Research and Extension Center in Weslaco. His work involves combining a spinach gene with conventional citrus trees such as Rio Red grapefruit and Hamlin orange in order to create a “transgenic” tree resistant to HBL.

“He came yesterday and met with the Citrus Center faculty,” de Graca said.

“We’re putting together a proposal to try to get some of the money from this $22 million to actually test his trees in the field. We’re working closely with him.”

Mirkov is a decade ahead of other researchers in the field, de Graca said. Unfortunately, testing the theory will take a long time.

Since Mirkov’s transgenic trees are young, five to eight years must pass before they’ll bear fruit — or not — and settle the question of whether they’re actually HBL-resistant, de Graca said. It also remains to be seen whether transgenic citrus will taste right, he said.

“It’s going to be a number of years before we really know what’s happening,” de Graca said. “You have to be patient with citrus. But if we don’t get started now we could regret it.”