The discovery of citrus greening disease on an orange tree in a commercial grove in the Texas Rio Grande Valley last week may be unsettling to growers, but a comprehensive management plan, extensive surveys and preventive control measures over the last three years gives local growers reason for hope. Citrus growers say they have invested substantial time and money preparing for what many are calling the inevitable arrival of the dreaded disease.

“We have known for a long time that there was a good chance the disease would arrive on our doorstep. For one, the highest concentrations of citrus greening disease in North America can be found across the border in Mexico,” reports Dr. Robert Mangan, acting director of the USDA Kika de la Garza Subtropical Research Center in Weslaco. “The disease is difficult to detect and it often takes years before the disease is confirmed on a plant.”

Mangan says the research center, now scheduled for closing in June as part of a USDA plan to trim $150 million from its budget, previously proposed placing Asian citrus psyllid traps on Mexican trucks headed across the border in an attempt to test for the moth that spreads the disease. But that plan was met by federal and industry opposition because the traps had not been tested on truck shipments.

The Asian citrus psyllid, which is responsible for spreading the disease, has long been detected in Texas, but confirmation of citrus greening disease in the Valley this month represents the first confirmed report of the actual disease in the state. Citrus greening, first identified in 2005, has destroyed hundreds of thousands of acres of citrus in Florida. It also has been found in Georgia, South Carolina and Louisiana.

“The outbreak of citrus greening in Florida and the resulting damage to the citrus industry there served as a wake-up call to other citrus producing areas including Texas, California and Arizona,” Mangan adds.

The Texas Department of Agriculture announced a five-day emergency quarantine surrounding the infected tree this week until further investigation can determine if other trees or groves in the Valley exhibit signs of infection. An expanded quarantine is expected later this week following results of a field survey currently underway. Under terms of the quarantine, citrus nursery stock may not be shipped outside the area. Fruit may be shipped out, but it must be free of leaf material and debris.

“Citrus greening disease doesn’t show up overnight. In fact, the disease may have been present on the tree in question for some time, so additional inspections are required to determine if this is an isolated case or if there are other instances across the area,” Mangan said.