EPA allows massive use of antibiotics on citrus trees despite federal warnings antibiotic-resistant diseases will spread

The Asian citrus psyllid, which spreads
the disease (USDA photo)

Florida citrus production has dropped 70 percent in the past 15 years because of citrus greening, a disease spread by a tiny insect that carries a harmful bacteria. "The rapid onset of the disease has left growers with few effective management strategies. Since 2016, the Environmental Protection Agency has allowed citrus farmers to spray medically important antibiotics on their groves in hopes of reversing the devastating trajectory," H. Claire Brown reports for The Counter, formerly The New Food Economy. "But this last-ditch solution has its consequences: It’s expensive, and scientists aren’t sure it works very well, while public health advocates worry it’s hastening the spread of antibiotic resistance."

Today, about 90 percent of Florida's citrus trees are infected; the state produces more than two-thirds of the nation's citrus and more than 90% of its orange juice. By 2016, Florida citrus farmers were reporting an average loss of 40% of their crops from the disease. That year, EPA began allowing farmers to spray the streptomycin and oxytetracycline on citrus crops, as "emergency applications," Brown reports. Since both antibiotics are used to treat medical problems in humans, including urinary tract infections, syphilis, and tuberculosis, many public-health advocates were concerned.

"The agency was proposing to allow as much as 650,000 pounds of streptomycin to be sprayed on crops each year. That’s more than 10 times the amount used to treat human diseases. The concern was that the widespread use of antibiotics on crops would select for antibiotic-resistant bacteria, which would then spread throughout the ecosystem," Brown reports. "Antibiotic-resistant infections are expected to claim 10 million human lives by the year 2050, and critics worry the spread of so-called 'superbugs' will be aided by the extensive use of antibiotics in agriculture."

In late 2018 the EPA approved routine use of oxytetracycline on citrus groves, ignoring objections from the Centers for Disease Control and Prevention and the Food and Drug Administration, Brown reports. Emergency use of streptomycin has also been approved in California.

Despite the possible public health risk, it's unclear that the antibiotics are helping. Paul Meador, a fourth-generation citrus farmer, said the antibiotics make farming much more expensive. "He remembers spending $1,000 per acre on production costs less than two decades ago. Now he spends $3,000. And the rising bills have been accompanied by a slump in yield. Production on his land has diminished by half, if not more," Brown reports.

Meador said the antibiotics have substantially diminished his crop loss though, especially compared to citrus farmers who weren't using the antibiotics. A 2019 University of Florida study seemed to contradict Meador, finding that oxytetracycline didn't help much over six months, but that study didn't test streptomycin, which Meador uses. The study also found that injecting the antibiotics directly into tree trunks instead of spraying them on leaves might help fight the bacteria better, but injection isn't an EPA-approved application method.