Ninety-five percent of the limes consumed in the U.S. come from Mexico, and Mexico’s lime harvest is being held hostage—sometimes literally—by weather, criminal entrepreneurship, and disease. Severe rains last fall knocked the blossoms off of most of Mexico’s lime trees, decimating the current yield. Armed gangs linked to drug cartels have seized on the shortage, and the resulting price spike, to start grabbing lime shipments and stealing fruit out of the fields. Growers have had to hire armed guards, and all this has only driven prices higher.
Harvests are likely to rebound somewhat in the next few months from the effects of last fall’s storms. But another, longer-term threat to Mexico’s limes is a bacterial disease called huanglongbing, also known as citrus greening, that’s killing many of Mexico’s lime trees. Last summer the New York Times ran an in-depth story about the efforts of a U.S. Sugar (USGR) company, Southern Gardens Citrus in Clewiston, Fla., to develop a genetically modified orange tree that could resist the disease, which growers in Florida fear could wipe out much of the state’s orange trees.
The goal of the project is to rescue the orange tree, but it could help the lime as well. Southern Gardens President Ricke Kress is spearheading the orange effort, and he says they’re already working on limes. “The greening disease affects all citrus, so we are doing work on all forms of citrus. We’re looking at orange, we’re looking at grapefruit, we’re looking at lemons, we’re looking at limes,” he told me. “There’s no reason the technology won’t work on all forms of citrus. It’s not specific to orange.”
The technology in question is the insertion of a spinach gene that codes for a protein that kills the HLB bacteria. It was developed by Erik Mirkov, a plant pathologist at Texas A&M. The field trials on oranges and grapefruit have been quite encouraging: After 18 months, Mirkov says, the unaltered trees in the trial are mostly infected and the biotech ones are free of the disease. He has also successfully introduced the gene into lemons, which will soon be in field trials. With limes, Mirkov is just now introducing the antibacterial genes into seedlings.
Southern Gardens plans to commercialize only the orange. Kress says once the technology is developed, it will be available to the rest of the industry for a fee. “There will be some sort of cost assigned to the technology,” he says, “but today that can’t be defined, because we don’t know what it’s going to cost to get all the way through commercialization.”
Anyone who decides to do so will have to figure out how to overcome the public’s skepticism about genetically modified food—a skepticism that persists despite a broad scientific consensus about its safety. In Mexico, where the lime shortage is most strongly felt, a judge last fall ordered a halt to new GMO corn permits.