When the Environmental Protection Agency approved the spraying of certain antibiotics three years ago to fight a deadly bacterial infection decimating Florida's orange groves, growers thought they might have found a silver bullet. But public health advocates reacted with alarm, warning that the large-scale use of medically important drugs in agriculture could help fuel antibiotic resistance in humans.
Now a new study by citrus researchers at the University of Florida suggests the spraying of one of the recommended drugs could be for naught. That's not to say the drug is completely useless in the fight against citrus greening, which is spread by a pinhead-sized insect called the Asian citrus psyllid. Researchers carried out a parallel experiment by injecting the drug into the trees' trunks, instead of spraying, and they found a notable decline in citrus greening bacteria.