Making Citrus Delicious and Disease Resistant

There’s a reason Florida and oranges are so inextricably linked—the state grows 80% of the United States’ juicing oranges.

But a serious problem appeared in South Florida in 2005: citrus greening disease. Officially called Huanglongbing (HLB), it’s now infecting citrus trees around the world. HLB is caused by bacteria, it’s spread by a tiny insect, and there’s no cure. Florida’s orange production is now at about 40% of what it was in 2000.

“Ever since the disease has appeared, researchers have be…