It’s a triangular relationship that spreads Huanglongbing (HLB) or citrus greening. And this disease is unlike anything else that has impacted Florida agriculture.

“Our oldest and most experienced plant pathologists have related that if citrus canker is a hemorrhoid, then HLB is more like liver cancer,” explains Jim Graham, a retired University of Florida soil scientist.

The Asian citrus psyllid spreads the bacterium, Candidatus Liberibacter asiaticus, which then attacks how the tree moves energy and nutrients. The host tree displays symptoms such as yellow, wilted leaves; reduced root mass; premature and misshapen fruit; and a dramatic decline in fruit production. A psyllid can travel several miles. Adult psyllids can lay 800 eggs, and it only takes seven weeks for an egg to mature.

Today, the Florida and Texas citrus industries are combating citrus greening. California growers have identified the psyllid, and HLB has been found in the Los Angeles area.

“The takeaway from this disease should be that we really need to stop the spread of pests at international ports,” says Brent Sutton, president of Growers Fertilizer in Lake Alfred, Fla. “The U.S. is doing a better job than before HLB came, but we need protocols to ensure something like this doesn’t happen again.”

Read more in the April AgPro cover story and Citrus Greening: No Stone Left Unturned