"Abandoned Citrus Groves Produce Problems In Fla."

MELISSA BLOCK, Host:

From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.

ROBERT SIEGEL, Host:

And NPR's Greg Allen reports that the abandoned groves have become a threat to producers of the state's signature crop.

GREG ALLEN: This time of year, many trees are still heavy with fruit. There are also many groves that aren't doing so well.

PHIL STRAZZULLA: This is a grove in Vero Beach. This is a commercial grove, 140 acres. You could see there's still little pieces of fruit on the trees. But for the most part, this grove is dead.

ALLEN: Strazzulla's concern is not for the abandoned grove but for a healthy and productive grapefruit and tangelo producer just next door.

STRAZZULLA: This is a commercial grove still, but it's starting to decline. You'll start seeing a few missing tree spaces. You'll start seeing trees that are going down. And this is a direct result of the disease pressure from that dead grove just, you know, across the ditch.

ALLEN: Strazzulla pulls his pickup over close to a tree and pulls off a piece of fruit that's nearly as large as a softball.

STRAZZULLA: This is a honeybell orange.

ALLEN: Right.

STRAZZULLA: This is probably one of the best eating, best marketing oranges - highest dollar volume, highest return to a grower. So losing this block for this grower will be painful.

ALLEN: Citrus growers have always had to fight disease. But in recent years here in Florida, it seems that disease is getting the upper hand. Most recently, two - canker and citrus greening - have been very difficult to control, requiring more care and nearly constant spraying for pests.

BLOCK: She's an agriculture extension agent with the University of Florida in Indian River County. Kelly-Begazo says during the housing boom, speculators paid top dollar for citrus groves.

CHRISTINE KELLY: Now, if you bought acreage at that time, speculating that you were going to be able to make some money off of agricultural development or whatever, and then the development boom busted, there's no incentive now. And that acreage is actually costing you money now. So they have abandoned the groves and - but they're not building on them either.

ALLEN: How beautiful.

BOB ADAIR: Yeah. These are flame grapefruit. Got a beautiful color.

ALLEN: Bob Adair is a citrus researcher. We're in the middle of his small grove in Vero Beach, doing some tasting.

ADAIR: Now, this is going to be a little bit acid. Juicy, huh?

ALLEN: Yeah.

ADAIR: You got juice on the microphone.

ALLEN: Adair is working with USDA in the University of Florida, looking for better ways to control the ever-growing list of citrus diseases. At the top currently is greening disease. It's spread by a tiny insect called psyllid. Adair says in his grove, it's infected nearly a third of all his trees. On a tangelo tree, he lifts a branch that's beginning to show the effects.

ADAIR: This is the feeding damage caused by the psyllid. We call those notched leaves. The other symptoms that you see here are these very, very small leaves.

ALLEN: Citrus producers in Indian River have begun a program to bulldoze and burn trees in abandoned groves. But it's costly and depends on the cooperation of sometimes absentee owners. It's the latest of many challenges for an industry that's long grown one of Florida's most lucrative crops. Adair says the last three decades have presented citrus growers with one new disease after another. The reason, he says, is globalization.

ADAIR: What we did was we very efficiently took citrus from another hemisphere, brought it into the United States, into Florida, and grew it as an exotic species. We took it away from its natural enemies. And what we're seeing right now is all the natural enemies of citrus have found it here in Florida.

ALLEN: Greg Allen, NPR News, Miami.