Drones and dogs deployed in the battle to save the guacamole

MIAMI With the killers hiding in the trees, heat-sensing drones are launched. When their whereabouts is narrowed, the dogs are sent in. When it comes to protecting the world’s supply of guacamole, no weapon can be spared.

In South Florida, researchers are doing battle with a deadly fungus, laurel wilt, which is spread by a tiny beetle and has the potential to decimate the state’s avocado crop.

“This is probably the biggest threat to the Florida avocado that’s ever been seen” said Jonathan Crane, a tropical fruit crop specialist at the University of Florida.

Laurel wilt is spread by the ambrosia beetle, a species from Asia. It first appeared in Georgia in 2002, and has spread around the Southeast, mostly in redbay laurel trees. Avocados are in the same family, and once infected, the tree can be dead within six weeks.

Avocados are Florida’s secondbiggest fruit crop, behind citrus. California produces nearly 90 per cent of the nation’s avocado crop and it’s worth about $400 million annually — which is why it’s essential to stop laurel wilt’s spread.

On a recent day, scientists from Florida International University and the University of Florida, along with the owners of a drone company and a canine detection team, converged on a ranch under a blistering sun. Part of the challenge is that by the time a farmer sees evidence of the disease — hairlike prongs sticking out from trunks and limbs that are really the sawdust residue left behind by the burrowing beetle — it’s too late to save the tree. But if farmers can catch the disease in its infancy, before symptoms emerge, there’s hope of saving the tree with fungicide.

The first step is finding which part of the grove is infected. That’s where the drone comes in. According to Ty Rozier, owner of Elevated Horizons, the vehicle carries a thermal digital imaging camera as it soars over the groves. Researchers analyze the images and videos to find the stressed trees. Then, they send in the dogs.

“It’s almost like cancer detection,” said Ken Furton, a professor of chemistry. “Multiple dogs have alerted on (infected) trees that show no signs of infection.”

The dogs are two Belgian Malinois and two shelter dogs. Once the dogs hone in on an infected tree, farmers can remove and burn it, then inject nearby trees with fungicide in hopes of saving them or staving off the disease.