Citrus greening disease has caused a 75% decline in Florida's citrus industry. Dogs might be our last hope.

By Meghan Overdeep
January 16, 2020

With their crops under attack from an invisible assailant, some Florida citrus farmers are fighting back with four paws and wet noses.

The Washington Post reports that in the 15 years since it first reared its ugly head, Huanglongbing (HLB), a bacterium that prevents fruit from ripening, has caused a 75% decline in the state’s $9 billion citrus industry and pushed roughly 5,000 growers out of business. In 2018, the Florida Department of Citrus called it “the biggest threat the Florida Citrus industry has ever faced.”

HLB, also known as "citrus greening disease," is spread by a tiny insect called the Asian Citrus Psyllid. The incurable disease turns fruit bitter and eventually kills the tree. Visual symptoms can take months, even years to appear, giving the disease time to spread rapidly and destroy entire groves.

That’s where the dogs come in.

Post reporter Duncan Strauss recently tagged along as a springer spaniel named Bello went to work on Andy Jackson’s 25-acre grove in Perry. He watched as she ran through the rows of trees, sitting when she detected the disease.

Bello and her handler work for F1K9, a Florida firm that trains and provides dogs for detecting everything from explosives to agricultural disease.

According to the USDA, dogs can sniff out HLB with 99% accuracy within two to three weeks of inoculation. All 19 dogs with this expertise are owned by F1K9.  These superstar sniffers have been deployed in Florida and California.

The first time Jackson hired F1K9 to come to his grove in November 2010, the dogs detected HLB in 79 trees. After a stiff drink, he said he removed every infected tree. This time around the dogs flagged about 25 diseased trees. Those will have to go too.

Orange Grove in Orlando
Credit: Adam Jones/Getty Images

While experts say dogs might be too little too late to save the citrus industry, they do offer the fastest and most accurate diagnosis available.

“The dogs are detecting it months to years earlier than the two prevalent methodologies,” Tim R. Gottwald, the plant epidemiologist with the USDA who pioneered the use of dogs for plant disease detection, told the Post.

As for Jackson, he said it’s likely he’ll hire F1K9 again.

“It’s another tool in the drawer.”