Drones and trained dogs could be the answer to stopping an invasive fungus from attacking avocado crops, an industry in South Florida that brings in more than $50 million a year and positions the region as the country’s second largest supplier of the fruit.

The redbay ambrosia beetle transmits the Raffaelea lauricola fungus that devastates avocado plantations, with more than 90 percent of the trees dying within six months after they are infected.

The beetle the size of a grain of rice is a fungus carrier, and when the tree detects it, its own vascular system tries to defend itself by creating walls in its system to isolate it, but which in turn blocks the flow of nutrients and water in the wood.

“This beetle and the fungus it transports have decimated trees of the Lauraceae family in woods from the Carolinas to Florida, and are also found in Mississippi. Given that most wild laurels in Florida have died out, the beetle has begun to attack avocado trees,” Dr. DeEtta Kay Mills, a professor in the Department of Biological Sciences at Florida International University, told Efe.

Avocados are a big cash crop in South Florida and the loss of these plantations could signify replacement costs of more than $400 million, Mills said, adding that the industry employs unskilled laborers who earn a minimum wage.

“Families that depend on avocado crops will really be hurt if they lose these jobs in an area hit hard by recession and the slump in the housing market,” she said.

To find a solution to the problem, FIU researchers with the support of the Florida Department of Agriculture have launched an early detection program using specially trained dogs to locate the fungus in apparently healthy trees. They also use drones.

“The canines have been trained to detect the odor of infection in the wood. Root samples are taken and tested for the DNA of the fungus to prove whether the trees are infected or not,” the doctor said.

Drones are used to find trees that show visible signs of infection with instruments that digitize thermal images.

“Drones allow us to cover more territory, identify the thermal changes in trees that are infected, which afterwards allows us to send out the dogs to specific points to confirm the infection using DNA-analysis technologies,” the researcher said.

Mills stressed that early detection makes it possible to employ rapid procedures to cure the trees and keep the disease from spreading.

“The loss of 6,000 avocado trees is already taking its toll in South Florida’s agricultural area,” Mills said.

The researcher said that, according to predictions, the 2015-2016 season could see the disease spreading to the point that it becomes uncontrollable if measures are not taken such as early detection, the elimination of trees and the use of preventive fungicides.

Source - http://news.co.cr/