Courtesy Agricultural Research ServicePlant pathologist Yongpin Duan (in orange) and colleagues believe that heat can be used to treat citrus greening-infected citrus trees.Researchers are turning up the heat on citrus greening.
U.S. Department of Agriculture scientists in Fort Pierce Fla., have found that treating potted citrus plants in plastic growth chambers can rid the plants of citrus greening symptoms, according to a news release.
The group, led by plant pathologist Yongping Duan, subjected 2.5-year-old container-grown seedlings to varying temperatures for two to 10 days.
Infections were measured a week before heat treatments, then 30 days, 60 days and 270 days afterward.
The results showed that exposing the seedlings to at least 48 hours of temperatures of 104-107 degrees significantly reduced and often eliminated huanglongbing, or HLB, infection.
Monitoring showed the effects can last for up to two years.
Another trial looked at encasing infected trees in opaque plastic tents to heat them up for about a week.
Once the tents were removed, the top 10-12 inches of the tree tops were pruned to remove the part damaged by the heat.
Preliminary results showed that the solar heat triggered disease remission and prolonged the trees' productivity.
The treatments work best in nurseries and greenhouses, where constant temperature can be maintained and infection is in the early stages and hasn't yet reached plant roots.
The tents could be an option to growers with infected trees in groves, according to the release.