Courtesy University of FloridaA promising rootstock (vigorous tree) appears to more tolerant of citrus greening than some commercial rootstocks in this grapefruit trial.University of Florida researchers have found 16 citrus rootstocks that are less susceptible to citrus greening than some of the commonly used varieties.
Although information on their field performance is limited, the university decided to fast-track their release this summer for larger-scale testing, according to a news release.
The trials could begin as early as March 2014, but it would be another three to five years before the rootstocks were available to growers.
The varieties were developed by Jude Grosser and Fred Gmitter, horticulture professors at the Lake Alfred Citrus Research and Education Center, and by Bill Castle, a horticulture professor emeritus.
“What’s happening is fields are becoming living laboratories now because the greening disease is spreading so quickly,” Grosser said in the release. “Some people have estimated that 70 percent of the trees in the entire state are infected now, and it’s predicted to go up in the 90s in a very short time.”
In some trials, the researchers saw 70 percent infection rates compared with experimental varieties that had only 10 percent to 20 percent rates.
The experimental lines were still producing fruit after four years exposure to the disease.
Citrus greening, also known as huanglongbing or HLB, is a bacterial disease spread by the Asian citrus psyllid. Although it is harmless to humans and other animals, it can weaken and even kill citrus trees.
There is no known cure.