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| 8-18-09
Lake Wales citrus grower Deeley Hunt didn't feel relief from a recent survey showing a low infection rate for the fatal citrus greening disease in the 2007-08 season.
"I don't think you can say it's good news. We've found way more greening this year than we did in 2007-08," said Hunt, the head of caretaking operations for his family's citrus business, Hunt Bros. Inc., which has about 5,600 grove acres in Florida.
"The problem is it spreads," he said Tuesday. "In five years, it will be a struggle to grow citrus in Florida."
Hunt was commenting on a survey of Florida orange growers done by Allen Morris, an economist at the University of Florida's Citrus Research and Education Center in Lake Alfred, with a team of state and federal officials. The survey released Tuesday asked growers to report their losses to greening and citrus canker, another bacterial disease that is not fatal but does weaken trees.
Based on 949 growers responding from across the state, the study estimated just more than 1 million orange trees with new greening infections, or 1.6 percent of the state's 65.8 million orange trees. The survey covered only the period from Sept. 1, 2007, to Aug. 31, 2008.
The greening infection rate is comparable to those reported in Brazil during its 2007-08 citrus season, Morris said.
Kuang-Ren Chung, an associate professor of plant pathology at the Citrus Research Center, said the infection rate was low but still "scary."
Chung agreed with Hunt that Florida growers cannot minimize the greening threat because the disease has spread to every corner of Florida's citrus growing region since the disease's initial discovery in September 2005 in Homestead. It first appeared two years later in Polk County, the state's largest annual citrus producer.
"It still threatens the existence of citrus in Florida," Chung said. "Everybody has a risk right now. You can't walk away anymore."
Ron Brlansky, also a plant pathologist at the Lake Alfred center, agreed the 1.6 percent infection rate was low but not necessarily good news.
"I don't think any grower wants to lose even 1 percent of his trees," he said.
Brlansky cited a case study from Evans Properties Inc., one of the state's five largest growers based in Vero Beach. It can be found at the center's Web site: www.crec.ifas.ufl.edu/extension/greening/GrowerExperiences.htm
Evans reported finding a 1.7 percent infection rate among 720,961 trees when it completed its first greening survey in October 2007. Even after taking recommended anti-greening measures for the following year, the infection rate rose to 6.8 percent.
"If these numbers were to double each year and the company did nothing to manage the disease, then there will be no viable groves by the fifth year," the company reported.
The study did not get enough responses to report statistically significant results on greening infections by county or region, Morris said.
In general, he said, "as you go north of the Indian River area and southwest Florida, the incidents of greening infection dramatically declines."
Growers reported they survey their groves for greening symptoms twice a year on average, or half the recommended level of four surveys per year, the report said. Many growers in high infection areas reported doing four surveys.
Growers reported spraying for psyllids, the insect host of the greening bacteria and the primary cause of its spread, four times a year on average. Scientists recommend spraying four to six times a year, depending upon the area's level of psyllid infestation.
The survey also found a 15 percent canker infection rate for the 2007-08 period. Canker has been in Florida since 1995.
Read the original article from The Ledger.