What is in this article?:
- It is only a matter of time until many more California trees are infected with citrus greening disease and a full-scale war breaks out to contain the spread.
- Citrus greening cost Florida growers $331 million annually from 2006 through 2011. An estimated 8,257 jobs were lost in Florida due to greening during that period.
- A solution may hinge on genetically modified citrus trees, which would be a challenge to educate consumers on due to the highly charged anti-GMO atmosphere.
Southern Gardens Citrus’ processing plant in Clewiston, Fla., processes more juice in a day, 25,000 tons, than all of California in a year. It produces more than 50 percent of the private label not-from-concentrate orange juice in America. It processes 900,000 tons of oranges annually into juice. Florida’s citrus industry is primarily a juice business, while California is mostly fresh market.
Owned by U.S. Sugar, Southern Gardens owns and/or manages 16,500 net acres of citrus groves in Southern Hendry County. These groves contain 1.8 million trees.
HLB is the “worst challenge we have ever faced,” greater than the citrus canker that took out 4,500 acres of the 32,000 acres Southern Gardens was farming before the canker came in.
Cress said four things are grown in southern Florida: “Citrus, sugar cane, cattle and alligators.” Southern Gardens must continue to grow citrus. It has no other farming options.
“We had to find a solution,” after HLB was found on the property in 2005.
The first step was to identify diseased trees and destroy them quickly. That has been a $1 million per year expense.
Infected groves quickly disappeared to be replanted. Older trees take longer to die. “I have seen four-year-old trees literally die before my eyes,” he said. Typically, it takes two to two and a half years for an HLB-infected tree to die. “It looks like a Charlie Brown Christmas tree,” he added.
One of the approaches used to battle back has been nutritional. Growers heavily fertilized to keep diseased trees alive. This is expensive and does not save trees in the long run, said Cress. It just prolongs productivity of infected fruit.
Cress said this approach to counter HLB has improved the understanding of the nutritional needs of citrus. “No nutritional program has ever cured a disease.” Besides, “There is no hard data to support,” that the nutritional approach is winning the battle, even temporarily.
The yield per tree is less than healthy trees, even with the nutritional approach. This is a disease effect, not inadequate fertility. These trees also do not handle stress well.
He adds this may keep the tree green, but the fruit is tainted. Fruit from an HLB tree is very bad tasting, he says.
Overall, the psyllid and the disease have increased Florida growing costs by 50 percent.
Typically, most Florida growers aggressively treat to control the psyllid to protect the new plant — after taking out an infected tree.
Pesticides to control the disease vector are not economical in the long run, and there are environmental challenges as well as spraying to kill the psyllid. Resistance is another issue after continually treating with a limited number of registered pesticides.
Another approach is to take out infected groves and replant with high density groves, hoping to make money quickly before trees die. A normal planting is about 145 trees per acre. Southern Garden has one trial of 600 trees per acre. In Brazil growers are moving far away from infected areas and planting densities of 200 to 300 trees per acre, figuring to get 15 to 16 years of high production before infections kill trees.