BONITA SPRINGS, Fla. — Cooperative efforts among growers to control the Asian citrus psyllid in 38 regions of Florida are beginning to pay dividends with lower populations of the pests, which spread citrus greening disease.
The theory behind citrus health management areas, or CHMAs, is if you reduce psyllid populations, you reduce the potential for them to spread huanglongbing, also known as HLB and citrus greening disease.
“We have to be encouraged,” said Mike Sparks, president and chief executive officer of Lakeland-based Florida Citrus Mutual.
Nevertheless, he said that many of the control measures, including CHMAs, are stopgap as the industry seeks long-term, sustainable solutions, such as HLB-resistant trees.
Part of Sparks’ job is to educate consumers and buyers that the Florida citrus industry continues to be viable, despite HLB and Asian citrus psyllids.
“We still have 550,000 productive acres and produce nearly 1 billion gallons of orange juice,” he said.
That’s down from 1.3 billion single-strength equivalent gallons only 10 years ago, according to U.S. Department of Agriculture figures.
Although HLB can be blamed for some of that reduction, Sparks said hurricanes, urban development and citrus canker also took out groves.
Sam Jones, Eastern citrus division operations manager for Duda Farm Fresh Foods, LaBelle, said educating buyers about fresh citrus availability is an ongoing effort.
“When we meet the customers face to face, we do take the opportunity to explain the challenges, so they understand how that may or may not impact supplies,” Jones said.
He said having a personal relationship with customers is paramount to managing public perception of the disease.
“We put a lot of stock into that relationship with our customers,” he said. “There are often times we will invite the customers to Florida to spend time with us in the groves.”
Strength in numbers
CHMAs are voluntary efforts among growers within production regions to coordinate citrus pest control measures.
Although growers form the CHMAs, they typically seek input from University of Florida citrus experts about what to spray and when. The theory behind the management areas is if everybody sprays at one time, Asian citrus psyllids can’t seek refuge in nearby untreated groves.
The USDA and the Florida Division of Plant Industry in August 2011 began scouting about 25% of groves for psyllids every three weeks.
They report their findings to CHMAs to determine when to treat.
It’s paying off, said Michael Rogers, an entomologist at the Citrus Research and Education Center, Lake Alfred.
He presented a series of maps at the Florida Citrus Industry Annual Conference June 14, showing CHMAs and color-coded psyllid populations.
As the months progressed from August 2011, the populations throughout the citrus belt dropped significantly.
“This is showing that the efforts going on are having an impact on psyllid populations in the state,” Rogers said. “You can’t just attribute it to winter and cold weather.”
Quite the contrary, he said. The 2011-12 winter was warmer than normal so you’d expect higher psyllid numbers, if anything.
As growers quit spraying in March and April to protect bees during bloom, the maps showed psyllid numbers rebounded, but not to the numbers they were when monitoring first started in 2011.
Rogers also pointed out that abandoned groves, which go untreated and can harbor psyllid populations, can cause hotspots in otherwise vigilant CHMAs.