Leading The Greening Fight

From left to right. Frank Giles, editor of Florida Grower, Jim Snively, 2008 Citrus Achievement Award winner, Keith Griffith, North American market development manager for Chemtura.

Many people may not have recognized it back then, but Florida’s citrus world changed in October 2005. When the first case of citrus greening was confirmed that month, Jim Snively knew right away the challenges that lie ahead.

Only weeks after the first find, Southern Gardens, where Snively serves as vice president of grove operations, confirmed the second case of greening in the state. Immediately he and his team sprung into action.

“We were fortunate that we had some relationships with Brazilian growers who had been dealing with greening for a year or so,” says Snively. “Our first reaction was to call them and find out what they were doing and get a plan into place.”
That first day of confirmation on Oct. 11, 2005 set Snively and Southern Gardens on a course of action against what he calls one of the greatest threats ever to Florida’s citrus industry. The battle has seen Southern Gardens remove more than 300,000 infected trees (approximately 2,000 acres) and add $3 million to its annual pest control cost.

“Recently, we had a leading scientist from a panel organized by the National Academy of Sciences tell a group of us that greening is one of the worst agricultural problems he has ever seen because it is spread by a vector (psyllid) and the long and unknown latency period in the trees,” says Snively.

Confident But Cautious
Despite the challenge greening presents, Snively is confident in the future of Florida citrus. He says science will catch up to the problem, maybe in the form of a resistant tree. In the meantime, growers must follow an aggressive program to mitigate the disease.

The program Snively and his team at Southern Gardens put into place has been a model for many other growers in the industry. They even invested in a PCR testing lab, which they have opened up to other citrus producers in the state free of charge to help the industry keep track of the disease’s spread.

“We are providing lab testing for greening to growers at no costs,” he says. “Why? We have a processing facility with a 20-million-box capacity. We opened the lab in hopes that others would get onto a program like ours. The way we see it is our processing facility is going to benefit as long as there are live trees around.”
According to last year’s winner of the Citrus Achievement Award, Dan Richey, Snively’s strong voice regarding the importance of addressing greening has been felt industrywide.

“Jim’s unselfish and tireless efforts on behalf of the citrus industry these past couple of years has been second to none,” says Richey. “With folks like Jim, we know this industry is in great hands and no doubt will survive these short-term challenges. The industry owes him a debt of gratitude for all he does.”

Plan Of Attack
“The first thing the Brazilians told us we had to do was inspect our groves to better understand where we stood with greening,” says Snively. “Then we had to remove infected trees and control the psyllid. Finally, they stressed the importance of having clean nursery stock and being aggressive in protecting young trees from the psyllid.”
Snively wanted to get the first inspection done as quickly as possible, so they checked every other row on bed tops and checked more closely in blocks where infected trees were identified.

“It took us a while to get the people, equipment, and logistics in place to inspect groves,” he says. “It took about six months to get across all the groves for the first time, and when we were done, we had only found 2,000 infected trees. We were like, ‘wow, maybe this is not such a big problem.’”

But subsequent and more thorough inspections unveiled a more serious issue. Up until the fifth grove inspection, the disease seemed to stay at bay with less than 2% of trees showing positive.

“I double checked my numbers before the 5th inspection and we had a cumulative infection rate of 3.9% across all of our groves,” he says. “At the completion of the fifth inspection, we had a cumulative rate of 8.7% across all of our groves. Today, Southern Gardens is at 12% cumulative for all the groves.

“If we can get down to 3% of trees lost to greening with another 2% to 3% lost to other things, we can live with that, but we have to get there first. This raises the question of when do we know where we are at in terms of our control program. We really didn’t get our psyllid control program going until the first of 2006 and finally saw their populations drop in June of that year. Brazil tells us it takes three years from when you reduce psyllid populations until you see what effect you are having on greening numbers. That would put us toward the end of 2009, and who knows, we may get up to 20% to 25% infected trees before the percentages start to drop.”

Squashing Psyllids
Current research suggests that about 30% of psyllids are positive for greening. Snively stresses the importance of controlling the vector in stemming the spread of the disease. He adds he is fortunate to have Tim Gast on staff as a citrus horticulturist to help develop their scouting and spray programs. Gast has prior experience with greening from his days working in China’s citrus groves.

“Tim and I kind of play off each other on how much progress we are making with our greening program,” he says. “When we started the program, we would go into our groves and psyllids would be everywhere. Today, when we have a flush, you really have to search to find any psyllids. We can go for periods of two months without even seeing one. Tim and I agree we have to be making some difference by reducing their population by that much.”

Snively says they are working to develop a method for testing psyllids for greening using their PCR lab machine.

“We need to know what percentage of psyllids is positive in our groves,” he says. “We may find certain times when they are more active than others, allowing us to adjust our spray program to be more effective and efficient.”

Leading By Example
A key characteristic of Citrus Achievement Award winners is leadership by example, which Snively embodies in his tireless efforts to educate the industry on the importance of implementing a greening program and calling the industry to action.
“Even if I had zero greening in my groves today, I would be doing what I am doing right now and hope my neighbors would be doing it too, because at the very least, the infection source would be less.”

The growers who don’t take these steps not only are doing a disservice to their neighbors, they also underestimate the speed at which greening can devastate a grove. Snively relates a story of a meeting Southern Gardens hosted to show other growers their program to keep greening in check. One of the growers who attended the meeting didn’t take action. Within two years, greening had taken over his groves.
“He finally had the grove inspected,” he says. “One block came back 50% to 60% positive for greening and another block was in the high 80% range. In addition, the grower reported that about 30% of his yield had been lost that year. That all happened in the span of two years.”

Science On The Scene
According to Snively, the scouting and control program he strongly advocates now is a short-term solution. How long is short term? He says probably 20 years, while the long-term answers are uncovered by scientists.

With a team from the National Academy of Sciences and some of USDA’s top scientists on the greening case, along with the other researchers who have already dedicated their expertise, Snively is optimistic about the future.

“We have some of the smartest folks in the world working on this problem now,” he says. “I grew up in this industry and this is where my heart is. We are taking all these steps to control greening because we want to still be in citrus production when science finally does catch up to the problem.”