We Will Survive

The USDA Horticultural Research Lab in Ft. Pierce has marshaled its resources in recent years to help in the battle against citrus greening (HLB). While the disease was first officially identified in Florida in 2005, Dr. Tim Gottwald, plant pathology research leader at the lab, has been studying the disease for many years in countries where it is present including India, China, South Africa, and Brazil.

When greening was confirmed in Florida, Gottwald predicted, based on his previous knowledge, infected trees could die within three to four years and that the disease would spread across the state in about the same timeframe.

According to Dr. Calvin Arnold, laboratory director in Ft. Pierce, Gottwald’s predictions have unfortunately turned out to be true. He says because of the threat posed by citrus greening, the research facility redirected resources toward greening study.
“When HLB was confirmed, we looked very closely at our research with encouragement from growers and industry,” he says. “We began moving resources from programs, especially from CVT and diaprepes root weevil to HLB research. Since then our HLB research has expanded rapidly and we remain heavily committed to the program.”

Approximately 60% of all the research conducted at the Ft. Pierce facility is focused on citrus and 75% of the citrus research is focused on greening. There are about 40 active projects at the lab focused on the disease, each with multiple experiments under way in the lab, growth chambers, or in the field. According to Arnold, roughly half of the scientists at the lab are working on greening research.

Signs Of Promise

While growers should take hope from all the work being done by researchers at USDA, Arnold notes a couple of projects show signs of promise. In 2006, Andrew Fire and Craig Mello shared the Nobel Prize in Physiology or Medicine for their work on RNA interference or RNAi. Since then, much of modern medical research has focused on using RNAi techniques that promise major breakthrough in the treatment of human illness.
Researchers at USDA are using the same technology in hopes of targeting the psyllid. Wayne Hunter is conducting the RNAi research which aims to disrupt psyllids. He says the approach is very attractive because it is a natural approach that would only target the psyllid, leaving beneficial insects in the groves to do their work.
 
While the research is highly technical, RNAi basically disrupts the genetic code of the psyllid. Ideally, the compound could be sprayed on trees and translocate throughout, providing residual control of psyllids for a few months.
 
While this is emerging technology, it has been done before. Hunter was involved with the development of an RNAi product used in honeybee colonies. Based on RNAi technology, the product called Remebee is formulated to silence Israeli acute paralysis virus. It is delivered in feed and sustains colony health in the presence of the virus. The product is currently commercially available to bee growers, giving rise to hope that RNAi techniques can be applied to psyllid control.

Map It Out

To deploy the RNAi technology, scientists will need to map out the full DNA genome of the citrus psyllid, which they are closing in on now.
“We are within a couple of months of identifying the complete genetic sequence of the psyllid,” says Arnold. “Dr. Yong-Ping Duan led a team of researchers here in Ft. Pierce to map out the genome of the HLB bacteria a couple of years ago. These are huge breakthroughs in the science of fighting greening.”
 
With the psyllid genome mapped, researchers can target specific genes in the psyllid to help control the pest. “If it is a good gene, we can make it more active,” says Arnold. “If it is a bad gene, we can silence it.”

Antibiotics Approach

There are many antibiotics available used in human medicine and in other crops. Some of those may be effective against the bacteria (Candidatus Liberibacter), which causes greening.
 
Currently, the Citrus Research and Development Foundation is hosting a competition for research projects that are seeking antibiotics that might have an impact on greening.
 
“We are very excited about the potential of antibiotics in fighting HLB,” says Arnold. “Of course, we know a lot about penicillin and other common antibiotics, but there are new types that might be effective against the bacteria. The key is finding one that will move readily through the tree.”
There are a number of antibiotics — when placed in direct contact with the HLB bacteria — that will kill it. The challenge is finding an antibiotic that will move through the phloem tissue of trees and access the HLB bacteria in all areas where it is present.

Loud And Clear

“We realize the industry has its back against the wall in this fight with HLB,” says Arnold. “So we are very committed in the research community to find solutions. I have been involved in ag research for many years and have never been involved in a project where so many scientists are working together and are so passionate. We’ve heard the growers loud and clear: this is not business as usual.”
 
Arnold says short-term breakthroughs to target the psyllid and nutritional programs will help growers hang in there until more permanent milestones will be marked in the area of genetics and disease resistance. “This is a very resilient industry,” he says. “We’ve survived freezes, hurricanes, and canker eradication. The industry will survive HLB. It will be different, but we will survive.”

Leave a Reply

Featured Stories
Tom Stenzel, President and CEO, United Fresh Produce Association, talks with members of the French Delegation, detailing United Fresh’s work to increase children’s access to fresh fruits and vegetables at schools across the country.
Farm Management
May 30, 2016
‘Fresh Attitude Week’ Promotes Variety In Fruits And Vegetables In School Meals
The largest U.S. urban school districts host weeklong celebration, Fresh Attitude Week, which highlights fresh fruits and vegetables and other nutrition education activities. Read More
The team at Lamont Fruit Farms  takes a progressive approach to staffing. “Give people the opportunity to excel,” Jose Iniguez says. “If our employees want it, we give them the chance.”
Apples & Pears
May 30, 2016
Is Your Orchard Ready For Mechanization?
Automation is on the horizon, and it would be beneficial if you’re planting with that in mind. Read More
high denisty apple orchard washington
Apples & Pears
May 29, 2016
Orchard Systems Matter With Mechanization
“It takes years to turn orchards from a big, wild 3-D tree to a narrow canopy — a lot of Read More
upclose of Israeli apple harvester
Fruits
May 28, 2016
Orchard Automation Is On The Horizon
Industry experts say the advent of fully automated orchard tasks are on the cusp of happening — with a few companies leading the automotive harvest charge. Read More
IFTA Washington Day3 6
Apples & Pears
May 27, 2016
Washington Apple Commission Elects New Leaders
The commission board also approved the export budget of $7.7 million for the upcoming 2016-17 crop, based on a crop of 135 million cartons. Read More
As this view of the San Luis Reservoir shows, California's drought is far from over. (Photo credit: David Eddy)
Fruits
May 27, 2016
California Drought Far From Over For
To preserve orchards and vineyards, growers are expected to fallow up to 350,000 acres of corn, wheat, cotton and alfalfa. Read More
These workers use a platform from Automated Ag for hand thinning. (Photo credit: Christina Herrick)
Apples & Pears
May 27, 2016
How Best To Integrate Man And Machine
If you want to implement labor-saving mechanization, you should start the conversation with the end user – your employees. Read More
Crowd protesting GMOs stock image FEATURE
Farm Marketing
May 27, 2016
Consumers Don’t Really Know What GMO Means, New Study Finds
A study from the University of Florida confirms what many farm marketers suspected: Consumers don't understand genetically modified food and organisms as well as they think they do. Read More
Asian citrus psyllid closeup
Insect & Disease Update
May 27, 2016
Alabama Agriculture Department To Conduct Citrus Psyllid Survey
Currently, Alabama is the only citrus-growing state that has not yet detected citrus greening. Read More
Ready To Spring
Insect Control
May 26, 2016
Temperature, Location Key To Predicting Leaffooted Bug Pressure
This year, leaffooted bugs are expected to be a significant problem in almonds and pistachios, but watching temperature and the Read More
The Latest
Farm Management
May 30, 2016
‘Fresh Attitude Week’ Promot…
The largest U.S. urban school districts host weeklong celebration, Fresh Attitude Week, which highlights fresh fruits and vegetables and other nutrition education activities. Read More
Apples & Pears
May 30, 2016
Is Your Orchard Ready For Mechanization?
Automation is on the horizon, and it would be beneficial if you’re planting with that in mind. Read More
Apples & Pears
May 29, 2016
Orchard Systems Matter With Mechanizatio…
“It takes years to turn orchards from a big, wild 3-D tree to a narrow canopy — a lot of Read More
Fruits
May 28, 2016
Orchard Automation Is On The Horizon
Industry experts say the advent of fully automated orchard tasks are on the cusp of happening — with a few companies leading the automotive harvest charge. Read More
Apples & Pears
May 27, 2016
Washington Apple Commission Elects New L…
The commission board also approved the export budget of $7.7 million for the upcoming 2016-17 crop, based on a crop of 135 million cartons. Read More
Fruits
May 27, 2016
California Drought Far From Over For
To preserve orchards and vineyards, growers are expected to fallow up to 350,000 acres of corn, wheat, cotton and alfalfa. Read More
Apples & Pears
May 27, 2016
How Best To Integrate Man And Machine
If you want to implement labor-saving mechanization, you should start the conversation with the end user – your employees. Read More
Farm Marketing
May 27, 2016
Consumers Don’t Really Know What G…
A study from the University of Florida confirms what many farm marketers suspected: Consumers don't understand genetically modified food and organisms as well as they think they do. Read More
Insect & Disease Update
May 27, 2016
Alabama Agriculture Department To Conduc…
Currently, Alabama is the only citrus-growing state that has not yet detected citrus greening. Read More
Insect Control
May 26, 2016
Temperature, Location Key To Predicting …
This year, leaffooted bugs are expected to be a significant problem in almonds and pistachios, but watching temperature and the Read More
Fruits
May 26, 2016
Consider Fumigating For Nematodes Before…
Stone fruit and almond growers looking to replant orchards might want to invest in soil samples to assess nematode populations Read More
Farm Marketing
May 26, 2016
Who Grows Organically — And Who Doesn…
We surveyed 816 fruit and vegetable growers and found that farm marketers and vegetable growers are much more likely than their peers to embrace the practice. Read More
Farm Marketing
May 26, 2016
Farm Dinners: Your Most Powerful Marketi…
Farm dinners are a hassle. They’re expensive. And ridiculously effective. Read More
Cucurbits
May 25, 2016
Whitefly Threat Has Florida Growers On H…
Researchers, state agencies working together to prevent a potential outbreak. Read More
Crop Protection
May 25, 2016
More Apps Help Growers Identify Insects …
Berries, apples, pears, and cherries now rolled into new app series from Clemson University. Read More
Citrus
May 25, 2016
Monsanto Says Bayer Bid ‘Financially Ina…
Proposal cited as undervalued, not able to address financial, regulatory risks. Read More
Stone Fruit
May 25, 2016
Researchers Study Why Cherry Cracking Af…
German researchers studied how water uptake and fruit skin determined a cultivar’s susceptibility to cherry cracking. Read More
Farm Management
May 25, 2016
Report Highlights Benefits Of Trans-Paci…
National Potato Council says report from the International Trade Commission offers the benefits the free trade agreement would offer growers. Read More
[gravityform id="62" title="false" description="false"]