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
Late blight shown in a tomato
Disease Control
January 19, 2017
Clues Found to Block Late Blight’s Blitz on Potatoes, Tomatoes
With food security at stake, breakthrough in genetic research could help prevent more strains of the deadly pathogen from entering the U.S. Read More
Grapes
January 19, 2017
U.S. Challenges Canadian Trade Measures Allege Discrimination against U.S. Wine
Trade enforcement action challenges British Columbia regulations that unfairly exclude U.S. wine from grocery store shelves. Read More
Sonny Perdue
Citrus
January 19, 2017
Trump Taps Sonny Perdue for Secretary of Agriculture Position
Ag leaders applaud pick to head up USDA. Read More
Citrus
January 19, 2017
New York Representatives Introduce Bill to Move H-2A from Department of Labor to Department of Agriculture
Legislators say the move aligns the program in the department to better fit the needs of agriculture businesses. Read More
Freeze protected peach trees in Florida
Citrus
January 19, 2017
New Technology Could Take Weather Intel to the Extreme for Farmers
Scientists aiming to make difficult climate-based production decisions easier for growers. Read More
Fruits
January 19, 2017
Funding Available to Improve Ag, Food Sciences Facilities at Land Grant Schools
USDA announces $18.9 million for ag education at 1890s land-grant colleges and universities. Read More
the sunset on a hot day
Citrus
January 18, 2017
NASA, NOAA Concur 2016 Was World’s Warmest Year on Record
For the third time in three years, the bar is raised on surface temperature statistics. Read More
Vegetables
January 18, 2017
Southwest Growers Are Best Prepared for Succession
Almost half of all Southwest operations are grooming its next generation of leadership — an alarmingly low statistic, but one that is the highest in the country, according to American Vegetable Grower magazine's 2017 State of the Vegetable Industry survey. Read More
Vegetables
January 18, 2017
The Midwest Is Nurturing the Next Generation of Operations
It has more young businesses, percentage wise, than other regions: 39% of responding businesses are less than 10 years old. Read More
Vegetables
January 18, 2017
The West Had the Highest Increase in U.S. Vegetable Production in 2016
The West not only has the largest vegetable operations, it also saw the strongest growth in production in the U.S., according to American Vegetable Grower magazine's 2017 State of the Vegetable Industry survey. Read More
The Latest
Disease Control
January 19, 2017
Clues Found to Block Late Blight’s…
With food security at stake, breakthrough in genetic research could help prevent more strains of the deadly pathogen from entering the U.S. Read More
Grapes
January 19, 2017
U.S. Challenges Canadian Trade Measures …
Trade enforcement action challenges British Columbia regulations that unfairly exclude U.S. wine from grocery store shelves. Read More
Citrus
January 19, 2017
Trump Taps Sonny Perdue for Secretary of…
Ag leaders applaud pick to head up USDA. Read More
Citrus
January 19, 2017
New York Representatives Introduce Bill …
Legislators say the move aligns the program in the department to better fit the needs of agriculture businesses. Read More
Citrus
January 19, 2017
New Technology Could Take Weather Intel …
Scientists aiming to make difficult climate-based production decisions easier for growers. Read More
Fruits
January 19, 2017
Funding Available to Improve Ag, Food Sc…
USDA announces $18.9 million for ag education at 1890s land-grant colleges and universities. Read More
Citrus
January 18, 2017
NASA, NOAA Concur 2016 Was World’s Warme…
For the third time in three years, the bar is raised on surface temperature statistics. Read More
Vegetables
January 18, 2017
Southwest Growers Are Best Prepared for …
Almost half of all Southwest operations are grooming its next generation of leadership — an alarmingly low statistic, but one that is the highest in the country, according to American Vegetable Grower magazine's 2017 State of the Vegetable Industry survey. Read More
Vegetables
January 18, 2017
The Midwest Is Nurturing the Next Genera…
It has more young businesses, percentage wise, than other regions: 39% of responding businesses are less than 10 years old. Read More
Vegetables
January 18, 2017
The West Had the Highest Increase in U.S…
The West not only has the largest vegetable operations, it also saw the strongest growth in production in the U.S., according to American Vegetable Grower magazine's 2017 State of the Vegetable Industry survey. Read More
Vegetables
January 18, 2017
One in Five Southeast Growers Use H-2A
American Vegetable Grower magazine's 2017 State of the Vegetable Industry survey revealed quite a few qualities about the Southeast that may surprise you, including it being more likely to use H-2A than other regions. Read More
Vegetables
January 18, 2017
The 2016 Drought Is Having a Big Impact …
The 2017 State of the Vegetable Industry gave us insight into each region of the U.S. Sifting through the data, we flagged those responses that were markedly higher or lower than other regions. Responses from Northeast growers made it clear that the 2016 drought had taken a toll. Read More
GenNext Growers
January 18, 2017
$858,000 in Grants to Encourage Careers …
Funding to invest in programs that educate, promote science in the classroom. Read More
Vegetables
January 18, 2017
Mississippi Greenhouse Tomato Short Cour…
Online registration is now open for the Greenhouse Tomato Short Course, which takes place March 7-8 in Raymond, MS. This Read More
Fruits
January 18, 2017
Spotted Wing Drosophila Control the Topi…
Research updates, recommendations to be presented on devastating pest. Read More
Varieties & Rootstocks
January 18, 2017
5 Florida Citrus Nursery Trends Worth Wa…
Gleanings from recent grower gatherings expose opportunities and possibilities in new variety development and management. Read More
GenNext Growers
January 17, 2017
9 Financial Resolutions to Boost Your Fa…
If a goal for the new year includes increasing profitability, there are ways you can better manage your business. Read More
Farm Management
January 17, 2017
Will Big Data Yield Big Returns for Farm…
Modern tools of hort tech are ripe to inspire the next generation of productivity and profitability. Read More