Wise old oak trees may hold an extract that citrus growers can use to protect their fruit trees from the deadliest citrus crop disease the world has known.
The plant disease is called huanglongbing, or HLB, also known by its English name, citrus greening. The disease shows its presence when leaves turn lighter shades of green.
According to University of Florida Institute of Food and Agricultural Science’s (UF/IFAS) officials, HLB is responsible for a 90 percent reduction in the production of Florida’s most valuable crop.
“Research scientists work with a sense of urgency to contain the pathogen and to manage HLB’s impact on our important crop,” said Lorenzo Rossi, assistant professor of plant root biology at the UF/IFAS Indian River Research and Education Center (IRREC), located in Fort Pierce, at the center of the Indian River District. The district is known for its peerless grapefruit quality, where it borders the state’s central east coast, from its northernmost point in Micco, Florida, to its southernmost point in northern Palm Beach County.
For several years, growers across the state have noted that citrus trees that stood under oak tree canopies, or alongside oak trees, are healthy. However, grapefruit trees in a row or two away from the oak trees showed signs of HLB.
Rossi, along with his UF/IFAS and U.S. Department of Agriculture colleagues, works to develop management tactics for production of fruit on trees affected by HLB. Marco Pitino and Robert Shatters with the U.S. Department of Agriculture U.S. Horticultural Agricultural Service in Fort Pierce, along with Rossi, were responsible for design of the experiment and preparation of the manuscript. Liliana Cano, a plant pathologists with UF/IFAS, and Kasie Sturgeon, Christina Dorado and John Manthey were responsible for planning, conducting the experiment, and analysis of data and preparation of the manuscript.
Rossi’s co-workers who study citrus horticulture and hydrology developed water and nutrition management practices. Irrigation and plant nutrition remedies help HLB-affected trees tolerate the disease and extend their production years. Projects funded by the Citrus Research Development Foundation and the USDA are underway.
Rossi and his collaborative research scientists have also been conducting research experiments to test the growers’ field observations, which they found to be a positive option to help the growers manage operations with infected fruit trees. The scientists’ work appears in this month’s issue of Plant Physiology and Biochemistry, an internationally prominent science journal. “Quercus leaf extracts display curative effects against Candidatus Liberibacter asiaticus that restore leaf physiological parameters in HLB-affected citrus trees,” is the publication title. Quercus is Latin for oak; Candidatus Liberibacter asiaticus is the scientific name for the bacterium that causes HLB.
“We found that the application of oak leaf extracts in a greenhouse provides substantial inhibitory effects against the bacterium that causes HLB,” said Rossi.
The researchers’ findings were that citrus leaves treated with oak extracts showed a decrease in the presence of bacteria. Other research results were increased chlorophyll content and plant nutrition. The HLB-affected citrus plants treated with oak leaf extract were better able to uptake nutrients than were the citrus plants treated with only water.
“This study suggests that oak leaf extract will provide a new management treatment program to protect trees that have HLB,” said Rossi. “We will continue to develop a protocol for growers to produce our high-value citrus crops and to reduce the symptoms of HLB on the trees.
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Comments:
October 22, 2021
Thank you for your wonderful comments! Mr. Croxton--please email me at koestoyo@ufl.edu We need a letter of support for an award nomination. Thank you!
October 4, 2021
The fungi are endemic to Central Florida. Dr. Avery has presented on this topic at the Florida Citrus Show for the last two years. Thank you for your encouraging comments. We are excited about the possibilities.
October 4, 2021
Hey there! I could have sworn I've been to this site before but after reading through some of the post I realized it's new to me. Anyways, I'm definitely happy I found it and I'll be bookmarking and checking back frequently!
October 2, 2021
Yes Good work was wondering where the fungi are found and why didn’t we know about it sooner?
October 2, 2021
Hi Rick. Did you want to comment?
October 2, 2021
September 18, 2021
Thanks much, Beth :)
September 17, 2021
Congratulations Martine
September 10, 2021
Thanks for your kind words, colega. I am also rooting for you here!! Tons of love from this beautiful strip of land :)
August 31, 2021
Dr. Minteer has graciously volunteered her time and expertise to work with an aspiring biocontrol researcher at my high school in Florida. I'm so grateful for her investment and congratulate her on this well-deserved recognition. Outstanding Scientist indeed!
August 31, 2021
As a teacher in the high school that Carrie attended, North Pulaski in Jacksonville, AR, let me say how proud all of the former students and teachers are that one of their own is making such a positive impact in the world of biological science! I am also proud to see that Dr. Minteer is actively involved with the young people of today, exposing them to the fascinating world of science. Dr. Carrie Minteer, thank you for making a difference!
August 24, 2021
So grateful to meet people like you, my dear collegue. I'm pretty sure that you'll achieve all your goals. I send you a hug from Valle de Bravo, MX.
August 2, 2021
Great work on trying to keep Florida Citrus Growers economically viable. They have weathered a lot over the last decades. Congrats to UF/IFAS!
November 21, 2020
Hello. We need funding to mass raise the thrips for public distribution. Meanwhile, the insects we did raise are at work on state lands and private ranches
October 10, 2020
How can we get ahold of this thrip? I live in Jacksonville Beach, at the marsh and we have a lot of Brazilian Pepper in City of Jax Beach Cradle Creek Park ( and quite frankly at my house I too, keep hacking at it) The Parks and Rec Dept of Jax Beach would be the contact I guess for this. We did a invasive BP round up one weekend day, but we barely dented the surface of this invasive at Cradle Creek. Please help
September 29, 2020
Hi Koestoyo, Such an amazing article. It's very interesting to read more about how AI can be used in the industry. You would love to see my python course duration and fees in pune site as well. Thanks once again.
September 25, 2020
This is fantastic. I would love to see the flow of the process from original elementary product and subsequent break down and by products. Isn’t Florida rich in phosphorus over by Route 60 in western side of state? Thank you for your brilliance. - Betty Jo Starke..
September 11, 2020
Very insightful! With your wealth of experience,I trust you’ll be a great addition to IRREC
August 12, 2020
Hello Asghar, I have heard from three of our scientists and none of them know about artificial breeding of Telenomus baseola. One of the scientists did suggest that you simply add those keywords to the Google search engine. They feel the answer is somewhere online.
August 7, 2020
I will ask our entomologists and get back to you after they respond.
July 29, 2020
Hello I am an Entomology PhD student at Chamran University of Iran. I am working on artificial breeding of Telenomus baseola. If you have any information about its artificial food send me please.
July 26, 2020
Thank you very much Şahin Hocam! Being your student was a great chance and privilege!
July 22, 2020
We are proud of Egem Özbudak. It was clear to see that he is going to be a scientist in the future when he was our student in high school in Izmir, Turkey.
July 18, 2020
The naturally occurring benefits were on citrus trees growing near the canopy of oak trees. This would say to me that it must be the leaves falling from the oaks to the ground that is giving the citrus trees the oak leaf extract.Therefore, it's brown leaves off the ground that you can use to make your oak leaf tea. I've just been brewing a 5gal. bucket of brown leaves, and watering my trees with the tea once a week. I've had normal looking fruit from my kumquat tree this spring already, so it might be working!
June 16, 2020
Hello, have you seen any changes in your citrus trees?
June 11, 2020
I think this is a real great blog post.Much thanks again. Really Cool.
May 16, 2020
Very good interview with lots of insight. I trust Doc. Tolu will make IRREC proud.
May 14, 2020
Bravo Doc. I know you will be a great addition to IRREC. More of those giant strides!
May 6, 2020
Darlington oak.
May 6, 2020
Mimic nature. I’m trying it myself, I have nothing to go on but instinct. I’m soaking a 5 gallon bucket full of green leaves for two days, then straining and diluting in my 50 gallon sprayer. Haven’t seen much change but it’s only been 3 weeks, once a week.
May 1, 2020
It is better if the oak leaves are green.
May 1, 2020
If I was to make oak leaf tea to spray my citrus, does it matter if the oak leaves are green or dried brown?
February 27, 2020
I have several feral citrus trees growing under oak trees in Palm City. Some may be sour oranges, but based on where my dog used to bury grapefruit I believe some are the Duncan variety. I offer these trees for a UF trial study if that would be useful.
January 28, 2020
Program and release in Brevard County will be at the Extension Service, 3695 lake /dr. Cocoa, on April 9th. Registration for the even will be on Eventbrite.
January 25, 2020
I would be curious about the rest of the layers of plants around the citrus and the varietals of oak.
January 25, 2020
What about integrating the fallen leaves into the soil? &/or using it as mulch?
January 24, 2020
Where would one import such a map please?
January 24, 2020
So is it possibly people are not seeing the forest for the trees on this one. Is it possible that the soil is healthier around oak trees than in a monoculture environment and maybe there is more beneficial bacteria and mychorizae associated with them than a field type environment. ?
January 23, 2020
Maybe this link to the video will work: https://www.youtube.com/watch?v=jtO0Pa6tD8s&t
January 23, 2020
Check out a poductive feral citrus population videotaped in an oak understory and you can see the benefit. Search youtube for the following, "Wild Citrus in a Florida Forest? Why It's a Big Deal."
January 23, 2020
If the extract of the Oak Tree leaves is effective against HLB, It would appear by developing a harvesting method for the leaves could be achieved and have the extract made into a finished spray in quanties at a processing plant like.Bayer chemicalThey being a good place to start. The challenge to Bayer et.al would be to turn this into a systemic treatment which lasts longer than spraying. Bayer et.al have technology in place which they use on the ash boer as an example.If effective systemically on HLB ,is the need to check the toxicology of the extract regarding potential human consumption.is probably required. The toxicology study would be required for sprays as well. Currently existing for other application using systemics on tree can be effective for a year with one application to the base of the tree.The average cost to do an application tree using an application of 1 ounce per 1 inch of circumference of the trunk of the tree should be affordable.
January 22, 2020
Please import 3D map of citrus + oak inter cropping method
January 22, 2020
Would mulching with oak leaves be of any benefit?
January 22, 2020
Could new groves be set up with interplanting of oak and citrus trees? It seems like the citrus trees would have to be resprayed regularly, an expensive process.
November 26, 2019
merci pour les informations
November 9, 2019
Just saw this too late. This is wonderful. Is there a way for me to release in a residential area in Indialantic?
September 12, 2019
Hello Mr. Burchianti. Thrips will be made available to the public in about a year. At this time the scientists are releases thrips during news conferences. A news conference is scheduled for October 24.
September 12, 2019
PRESS RELEASE The Air Potato Biological Control Extension Program Comes to Successful Conclusion Research and extension faculty with UF/IFAS have reached successful completion of the five-year Air Potato Biological Control Extension Program. UF/IFAS project partners are: Dr. Carey Minteer (lead) with the Indian River Research and Education Center and Ken Gioeli (co-lead) at the UF/IFAS Extension St. Lucie County. This program began in 2014 as an initiative by the UF/IFAS Indian River Research and Education Center and the UF/IFAS Extension St. Lucie County in collaboration with Extension offices and partner agencies throughout Florida. The focus of the project involved the introduction of a new biological control agent Lilioceris cheni (Coleoptera: Chrysomelidae) to helped teach residents how to use the insect to manage the invasive air potato (Dioscorea bulbifera). Floridians struggled to control this invasive vine which can grow up to eight inches per day and smother native vegetation. This UF/IFAS research and extension program was paired with a mass rearing effort and distribution process that helped citizens throughout Florida. Researchers at USDA ARS are credited for discovering L. cheni as a viable biological control agent for air potato. The program has been highly successful with tens of thousands of L. cheni beetles provided to stakeholders for release. It significantly increased the general knowledge of invasive species of the people surveyed by an average of 227 percent and general knowledge about biocontrol by an average of 401 percent. Perception of the safety of biological control increased by an average of 434 percent and perceived effectiveness of biocontrol increased by 344 percent. The combination of a charismatic and effective natural enemy along with an educational program has significantly increased the knowledge about invasive plant species and the knowledge and acceptance of biocontrol as a safe and effective control method. The Air Potato Biological Control Extension Program was recognized with three national awards and one state award. While UF/IFAS has completed research and extension activities with this project, educational resources will continue to be made available online at http://bcrcl.ifas.ufl.edu/airpotatobiologicalcontrol.shtml. This website features information about insect availability from project partners. For additional information, please call Natural Resources and Environment Extension Agent IV Ken Gioeli with the UF/IFAS Extension St. Lucie County at 772-462-1627 or ktgioeli@ufl.edu.
September 12, 2019
PRESS RELEASE The Air Potato Biological Control Extension Program Comes to Successful Conclusion Research and extension faculty with UF/IFAS have reached successful completion of the five-year Air Potato Biological Control Extension Program. UF/IFAS project partners are: Dr. Carey Minteer (lead) with the Indian River Research and Education Center and Ken Gioeli (co-lead) at the UF/IFAS Extension St. Lucie County. This program began in 2014 as an initiative by the UF/IFAS Indian River Research and Education Center and the UF/IFAS Extension St. Lucie County in collaboration with Extension offices and partner agencies throughout Florida. The focus of the project involved the introduction of a new biological control agent Lilioceris cheni (Coleoptera: Chrysomelidae) to helped teach residents how to use the insect to manage the invasive air potato (Dioscorea bulbifera). Floridians struggled to control this invasive vine which can grow up to eight inches per day and smother native vegetation. This UF/IFAS research and extension program was paired with a mass rearing effort and distribution process that helped citizens throughout Florida. Researchers at USDA ARS are credited for discovering L. cheni as a viable biological control agent for air potato. The program has been highly successful with tens of thousands of L. cheni beetles provided to stakeholders for release. It significantly increased the general knowledge of invasive species of the people surveyed by an average of 227 percent and general knowledge about biocontrol by an average of 401 percent. Perception of the safety of biological control increased by an average of 434 percent and perceived effectiveness of biocontrol increased by 344 percent. The combination of a charismatic and effective natural enemy along with an educational program has significantly increased the knowledge about invasive plant species and the knowledge and acceptance of biocontrol as a safe and effective control method. The Air Potato Biological Control Extension Program was recognized with three national awards and one state award. While UF/IFAS has completed research and extension activities with this project, educational resources will continue to be made available online at http://bcrcl.ifas.ufl.edu/airpotatobiologicalcontrol.shtml. This website features information about insect availability from project partners. For additional information, please call Natural Resources and Environment Extension Agent IV Ken Gioeli with the UF/IFAS Extension St. Lucie County at 772-462-1627 or ktgioeli@ufl.edu.
August 16, 2019
How fortunate we are to have such a 'treasure' in our community. The word is dependent upon such research.
August 13, 2019
Great article. Wish we had more researchers lik you, Jonny.
July 24, 2019
interested in acquiring the "thrips" insect for control of brazalian pepper trees
July 18, 2019
How can I get more air potato beetles? Since I released the last batch I've found three more areas separate from the original where air potatoes are taking a hold. I appreciate any direction you can give. Sincerely, Laura Stapleton
June 28, 2019
Hello. I am extremely interested in obtaining as many red beetles as possible. I have over 5 acres that is overrun by potatoe vines. They are consuming our entire property. I am willing to pay for assistance in getting rid of or atleast deterring this problem. Please let me know if you can help. Thank you so much.
April 18, 2019
Ah great initiation happening around in Florida. In Nepal our citrus groves are in the state of exhaustion. But no one giving a priority to react. https://thehimalayantimes.com/opinion/citrus-greening-nepals-groves-under-threat/
April 13, 2019
A very accomplished career. A gentle giant that will be greatly missed.
April 13, 2019
We didn’t know Dr. Calvert, but his son, Victor, came surely from the same mold. An honorable, hard-working man who contributes much to the lives of others. Blessings on the family, all of you. May the memories of Dr. Calvert encourage you to continue his lifestyle.
April 3, 2019
My condolences to the Calvert family and UF Ft Pierce..
October 9, 2018
I had the chance to be Mr ÖZBUDAK's teacher at high school. I am proud of him. I am sure he will be successful on his research.
March 30, 2018
正在找这个，谢谢！
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December 8, 2017
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September 27, 2017
Congratulations Dr. He and Dr. Wright
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