The All In For Citrus Podcast

All In For Citrus, Episode 66 February 2024

Florida citrus growers are now well into their second application of oxytetracycline (OTC) via trunk injection to treat HLB. Per the label of both registered OTC products, after two applications, there is a one-year treatment pause.

So, growers will be formulating plans on what to do during the off-season for OTC-treated trees. That was the subject of discussion during the February episode of the All In For Citrus podcast. Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, advised that a solid fertilizer program is going to be critical.

“We can’t stress enough the importance of nutrition when we are dealing with HLB. I know that sounds like a broken record because we are constantly saying that, but it really is the No. 1 thing that you can do to keep trees productive and healthy,” Rogers said. “In some of our research blocks, we really have had some excellent results with some of our more expensive fertilizer programs. After four or five years, these trees have really healthy root systems, the canopies are lush and green, and the Brix has been very high in fruit. This is where we’ve been using these expensive controlled-release fertilizer applications.”

The high cost of these nutrition programs can be difficult for growers to afford, so researchers are beginning to seek out which elements are most responsible for the great results evident in those blocks.

“We do know there are differences in the micronutrient and macronutrient amounts and how they are delivered to the tree,” Rogers said. “We have allocated some funds to seek out how we can develop the right blend of minor and major nutrients at a cost much lower to growers.”  

To hear more about this research and catch up with Flavia Zambon, who was recently named UF/IFAS assistant professor of production horticulture of citrus and other tree crops, don’t miss the February episode. Also in the podcast this month is a sneak peek at upcoming events, including the Florida Citrus Show.

The All In For Citrus podcast is a partnership between UF/IFAS and AgNet Media. Find all the episodes here.

All In For Citrus, Episode 65 January 2024

If you grow citrus in Florida, you’ve probably heard the term CRISPR used in discussions about gene editing to find HLB resistance. CRISPR is complicated science but holds great promise in fighting both human and plant diseases.

At the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), Nian Wang, a professor of microbiology and cell science, has been developing CRISPR citrus trees that hopefully will deliver HLB resistance.

During the latest episode of All In For Citrus podcast, Michael Rogers, director of the UF/IFAS Citrus Research and Education Center in Lake Alfred, has an extended conversation with Wang about his work with CRISPR and gene editing.

Rogers and Wang break down the science of gene editing and discuss the progress made toward finding tolerance or resistance to HLB. It has been a long process, but now potentially HLB-resistant trees have been grown out from a single cell into trees almost ready to be planted in a grove for testing in the real world.

Wang has been working with CRISPR in citrus since 2013. The first transgenic-free, gene-edited citrus plants were accomplished in 2022. The research team has been working with about 40 different targets that might have potential in resisting HLB. Because of the inability to culture the HLB bacterium, it has been harder to narrow down the target genes than it was for citrus canker. However, Wang believes there are seven or eight genes that hold promise in promoting HLB tolerance or resistance.

During the podcast, Wang goes into more detail about the process of taking a single cell in a petri dish to a citrus tree growing in a grove. Don’t miss the January episode of All In For Citrus to learn more about the pioneering science of CRISPR.

The podcast is a partnership between UF/IFAS and AgNet Media.

All In For Citrus, Episode 64 December 2023

All In For Citrus, Episode 63 November 2023

Michael Rogers, the director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, and some of his colleagues recently attended the Asian Citrus Congress in India. During the November All In For Citrus podcast, Rogers discusses what was learned and observed on the trip.

While many of India’s citrus groves are small-scale operations, the country’s citrus production is growing. This is despite being among the first countries to deal with HLB, because the disease’s origins are believed to be in Asia. Rogers said a Florida contingent visited several citrus-producing areas in India to learn how growers are surviving with HLB.

“If you look at where India sits, they are ranked No. 3 in global citrus production. If you look at metric tons produced, they are a big player in citrus,” Rogers said. “The United States is No. 6 on the list, and they are doing almost double the production that we are.”

Rogers said it is worth looking at how India’s citrus industry is continuing to survive and grow in the presence of HLB. At the conference, HLB was top of mind because it seems the disease is causing more problems recently than in the past.

“That raises the question: Why now for these growers? We heard from the speakers that there has been a lot of changes in weather patterns, and it is creating a new environment for citrus that is playing a role in HLB expression in that part of the world,” explained Rogers. “They are seeing a lot of variation not so much in the amount of rainfall but in the distribution of rain. So, there are now extended periods of time where there is no rain, followed by a lot of rain. This is causing issues for the trees and root health.”

Rogers said, like in Florida, these stresses put on trees are allowing HLB symptoms to be expressed more acutely. This is driving growers and researchers to develop more region-specific water management practices in India to deal with these changing weather patterns. To hear more from Rogers, check out the November episode of All In For Citrus. The podcast is a joint partnership between UF/IFAS and AgNet Media.

All In For Citrus, Episode 62 October 2023

Many people believe genetics will be the eventual key that unlocks more permanent solutions to HLB. Whether it be traditional breeding or new technologies, one day there could be a citrus tree that is resistant or tolerant enough to make the disease a non-factor.

One such key could be CRISPR technology to deliver a tree that is engineered to resist HLB. That is the topic of the All In For Citrus podcast October episode. Podcast host Frank Giles and Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, have an extended discussion on the topic.

Rogers said there has been a great deal of interest among growers about the potential use of CRISPR to develop a tree resistant or tolerant to HLB. While a good deal of research progress has been made with the technology, he wants to set realistic expectations about the timeline of the research. It is a time-consuming process that targets single genes within the citrus DNA. Cells are grown starting in a Petri dish before eventually growing into a traditional citrus plant. Only then can testing in the field be conducted to see if true resistance has been achieved.

During the podcast, Rogers details the research being conducted by Nian Wang, a UF/IFAS microbiologist, who has pioneered CRISPR work in citrus. Wang was the first scientist in the world to transform citrus using the CRISPR technique.

Wang has already transformed four lines of citrus to be resistant to canker. These plants are a proof-of-concept as the research targets HLB resistance. Rogers said there is more work to be done, but Wang’s CRISPR science holds much promise.

To hear more about CRISPR and the search for HLB resistance, don’t miss the October episode of All In For Citrus. The podcast is a joint partnership between AgNet Media and UF/IFAS.

All In For Citrus, Episode 61 September 2023

One of the overlooked casualties of tropical storms and hurricanes is field research conducted by scientists at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). Research on new varieties, plant treatments and other practices can be upended in a day by a violent storm.

That happened to some of Christopher Vincent’s research. The UF/IFAS assistant professor of environmental physiology saw some of his grove trials disrupted by Hurricane Ian last year. So, he decided to turn lemons into lemonade by shifting the focus of his research to study the after-effects of the hurricane and what mitigation efforts seem to help groves recover.

Vincent joined the September All In For Citrus podcast to discuss this research and what he found in the aftermath of Ian. He said it can take as long as six months for citrus trees to fully decline after being impacted by a hurricane. Vincent noted his research will help growers establish benchmarks of what to expect during future storms. It also will add to existing knowledge on production practices that are most beneficial after tropical systems.

Gillian Zeng Michalczyk, a UF/IFAS master’s student who assisted on the project, joined Vincent in the podcast discussion.

A grower-cooperator, Jake Pendergrass, also participated in the podcast to discuss how Hurricane Ian affected his groves and steps he took to rehabilitate them.

On a positive note, Pendergrass spoke about his experience injecting citrus trees with oxytetracycline (OTC) for the first time this season. He treated about half his family’s grove acreage. Pendergrass reported that treated trees look good and seem to be responding well to OTC. Meanwhile, those trees not treated with OTC continue to decline. That makes him believe OTC is having a positive benefit on HLB-infected citrus.

Listen to the September episode of All In For Citrus. The podcast is a joint partnership between UF/IFAS and AgNet Media.

All In For Citrus, Episode 60 August 2023

With the trunk-injection season winding down in Florida groves, growers anxiously await to see positive results in HLB-infected trees. Two oxytetracycline (OTC) products have been approved for use in Florida citrus as HLB treatments. A third OTC formulation expects Environmental Protection Agency approval soon.

Trunk-injection treatments are the focus of the latest All In For Citrus podcast. Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred, joins Ute Albrecht, UF/IFAS associate professor of plant physiology, for an in-depth conversation about OTC injections. They discuss what was learned as the first application was made in groves.

Albrecht noted that OTC trunk injection is among the most significant breakthroughs in HLB research since the disease was confirmed in Florida nearly two decades ago. She has been a leading UF/IFAS researcher on OTC usage in citrus. Albrecht said if results in commercial groves mirror that of research trials, the industry could see some significant improvements in tree health and production.

While it is still too early to know for sure, she said there are some encouraging reports that trees are responding. But it will likely be after next season’s harvest before it is fully known just how beneficial the OTC treatments have been.

The podcast takes a deep dive into previous research, best application practices and what’s next when it comes to trunk-injection therapies. While Rogers and Albrecht acknowledge OTC therapy is not the silver bullet, it hopefully serves as a significant bridge to help growers remain viable until a long-term solution is found.

Don’t miss this episode of the All In For Citrus podcast to get the latest on OTC trunk injection. The podcast is a joint partnership between UF/IFAS and AgNet Media.

All In For Citrus, Episode 59 July 2023

The Citrus & Specialty Crop Expo is fast approaching, scheduled for Aug. 16–17 at the Florida State Fairgrounds in Tampa. The event is the subject of the July All In For Citrus podcast.

Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, previews the presentation he will be giving during the Expo. While there has been a lot of attention paid to near-term ways to fight HLB in groves, it is important not to lose sight of the longer-term solutions researchers are working on. In his Expo presentation, Rogers will address progress on moving a genetically modified (transgenic) citrus tree through the breeding, evaluation and regulatory processes. And he will give an update on CRISPR gene editing. Both approaches have created trees that hold up very well against HLB. He says it is important growers understand where UF/IFAS research is with both of these techniques.

Tripti Vashisth, UF/IFAS associate professor of horticultural sciences, joins the podcast to talk about the citrus educational seminars that will be held on both days of the Expo. Some of the key citrus scientists will be stepping out from behind the speaker’s podium to participate in a panel discussion so growers can engage with them in a more conversational way about the latest HLB therapies and how to apply them in groves.

Another panel will feature growers who are having success in mitigating the effects of HLB. Some of their groves look healthy and are producing great yields.

Jamie Burrow, UF/IFAS Extension program manager, gives a preview of the UF/IFAS trade show booth. She said the booth will have several interactive elements, including a demonstration on how to use the new Canopy Assist application that helps growers quantify tree health in their groves. There will also be a demo on how to pick the right individual protective cover for newly planted trees.

Burrow notes there will be plenty of “swag” (pencils, pens, notepads, etc.) for growers to pick up while visiting the booth. In addition, there will be lots of educational materials available for the taking.

Hear more about the Citrus & Specialty Crop Expo in the July episode of All In For Citrus. The podcast is joint partnership between UF/IFAS and AgNet Media.

All In For Citrus, Episode 58 June 2023

Speaking at the Florida Citrus Industry Annual Conference in June, Scott Angle, leader of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), reaffirmed the urgency the institution has placed on finding viable solutions to HLB. 

This includes presenting the citrus industry with a road-map document to lay out UF/IFAS HLB research priorities and objectives. One of the approaches will be turning over every stone in the search for solutions. Part of this effort is UF/IFAS researchers traveling to other citrus-producing regions across the globe to assess the impact of HLB and how growers are dealing with the disease.

Christopher Vincent, UF/IFAS assistant professor of environmental physiology, embarked on one such trip recently to Nepal. He joined the June All in For Citrus podcast episode to discuss his trip. Vincent said citrus growers in the region have been dealing with HLB for many years, and like in Florida, the impact on trees varies from one planting to the next.

Citrus in Nepal is grown in mountainous areas on very small plots. Growers don’t have access to the same type of inputs as U.S. growers, but they have managed to produce citrus for hundreds of years.

Vincent said one important observation made during his trip was that growers with good fertilizer and irrigation programs had trees that were withstanding HLB much better than those who did not have good programs. This reinforces what has been observed in Florida — solid production programs are essential in the era of HLB.

Larry Duncan, UF/IFAS professor of nematology, joined the June podcast to discuss a citrus production course that will be offered this fall. It is a great educational program for not only students, but also growers or production managers who want to brush up on their skills.

Hear more about Vincent’s trip to Nepal and the citrus course in the latest episode of All In For Citrus. The podcast is a joint partnership between AgNet Media and UF/IFAS.

All In For Citrus, Episode 57 May 2023

The latest All In For Citrus Podcast takes an in-depth look at a new product allowing growers to hone-in on the health of their citrus trees.