Finger Limes: An HLB-Tolerant Prospect for Florida Growers

Finger limes appear as a promising choice to growers searching for alternative citrus crops thriving in Florida. The Australian Lime Improvement Program hosted the most recent Finger Lime Field Day to highlight ongoing research and market potential for this unique fruit, offering insights into its future as a viable specialty crop for Florida growers.

A hand holds a halved red finger lime, revealing juicy, jewel-like pulp against a blurred outdoor background of greenery and trees. — The ‘UF SunLime’ is a hybrid finger lime with unique “citrus caviar” vesicles that grow to about 3 inches in length and produce a rich, red color when mature. Participants picked and tasted the different varieties developed by Dr. Dutt’s team.

Often referred to as “citrus caviar” because of their pearl-like citrus kernels, finger limes (Citrus australasica) are a small, elongated Australian fruit. These juice-filled pods burst with a tangy flavor, making them a sought-after ingredient in gourmet cuisine or as specialty fruit. Australian and Californian growers successfully cultivate finger limes, and Dr. Manjul Dutt, an Assistant Professor in the Horticultural Sciences Department at CREC, is leading the team of researchers working to bring this crop to Florida’s citrus industry.

A group of visitors gather in and around a field of finger lime trees and stand behind an orange and blue sign that reads: Dr. Manjul Dutt, Horticultural Sciences. Their backs are turned to the camera as they listen to an unseen speaker. — Attendees at the Finger Lime Field Day tour. Dr. Dutt speaks on how HLB tolerance can be incorporated into conventional citrus cultivars to create new tolerant citrus hybrids.

Florida’s Next Specialty Crop

One of the most promising aspects of finger limes is their natural resistance to HLB, also known as citrus greening, a disease that has highly impacted Florida’s citrus industry. A bacteria spread by the Asian citrus psyllid causes HLB, leading to yellowing of leaves, premature fruit drop, and the overall decline of citrus trees. While most commercial citrus varieties suffer from this devastation by HLB, finger limes show remarkable resilience, providing an opportunity for growers to reinvest in citrus production.

Finger limes offer an opportunity for growers whose acreage has been lost due to citrus greening, to reinvest in a new and viable crop. This tolerance and ability to thrive in environments affected by HLB presents an opportunity for growers to diversify their crops and reinvest in viable, disease-tolerant plants.

Finger limes show strong market potential beyond disease tolerance. The individual sale of finger limes, rather than by weight, positions them as a high-value specialty fruit, increasing their profitability compared to traditional citrus fruits. Florida’s subtropical climate also matches the conditions where finger limes thrive, making them naturally well-suited for production in the state.

Ongoing Research and Breeding Efforts

Dr. Manjul Dutt has been leading research and breeding efforts to develop improved finger lime varieties for Florida’s growing conditions for almost 15 years. One of the most exciting advancements from Dr. Dutt’s program is the development of red pulp varieties that retain their color even in hot climates. Red pigmentation is lost in warmer conditions, but these new varieties maintain their appearance, meaning fruits grown in Miami will have the same attractive red pulp as those grown in central or northern Florida.

Another primary focus of the research is the development of seedless triploid finger lime varieties and those bred using conventional irradiation techniques. Several successful seedless varieties have already been created through this method, including the widely recognized, Tango (pictured below). More seedless options are currently in development.

Researchers are also working on cold-tolerant varieties to expand finger lime production using high tunnels to allow growers in North Florida to cultivate the crop more effectively. “High tunnels could be a game-changer for growers in North Florida, helping to extend the growing season and protect the trees from extreme temperatures,” Dr. Dutt explains.

Now that breeders have developed a variety that performs well in Florida, they will continue to evaluate the fruit in the field and understand how the plant interacts with careful rootstock selection. Since every citrus tree consists of a rootstock and a scion, choosing the right rootstock is crucial for plant health, disease tolerance, and adaptability to various soil conditions.

“Every citrus tree is a combination of a rootstock and a scion. The rootstock is the bottom part that anchors the tree to the soil and provides advantages like disease tolerance and soil adaptability. A particular rootstock that does well in one environment may not do well in another. By utilizing different rootstocks, growers across different regions can grow the same variety in different conditions,” said Dr. Dutt.

Beyond seedlessness, reducing thorniness in finger lime trees is a key objective. The trees are very thorny and complicate harvesting. A less thorny, or even thornless, variety would significantly improve the harvesting process.

Post-harvest research is underway to identify packaging, storage, and transportation methods that extend shelf life while preserving fruit quality. At Finger Limes Field Day, Dr. Tie Liu, Assistant Professor for the Horticultural Sciences Department, discussed research on how the cell walls of finger limes change over time and how these changes impact shelf life. By understanding what makes the fruit last longer or spoil faster, growers can optimize harvest and storage practices to maintain fruit quality. This research aims to improve postharvest management, reduce losses, and enhance marketability, ultimately increasing profitability for growers by reducing waste and delivering higher-quality fruit to buyers.

“Finger limes have delicate pearl-like vesicles that can lose moisture and texture postharvest. Optimizing storage conditions, packaging, and handling techniques can help maintain their freshness, texture, and flavor, ensuring better market value and consumer satisfaction.” -Dr. Tie Liu

With ongoing advancements in breeding, field research, and post-harvest technology, finger limes the hope is for finger limes to become an increasingly viable crop for Florida growers for long-term sustainability in the citrus industry.

Dr. Tie Liu, an Undergraduate Advisor and Assistant Professor at the UF/IFAS Horticultural Sciences Department, is tasting ‘UF RedLime’ finger limes in the research field with other attendees. Dr. Liu presented at the Field Day on their shelf life and other post-harvest factors.

Profitability and Consumer Insights

Although the finger lime program in Florida is still relatively new, with the first field trial established in 2012–2013, early data suggests promising fruit yields. A fully grown finger lime tree, typically around five years old, can produce an impressive yield of 150 to 200 fruits per tree. Unlike traditional citrus, like oranges or lemons, finger limes are marketed individually rather than sold by the box, allowing for a higher price point and increased profitability for Florida farmers.

In Florida, growers who already have established markets for specialty crops are among the first to adopt finger lime cultivation. Economic research, initially led by Dr. Trent Blair and now continued by Dr. Angelia Chen, Assistant Professor at the UF Food and Resource Economics Department, aims to identify key markets and consumer trends. While plant breeders focus on developing varieties for growers, economists and marketers are working to ensure that the crop finds its niche in the marketplace.

A woman with long black hair wearing a stylish blue blazer and matching skirt stands near a man in a field of finger limes. The trees are bright green with red fruit peppered among the leaves. The man wears a gingham gray and brown button up shirt and camouflage cap. Both are looking into the camera, smiling. — Dr. Lijun Angelia Chen is an assistant professor in the Food and Resource Economics Department at the University of Florida. Here, she explores the field with Union County’s county Extension Agent, Jim DeValerio. At the event, Dr. Chen spoke about exploring the market potential of Florida finger limes.

With the specialized nature of the finger lime market, growers can expect higher profits due to the fruit’s status as a specialty crop. Financial potential is significant. Finger limes are a specialty crop; this marketing strategy means they can command a higher price per fruit. Research is currently being conducted on consumer preferences and marketing strategies to determine how best to introduce them to a wider market.

“In the U.S., while consumer awareness and knowledge about finger limes remain low, highly-involved consumers, such as food enthusiasts, connoisseurs, and adventurists, are indicating strong interests in this novel, specialty citrus. Finger limes, positioned as a specialty/luxury product due to novelty and high price points, have gained significant attention in high-end culinary and mixology scenes.” Dr. Chen continued, “Servers, chefs, mixologists, and internet food influencers are important “opinion leaders” showcasing how finger limes can be used in food and drinks, informing individual consumers to relate finger limes usage in their households, shaping the initial demand.”

There are still a few challenges before large-scale production can be fully realized. Understanding post-harvest handling, shelf-life extension, and packaging solutions are necessary for commercial success. As Australian Lime Improvement Program continues events like Finger Lime Field Day connects researchers, growers, and industry stakeholders to ensure the future success of finger lime cultivation.

Finger Lime Field Day

This year’s Finger Lime Field Day was hosted at the University of Florida/IFAS Plant Science Research and Education Unit (PSREU) in Citra, Fla.

A group of people gathers outdoors under tall trees, listening to a speaker at the front. Wooden benches line the left side of the path, and attendees are dressed casually, some holding water bottles and backpacks. Some are seen in conversation, others walking around the field observing the trees. — Visitors walk through a field of finger lime varieties for the tour and fruit sampling portion of the event.

The event provides a platform for discussing new developments, sharing knowledge, and encouraging collaboration. By bringing together research and industry insights, these events help new crops like finger limes to gain a foothold in Florida’s agricultural landscape.

A man in a UF/IFAS polo shirt and cap gestures while speaking to another man with glasses and a camera around his neck outdoors in a finger lime grove. A utility vehicle and several people are visible in the background among plants and trees. The second man with the digital camera strapped around his neck, is holding his hand under his chin in contemplation of what is being said. — Dylan Hacker, Biological Scientist I at the UF/IFAS Citrus Research And Education Center speaks to attendees about finger limes.

“The main importance of hosting a field day is to increase stakeholder awareness and provide a forum where different research conducted on finger limes can be brought together from an extension point of view, it’s important to gather feedback after the meeting. We get responses from stakeholders, growers, and participants, which helps us gauge their interest and improve.” reflected Dr. Dutt.

Finger limes could become a sustainable and profitable option for Florida growers while researchers continue refining breeding efforts. As challenges are addressed and the market continues to grow, Growers interested in diversifying their crops should stay engaged with UF research efforts and explore the prospects of finger limes as a new specialty fruit for the region.

Three men examine a small tree in a wooded area. One man holds his phone to take a picture of the young finger lime tree, while the other two look down in observation. Additional people and a vehicle are visible in the background. Both men are smiling as they talk. — Phillip Russell, visiting USDA Agent, and Dr. Steve Sargent, Professor and Associate Chair for the UF/IFAS Horticultural Sciences Department, gather around new varieties of red-pigmented finger limes.

For updates on future field days and research developments, be sure to follow Dr. Dutt’s Australian Lime Improvement Program and the UF|IFAS Horticultural Sciences Department.