A new University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) study looked at how multiple varieties of pineapple tolerated different levels of salinity. Lukas Hallman, postdoctoral research associate at the UF/IFAS Indian River Research and Education Center (IRREC), along with members of the Postharvest Physiology Lab studied two varieties of pineapple to determine how different salt levels impact the root system architecture, plant physiology and the plant’s biomass.
The study is part of a broader effort to identify profitable alternative crops for the Treasure Coast. Hallman’s research focused on whether specialty pineapple varieties could tolerate the levels of salinity commonly found in irrigation water across the region.
“There’s a lot of research focused on identifying alternative crops for our region,” Hallman said. ” Agriculture on the Treasure Coast is facing two major challenges: citrus production continues to decline because of citrus greening disease, and productive farmland continues to be lost to development. We need crops that are both economically viable and well suited to our local growing conditions. Pineapple has real potential.”
Pineapples are not a new crop to Florida, either. In fact, the Treasure Coast region was once the largest producer of the fruit in the world, particularly around Jensen Beach. Much of the pineapple industry in the region collapsed in the early 1900s due to reasons like environmental conditions disease and market competition. He said many of those challenges from that time can be overcome.
The two pineapple varieties evaluated in the study were White Jade and Sugarloaf. Both are specialty varieties prized for their sweet flavor, low acidity, and edible cores. By comparison, the typical variety often found in grocery stores are called MD2. Which is primarily grown in Costa Rica and in other parts of Central America.
“The MD2 is a great piece of fruit that was developed to provide consistent fruit quality, long shelf life and excellent shipping performance,” Hallman said. “Our goal isn’t to compete with supermarket pineapples. Instead, we’re interested in evaluating specialty varieties that offer unique flavors and could be grown locally.”
“These are specialty varieties that are rarely available in grocery stores and could help create a unique local market.”” he continued.
There are well over 100 pineapple varieties grown around the world, offering an incredible diversity of fruit sizes, shapes, colors, and flavors. Hallman believes additional varieties may prove to be an excellent fit for the Treasure Coast.
“We’re trying to answer the fundamental questions about whether these pineapple varieties can be grown commercially on the Treasure Coast. What does it take to grow
them? What inputs do they need? Are there pests or diseases that could limit production? How tolerant are they to salinity? This study is helping answer one of those questions.”
One potential challenge to growing pineapples on the Treasure Coast is their ability to tolerate salinity. During the dry season, groundwater levels decline, requiring growers to rely more heavily on irrigation. Along the Treasure Coast, increased demand for freshwater and saltwater intrusion can increase the salinity of irrigation water.
The study sought to answer questions such as: How much salinity can these pineapple varieties tolerate? At what point does salt begin to limit growth? Are some varieties more tolerant than others?
The pineapples were exposed to five salinity treatments three of which represented levels found in irrigation water on the Treasure Coast.
Throughout the study, the team monitored plant growth and health by measuring traits such as plant height, leaf length and chlorophyll content. At the conclusion of the study, researchers measured plant biomass and analyzed the root systems using specialized imaging equipment to evaluate root length, diameter and branching patterns. Research Assistant JP Fox is also using fluorescence microscopy to examine how salinity affects root anatomy and internal tissue structure in the different pineapple varieties.
As salinity increased, plant growth, chlorophyll content and root development generally declined, which was expected. However, both varieties tolerated low to moderate salinity levels relatively well, which is promising for their potential as alternative crops on the Treasure Coast.
This research is part of a larger effort to evaluate pineapple production on the Treasure Coast,” Hallman said. “We have a second study already underway, and our next step is to establish field trials at the Indian River Research and Education Center in collaboration with the Horticulture Crop Production Lab.
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