Pongamia trees grow where citrus once flourished, providing renewable energy and plant-based protein

An ancient tree native to India is now thriving in Florida citrus plantations where it once grew, and could help provide the nation with renewable energy.

As much of the Sunshine State’s once-famous citrus industry has all but dried up in the past two decades due to two deadly diseases, citrus greening and citrus canker, some farmers are turning to the pongamia tree, a climate-resistant tree with the potential to produce plant protein and sustainable biofuel.

For years, the pongamia has been used as a shade tree, producing legumes – small brown beans – that are so bitter that wild boars won’t even eat them.

But unlike the orange and grapefruit trees that have long occupied these rural Florida groves northwest of West Palm Beach, pongamia trees don’t need much attention.

Pongamia trees don’t need fertilizers or pesticides. They thrive in drought or rainy conditions. And they don’t require teams of workers to pick the beans. A machine simply shakes the tiny beans off the branches when they’re ready to be harvested.

Terviva, a San Francisco-based company founded in 2010 by Naveen Sikka, then uses its patented process to remove the biopesticides that cause the bitter taste, making the beans suitable for food production.

“Florida presents a rare opportunity for both Terviva and legacy citrus growers. The historic decline of the citrus industry has left farmers without a crop to profitably grow on hundreds of thousands of acres, and a highly scalable replacement needs to be found, very soon,” Sikka told The Associated Press. “Pongamia is the perfect fit.”

What is the pongamia tree?

Pongamia is a wild tree native to India, Southeast Asia and Australia.

The legume is now used to produce several products, including Panova cooking oil, Kona protein bars and protein flour.

Pulses also produce oil that can be used as biofuel, largely for aviation, which leaves a very small carbon footprint, said Ron Edwards, Terviva chairman and a longtime Florida citrus grower.

Transforming a wild tree into a domestic tree was not easy, Edwards said.

“There are no books to read on the subject either, because no one else has ever done it,” he said.

Bees and other pollinators feed on the pongamia flowers, promoting local biodiversity, Edwards said. One acre of the tree can potentially provide the same amount of oil as four acres of soybeans, he added.

What’s left after extracting the oil from the pongamia bean is “a very high-quality protein that can be used as a substitute in baking, smoothies and all sorts of other plant-protein products,” Edwards said. “There’s great potential for the food industry and the oil industry.”

Why Florida?

“We know that pongamia grows well in Florida and that the end markets for the oil and protein that comes from pongamia seeds – biofuel, animal feed and food ingredients – are huge,” Sikka said. “So farmers can now reduce their costs and get closer to leading-edge sustainable farming practices.”

At a nursery near Fort Pierce, workers skilled in pongamia grafting techniques attach a portion of the mother tree to a pongamia rootstock, ensuring that the genetics and desired characteristics of the mother tree are carried forward into all of Terviva’s trees.

Pongamia vs. Citrus

Citrus was Florida’s main crop for years until disease overtook it starting in the 1990s with citrus canker and subsequent greening.

Citrus canker, a bacterial disease, is not dangerous to humans, but causes lesions on fruits, stems and leaves. Eventually, it makes trees unproductive.

Citrus greening, also known as Huanglongbing, slowly kills trees and degrades fruit, according to the U.S. Department of Agriculture. The greening has spread throughout Florida since 2005, devastating countless orchards and reducing citrus production by 75 percent. The disease has spread to Louisiana, Texas and California.

Hurricane Ian caused an estimated $1.8 billion in damage to Florida agriculture in September 2023, hitting the citrus industry early in its growing season.

Diseases and climate problems have also affected most major citrus-producing countries. For example, this year’s harvest in Brazil, the world’s top exporter of orange juice, is expected to be the worst in 36 years due to flooding and drought, according to forecasts by Fundecitrus, a citrus growers’ organization in the state of Sao Paulo.

But climate and disease have little effect on pongamia trees, company officials said.

“It’s a tough tree, it’s been tested in the jungle,” Edwards said. “It stands up to a lot of abuse with very little maintenance.”

Pongamia also grows well in Hawaii, where it now thrives on land once used for sugarcane.

What do citrus growers say?

John Olson, owner of Circle O Ranch west of Fort Pierce, replaced his grapefruit groves with 215 acres (87.01 hectares) of pongamia trees.

“We went through all the ups and downs of the citrus industry and because of greening, we eventually got out of citrus production,” Olson said. “The citrus industry basically died in Florida.”

Although the grapefruit plantation is modest, it was common for a plantation of this size to be profitable in the 1980s and 1990s, Olson said.

According to Edwards, farmers used various products to kill the insect that spread the disease. Over time, the cost of maintaining citrus trees became too high.

That’s when he decided to take another path.

“What attracted me to pongamia was the fact that it allows us to reuse fallow land that used to be citrus plantations and is now dormant,” he said. “From an ecological perspective, it’s very interesting because it can replace some of the oils and plant proteins that are currently produced by products like palm oil, which is a much more environmentally damaging crop.”

What about biofuels?

In December 2023, Terviva signed an agreement with Mitsubishi Corporation to supply biofuel feedstock that can be converted into biodiesel or renewable diesel.

“Our partnership with Mitsubishi is on track,” Sikka said, noting that the company works closely with Mitsubishi on tree planting, product development and sales. “Terviva’s progress has been accelerated by Mitsubishi’s expertise and leadership worldwide in all aspects of Terviva’s business.”

What food products does Pongamia produce?

The research is ongoing, but Edwards said they’ve made some really good graham crackers in addition to cooking oil and other plant-based protein products, including flour and protein bars.

Pongamia offers an alternative to soy and yellow pea proteins “if you don’t want your protein to come from meat,” he said.