Oranges are collected in a trolley at an orchard in Arcadia, Fla. on March 14. Orange orchards in Florida – the world's second largest producer of orange juice after Brazil – have been suffering from a citrus tree disease. A bacteria spread by the insect Asian psyllid causes the disease, which makes trees produce a green, bitter fruit that is unsuitable to sell, before dying within a few years.CHANDAN KHANNA/Getty Images
Three-year-old James Spinosa loves being out on his family’s farm, among the lines of orange trees, each 20 feet high, drooping with golden fruit. His favourite part is sitting on his dad’s lap and “driving” the tractor, which his father, Christian Spinosa, always lets him do.
Mr. Spinosa, 33, looks forward to the days when his son can chip in. He has 1,000 acres of farmland spread across Perry County, around one hour’s drive south of Orlando. He hopes to one day leave Putnam Groves – which has been in the family for five generations – to James.
“My goal is to keep this thing going,” Mr. Spinosa said. “To make sure that we always have this greenspace here for the next generation.”
But keeping the farm in business is no easy task.
Mr. Spinosa is among thousands of growers of Florida’s quintessential fruit that are fighting to survive a bacterial disease threatening to decimate crops – on top of the damage already being done by hurricanes and freezes.
The disease – named huanglongbing (HLB), but more commonly called “citrus greening” – was first discovered in Miami in 2005, and is now spreading uncontrollably in Florida’s orange groves. It has ravaged the industry. In 2004, 240 million 90-pound boxes of oranges were produced in the state annually. This year, the state is forecast to produce just 16 million.
The race is on to find a solution, but the research is in its infancy. Growers, exhausted and giving into the temptation of booming land prices, are dropping out. And ultimately, consumers feel the pinch. In August, orange juice prices hit an all-time high on the Intercontinental Exchange (ICE), 111 per cent higher than in August, 2013.
A Green Wave
Citrus greening has existed in China for at least a hundred years, and is carried by Asian citrus psyllid, a bug about the size of a seed. The disease was first detected in Florida in 2005.
The bacteria are carried in the insect’s saliva and passed to the tree when the bug feeds on the leaves. The bacteria then choke the flow of sugar and minerals in the phloem, the vein of the tree that transports nutrients. The disease is like plaque building up in the veins in humans and restricting the movement of blood – and in the case of the tree, it is effectively starved.
At first the symptoms look like routine nutritional deficiencies, but in eight to 10 years the tree will stop producing fruit and die. For a mature tree this could take longer, up to 20 years. For a young tree it could happen within five years. (A healthy orange tree, in contrast, can live for 50 years.)
“It’s a slow, slow decline,” said Michael Rogers, the director of the centre for citrus research at the University of Florida. “We’ve got this disease spreading, unknown, for a long time before you see the first symptoms.”
Outside of the tree, on the other hand, the disease moves fast. The tiny psyllid can fly more than a mile in less than two weeks, and pesticides cannot keep up. In applying the amount needed, growers found they killed more good bacteria than bad.
Citrus greening is a worldwide problem. Brazil, the global leader in orange juice production, is facing record-low inventory, according to a statement released by industry group CitrusBR. The disease has also infected groves in Texas and California. There are some European sectors that have not detected it, but it is just a matter of time, Dr. Rogers said.
Greening is particularly problematic in Florida, where growing is not as consolidated as it is in Brazil. The scale of production in Florida is not large enough to cover the costs from a mass outbreak. Brazil also has a particularly large fertile land mass for orange trees, meaning they can move operations more easily to replace infected trees with new ones.
Florida is also prone to hurricanes, as seen once again when Idalia made landfall on Aug. 30. So far, it seems that the damage from Idalia was minor; the hurricane swept up the Gulf Coast, and orange groves are concentrated in the centre of the state.
However, last year, growers were not so lucky.
In September, 2022, Hurricane Ian swept through the region, with 240-kilometre-an-hour wind ripping fruit off branches and uprooting trees. In some cases, the hurricane left groves three feet under water. Growers lost between 50 per cent and 90 per cent of their crop. Mr. Spinosa lost around 60 per cent. The economic loss to the citrus industry came to US$247-million, according to the Florida Department of Citrus.
A worker puts oranges in a bin at an orchard. The double crises of Hurricane Ian and the disease have wreaked havoc on the industry, which is so integral to Florida's identity that the orange is even on the state license plate.CHANDAN KHANNA/AFP/Getty Images
Combined with an uncharacteristic freeze in December, 2022, and greening, Ian led to the lowest harvest in a century. It also destroyed trees. Of the nearly 56 million commercial trees, 11 per cent were lost.
The price of land in Florida has also increased. In Orange County, for example, the estimated value of properties increased from US$181.7-billion in 2022 to US$203.8-billion in 2023, a 12-per-cent increase in one year alone, according to the Orlando Sentinel.
Growers are therefore selling their land to developers, an attractive option given not just the poor conditions for farming but also the soaring price for real estate. In 2022, citrus inventory stood at 375,000 acres of orange and grapefruit trees statewide, less than half of the 800,000 acres in 1996.
The value of the orange crop in Florida is in free fall. It was valued at US$1-billion a decade ago. Now the sector is worth US$358-million.
The economic fallout to the farming communities is significant. The industry employs 33,000 people and provides an annual economic impact of US$6.9-billion to the state, with US$150-million in tax revenue. This is also the major industry in large swaths of central Florida, a region where the tourism industry is not as developed.
The Race
Armed with a recent influx of US$16-million in grants from the U.S. Department of Agriculture, the University of Florida has launched a statewide army of researchers to fight citrus greening.
Progress has been made. For example, the team of over 200 researchers and staff have discovered that feeding infected trees fertilizer in increments is effective. The gradual destruction of the phloem means that the tree cannot absorb all the nutrients in one go, but it can absorb smaller amounts over a longer period of time.
For growers this means multiple rounds of fertilizing and watering.
“Think of it like spoon-feeding the trees constantly, both water and nutrients,” Dr. Rogers said.
Other solutions being explored include screening in citrus trees to fend off bugs, and whether gibberellic acid, a natural plant hormone, could stimulate growth for citrus trees that are fighting to survive greening.
“All that taken together we’ve been able to limp along a little bit,” Dr. Rogers said. “Keep production going on right now until we get those long-term solutions.”
Hope for a long-term solution rests mostly with CRISPR (pronounced “crisper”), a game-changing gene-editing technology. Referred to as “molecular scissors,” it is a fast and precise way to find and slice DNA. In essence, it allows scientists to transform a cell or species DNA into a digital document where individual genes can be searched out and eliminated or replaced.
Dr. Nian Wang at the University of Florida used CRISPR to precisely cut selected genes from the citrus tree DNA to make it more resistant to canker, a bacterial disease that causes trees to drop their leaves and fruit prematurely. They are hoping to repeat the same process for greening.
However, the process will take years. Researchers do not currently know which genes are vulnerable to greening. Once this is discovered the genes must be removed, the greening-resistant tree grown, tested and then mass produced. Orange trees are also not fast-growing fruit trees. They can take up to five years to produce a decent crop.
An added challenge for scientists is that they cannot add any gene sequences to the DNA, as was done with the canker-resistant grapefruit trees. This would warrant the label of “genetically modified,” which makes the product harder to market (despite little evidence proving that such crops are inherently bad for health or the environment).
“The ultimate test will be to see how they survive in the fields,” Dr. Rogers said. “It’ll be a few more years until we know if those plants actually work.”
Staying Green
Mr. Spinosa says that it’s hard to be patient. He inherited the farm from his uncle 10 years ago when he was 23. Over the past decade, he’s had to work harder. Spoon-feeding the trees fertilizers and nutrients takes more maintenance, while erratic weather and disease mean he has little control over how much he gets come harvest.
He says that other growers, many of whom are dropping out of the industry, don’t understand why he persists. But, despite the rocketing price of his land, he’s not tempted to sell. He believes there is a future where his groves will be filled with tolerant and resilient trees.
“I’ve been told that I’m young and dumb,” Mr. Spinosa said. “But I love what I do, and I still see a future. I don’t see there ever going to be a world where there’s no longer orange juice.”