Citrus season is just getting started and the special varieties only available for a few months out of the year have begun showing up at grocery stores. But US citrus growers, along with their counterparts all over the world, are facing a stark reality. This year’s harvest is predicted to be the smallest in 70 years, due in part to multiple hurricanes, but also due to the crippling disease that has been plaguing citrus growers and changing the face of Florida agriculture for 10 years — citrus greening.
Also known as Huanglongbing (HLB), this bacterial disease causes citrus fruits, most notably oranges although all varieties of citrus are susceptible, to turn yellow and spotted on leaves and fruit. Affected trees grow small, partially green fruit with a medicinal, sour flavor.
The disease is mainly spread by tiny insects, but it can take years to take full effect, plus new trees take years to grow, making the work of finding a solution slow and painful. Some estimates say that up to 90% of Florida’s citrus may be affected.
Tom Schenck of TerViva, an agtech startup working with citrus growers in Florida, says the disease has changed the face of the sunshine state.
“This is such a nasty disease. Your tree looks fine and you don’t know that there’s anything wrong with it, but once you notice that something looks sickly about your trees, you’ve lost 20-30% of your root mass and you’ve gotta cut the branches.”
It’s a disease you can see from the roads that run up and down Florida, says Schenk describing an almost post-apocalyptic scene of abandoned grove after abandoned grove.
Schenk says that some growers are choosing to keep growing citrus but at higher densities since they know that the yield will be lower. It’s not a great strategy for long-term health, but the growers figure that the disease is coming anyway.
This year’s hurricanes made matters worse. The Florida Fruit and Vegetable Association estimated in October that between 30% and 70% of the citrus harvest was lost to Hurricane Irma — the value of which has been estimated to be $760 million. Not only did Hurricane Irma take down many citrus groves, the trees left standing are weakened and therefore more susceptible to the disease.
Public Sector Solutions
Though public awareness has been slow to build, HLB has been in effect for over a decade. According to a USDA “Pest Alert” announcement regarding HLB in 2011, the disease was discovered in the US in 2005. By 2011, every county in the state was affected and Florida remains under quarantine, which means no live trees or cuttings may be transferred outside the state. Quarantines are in effect in several other states and territories where the disease has been detected including Georgia, Louisiana, Texas, Puerto Rico and the US Virgin Islands.
“The economic impact of citrus greening disease is measured in the billions,” said National Institute of Food and Agriculture Director Sonny Ramaswamy in a statement.
In January, the USDA released that it had spent $400 million on the disease since 2009, with $57 million of this USDA research grants awarded since 2014. Most of this funding went to agriculture universities and local USDA offices.
While no cure has been discovered, a few possible solutions have emerged. First is a genetically modified virus that media reports suggest could be approved for use by 2019. The virus, which would be applied to trees through grafting an infected limb onto a sick tree, would carry a “defensin” protein from spinach around the tree. The protein would fight the disease and inoculate the tree. A few sprays have been developed to slow the spread of the disease as well.
Startups are also bringing technology to bear to try and help.
Startups Wade In
In October, agricultural biotechnology and micropropagation company Phytelligence announced a licensing agreement with Florida Foundation Seed Producers to grow citrus greening-resistant rootstock. Though this new tree is not a cure, the University of Florida, where the stock was developed, says that it can show a reduced frequency of infection.
Phytelligence’s patented MultiPHY process enables crops like apples, cherries, peaches, pears, grapes, hops, berries and nuts to grow five times faster with fewer inputs using a non-soil, nutrient-dense growing medium. This speeds up the process for growers to get new, designer fruit varieties like Honeycrisp apples and cotton candy grapes to market, as well as alleviating age-old industry bottlenecks. Phytelligence founder and chief science officer Amit Dhingra said it will do the same for citrus-greening resistant orange trees.
The startup offers tissue culture and genetic testing for trees already in the field, as well as selling rootstock and plants that are genetically verified in a field where it’s very difficult even for expert growers to verify that the rootstock they receive is what they ordered.
Phytelligence CEO Ken Hunt told AgFunderNews that 10% of apple trees sold through traditional channels were mislabeled as to their type.
With so many growers incurring massive financial risk to replant citrus groves in the first place, precise genetics in these new resistant rootstocks is paramount, especially because nothing about the appearance of a tree can confirm the disease before it bears fruit, and the affected fruit may take years to develop.
“The farmers cannot afford to plant the wrong materials,” said Dhingra.
The idea is to get new rootstocks onto farms before farms have to shut down or completely convert to other crops, which is where Phytelligence’s faster growing time becomes essential. Not only because growers need new rootstock as soon as possible, but also because the lag time in getting new rootstock to market gives diseases time to evolve.
“When you develop varieties on the timescale of 10 to 20 years, pathogens have not just been sitting around,” said Dhingra.
Phytelligence is in the process of setting up facilities in Florida now.
Working on a true cure is Copia Ag & Food Technologies, an Israeli venture development fund that works to commercialize technology out of Israeli universities.
“The technology in which we invested is based on a new, previously unidentified endophytic Bacterium, that can enter the phloem of plants, emits compounds that are lethal to the phloem bacterial pathogens, but doesn’t create any damage to the plant,” Ohad Zuckerman, managing partner Copia, told AgFunderNews.
HLB is a phloem bacterial disease, explained Zuckerman, meaning it spreads through the plant equivalent of veins. Copia has invested in a technology that addressing such diseases currently plaguing many crops such as dates palms, grapes, potatoes, and timber. Field and lab trials of Copia’s solution, a previously undiscovered bacterium according to Zuckerman, have effectively inhibited the growth of Carrot Yellow Disease, which is from the same family as greening in citrus.
Trials in Florida are in process now for both a synthetic and biological version of Copia’s solution and results are expected in the first and second quarters of 2018.
Offering an Alternative
Startups are also looking to provide Florida citrus growers with alternative crops to ease the burden while they wait for a cure. TerViva plants pongamia, a perennial legume tree, and processes it for vegetable oil and protein-rich animal feed on degraded or unproductive land.
Pongamia is arguably a more efficient source of protein and oil than soybean: it can produce eight times more vegetable oil per acre than soybean, two times more protein animal feed per acre than soybean and used one-tenth of the water and chemicals, according to TerViva.
The TerViva team moved into the Florida market around 2012 when hundreds of thousands of acres of citrus had been lost but found that growers had a strong sense of earned skepticism. “There were quite a few scoundrels that had been in there before us,” said Tom Schenk, vice president for corporate development at the company.
TerViva convinced one grower, Peter Mcclure, and they planted just five acres, splitting the profits fifty-fifty. McClure was in the process of trying 30 different crops and waiting for an HLB cure, said Schenk. TerViva’s customers are the growers, but so are the end users and distributors of Pongamia’s various byproducts. TerViva provides growers with trees, helps them plant, then processes the offtake and distributes it.
“Over the years since we’ve been in Florida, we’ve been hearing that a cure was around the corner,” said Schenk. “We planted between the stumps of the old trees.”
Today TerViva has spread Pongamia to 200 acres in Florida with 400 more scheduled for planting in 2018. Peter McClure is now TerViva’s chief agricultural officer.
