The Light Fantastic

PALMERSTON NORTH, New Zealand—

On four narrow shelves in a windowless room in a nondescript building in the New Zealand city of Palmerston North, eight dozen little cannabis clones are quietly and invisibly revolutionizing agriculture.

Banks of LEDs sit above each row of plants, bathing them in purple light. Some of the tiny diodes are blue, some are red—standard grow lights that mimic sunlight and enable crops to be grown indoors. But other LEDs are ultraviolet, producing various wavelengths that can’t be seen by human eyes. They’ve been electronically programmed at certain intensities and frequencies, and to turn on and off at particular intervals, according to a commercially-secret ‘light recipe.’

The plants will spend six days on these shelves, soaking up the UV like starlets on sunbeds—and by the end of the week, they’ll be changed forever.

These light recipes are not just for cannabis—far from it. The science on display here is being developed at the international headquarters of BioLumic, a New Zealand-based agritech startup that’s been shortlisted for the Food Planet Prize for its work investigating a big and wild idea: that briefly exposing all kinds of young plants and seeds to specific ‘recipes’ of energy-efficient ultraviolet light can cause physiological changes that result in significantly faster growth, higher yields, and greater resilience to pests and diseases for the rest of their lives. 

So far, BioLumic has proven the technique works with a handful of crops—lettuces, corn, tomatoes, cannabis, strawberries, soybeans—and is experimenting with a dozen more, including many of the world’s staple grains. They’ve already shown that ultraviolet light can boost the yield of strawberries by 47 percent, and increase the vigor of soybean plants by 39 percent. 

Best of all, it’s completely organic. No extra fertilizer or pesticides, no genetic modification, no energy-intensive hydroponics or lifelong grow lights. All the plants need is a few days—or in the case of seeds, a few seconds—of light.  

It does sound too good to be true, admits BioLumic founder and Chief Science Officer Jason Wargent—but the science is sound. “The idea of programming plants with light to express their potential? Yeah, it’s a sales pitch, but it’s an amazing one. It’s like a whole otherworldly future.”

The explanation for how it all works, however, begins in the deep past—around half a billion years ago, back when the first terrestrial plants began evolving. 

“The story of the company was actually 600 million years in the making, because that’s when the first mechanistic changes occurred in plants,” Wargent says. 

Ultraviolet light is not just one ‘color’—there’s a whole invisible rainbow of it. Scientists generally split the rainbow into three groups of wavelengths. UVC waves are the shortest and strongest, but are completely absorbed by the ozone layer and atmosphere. UVA wavelengths are the longest and weakest. The ozone layer in the stratosphere blocks most of the UVB waves, but those that sneak through are responsible for sunburn in humans—and in high concentrations, they can damage DNA, cells, and crucial proteins in plants. They can’t penetrate far into water.

Around 600 million years ago, the fledgling ozone layer had developed enough for organisms to venture out of the deep sea and into the shallows, resulting in the Cambrian Explosion—a massive diversification of life. By about 400-500 million years ago, the ozone layer was thick enough that the first plants could emerge onto land. But it was still a lot thinner than it is now, says Nick Albert, who studies the evolution of UV protection in plants at the New Zealand Institute Plant and Food Research, and is not connected with BioLumic.

That wafer-thin ozone layer meant more UVB was able to penetrate to the surface. To survive, terrestrial plants evolved mechanisms to detect levels of UVB radiation and defend themselves from it—making compounds called flavonoids that act as a kind of sunscreen.

Those protections enabled plants to multiply, evolve leaves and trunks and flowers, and spread across the landscape. Ultraviolet radiation gradually fell to roughly modern levels, but has periodically spiked numerous times since then due to geomagnetic reversals or ozone-layer depletion from climate change, potentially even leading to mass extinctions in the past.

Even under normal conditions, Albert points out, a tree can fall in the forest and suddenly expose the understory to a blaze of unaccustomed UV.  It makes evolutionary sense, then, that plants have held on to the ability to sense ultraviolet light and to change the way they grow in response. “Measuring and responding to UV light has been something that plants have been doing for a long, long time,” Albert says. “If it’s been retained throughout, then it must be really important.”

Research into plants and UV began in the 1970s and 80s, when scientists discovered that chlorofluorocarbon (CFC) emissions were severely depleting the ozone layer—the so-called ozone ‘hole’.  Seeking to understand how the corresponding rise in UVB radiation might affect the world’s crops and ecosystems, they initially focused on its harmful environmental effects at high concentrations. 

However, after CFCs were banned under the Montreal Protocol in 1987—signed by all 198 United Nations member states and without which, scientists have calculated, plants worldwide would have suffered and climate change would be a lot worse—scientific interest shifted to the more subtle ways in which exposure to ultraviolet light helps to regulate plant growth on a daily basis. 

That’s what Jason Wargent was working on when he moved to Palmerston North from Lancaster in the United Kingdom in 2010 for an academic job as a plant photobiologist at Massey University. In 2011, scientists in Germany and Scotland discovered a protein called UVB resistance 8 (UVR8) that enables plants to perceive UVB. At around the same time, the development of ultraviolet LEDs made it possible to conduct much more fine-tuned experiments.  

Research at Massey and elsewhere confirmed that when plants perceive the everyday presence of ultraviolet light with the UVR8 protein, they make minute adjustments to the way they grow in response. “Like they’re getting ready,” says Wargent. “Like they’re putting their armor plating on a little bit. And that gave us a toolkit to think about actually programming plants with UV.” 

Wargent founded BioLumic in 2013. Early tests on lettuce in California showed that exposing young plants to specific recipes of ultraviolet light could cause a doubling of yield once they were planted out in fields that had half the typical amount of fertilizer applied. The treatments also reduced the plants’ susceptibility to downy mildew, a crippling fungal disease that deforms leaves and kills plants, by around 50 percent. Wargent’s theory was that the UV prompted them to make flavonoids—plant-based chemical compounds—that helped to resist the disease.

At the same time, trials on strawberry seedlings led to each plant producing 43 percent more strawberries without any loss of fruit size or sweetness.  

More recently, the company also began trials on cannabis. Unlike strawberries, cannabis plants are cloned and grown year-round, meaning there’s a consistent commercial opportunity for light-treatment. Wargent was also excited about the science. Cannabis’ status as an illegal drug for the past half-century has meant there’s been limited research into the plant’s potential benefits—until now. 

The treatments for cannabis are generally the same as for other BioLumic seedlings. Wargent’s team takes small cuttings from the mother plants, then places each clone in a sterile foam cube. Once the little plants have grown some roots, at around 2-3 weeks old and 4-5 inches high, they’re moved to the UV treatment shelves, where BioLumic’s (mostly female) scientists trial different light recipes on the various strains. The simplest way to think about the recipes, Wargent says, is that they’re unique combinations of wavelengths, time, frequency of timing, and strength. He won’t reveal any more detail—the rest, for now, is confidential. 

After six days—“just a tiny amount of their life,” he says—they get transplanted into larger pots, and when they’re big enough, they’re moved to the ‘flowering room’, where the (non-ultraviolet) lights mimic the shorter days of autumn, triggering blooms to form. 

The company started cannabis trials in early 2020. As the flowers ripened, the coronavirus spread around the world. In March, New Zealand Prime Minister Jacinda Ardern announced the country would be placed in lockdown, one of the world’s strictest at the time. “We thought, what are we going to do? Our babies!” says Wargent. The evening before the restrictions came in, the entire team pulled together to harvest the marijuana flowers and send them off for analysis.

As they all isolated at home, the results came through: the flower yield—the mass—had increased by an average of 44 percent in the treated plants compared to controls. 

Since then, the scientists have refined the recipes, and have had more success with some cultivars than others. BioLumic treatments have boosted the yield of the ’White Cheese’ strain by 59 percent, increased the cannabinoids in its flowers by 27 percent, and the THC by 94 percent.  Wargent points out that they’re not being grown for recreational purposes, but for medicinal cannabis companies that harvest the active ingredients for health products. Greater yield could make for cheaper products for those that need them. 

Increasing yield is the “holy grail” of agricultural research, Wargent says. If you can make a plant produce more with the same inputs (water, fertilizer, pest and disease control) you can feed more people more quickly with less land. Fewer forests need to be cut down, less energy is needed, farmers can earn more, and food will cost less.  The techniques BioLumic is perfecting on cannabis could have far wider implications for global food security.   

Treating tiny plants with light is one thing—leaves are light-detection machines, after all—but seeds are another. Discovering that the recipes worked even with seeds was a ‘eureka moment’, says Wargent, which significantly broadens the technology’s potential global impact: most staple food crops are grown from seed, and are sown en masse directly where they will grow.

The team started by treating already-germinated seeds for 24 hours, placing them on a tray under the UV LEDs in a fridge-like cubicle. Further experiments revealed it was enough to treat a dry seed for a matter of minutes, even seconds, to change the trajectory of its life. “Almost by the time you shut the door, the treatment’s over,” says Wargent.  

And it doesn’t seem to matter what kind of seed it is. So far, the team has experimented with soybean, corn, canola, lettuce, and broccoli seeds, with tests just beginning on peas, ryegrass, wheat, oats, barley, and rice.  

“So far, all the seeds we’ve tried, it’s worked,” says BioLumic New Zealand R&D lead Ana Pontaroli, who was previously a wheat breeder in Argentina. It seems incredible, but seeds are not dead, just inert, she says. They lie in wait for a signal—light, water—that tells them to start growing. It seems BioLumic’s treatments simply provide an additional stimulus to which the seeds respond. 

Field trials with BioLumic-treated soybeans in the United States showed they grew faster, resulting in a 25 percent yield increase compared with controls. Commercial breeding programs would typically invest in a variety that showed a 2 percent yield, says Wargent. “So to get double-digit percentage gains by just turning a little switch…”

In addition, when the US team deliberately inflicted a pest attack on the leaves of the fully-grown plants, they found that those that had been light-treated as seeds had half the amount of insect predation than the control plants did. 

“Crops with early vigor can be more efficient in uptaking nutrients and water and competing with weeds,” says Pontaroli.  “And if that translates into final yield, that’s obviously a gain for the farmers. That’s something that gives us hope it can be translated into a product.”

The few farmers with direct experience of BioLumic seeds are already impatient to get their hands on more of them.

West of Palmerston North, the landscape is flat, farming heartland. Dairy cows stomp mud across neon green paddocks. On one horizon, hundreds of wind turbines are strung along the Tararua Range. On the other, the massive snow-draped volcanic peaks of Taranaki and Ruapehu loom surreally above the plains. 

Near the agriculturally-named town of Bulls—adorned with bovine statues on every street corner—is Waitatapia Station. The name means ‘plenty of good water’ in Māori, and the farm stretches across 2200 hectares of sandy country in five blocks near the Rangitikei River.

Three generations of Hew Dalrymple’s family have farmed here for a century. Around 25,000 lambs and 2,000 beef cows are fattened here each year, the paddocks interspersed with forestry blocks of radiata pine. The Dalrymples also grow maize, barley, and wheat, and vegetables for the frozen and fresh markets—sweetcorn, peas, beans, cabbages, broccoli, cauliflower, and parsley. 

The scale allows Dalrymple to be an early-adopter of new technology, equipment, techniques and crops. “In the last 25 years, we’ve had some form of trial on the farm every single year, and quite often multiple trials on different things.” 

So when Wargent came to him a few years ago asking to test BioLumic corn on the property, Dalrymple immediately agreed.  Light affecting plants’ growth seemed logical, he thought, but seeds? “I thought to myself, now we’re getting a little bit extreme—light treatment on a seed? But I did think that if it works, that’s outstanding, because there’s only a limited amount you can do with treating plants. You can’t efficiently go and treat a paddock of maize with light.” 

Wargent’s team treated around 1000 corn seeds with UV, and planted them in a 10×20 meter patch inside one of Waitatapia’s cornfields. In every other way, the seeds were identical to the rest of the crop. But at harvest time, when Darymple walked out among the swaying green stems and came to the BioLumic patch, he was staggered at what he saw. 

“It struck me down,” he says, shaking his beanie-clad head. “It was unbelievable. Unbelievable.” 

In a typical maize paddock, he explains, the plants are uneven. Although they’re genetically identical, some are taller and stronger, while others are weedy and small. But in the BioLumic area, all the plants were the same. The best plants weren’t any better than the biggest control plants, but there weren’t any that were stunted.  

When the scientists lifted the corn from the soil, the BioLumic plants had much larger root systems. And when they analyzed the yield, the treated plants produced at least 10 percent more kernels by weight. (A second trial in 2022 recorded a 15 percent increase.) It wasn’t that the cobs were bigger, it’s just that they were all big. The plants had maximized their potential. “It came from lifting the bottom ones up,” says Dalrymple.

A ten percent yield increase would equate to hundreds or thousands of extra dollars in his pocket, he says, and if the treatment costs less than that, “why wouldn’t you do it?” That’s without even considering the other potential benefits. BioLumic hasn’t conducted fully organic trials yet, but even having to apply less fertilizer and pesticide would have environmental as well as economic upsides, he says.  

“This is game-changing stuff in my opinion—it is extraordinary tech.” He was so impressed by the results, in fact, that Waitatapia Station made a small investment into BioLumic. “People could say you have a biased view, but I wouldn’t have said anything different to you if I didn’t have a cent in it,” he says.

BioLumic can now show that their recipes work, but they’re still unraveling exactly how. We know that plants sense UVB with the UVR8 protein, which then triggers a bunch of genes to be expressed. But plants have many different receptors to sense visible light, so it’s possible there are other UV receptors we haven’t discovered yet.  

The company’s scientists also aren’t yet sure exactly what is going on inside the plant that leads to increased yields or increased cannabinoids—just how the UV light “unlocks its potential”, as Leyla Bustamante, BioLumic R&D Science Manager puts it. “You could be an athlete, you just need to train—so likewise there’s this potential in the plants to do the things that normally they don’t.”

Originally from Colombia, Bustamante is a molecular biologist who worked on malaria in the UK for 17 years before moving to New Zealand and joining BioLumic in 2019. Although she had never worked on plants before, as a biologist, she was “interested in anything that has a good question and a good hypothesis and good data to answer those.” She found BioLumic’s question fascinating: “Just like, what is happening inside that is telling this little organism to change, to be better? As a biologist, that’s just beautiful.”  

The company’s scientists are beginning to glimpse the genetic basis of the changes wrought by the light treatments, Wargent says. They take a tiny leaf sample the day after the plants come off the UV shelf, crush it up in a mortar and pestle, and run the genetic material through a desktop PCR machine.

That’s enabled them to identify ‘marker’ genes that are expressed in the treated plants, but not in the controls. Wargent hopes those markers may allow them to play detective, and investigate the pathways that lead to increased yield—or even reduced inputs of fertilizer, fungicides, or pesticides. 

As the genetic data mounts, he plans to use machine learning to predict which recipes are likely to be successful for which varieties. “We think there are billions of these potential recipes, even just in the UV space—different timings, intensities, durations, wavelengths. Billions. So how are we going to test all those? We have to predict them.” 

The knowledge gained in the process could even have much broader implications. 

“We’ve got a reasonable chance of understanding [how] yield might be controlled in a way that no one understands today,” Wargent says. And light might only be one route to influencing it. “There could be other ways you could pull instantaneous within-lifetime levers in crops.”

If Hew Dalrymple could plant entirely BioLumic corn tomorrow, he would. But the start-up is only on the cusp of commercialization. To illustrate the problems of scale, Dalrymple does a few sums. Waitatapia alone uses around 105,000 seeds per hectare of maize, and last year, they planted 115 hectares. That’s more than 12 million corn seeds every year, just on one New Zealand farm.  Globally, “there’s trillions, there’s kazillions of seeds grown a year.”

Reaching that scale isn’t impossible, it will just take time, Wargent says. In the US, BioLumic is experimenting with a conveyor belt system to treat more seeds at once. In 2021, they trialed light-treated soybean seeds on 1700 field plots in 74 locations. The company is close to commercializing a cannabis product in collaboration with an Auckland medicinal marijuana company.  

The business model is not selling devices or hardware. Instead, BioLumic plans to license the light recipes, providing the hardware for free or through partnerships with manufacturers (they have just signed a deal with global grow light company Fluence.) 

That means farmers wouldn’t have to make an expensive investment up-front; they would simply pay a royalty on top of the cost of their seeds, just as they do already for other common treatments and coatings. The price of the BioLumic treatment would be similar, too, Wargent says. “It has to work for the farmer.” 

Ultimately, he envisions a future where a seed cooperative in Africa can take out a license to provide a BioLumic UV treatment locally to smallholders, with the confidential recipes beamed wirelessly from New Zealand to the LED device at the push of a button.  

But in addition to logistics and scale, and developing the precise products for each crop, a few more years of field trials are needed, Wargent says. “Having repeated seasons in different varieties of each crop, proving beyond doubt that your technology provides benefits to farmers.” 

“Farming is hard, and it takes time, and science is also hard and takes a long time. You don’t go from promising work to something that is scaled across the planet in 12 months. We’ve developed the technology. Now we’re developing the product.” 

Sitting in his farm truck on a winter morning in June, looking out over the stubble where the latest BioLumic corn trial was harvested, Dalrymple is as close to excitement as a Kiwi farmer typically allows himself to be. “Ten years ago, if someone said to me, we’re going to alter the yield of plants just by zapping light onto a seed, I’d have said, I don’t think so. But here we are—there’s no debate about it. It’s just a fact now that light treatment of seed is going to be part of the farming world.” 

But in addition to logistics and scale, and developing the precise products for each crop, a few more years of field trials are needed, Wargent says. “Having repeated seasons in different varieties of each crop, proving beyond doubt that your technology provides benefits to farmers.” 

“Farming is hard, and it takes time, and science is also hard and takes a long time. You don’t go from promising work to something that is scaled across the planet in 12 months. We’ve developed the technology. Now we’re developing the product.” 

Sitting in his farm truck on a winter morning in June, looking out over the stubble where the latest BioLumic corn trial was harvested, Dalrymple is as close to excitement as a Kiwi farmer typically allows himself to be. “Ten years ago, if someone said to me, we’re going to alter the yield of plants just by zapping light onto a seed, I’d have said, I don’t think so. But here we are—there’s no debate about it. It’s just a fact now that light treatment of seed is going to be part of the farming world.” 

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