There’s rice growing in Palmerston North. It’s indoors and being paid for by the Bill & Melinda Gates Foundation. What is unusual about this rice is that it’s not flooded with water. Such rice is known as dry-seeded rice and it uses far less water than paddy field rice, which is how almost all rice is grown worldwide. It also avoids the underwater microbial action in flooded fields that makes rice production a surprisingly high methane emitter, albeit much less so per kilo of food than many animal products. Rice is the staple food of about half the world’s population.
It is being grown by BioLumic, which has research centres in Palmerston North and the United States and was this year awarded $3.5 million by the Gates Foundation. It aims to develop seed treatments that enhance rice germination rates, seedling growth, weed competitiveness and drought tolerance, which will help enable small-scale growers in India grow dry-seeded rice.
BioLumic’s method is unique internationally, according to its founder Jason Wargent. It exposes seeds and sometimes plants to fluxes of ultraviolet (UV) light – specifically the wavelength range known as UVB. This triggers protective responses that, he says, increase yield by 10% or more, meaning boosts in plant parts such as leaves, flowers, fruit or beans, depending on the plant. “That’s nirvana for agriculture,” says Wargent. “Usually you’d be pleased with 2% from a new technology.” With strawberries, the yield increase has hit 45%.
Wargent, a professor of plant photobiology at Massey University, has worked in this field for 20 years. He says all plants have a dedicated photoreceptor to detect UV light, which is part of sunlight but too energy-intense to be used for photosynthesis. His research showed that the right “recipe” of UVB exposure prompts plants to acclimatise via a cascade of genetic changes.
For each seed variety, BioLumic tweaks the UVB wavelength, irradiance and duration. It does so by tracking changes that UVB initiates in key genetic markers that correspond to yield increases and uses a “big data” high-throughput computer program to calculate the optimal recipe.
The full suite of genetic changes caused by UVB priming isn’t yet known, but Wargent knows it works partly by making photosynthesis more efficient. Plants often downgrade their rate of photosynthesis, particularly if there’s too much light, so there’s room for gains.
Nick Albert, a plant scientist at Plant and Food Research, says the apparent effects on photosynthesis are exciting. “It’s not something a lot of people have looked at, but it needs exploring more widely.” BioLumic understandably keeps its intellectual property private, although Wargent published some of his research before founding the company.
Albert agrees that plants detect and acclimatise to UVB light, and he and his colleagues have shown that UVB exposure increases sunscreening compounds and antioxidants in perennial fruit plants.
Wargent says the UVB technique can address sustainability challenges. Better yield means less land is needed, and he talks of reduced fertiliser and irrigation needs and boosting the plant’s defences against pests and disease. The process uses energy-efficient LED lights and takes just a few minutes. It needs no regulatory approval, unlike techniques such as breeding, treating or genetically altering seeds.
BioLumic also works on medicinal cannabis and has improved yields of soy and corn in US field trials. Midwestern seed company Gro Alliance is integrating BioLumic’s UV-light treatment into its seed processing system.
BioLumic will license its light recipes, says Wargent, who wants all scales of seed producers to be able to affordably access the technology. Commercialisation will take time, he says, but “we have a clear road-map.”
