"We’ve seen some amazing results, particularly for crops such as Amaranth, where treated seeds have resulted in significant reductions in infections, improved germination rates, higher yield, and reduced losses,” says Dr. Katie Wilkins, Senior Plant Scientist at Vertical Future, about Zayndu’s ‘activated air’ seed cleaning technology. Trials have shown baby leaf salad crops germinate a day faster following treatment and Zayndu is to announce its findings at the Global Vertical Farming Expo (GVFE) 2021 on 1-2 December 2021.
Ralph Weir is CEO of Zayndu, a spinout from Loughborough University. He explains that its technology uses a ‘cold plasma’ generated when an electrical current moves through air, splitting the oxygen and nitrogen molecules and creating a powerful disinfectant with no residues.
“Our initial focus was removing fungal spores from seeds, and this has been successful,” he says. “We then observed that treated seed was germinating faster and had a higher germination success rate. For crops such as microgreens, where there is a 10-day cycle, 1- or 2-days faster germination will have a massive impact on productivity.
“Cleaning seed with activated air has the potential to increase productivity by 10% or more and reduce the risk of fungal disease, without the need for chemicals or hot water.”
The company is collaborating with Vertical Future and NIAB on CHOPS (CEA Heirloom Optimisation and Pathogen Control of Seed), an Innovative UK-funded project to create a quality-marked, high health status seed system.
Vulnerable to fungi
Vertical farms are closed systems, so they are vulnerable to rapidly spreading fungal diseases. To prevent this, the highest levels of hygiene are required, including cleaning seeds to remove fungal spores, the options for which are currently limited.
Katie continues: “We are very excited to be working with Zayndu and NIAB on this project and using this technology in our vertical farms. Increasing yield has a significant impact on the productivity and sustainability of this industry.”
Dr. Jane Thomas, a senior pathologist at NIAB, comments: “A non-chemical approach is really advantageous for vertical farms. Zayndu’s cold plasma treatment is a good technology and one of the few options available for vertical farming. The alternatives are hot water treatment, which can knock back germination of viable seed, or possibly UV lighting, which has the potential to damage the seed.
“The accelerated germination rates are very interesting. It could be that the treatment is ‘priming’ the seed by physically altering its coating which is encouraging rapid germination. Salad leaves are a short-lived crop, so reducing the cycle by a day will have a big benefit for productivity, allowing more harvests within a fixed period and space.”
Zayndu’s activated air technology is completely dry and chemical-free. The company launched its small mobile unit Aurora Z10 earlier this year to allow small batches of seeds to be disinfected by growers as they are required. For the first time, it enables seeds such as tomatoes or fast-growing seeds like rocket to be disinfected.
Ralph says the technology may also allow more species to be grown undercover. “Our technology removes fungal spores from seeds, which can be a godsend – for example, we remove 100% of fungus from peas, which are notorious for carrying high fungal loads.
“Infected pea shoots become slimy, smell horrible, lead to the crop being destroyed, and they may infect other crops within a tightly-packed vertical farm. Removing the fungi would make it easier to grow high-value pea shoots in a controlled environment.”