News
Anti-viral technologies can reduce pathogen transmission in the greenhouse

April 6, 2023 – A recent Ontario Greenhouse Vegetable Growers (OGVG) research project tested three anti-viral technologies that aim to prevent the transmission of both COVID-19 and an economically significant plant virus affecting tomatoes inside commercial greenhouses. The project included three approaches developed by service provider PRODIGie – Innovation Evolved Inc.

For the last several years, Ontario’s greenhouse vegetable growers have been dealing with COVID-19 and Tomato Brown Rugose Fruit Virus (ToBRFV), first detected in Ontario in 2019. ToBRFV causes mosaic and distortion of leaves, as well as brown, wrinkly spots on the fruit, making them unmarketable.

A big challenge for growers is that ToBRFV can survive for long periods on surfaces away from tomato plants and can be easily picked up by people, tools, and equipment – increasing the chance of infection and spread through the greenhouse. COVID-19 has been a leading threat to human health, food security, and business continuity since it emerged on the global stage early in 2020.

With both pathogens, time was of the essence to keep the spread and impact to a minimum, leaving the industry searching for quick solutions. Funding from the Greenhouse Competitiveness and Innovation Initiative (GCII) helped OGVG test the suitability of various anti-viral technologies as possible tools to control the spread of both pathogens.

The first anti-viral technology tested, Novel Composite Cold Spray Coatings, can be applied to static objects like door handles and other high-touch areas. According to a news release by the Agricultural Adaptation Council, it performs like a barrier, aiming to prevent microbial adhesion to surfaces.

These studies demonstrated up to a 97 per cent reduction in ToBRFV on surfaces where the Cold Spray Coatings were applied. This was a ten-fold increase in effectiveness compared to current copper benchmarks.

The second technology that was evaluated was a non-alcohol oil-based hand rub with antimicrobial properties. It’s aim is to inactivate pathogens on the hand and also does not need regulatory approval since it is considered a personal care product.

Currently, many greenhouse workers use nitrile gloves to minimize the risk of the spread of ToBRFV, but the virus could still adhere to the gloves, so changing them often is critical. This hand rub has the potential to provide longer protection and reduce the overall spread by workers’ hands.

The third solution that was tested was an ozone treatment that contains oxidizers that can kill microorganisms or inactivate viruses when applied to surfaces.

There was a 98 per cent reduction in ToBRFV after three minutes of contact with aqueous ozone, which is a shorter contact time than what is necessary for many commercially available disinfectants. Although efficacious, work is still underway to determine the best and most critical uses for this product.

All three solutions can be used together. The next step is determining how they can be best commercialized. There has been initial interest from growers, but grower trials are needed to validate that interest.

For OGVG, the ultimate goal is to make the sector more resilient to pathogen threats to both its workforce and its crops and keep growers competitive and productive. Achieving that could mean changing the crop protection strategies from reactive to proactive and looking for solutions that are effective yet don’t require lengthy regulatory approval processes.

This project was supported through the Greenhouse Competitiveness and Innovation Initiative, a cost-share program funded by the Ontario government and delivered by the Agricultural Adaptation Council on behalf of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).