Breeding Better Tomatoes: Homegrown Solutions Support Ontario Value Chain
Dr. Steve Loewen always has his sights on traits that tomatoes will need in the future. After almost four decades as a processing tomato plant breeder, his curiosity and focus on improving the odds for this segment of Ontario agriculture is still what gets him out the door every day.
Published: February 9, 2026
Lead photo: Loewen develops lines of tomatoes for seed companies to further breed, develop and release as commercial varieties to Ontario processing tomato growers.
Impact
Loewen’s work supports the processing tomato sector, which harvested over 670,000 tonnes of tomatoes in 2025 and has a gross farm value of nearly $100 million.
“Steve has been breeding tomatoes for Ontario conditions for as long as I can remember,” says Peter Epp, tomato grower and vice-chair of the Ontario Processing Vegetable Growers. “His name may not be on be on many varieties but if you check the DNA of popular hybrids grown in Ontario, the U.S. Midwest and even some in California, you will find Steve’s work.”
“I have a very long view and long history with this sector and I really want to make a difference in the lives of farmers,” says Loewen, researcher and acting interim director at the University of Guelph’s Ridgetown Campus.
Growing up on a fruit and vegetable farm in Norfolk County, a hotbed of horticulture production in Ontario, Loewen watched how quickly weather and other challenges could upend a productive season and knew he wanted to help tomato growers. His father and grandfather both grew processing tomatoes, and Loewen has been collaborating with industry throughout his career to develop breeding lines that are genetically diverse, adapted to the local region and more nutritional for consumers.
Diversity leads to resilient crops
Loewen is a “pre-breeder” who develops lines of tomatoes for seed companies to further breed, develop and release as commercial varieties to Ontario processing tomato growers and beyond. It’s a long process that can take up to a dozen years and forces Loewen to always be looking down the road at what the industry may need.
“We have the opportunity to take on the high-risk, long-term work that ultimately provides new options and opportunities for the processing tomato industry, right down to the consumer,” says Loewen.
One of his key areas of focus is increasing the genetic diversity of tomatoes in Ontario. “We expect to have more variation in the weather, and greater genetic diversity in commercial processing tomato varieties builds greater resilience in crops,” says Loewen.
Diversity is bred into new breeding lines by crossing cultivated tomatoes with wild species from South America, and Loewen tracks the tremendous progress he’s made in the breeding program. “We now know that about 25 to 30 per cent of all the breeding lines I’m releasing represent new genetic material compared to the rest of the processing tomato breeding programs in North America,” he says.
Balancing dependability with new traits
Loewen deliberately runs a general breeding program at the Ontario Crops Research Centre in Ridgetown—a research centre owned by Agricultural Research and Innovation Ontario—that covers what he calls a constellation of traits.
“I believe this approach adds value to the processing tomato industry in Ontario,” he says. He knows it requires a balance of breeding for new traits that doesn’t come at the expense of the traits the industry depends on – yield, fruit size, colour, firmness as well as disease resistance.
Recently, he’s been working on lines to boost the nutritional value of canned tomatoes. Two of the components he’s focused on are lycopene, an antioxidant related to beta-carotene, and anthocyanins, which have been shown to reduce inflammation. “I’ve worked hard to elevate the levels of lycopene so when consumers choose these Ontario-grown tomatoes, they are getting the benefits,” he says.
Industry support for tomato breeding research
Loewen has always had solid support to fund his breeding program through the Ontario Agri-Food Innovation Alliance, a collaboration between the Government of Ontario and U of G, and the Ontario Processing Vegetable Growers (OPVG). OPVG has been a long-time supporter of tomato breeding research and knows that Loewen’s research is vital for developing new tomato varieties with improved quality and strong disease resistance.
“Steve has been breeding tomatoes for Ontario conditions for as long as I can remember,” says Peter Epp, tomato grower and vice-chair of OPVG. “His name may not be on be on many varieties but if you check the DNA of popular hybrids grown in Ontario, the U.S. Midwest and even some in California, you will find Steve’s work.”
It’s tricky for Loewen to directly measure the impact of his breeding work on the processing tomato sector in Ontario as he doesn’t release commercial varieties. But considering that his own breeding program comprises 800 to 1,000 different lines every year—and more than 200 of the breeding lines he developed are under active license—that could add up to about a 20 per cent contribution to a commercial breeding program of comparable size.
This research is funded by the Ontario Processing Vegetable Growers; and the Ontario Agri-Food Innovation Alliance, a collaboration between the Government of Ontario and the University of Guelph.
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