Researchers at the University of Guelph's Ridgetown campus are testing a heartier strawberry that relies less on daylight than other varieties. (Pat Wellenbach/Associated Press)

Researchers at the Ridgetown campus of the University of Guelph in southwestern Ontario are hoping to extend the strawberry growing season by at least another month with a type of berry that's less sensitive to weather conditions than its traditional counterparts.

The "day-neutral berry," as it's called, relies less on daylight to bud than the typical June-bearing strawberry, and produces fruit "as long as the weather conditions are good," said Prof. John Zandstra, who specializes in fruit and vegetable cropping systems.

The growing process is helped by a high tunnel, a lightweight, solar-heated greenhouse commonly used to extend the growing season of horticultural crops.

So while a low of –1 C expected in Ridgetown Tuesday night should wipe out any remaining outdoor strawberry crops, Zandstra expects his indoor strawberries "will be quite happy."

"We've got our [high] tunnel pretty much closed up," he said. "As long as we get some sunshine during the day to warm things up, they'll carry through the night."

Increasing demand

Day-neutral strawberries are not a new phenomenon. They emerged 20 years, but "the quality at that time wasn't the greatest and people didn't really do much with strawberries" in the fall, Zandstra said.

Researcher John Zandstra, who studies fruit and vegetable crop production at the University of Guelph, has spent five years studying the day-neutral strawberry. (University of Guelph)But demand for strawberries has increased steadily since 1975, and "imports have rapidly outpaced our declining domestic production," according to a report by Statistics Canada.

In 2006, Canada imported almost 85,000 tonnes of strawberries, more than four times the 18,000 or tonnes it produced.

In 2007, Canada imported more than $234.8 million worth of strawberries, according to the Canadian Produce Marketing Association, mostly from California but also as far away as Spain and Poland.

"With a lot of fruit coming in from California, essentially year-round, people realize there are berries available that time of year," Zandstra said. "So when we grow them locally they tend to pick them up a little easier."

Production costs and consumer skepticism mean day-neutral berries, while increasingly popular, are "not terribly widespread yet," Zandstra said.

"You sell berries to people in August and say they're locally grown, they kind of raise their eyebrows on occasion," he said.

Zandstra and his team of researchers expect to harvest their strawberry crop in mid-November.

Zandstra has been studying the day-neutral strawberry for five years.