[deck]Cooler temperatures and shorter growing seasons make growing sweet potatoes a challenge in Canada. Research underway in Eastern Canada could prove to be a real game-changer when it comes to producing the popular tubers in this country.[/deck]
It’s no secret that sweet potato consumption is on the rise in Canada. The numbers certainly back that up.
According to Jean Mukezangango, a senior market development analyst with Agriculture and Agri-Food Canada, sweet potato consumption in Canada nearly doubled from 2007 to 2012. Canadians ate an average of 1.43 kilograms of sweet potatoes per person in 2012 compared to 0.72 kilograms in 2007.
Kevin MacIsaac, general manager of the United Potato Growers of Canada, says the increased demand hasn’t come as much of a surprise to the potato industry. He says the increase is attributable to two main factors — a public perception that sweet potatoes are healthier than traditional types of potatoes and the recent explosion in the popularity of sweet potato french fries.
“There always was some production of sweet potatoes across North America, but until processing companies figured out how to make a good french fry, that’s what really led the charge with getting people to buy it,” he says.
MacIsaac says while Canada’s growing appetite for sweet potatoes is potentially good news for producers in this country, they face some serious challenges in trying to meet that demand. Most popular varieties require high heat units and longer growing seasons, something in short supply in many parts of the country.
Production Challenges
Researchers in Eastern Canada are hoping to change all that. Led by Valerio Primomo, a research scientist and vegetable-breeding expert with Vineland Research and Innovation Centre in Ontario’s Niagara region, these researchers are investigating ways of increasing domestic sweet potato production.
Covington, which was developed in North Carolina, is currently the most popular sweet potato variety grown in Southern Ontario. The challenge is that growers have a small window for planting and harvesting this long-season variety, and as a result yields are lower when compared to production south of the border. Developing varieties that are better adapted to short growing seasons and cooler environments will allow the expansion of sweet potato production in Canada.
Primomo says one of the main reasons he started his research three years ago was the growth potential he saw in the sweet potato industry. There are currently about 1,500 acres of farmland in southern Ontario currently being used for sweet potato production; an additional 6,000 acres would be needed to offset Canada’s current import needs.
“That’s a huge opportunity. If you look at all the crops, this is the biggest one right now in terms of per cent increase in consumption,” Primomo says.
He adds the primary aim of his research is to develop new varieties adapted to southern Ontario’s climate that can be planted earlier, harvested sooner and can better tolerate cool temperatures.
“Right now if they plant in June, [growers] need at least 100 days to get a good crop, so you’re going into September. By late September it starts to cool down, so the growers run the risk of getting chilling injury in their harvest,” Primomo says. “Some growers will try to harvest it earlier. The problem is if you start harvesting earlier you’re not going to get the premium grades retailers are looking for.”
While it takes many years before most breeding programs produce any solid results, Primomo is optimistic Vineland’s efforts will be rewarded much sooner. Vineland has teamed up with Louisiana State University, which is providing the research centre with access to hundreds of crossed seed from its breeding program.
“They have thousands and thousands of crossed seed, which is more than enough for their breeding program. They’ll send us a few thousand seeds each year and each seed is a potential new variety,” Primomo says. “The first year we tested 500 seeds. Last year we did 900. This year we’re going to test another 500.”
Of the 500 initial lines that were tested at Vineland, 86 were chosen for further testing in replicated trials. Those trials were used to determine the top 15 lines best suited for southern
Ontario, and growers at four farm sites are testing them this summer. The potatoes will be harvested in September with all of the relevant data supplied to Vineland.
Primomo says there is the potential for Vineland’s research — which is funded by the Canadian Agricultural Adaptation Program, the Ontario Ministry of Agriculture, Food and Rural Affairs’ New Directions Research Program, the federal Agri-Innovation Program, McCain Foods Ltd. and Campbell Company of Canada — to produce a commercial result within three to five years.
“The demand is there. The opportunity is there. I know that as we talk to more and more growers, we can influence them to start growing sweet potatoes,” Primomo says.
Potential in Maritimes
The potential for increasing sweet potato production in Nova Scotia and the rest of the Maritimes is similarly encouraging, says Viliam Zvalo, a horticultural specialist with Perennia who is also partnering with the Vineland Research and Innovation Centre. Currently, there are just 35 acres of land devoted to sweet potato in the region and less than 10 per cent of the demand for fresh market sweet potato in the Maritimes is supplied domestically.
Zvalo’s research is focused on variety testing in Nova Scotia, fertility, and crop management techniques such as the use of black plastic and drip irrigation in sweet potato production. Last year, he evaluated 11 different lines of sweet potatoes produced by Primomo at Vineland. Although some lines look promising, Zvalo says it’s too early to read anything into the results after just one season.
One of the challenges Zvalo says he and his research colleagues face is increasing yield without a loss in quality.
“The challenge here is if we increase the maximum yield we will increase the size of the potatoes,” Zvalo says. “There’s little value in [jumbos]. They are sold at discount. The No. 1 sweet potato [grade] is where the money is. Anything below that or oversized sells at discount or isn’t marketable.”
The sugar content of sweet potatoes is something else to consider. “We monitor sugar content as it is an important parameter for the processing industry. However since the processing industry in the Maritimes is not sourcing any sweet potatoes locally yet, the sugar content in sweet potatoes destined for the fresh market is not that much of a concern,” Zvalo says. “We simply want to know how the sugar content of new varieties would stack up against U.S. varieties.”
A spokesperson for McCain Foods said the company has not conducted any sweet potato production in Canada for several years and has no immediate plans to resume doing so. The spokesperson added any decision to buy Canadian sweet potato would depend largely on price.
Zvalo says that in order to increase the supply of sweet potatoes grown on the East Coast, some thought will have to be given to increasing storage capacity. Sweet potatoes must be cured in a chamber using high humidity (85 per cent) and high temperatures (23 or 24 C) for up to 14 days prior to being placed in storage for up to 15 months.
“That in itself is a challenge for the producers to get into sweet potatoes, [because] you have to have an ability to cure the crop after harvest and then store it long term,” he says. “Right now we have just one long-term storage facility.”
Zvalo is hardly a novice when it comes to studying sweet potatoes in Canada. He began his research in 2004 when he investigated the suitability of a dozen lines of sweet potatoes for the Maritimes. Further research led to the discovery that using black plastic mulch is essential for sweet potato production in Nova Scotia.
UPGC’s MacIsaac predicts that more growers are likely jump on the sweet potato bandwagon once hardier varieties better suited to Canada’s cooler climate are introduced.
“I think there’s a big willingness among the grower community to find out more about this, and see if they can capture some of the consumer demand for sweet potatoes that’s really replacing their market right now,” he says.
“The way the potato industry used to be, you often shipped a whole tractor trailer load of one-sized bags or one kind of potatoes. The way the industry is now, you may have a couple of skids of organic, and you may have a couple of skids of reds, and a couple of skids of yellows. That would fit in well with the broker or shipper who’s feeding a marketplace that requires several kinds of product.”
