Nova Scotia strawberry farmers are hoping this season’s bitterly cold winter will stub out a stubborn virus that is threatening the province’s $17-million per year industry.
The virus — the result of two known viruses combining into a new, complex form — is spread by the strawberry aphid. The strawberry aphid is a small, soft bodied insect that siphons plant sap.
The virus weakens plants to the point where the berries themselves are undesirably small, or the plant fails to produce berries altogether.
In response to the outbreak last year, farmers plowed under almost a third of Nova Scotia's productive strawberry fields that had been badly damaged.
In September, a survey of fields that had been newly planted with clean and disease-free plants found 25 per cent were infected with the yellow-edge virus and 15 per cent had the mottle virus.
“That is still a significant amount of disease. The pain isn't over, this isn't a one year fix,” said John Lewis,a horticulturist with the provincial Crown corporation Perennial.
Lewis has presented the findings in four provinces and one U.S. state as the strawberry industry watches Nova Scotia respond to an epidemic that came out of nowhere.
The virus was long present in Nova Scotia at extremely low levels and only exploded recently along with the strawberry aphid that spreads the infection.
“We took it for granted that this was an issue that was long past for those that even remembered it,” said Lewis.
Lewis speculates that pest-friendly conditions like climate change and a succession of mild winters, along with large farms were among the factors contributing to a “perfect storm.”
“The conditions were in place over the last three or four years for it to turn into an epidemic that and once it gets going — that’s the nature of an epidemic — once it gets going it’s hard to stop,” he said.
In August, the Nova Scotia government announced it would provide up to $2.3 million in loans to help farmers. Some farmers were critical of the announcement, saying that was far to little to make a difference.
“We are making inroads here, we are making progress,” said Lewis.
Testing later this month will give scientists and farmers their first indication of what's ahead, including whether a brutally cold winter has knocked the aphid population down.