Late Blight

A strain of late blight known as US-23 is now the main culprit. Late blight presents as brown spots. (CBC)

If your tomato plant is presenting with brown spots, the province wants you to destroy it. The same disease that caused the Irish Potato famine in the 1840s is threatening P.E.I. potato crops now.

Provincial and federal agriculture officials are taking measures to protect the province’s potato crops from a new strain of blight that is taking a toll on backyard tomatoes.

Blight is an infection on plants that presents itself as brown spots on the leaves or the tomatoes themselves, eventually causing them to rot. However it can also spread to potatoes.

The first case of late blight was confirmed in a potato field in the Freetown area on Tuesday.

Agriculture Canada researchers are identifying different strains of late blight. A strain known as US-23 is now the main culprit.

In the past, late blight from potatoes was blamed for infecting home gardens. Now it appears the situation is reversed and home gardens are distributing spores to potato growing areas.

“And that is of concern because of course we have a billion-dollar potato industry here on P.E.I. And we don't want any risk to that industry,” says Rick Peters, a research scientist with Agriculture and Agri-Food Canada.

Peters is getting more calls from people who are experiencing late blight in their tomatoes. 

Rick Peters

Rick Peters, a research scientist with Agriculture and Agri-Food Canada, says late blight is a threat to potatoes. (CBC)

Officials suggest people drop off samples of plants they suspect have late blight to the provincial agriculture department. Then, they should put the plant in a plastic bag and dispose of it so it can’t spread spores.

"Unfortunately, by the time you detect an infection it's already too late to save your crop," says a government fact sheet on preventing blight.

Experts suggest using varieties of tomatoes that are resistance to the new strain such as Mountain Magic, Mountain Merit and Defiant.

“They range from cherry tomatoes right up to large tomatoes so there's different varieties available that way,” said Peters.

The provincial agriculture department has put out a new fact sheet about late blight available on their webpage.