- by Larry Powell Roblin, Manitoba, CA Se.22 - '10. Record rainfall and a disastrously wet season have already ruined millions of hectares of grain crops on the Canadian prairies this year. A soggy, unharvested canola field in western Manitoba. PinP photo Now, another scourge, also related to excess moisture, has emerged. Gov't. of MB photos A disease identified as “late blight” has decimated backyard vegetable crops, notably potatoes and tomatoes in Manitoba. Widespread reports from vegetable gardeners tell of crops ruined by the blight, which is a highly-contagious pathogen. It can linger in the soil and even spread in the wind. My wife & I lost our entire tomato crop this summer. l.p. Mandy Lewick of Manitoba Agriculture, Food and Rural Initiatives (MAFRI) in Roblin, says wet weather, such as