When late blight was discovered in many Alberta potato fields in 2010, growers, scientists and many others in the province’s potato industry were justifiably worried. Its return represented a serious threat to the Alberta potato industry, seeing as the province had been virtually late blight-free since the early 1990s. Caused by the fungal pathogen Phytophthora infestans, late blight is placed by scientists in a group called oomycetes, which are water moulds. The pathogen is highly aggressive and can potentially infect all plant parts, causing rapid dieback and death. Late blight is known for the extensive damage it can do if allowed to get out of control, not only reducing the yields of potatoes in the field but also causing major losses in tubers in storage. The disease was responsible, in large part, for the Irish Potato Famine in the 1840s, which resulted in the deaths and mass emigration of millions of people. More