Late Blight Update

Late blight, a devastating disease impacting tomatoes and potatoes, to date, has been documented in several states. Those states include North Carolina, Ohio, Florida, Kentucky, Louisiana, Michigan, New Jersey, New York, Massachusetts, Pennsylvania, Tennessee, Virginia, Vermont, Wisconsin, Maine, and West Virginia. (For updates on late blight occurrences, go to


Late blight usually develops in south Florida during the winter growing season. According to Cornell University’s Margaret McGrath, there were 22 confirmed reports from Jan. 3 to June 14 in 2013. (Click here for more information on recent outbreaks.)

Similar to 2012, the main genotype (strain) of the pathogen found so far this year is a new one, US-23, first detected in 2010. McGrath said US-23 is more virulent on tomato than potato. 

For more information on recent occurrences of late blight, challenges, and the future outlook, click here for a report from McGrath, who is in the Department of Plant Pathology and Plant-Microbe Biology at Cornell University.