Explaining Late Blight Lineages

Late blight is a disease that we deal with to some extent in the mid-Atlantic each year.  When reports come in you may see something mentioned about the lineage that was detected.  What exactly are we telling you when we mention this information?  

Each lineage has unique genetic characteristics that may impact management practices and also level of concern in the region.  Some lineages prefer to cause disease on potatoes, some tomatoes, and some both.  In addition, some are sensitive, intermediate, or insensitive to mefanoxam fungicides.  As a quick reference, you can view the recent lineages reported in the US HERE.  I have simplified the information for you below.

Source: udel.edu