Plants maintain complex relationships with a wide spectrum of microorganisms. A significant portion of these interactions are with plant pathogenic microorganisms, which cause diseases of various plant parts and thereby decrease crop productivity. Studying plant diseases is vital to understanding the biology of plants, which, in turn, provides crucial information for successful agriculture. Archana Vasanthakumar, Postdoctoral Fellow, Laboratory of Applied Microbiology, SEAS, Harvard University,Â will explore the impact of plant diseases on humankind, beginning with the Irish Potato Famine in the late nineteenth centuryâ€”an event that has been heralded as the beginning of plant pathology as a discipline. She will go on to examine the role of plant pathology in current agriculture. The program will take place Monday, September 24, from 7 – 8:30 at the Hunnewell Building at the Arnold Arboretum. Free, but registration requested (www.arboretum.harvard.edu).