Oomycetes are some of the most devastating plant pathogens. Some of you may have family who settled in the United States as a result of the Irish Potato Famine in which over one million people died, while another one million emigrated. The pathogen that devastated Ireland's potato crop in the mid-1800s is an oomycete calledPhytophthora infestans. Some oomycetes that are likely more familiar to us here in Iowa are Phytophththora sojae and Pythium species. These pathogens are usually associated with seedling blights on corn and soybean, although P. sojae can affect soybeans throughout the growing season. Some of you may have experienced "devastating losses" to these pathogens in your corn or soybean field.