Last year we started a project focusing on determining origins of Phyllachora maydis, the causal agent of tar spot of corn, in the United States. As part of this project, we need to collect Phyllachora species from different hosts and areas. Today I went for a lunchtime walk and was able to find Phyllachora spp. on four different grass hosts. Note the large, somewhat raised stroma that follow the veins on most occasions. They can have halos around them as well. If you are walking fields, gardens, parks and happen to come across any putative Phyllachora, please send leaves and seed heads to the UIUC plant diagnostic clinic
at S-417 Turner Hall, 1102 S.Goodwin Ave. Urbana, IL 61801 ATTN Tar spot survey. We really can use your help in this regard!
Nathan Kleczewski- Extension Plant Pathologist UIUC