Do you know the difference between Phytophthora root rot and gray leaf spot? If not, you may want to contact the Iowa State University Plant Disease Clinic. Last year almost 5,000 Iowans did just that. The clinic, located on the third floor of Bessey Hall, received 1,719 samples during 2004--including whole plants, dry leaves, green leaves, stems, roots, branches, and twigs. The staff also answered 3,267 calls, e-mails, faxes, and letters about plant problems.