Studies the epidemiology and control of all important diseases of sunflower in the U.S.  Works in conjunction with project geneticists and botanist in evaluating disease resistance of both cultivated breeding lines and wild Helianthus spp. accessions, and in determining the inheritance of resistance.  Current pathology research is concentrated on integrated control of Sclerotinia wilt and headrot, (including genetic resistance, biological and cultural controls), and control of metalaxyl-resistant downy mildew through new resistance genes complimented with the new fungicides.  In cooperation with our molecular geneticist, we are looking for markers associated with resistance to downy mildew, and to both Sclerotinia head rot and stalk rot.  Other research topics include finding resistance to a new strain of Verticillium wilt and continued work on Phomopsis stem canker.  Cooperative research programs in place with scientists in Russia (dealing with Phomopsis), France (downy mildew), Argentina (Verticillium and Sclerotinia) and Australia (rust).