Vistas of tan spot research

Tan spot of wheat is, in many respects, a disease problem of human creation . Reduced tillage, intensified wheat production, and cultivars resistant to the rusts have created an agricultural landscape radically different from that of a generation ago. Tan spot is one of the newly important stubble-bo rne diseases agriculturists now face worldwide. Rather than trying to recre ate the past, agricultural researchers must endeavor to optimize new produc tion practices. Phytopathological research on tan spot began in earnest in the 1970s with the pioneering work of R.M. Hosford Jr. in North Dakota, U.S .A. and R.G. Rees in Queensland, Australia. A milestone was reached in the late 1980s when a host-specific phytotoxin was described independently by r esearch groups at Kansas State (U.S.A.) and Manitoba (Canada) universities. Immediately thereafter, the genetics of the pathosystem began to be carefu lly dissected by L. Lamari, C.C. Bernier and coworkers. Today, researchers are peeling back the layers of interaction mechanisms, and findings so far have contributed to science's understanding of plant disease causation and development. Hosford reviewed the tan spat literature for the First Interna tional Tan Spot Workshop (Hosford 1982) and Rees similarly related developm ents in Australia for the second workshop (Rees & Platz 1992). Also for the second workshop, Krupinsky (1992c) compiled a useful bibliography. In this spirit, we offer this review and (often personal) vistas of tan spot resea rch in commemoration of the Third International Tan Spot Workshop.