During 1961 losses from stripe rust (Pucciniu glumarum) in California were higher than known for any previous year. The unprecedented severity of this rust in the Sutter Basin in 1961 may be attributed in part to favorable environmental conditions or, on the other hand, may indicate a recent shift in pathogenic races of the organism.

The authors gratefully acknowledge the assistance of Coit A. Suneson, USDA Agronomist at Davis, for his observations on the relation of nitrogen fertilization to rust response. The above progress report is based on Research Project No. 979-Davis.