Stem Rust on Wheat Head (image) University of Sydney Share Print E-Mail Caption The stem rust pathogen infects all above-ground parts of the wheat plants, including the head. In this case, control with fungicides is usually not possible because of end-product contamination, or economic. Credit Karanjeet Sandhu, University of Sydney. Usage Restrictions Must credit Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.