Stem Rust produces elongated reddish uredia (pustules). Pustules are bigger than those of both stripe rust and leaf rust, and they are not arranged into stripes. Stem rust pustules are common on leaves, stems, and other plant parts. Black telia (pustules) are formed within a few days after the production of uredia.
Physiological Leaf Spot (PLS) is a complex problem, common in the U.S. Pacific Northwest. It is not caused by any fungi or bacteria. The problem is associated with the deficiency of chloride and/or zinc in the soil. Diseased plants have chlorotic or necrotic round to irregular spots or blotches that range from very small and up to 1-2 cm long. The center of the blotches are usually light colored and later become dark as saprophytic fungi grow on the dead leaf tissue. Applying chloride early on in the growth season can reduce symptoms.
Cephalosporium Stripe (C Stripe), caused by the fungus Cephalosporium gramineum, is a common disease in the U.S. Pacific Northwest. The disease initially shows up as continuous yellow stripes from the bases to the tips of leaves. The yellow stripes later change to dead tissue. Plants in severely infected fields can produce white heads.