Puccinia hordei on barley, Puccinia reconita on triticale and rye. Leaf rust is favored by moist weather and temperatures ranging from 55 to 75 degrees F. Symptoms. Leaf rust symptoms appear as small, round, light orange-brown pustules on the leaf blade and leaf sheath. They may also occur on heads of very susceptible cultivars in the advanced stages of an epidemic. Brown, oblong pustules appear later in the season.
Resistant varieties are the most practical control measure.
But, because of the limited acreage of these crops, fungicide use would be expensive. The septoria leaf and glume blotch disease complex is a common disease of rye, barley, and triticale. Glume blotch of rye, barley, and triticale is caused by S. nodorum. Septoria diseases are favored by warm, wet weather. Spores produced during wet weather are spread by splashing rain, and they initiate infections throughout the year.