To the barley grower, no other disease of the barley is probably of such economic importance as the late blight (Helminthosporium teres). When active work was begun in the summer of 1909, certain barley plots of the college showed that more than 90 per cent of the plants in those plots were infected. The disease presents itself in the form of brownish, orange colored spots, which at first are oval or circular, but later become elongated. As a result of infection, the greater surface of the leaves takes on a yellowish color. In contrast to this effect is the brick red color of the spotted areas. A marked feature, as a result of an examination of a diseased plant, is that a single individual shows all stages of attack. Ordinarily the fungus is noticed in this locality, during the early part of July. Usually at that time, the basal leaves will have become completely dried, while those above will show a progressive decrease to the point where no spots are present. This disease is closely related to the "Yellow Leaf." The last named form is not so destructive for the reason that "Yellow Leaf" singles out individual plants, while the Late Blight is broadcast in its attack.
Proceedings of the Iowa Academy of Science
© Copyright 1912 by the Iowa Academy of Science, Inc.
Bakke, A. L.
"The Late Blight of Barley (Helminthosporium teres Sacc.),"
Proceedings of the Iowa Academy of Science, 19(1), 93-102.
Available at: https://scholarworks.uni.edu/pias/vol19/iss1/13