Reaction of Helianthus Species to Erysiphe cichoracearum. M. Saliman, Graduate Student, Plant Science Department, West Texas State University, Canyon 79016. S. M. Yang, Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Conservation and Production Research Laboratory, P.O. Drawer 10, Bushland, TX 79012, and L. Wilson, Associate Professor, Plant Science Department, West Texas State University, Canyon. Plant Dis. 66:572-573. Accepted for publication 26 September 1981. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1982. DOI: 10.1094/PD-66-572.

Three annual species or subspecies (Helianthus bolanderi, H. debilis subsp. silvestris, H. praecox subsp. praecox) and 14 perennial species of sunflower (Helianthus spp.) were resistant to Erysiphe cichoracearum, which causes powdery mildew of sunflower, in field and greenhouse tests. H. grosse-serratus and H. maximiliani collected from some locations were resistant but from other locations were susceptible to E. cichoracearum. The reaction of sunflower species in greenhouse tests was in general agreement with their reaction in field tests, except for H. annuus, H. hirsutus, and H. mollis, which were resistant to E. cichoracearum in the field but susceptible in the greenhouse. These three annual sunflower species were good sources of resistance to E. cichoracearum, and this characteristic that may be transferable to cultivated sunflower (H. annuus).

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