Reactions of Jerusalem Artichoke Genotypes to Two Rusts and Powdery Mildew. S. M. McCarter, Professor, University of Georgia, Athens 30602. . Plant Dis. 77:242-245. Accepted for publication 8 September 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0242.

Thirty-six commercial and plant-introduction genotypes of Jerusalem artichoke (Helianthus tuberosus) were grown near Athens, Georgia, to determine their reactions to Puccinia helianthi, Coleosporium helianthi, and Erysiphe cichoracearum. Tuber characteristics and yields were also determined. The genotypes varied from highly susceptible to highly resistant to each of the three pathogens. Generally, genotypes that were highly susceptible to P. helianthi were mostly resistant to C. helianthi. The reverse was also true. The genotypes that had the largest and most desirable tubers and the inherent potential for high-tuber yield were often the most susceptible to P. helianthi. These studies show levels of resistance to these foliar pathogens within the germ plasms of H. tuberosus that could possibly be used to improve disease resistance in both this crop and sunflower.

Keyword(s): fructose, Helianthus spp., host resistance, inulin.