Diseases Limiting Production of Jerusalem Artichokes in Georgia. S. M. McCarter, Professor, Department of Plant Pathology, University of Georgia, Athens 30602. S. J. Kays, Associate Professor, Department of Horticulture, University of Georgia, Athens 30602. Plant Dis. 68:299-302. Accepted for publication 23 September 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-299.

Rust caused by Puccinia helianthi, powdery mildew caused by Erysiphe cichoracearum, southern blight caused by Sclerotium rolfsii, and tuber rots caused by either S. rolfsii during the growing season or by Fusarium and Pseudomonas spp. during refrigerated or field storage were the most important diseases of Jerusalem artichokes in Georgia during 1980–1982. Rust caused a severe foliage blight, and tuber yields from unsprayed plots were 29% lower than those from plots sprayed with mancozeb. S. rolfsii caused a 60% plant loss in plots in which Jerusalem artichokes had grown the two previous years, and yields from these plots were only 40% of those treated with methyl bromide. Metam-sodium and PCNB were only moderately effective in reducing losses to S. rolfsii and in increasing yields. Incorporation of tubers into soil increased disease severity, indicating that residual tubers from a previous crop may serve as a food base for the pathogen. Rot organisms caused serious deterioration of tubers held in sandy soils during the fall and winter. Results indicate that diseases may limit the potential of Jerusalem artichoke as a fuel alcohol crop in the southeastern United States unless a suitable crop rotation is followed.