Link to home

Characterization and Control of Garlic Rust in California

June 2001 , Volume 85 , Number  6
Pages  585 - 591

Steven T. Koike and Richard F. Smith , University of California Cooperative Extension, Salinas 93901 ; R. Michael Davis , Department of Plant Pathology, University of California, Davis 95616 ; J. Joe Nunez , University of California Cooperative Extension, Bakersfield 93307 ; and Ron E. Voss , Department of Vegetable Crops, University of California, Davis 95616

Go to article:
Accepted for publication 12 February 2001.

In 1998, a devastating outbreak of rust disease severely damaged the garlic crop in California, resulting in yield losses of 51% and an economic loss of 27% to the industry. The disease also occurred in 1999 and 2000, indicating that rust may have become an annual problem in some parts of the state. The presence of urediniospores, two-celled teliospores, and telial paraphyses indicated that the pathogen was Puccinia allii. Isolates from garlic infected onion and chives, but not leek, elephant garlic, or shallot in inoculation experiments. Garlic cloves obtained from diseased plants were planted under controlled conditions, but the resulting plants did not develop rust. Fungicide trials were conducted for 3 years and showed that none of the currently registered materials gave satisfactory control. However, tebuconazole and azoxystrobin provided good protection against rust if sprayed at 10-day intervals. A variety trial of 34 garlic cultivars and selections was planted, inoculated, and evaluated for resistance to rust. Although there was variability in rust severity among the selections, acceptable levels of resistance were not observed in any cultivar.

Additional keywords: Allium cepa, Allium porrum, Allium sativum

© 2001 The American Phytopathological Society