How to Manage Pests
UC Pest Management Guidelines
Pathogens: Leveillula taurica, Erysiphe cichoracearum
(Reviewed 1/07, updated 6/09, pesticides updated 5/15)
In this Guideline:
Two types of powdery mildew infect artichokes. Leveillula taurica is more commonly found and primarily colonizes the undersides of older leaves. Careful examination of leaf undersides reveals spores produced singly or in very short chains; however, the profuse white hairs of the leaf may obscure this sign. Severely infected leaves will turn yellow, then brown. With time the brown leaves may collapse and dry up. Leveillula infects only the older leaves; the younger leaves escape infection until they mature.
Powdery mildew caused by Erysiphe cichoracearum causes less severe symptoms. The flat, low-growing white to gray mycelia and spores of this fungus develop on the outside of flower bracts and on upper surfaces of both young and old leaves. The fungus produces abundant spores in long chains. Underlying tissue will turn brown.
Spores are dispersed by wind. Reports suggest that L. taurica from artichoke may be a different race than the L. taurica that occurs on tomato and other hosts.
If you see early symptoms, check weekly to monitor progress of the disease. Fungicides are not needed unless the disease becomes severe.
UC IPM Pest Management Guidelines: Artichoke
S. T. Koike, UC Cooperative Extension, Monterey County
Acknowledgment for contributions to Diseases:S. Colbert, Griffin Corp., Valdosta, GA