Document Type

Conference Proceeding

Publication Title

Proceedings--Shrublands Under Fire: Disturbance and Recovery in a Changing World; 2006 June 6-8; Cedar City, UT

Editors

Stanley G. Kitchen, Rosemary L. Pendleton, Thomas A. Monaco, Jason Vernon

Abstract

Cheatgrass (Bromus tectorum) is an exotic winter annual grass weed that has invaded millions of hectares in the Intermountain West. Restoration of cheatgrass-invaded wildlands is generally impractical without some form of cheatgrass control. We are investigating the possibility of manipulating indigenous fungal pathogens that already occur on cheatgrass for short-term biocontrol in conjunction with restoration seedings. Three potential biocontrol organisms have been identified. The head smut pathogen (Ustilago bullata) and the chestnut bunt pathogen (Tilletia fusca) infect at the seedling stage and prevent seed set, while the black-fingers-of-death pathogen (Pyrenophora semeniperda) kills seeds in the seed bank. Both head smut and chestnut bunt pathogen races on cheatgrass are host-specific, whereas black-fingers-of-death is a generalist grass seed pathogen that does not appear to form host specific races.Inoculation trials with the head smut pathogen yielded high levels of disease only when seedlings emerged at moderate temperatures in fall, whereas the chestnut bunt pathogen infects at near-freezing winter temperatures but requires persistent snow cover for successful infection. The black-fingers-of-death pathogen is most effective at destroying seeds in the carryover seed bank. A combined approach using all three pathogens shows some promise for biocontrol of this troublesome weed.

Pages

61-67

html

Publisher

United States Department of Agriculture / Forest Service

Publication Date

9-2008

Keywords

wildland shrubs, disturbance, recovery, fire, invasive plants, restoration, ecology, microorganisms

Disciplines

Biology

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