Herbicides for control of tall larkspur (Delphinium barbeyi)

Authors

M.H. Ralphs
D.L. Turner
L.V. Mickelsen
J.O. Evans
S.A. Dewey

Document Type

Article

Journal/Book Title/Conference

Weed Science

Volume

38

Issue

6

First Page

573

Last Page

577

Publication Date

1990

Abstract

Control of tall larkspur on mountain rangelands would substantially reduce cattle poisoning. Several herbicides were evaluated for their control of tall larkspur in subalpine and aspen vegetation types. Glyphosate (2.2 kg ai ha⁻¹) and picloram (2.2 kg ae ha⁻¹) killed more than 88% of larkspur plants in both vegetation types. Clopyralid and triclopyr were ineffective at comparable rates. Metsulfuron (88 and 138 g ai ha⁻¹) provided variable control. Glyphosate is nonselective and killed all perennial vegetation, except for Thurbers fescue and mountain brome in the aspen type. Picloram applied at 4.5 kg ha⁻¹ suppressed grasses on the subalpine site, but allowed grasses to increase at lower rates. All herbicides reduced forb cover.

Recommended Citation

Ralphs, M. H. et al. 1990. Herbicides for control of tall larkspur (Delphinium barbeyi). Weed Science. 38 (6): 573-577.