Chemical and Mechanical 

 Control of False Hellebore 

 {Veratrum californicum) in 

 an Alpine Community 



Val Jo Anderson 

 Robert M. Thompson 



INTRODUCTION 



False hellebore (Veratrum californicum Durand), also 

 known as wild com, cow cabbage, or veratrum, has not 

 only continued to spread in many high-elevation grass- 

 forb meadows, but has invaded some aspen stands in 

 the central Rocky Mountains (Spencer and Thompson 

 1984). This species has two deleterious effects: (1) it 

 is toxic to hvestock, causing abortion in gestating ewes 

 and congenital deformities in surviving lambs (James 

 and others 1980) and (2) the clonal growth and expan- 

 sion of this species on prime high-elevation sites, in 

 response to overuse of more desirable species in the 

 community, has substantially reduced the potential 

 for natural recovery of desirable species. 



While extensive research has been conducted on 

 the toxicity of false hellebore (Binns and others 1963; 

 Keeler 1969, 1990; Keeler and Stuart 1987; Knight 

 1989), research on false hellebore control is limited 

 to a few herbicide trials completed during the late 

 1950's and mid-1960's (Klomp 1958; May and others 

 1968; Street and others 1967, 1968). WiUiams and 

 Kreps (1970) evaluated 10 herbicides at application 

 rates of between 4 and 12 kg active ingredient per 

 hectare (ai/ha), reporting 55 to 95 percent control of 

 false hellebore the first year for the four most effec- 

 tive herbicides. This improved to 100 percent control 

 following a second 4-kg ai/ha treatment of the same 

 plots the next year with the amine salt of 2,4-D. Re- 

 evaluation of these treatments at 10 years (Williams 

 and Cronin 1981) and 20 years (WiUiams 1991) indi- 

 cates long-term control under proper management. 

 Regardless of the herbicide used, the most effective 

 time to apply herbicides for false hellebore control was 

 just after the last leaf expanded, before the flowers 

 began to open (Williams and Kreps 1970). 



The high application rates needed for control with 

 2,4-D and the need for two successive years of apphca- 

 tion tend to make large-scale treatment economically 

 unattractive. Since these trials in the 1960's, many 

 other herbicides have been developed that have not 

 been evaluated for control of false hellebore. 



A study to test alternative herbicides and possible 

 mechanical control methods was initiated by the tech- 

 nical staff of the Manti-La Sal National Forest at the 

 Price Ranger District in the early 1980's. A dense 

 stand of false hellebore was selected to test the follow- 

 ing control methods: 



Herbicides: Amitrole, picloram, glyphosate, 

 triclopyr, and 2,4-D. 



Mechanical: Hand cutting to ground level, 

 rototilling, and disc chaining. 



STUDY AREA 



The study area is at the head of Boulger Canyon 

 (2,896 m elevation) on the Price Ranger District. The 

 study plots were all located on a north aspect with 

 5 to 10 percent slope. This area is in a perennial 

 snowdrift site; snow sometimes covers the area imtil 

 mid-July. Soils are silty clay loams, 38 to 76 cm deep. 

 The site is grazed seasonally by sheep from July 1 to 

 October 1. 



METHODS 



Plots 15 by 15 m were dehmited in a dense patch of 

 false hellebore. Control treatments (except 2,4-D and 

 disc chaining) were applied on August 6, 1982, while 

 plants were growing rapidly and just before their pan- 

 icles opened. Plant height averaged nearly 91 cm. 

 Temperature at the time of application ranged from 

 15 to 18 °C, and the air was calm. A backpack sprayer 

 calibrated to deliver 350 L/ha of the herbicide and 

 water solution was used for foliar application of ami- 

 trole (4 kg ai/ha), glyphosate (2 kg ai/ha), and triclopyr 

 (2 kg ai/ha). Leaf surfaces were thoroughly wetted. 

 Picloram pellets were hand broadcast at the rate of 

 1 kg ai/ha. Plants receiving the cutting treatment 

 were cut near the soil surface using a hand sickle. 

 The rototill treatment consisted of one pass of a gas- 

 driven rotary tiller. Soil was tilled to a depth of 10 

 to 15 cm. False hellebore plant tops, rhizomes, and 

 roots were chopped and mixed into the soil. 



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