• IMMEDIATE FIRE EFFECT ON PLANT
• DISCUSSION AND QUALIFICATION OF FIRE EFFECT
• PLANT RESPONSE TO FIRE
• DISCUSSION AND QUALIFICATION OF PLANT RESPONSE
• FIRE MANAGEMENT CONSIDERATIONS

IMMEDIATE FIRE EFFECT ON PLANT:

Fire top-kills leafy spurge [106].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT:

No entry

PLANT RESPONSE TO FIRE:

Leafy spurge sprouts from the root crown and roots after top-kill by fire. Fire may increase leafy spurge density by promoting sprouting of previously dormant buds along the extensive rhizome and root system. Herbicide treatment followed by prescribed fire may help control leafy spurge, however [20,24,70]. 

Leafy spurge also establishes through seed after fire, although fire may reduce germination. Spring and fall burns within the Little Missouri Grassland of North Dakota reduced germination of leafy spurge seed compared to unburned controls, with spring burns reducing germination more than fall burns[106].

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:

Dix [24] compared burned and unburned paired plots on a blue grama-needle-and-thread grass (Hesperostipa comata) plains grassland in North Dakota. Leafy spurge was not present on most plots. Where it was present, it had a frequency of 17% on the unburned plot and 0% on the burned plot. 

FIRE MANAGEMENT CONSIDERATIONS:

Some studies suggest increased vegetative growth after burning [20,70]. July evaluations after early spring burning (April 23, May 2, May 14, May 26) in Nebraska showed a significant (p < 0.04) increase in leafy spurge stem densities [70]. 

Control of leafy spurge with herbicides can be enhanced by fire.  Vegetative growth stimulated by burning increases leafy spurge's vulnerability to herbicides [20].  Picloram and 2,4-D applied in the fall after spring prescribed fire resulted in good control of leafy spurge seedlings within the Little Missouri National Grassland in North Dakota [46]. Herbicides with or without fire were most effective in reducing density of mature plants. In 1992 and 1993 field tests performed by the USDA and the University of Nebraska revealed an 85% drop in leafy spurge after 2 herbicide applications followed by burning and seeding of switchgrass (Panicum virgatum) and big bluestem (Andropogon gerardii) [91].

Other studies suggest that burning after the application of herbicides helps control leafy spurge. An evaluation of the combined effects of herbicide and prescribed fire was conducted in Minnesota.  Application of picloram + 2,4-D followed by burning resulted in 100% control after 2 years.  After 2 years the burned plots were dominated by the annual grasses yellow bristlegrass (Setaria pumila) and witchgrass (Panicum capillare) [12].

The use of herbicides (picloram + 2,4-D) with or without burning provided better control of leafy spurge than burning alone within a mixed-grass prairie of big bluestem, little bluestem, western wheatgrass (Pascopyrum smithii), blue grama, and buffalo grass (Buchloe dactyloides) on the Little Missouri Grassland of North Dakota [106]. 

Related categories for SPECIES: Euphorbia esula | Leafy Spurge