VALUE AND USE
SPECIES: Gutierrezia microcephala | Threadleaf Snakeweed 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Threadleaf snakeweed is poisonous to livestock, especially when it is
growing on sandy soils.  It contains saponins and other chemicals that
cause abortions in cattle.  Clinical signs of threadleaf snakeweed
poisoning are described [24,34].

Threadleaf snakeweed has very little known value to wildlife [9].  It
may provide cover for small animals, and wildlife may eat the seeds.


PALATABILITY : 
Perennial snakeweeds are generally unpalatable to cattle [12,25] except
in early spring when other forage is lacking [34].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
NO-ENTRY


VALUE FOR REHABILITATION OF DISTURBED SITES : 
NO-ENTRY


OTHER USES AND VALUES : 
NO-ENTRY


MANAGEMENT CONSIDERATIONS : 
Threadleaf snakeweed invades and is an indicator of overgrazed and
disturbed rangelands [9,31].  Once established, threadleaf snakeweed
biomass can exceed 1,000 pounds per acre and reduce grass production to
less than 100 pounds per acre [33].  In 1987 approximately 22 percent of
Texas rangelands were infested with perennial snakeweeds [26].
Threadleaf snakeweed persists after grazing ceases [30] so it may
threaten diversity in native plant communities as well as decrease
forage values.

Various herbicide application techniques have been tested on perennial
snakeweeds.  Picloram and triclopyr give satisfactory control [21].
Picloram is most effective at controlling threadleaf snakeweed when
applied after fall flowering but before new terminal growth begins.
Control lasts at least 5 to 7 years under proper grazing management
[33].  The percent canopy reduction of threadleaf snakeweed was
substantially greater when herbicide was applied during the spring of an
above-average rainfall year than in a drought year [26].

Biological control of perennial snakeweeds is currently under study
[9,10].  A root-boring weevil from Argentina, closely related to the
native cerambycid root borer (Crossidius pulchellus), was released in
the late 1980s in Texas and New Mexico; the release marks the first
attempt to control a native weed with a foreign insect [10].  The native
cerambycid root borer is not useful for biological control because it
feeds only on large, mature plants, and damage is sporadic [10,30].

Related categories for Species: Gutierrezia microcephala | Threadleaf Snakeweed