How do I Prevent it?
Original methods of controlling Cheatgrass included the use of
herbicides, cattle grazing, tilling the land, and early season
burning of fields to prevent the seeds from dispersing (Meyer et al.
2008). These methods, however, tend to be expensive and dangerous!
Not only can perennial vegetation be harmed in these processes, but
sometimes the method being used for controlling the grass gets out
of control and the results are uncontrollable (Meyer et al. 2008).
Investigations
Bromus tectorum is a hard species to regulate, but there
are people out there doing research to try and find ways to get this
invasive species under control. So far, it is known that there are
other species similar to that of B. tectorum that limit th
e
production and establishment of the invasive species. Native species
tend not to be competitive with Cheatgrass, but other plants such as
E. elymoides, E. multisetus, and P. secunda have a
little fight in them and compete with Cheatgrass (Goergen et al. 2011). When competition occurs there is a decrease in
the production of flowers. One study done shows that there has been
a shift in other grass species ability to tolerate and live among
B. tectorum (Goergen et al. 2011). This
suggests that people might be able to use a mixture of these adapted
grass species that can now live amongst Cheatgrass to begin
restoring areas that are highly invaded (Goergen et al. 2011). For more information on the competitive nature of
Cheatgrass, go to the Interactions
page.
Another investigation is looking at the possibility of manipulating
fungal pathogens that are already seen in B. tectorum but
rather than using them for seedling restoration they want to use
them as a biocontrol organism to slow the growth of the invasive
grass (Meyer et al. 2008). Biocontrol is being looked at as a
possibility because there is a major need of Cheatgrass being
targeted and put in control. At this point in time there are three
fungal pathogens being looked at: commonly known as head smut,
chestnut bunt, and black-fingers-of-death, scientifically and
respectively known as Ustilago bullata, Tilletia fusca, and
Pyrenophora semeniperda (Meyer et al. 2008).
Infecting the Seedling
Both the head smut and the chestnut bunt pathogens infect the plant
when it is a seedling, and the black-fingers-of-death pathogen kills
seeds that area already in the seed bank. The head smut pathogen,
U. bullata, already infects a large genera of grasses.
Unfortunately, this pathogens infection rate is highly determined by
temperature, which can be a hard thing to control (Meyer et al.
2008). Successful infection tends to only happen when Cheatgrass
seeds germinate at temperatures of ten to twenty-five degrees Celsius in the fall
(Meyer et al. 2008). In order to produce the head smut pathogen in
large quantities “farming” Cheatgrass would have to occur to create
the spores needed for the fungal pathogen to become active (Meyer et
al. 2008). Scientists are currently trying to figure out how to
dehydrate the pathogen so it can be carried to the fields and be
tested in larger quantities. Another pathogen being studied is the
chestnut bunt, T. fusca. Unlike the head smut pathogen, the
chestnut bunt pathogen can infect seedlings under snow cover (Meyer
et al. 2008). It has also adapted and has a longer life expectancy
in the field and will stay in a soil spore bank (Meyer et al. 2008).
Problems are seen in this pathogen when it comes to infecting the
Cheatgrass because the spore of the plant must be placed on the soil
surface; direct contact with seeds does not tend to work as well
(Meyer et al. 2008).
Infecting Mature Seeds
The third organism being looked at as a biocontrol agent for B.
tectorum is the
black-fingers-of-death pathogen, P. semeniperda. Unlike
head smut and chestnut bunt pathogens, the black-fingers-of-death
pathogen infects mature grass seeds, but has higher success rates
for mortality when the seeds are in their second dormancy stage
(Meyer et al. 2008). This pathogen also tends to attack mainly cool
season gras
ses; though it is known for causing high mortality in
Cheatgrass under natural conditions (Meyer et al. 2008). The main
thing this organism would be used for is elimination of seed banks
that are going to carry on into the next growing season.
Best Option
By combining all three fungal pathogens, and possibly in
coordination with some of the original control methods, Cheatgrass
should be able to be taken under near-complete control (Meyer et al.
2008). The key to removing Cheatgrass, however, is persistence!
Once a process is begun, the treatment must continue to happen for
up to five years because that is how long Cheatgrass seeds can
survive in the soil (Zouhar 2003). It may take longer though. If you
are just a home owner with some of this invasive grass growing on
your property you can remove it by pulling it out with your hands,
mowing it, or weed whacking it (Zouhar 2003). However, the grass
still needs to be removed before it can mature or produce seeds, so
be sure to catch it before it turns brown. After you have removed
it, till the soil and plant the area with desirable, native species.