|
 Cogon
grass (Imperata cylindrica) is an invasive, non-native grass
that occurs in Florida and several other southeastern states. A
pest in 73 countries, and considered to be one of the "Top 10
Worst Weeds in the World", cogon grass affects pine productivity
and survival, wildlife habitat, recreation, native plants, fire
behavior, site management costs and more.
Cogon grass is
a tall (two to five feet.) perennial grass with bright
yellowy-green foliage. The leaf blades have a mid-vein that is
clearly offset to one side, and serrated (toothed) edges. The
rhizomes are hard, scaly, and cream-colored with sharply pointed
tips. The seed head is fuzzy, white, and plume-like
Cogon grass is
found on roadsides, borrow pits, and other areas of soil
disturbance, and is able to invade moist to dry upland pine
sites. Cogon grass often forms dense, field-like monocultures.
Cogon grass
spreads readily on disturbed sites and through movement of soil
contaminated with small pieces of rhizome or seed (often due to
site disturbance). Cogon grass infestations can reduce pine
survival and growth, and in fire situations, may result in
complete mortality of
 overstory
trees due to flammable oils in the grass blades raising the
intensity and severity of prescribed burns. Over time cogon,
grass may significantly impact management and productivity of
pines on infested sites.
Due to the
damaging effects of cogon grass invasion, cogon grass is listed
as a noxious weed by both the state and federal levels.
Prevention
Avoid soil disturbance, timber harvest, fire, etc. unless as a
part of a specific treatment regime. Always clean equipment
after operating in infested areas.
Mechanical/Cultural
Mow or prescribed burn prior to herbicide application to remove
built-up thatch and promote active growth herbicide uptake. Do
not mow when seed heads are present. Do not burn without a
follow-up herbicide treatment
Chemical
Allow 12 inches of sprout before applying a solution of 2%
glyphosate, 1% imazapyr (2lbs/gal) or a tank mixture of both.
Apply herbicide by spraying all foliage just until wet to the
point of run-off and be sure to use a surfactant.
For more information:
DACS Forrest Management at:
http://www.fl-dof.com/forest_management/fh_invasives_cogon.html
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IPM Procedural Guidelines