Transcript Powerpoint format (PPT 4.9 MB) - Center for Aquatic and Invasive

Torpedograss
Panicum repens (L.) Poaceae
Biology
• Native to Africa and or Asia
• Introduced into Florida in late 1800’s as a
wetland forage grass
• Perennial, spreads through stolons and
rhizomes
• Named for sharply pointed or ‘torpedolike’ growing tips
Background
Economic Uses
• Cultivated as
wetland forage
• Fast growth and
high productivity
• Readily grazed by
cattle
Distribution
• Found throughout much of north, central
and south Florida
• Commonly found along waterways
including canals, irrigation/drainage
ditches and low, wet areas
• Over 7000 acres in Lake Okeechobee
Torpedograss Distribution in Florida
Impacts
• Category 1 invasive species (FLEPPC)
– Very aggressive spread into undisturbed
sites, over 70% of public waters are infested
• Strong competitor, forms large floating
mats, impeding water flow and navigation
and recreation
• Displaces native species – flora & fauna
• Also a major problem in citrus and turf
Identification
Mature Plant
• Perennial grass,
roots on shore and
will extend several
feet out into
shallow water
• Will grow up thru
the water column
• Forms dense
monoculture along
shoreline of lakes
and ponds
Leaves
• Leaf blades are 2 to
4 inches long, ¼
inch wide, stiff and
folded
• Bluish green color
• Hairy on upper leaf
surface
Rhizome
• Rhizomes arise from
swollen crown tissue
(knuckles)
• Rhizomes are very
extensive, can
comprise over 90% of
total plant biomass
• Sharp, torpedo-like
tips
Panicle
• Up to 9 inches long,
numerous branches
• Reported poor seed
viability
Management
Preventative
Cultural
Mechanical
Biological
Chemical
Preventative
1. Limit planting as a forage
2. Remove existing plants, including
stolons and rhizomes before seeds
are produced
3. Prevent movement of plant material
into areas not infested with
torpedograss
Cultural
1. Cattle grazing will often keep in
check, but to a limited extent
2. Programs to educate farmers and
ranches about the problems
associated with torpedograss and
proper identification
Biological
1. There are no known biological control
agents available for torpedograss
management (with the exception of
grazing) in Florida or the southeastern
U.S.
Mechanical
1. Small infestations can be removed
with repeated, aggressive tillage
 Limited to non-flooded sites
2. Burning effective in removing above
ground biomass, may enhance
chemical control measures
Chemical
1. Broadcast applications for large areas
 Glyphosate at 2 to 4 lbs-ai/A
 Imazapyr at 0.5 to 1.0 lbs-ai/A
2. Spot treatment for smaller areas
 Glyphosate – 2 to 3% solution
 Imazapyr – 0.5 to 1% solution
3. Use surfactant at 0.25%
4. Adhere to irrigation restrictions for
imazapyr, may cause off-target damage
Useful Links
• Floridata Homepage:
http://www.floridata.com/main_fr.cfm?state
=Welcome&viewsrc=welcome.htm
• University of Florida Center for Aquatic
and Invasive Plants:
http://aquat1.ifas.ufl.edu/welcome.html
• University of Florida’s Cooperative
Extension Electronic Data Information
Source: http://edis.ifas.ufl.edu/index.html
Literature Cited
Langeland, K.A. and K. Craddock Burks.
1998. Identification and Biology of NonNative Plants in Florida's Natural Areas.
IFAS Publication SP 257. University of
Florida, Gainesville. 165 pp