Cogongrass in Georgia Winter 2016 Update
January 1, 2015 - December 31, 2015
Mark McClure, Forest Health Specialist
More cogongrass eradicated than discovered.
For the fourth consecutive year, more cogongrass spots were eradicated in Georgia than were detected. In 2015, Tift and Webster counties in south central and southwest Georgia were the only two counties reporting cogongrass for the first time. There were 88 new spots detected in 2015, making a total of 955 known cogongrass spots in the state, scattered across 58 counties. The 955 cogongrass spots encompass a total of 231 acres. There were 12 more detections in 2015 than there were in 2014. However, there were 102 sites eradicated in 2015 with only 88 new detections, marking the fourth consecutive year of eradication over detection gains. These figures reflect positive results in herbicide treatments. The status and treatment for each spot is at varying levels. The Georgia Forestry Commission recognizes a spot as eradicated after three consecutive years of finding no cogongrass resprouts. Presently, 539 spots are eradicated, 105 spots have been negative for two years, and 119 spots have been negative for one year, with the remaining 192 spots classified as active. Overall, approximately 80% of all known spots are now negative for cogongrass. Any landowner with questions regarding the status of the cogongrass spot(s) on their property should contact their Regional Forest Health Specialist.
2015 Cogongrass Status Summary
20%
56%
13%
11%
Active Year 1 Negative Year 2 Negative Eradicated
Cogongrass Status 2011-2015
1200 1000
800 600 400 200
0
87 220 327 437 539
147 157
137 131
123 139
112 118
105 119
204 188 182 186 192
2011 2012 2013 2014 2015
Eradicated Year 2 Neg. Year 1 Neg. Active
Where are cogongrass sites being detected?
The most common cogongrass detections in Georgia are located within thinned pine stands or along road and utility rights-of ways. Approximately 74% of all cogongrass detections have been in thinned pine stands and 18% in rights-of-way. An additional eight percent have been unique detections in places such as pastures, pond dams, urban landscapes, flower beds, welcome centers, wildlife food plots, and within the sand dunes along the coast. These sites are of special interest to specialists tracking the movement and spread of this exotic, invasive species.
Location of Cogongrass in Georgia
5% 1% 1% 0%
1%
18%
Pine Forest Right-of-Way
74%
Open
Yard
Planted
Where are the most detections being made?
The southwest corner of the state continues to be the cogongrass epicenter in Georgia. Decatur, Seminole, Early, Grady, Thomas, Miller, Mitchell, Baker and Worth counties are all located in southwest Georgia. Carroll County in west Georgia and Charlton County in southeast Georgia complete the top 11 ranking counties by number of detections.
Top 11 Cogongrass Counties in Georgia 2015
250 223
200
150
100
100 91 76 71
50
49 38 35 29 27 26
0
Total # of Detections
Which counties had most detections in 2015?
The top five reporting counties in 2015 were located in southwest Georgia. Decatur, Early, Thomas, Stewart and Mitchell counties were the top five counties reporting new cogongrass detections.
Top 5 Counties Reporting New Detections
18
16
14
12
10
8
16
14
6
12
Total # of New Detections in 2015
4
9
6
2
0 Decatur
Early
Thomas Stewart Mitchell
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Which counties in Georgia have cogongrass and how much?
The map below identifies cogongrass detections in each Georgia County.
What is the cogongrass status in these counties?
Approximately 80% of all known cogongrass spots in Georgia are considered inactive. However, this percentage varies among counties. The graph below displays the number of active and inactive spots for the top counties.
Cogongrass Activity in Georgia's Top Counties
250 200 38
150
100 50
17
18
22
10
8
11
1
6
7
4
185 83 73 54 61 41 27 34 23 20 22
0
Active Inactive
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The Cogongrass herbicide treatment program has been in effect for nine years. How much cogongrass is now inactive in each county?
The map below displays the amount of cogongrass in each county that is inactive. Cogongrass in all counties shaded red is 76-100% negative. That means less than 24%, or fewer than the total number of spots are still active. Counties shaded orange have 51-75% of the total spots inactive, while light green shaded counties are 26-50% inactive. Counties shaded dark green have 0-25% of the total spots inactive.
How many cogongrass spots have been reported annually since the Georgia Forestry Commission began its lead role in 2007?
The graph below shows annual detections since the year 2007.
Annual Cogongrass Detections
160
140
120
131
135 130
100 80 60
110
102
87
88
76
40 20 37
0 2007 2008 2009 2010 2011 2012 2013 2014 2015
Year
Cogongrass detections
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Georgia cogongrass facts as of 2015:
The Georgia Forestry Commission will continue to treat new cogongrass detections for landowners. All cogongrass spots are being monitored and treated annually until eradicated. Workshops, presentations, field days, etc. continue to be delivered to further educate Georgia citizens on identifying and controlling
invasive species. Georgia Forestry Commission Forest Health staff alone delivered the cogongrass message to over 120 groups in
2015. Many more programs were delivered by our task force partners.
80.3% of the total number of spots is negative (yr. 1, yr. 2, or eradicated) 81.1% of the total cogongrass acreage is negative. The average size cogongrass spot is between 0.10-0.25 acres. The largest spot treated in 2015 was approximately four acres in
size.
Fifty-eight counties have had positive cogongrass detections. Twenty-eight of 58 cogongrass counties are now negative. The map
below displays counties with active (positive) cogongrass spots in red, and counties with inactive (negative or eradicated) in green. Counties shaded white have no cogongrass detections.
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How to identify cogongrass:
Spring flowering season is the easiest time to detect cogongrass infestations. Cogongrass primarily flowers between April and early June. The white, fluffy seed heads are visible from a distance. However, the distinct golden brown coloration in late fall through winter following frost makes cogongrass visible during the colder months of the year. Cogongrass is most difficult to detect during the growing season. The most distinguishable feature of cogongrass is its dense, sharp, pointed rhizome root system, and it is recommended the rhizomes be dug up to make a positive identification.
Cogongrass identification brochure and pocket ID available from the Georgia Forestry Commission.
Contact your local GFC office or Regional Forest Health Specialist to obtain copies of these publications.
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How do I report a suspected cogongrass spot?
Call your county Georgia Forestry Commission office or contact your Regional Forest Health Specialist. A resource professional will visit the site to make a positive identification. The Georgia Forestry Commission will continue to spray all cogongrass detections in 2016 at no cost to the landowner. Landowners are required to sign a spray agreement with the Georgia Forestry Commission to legally allow resource professionals to access the property and spray the identified cogongrass. All positive detections are monitored annually until eradicated.
Landowners are encouraged to share information concerning cogongrass with their family, friends and adjoining landowners. It is important to realize that invasive plants such as cogongrass invade natural ecosystems and displace natural plant communities. Therefore, invasive species have a negative impact on our forest resources.
Forest Health Specialists:
North Region Lynne Womack 3086 Martha Berry Hwy, NE Rome, GA 30165 (o) 706-295-6021 (c) 912-515-5180 lwomack@gfc.state.ga.us
Southwest Region Mark McClure 2910 Newton Rd. Albany, GA 31701 (o) 229-430-5122 (c) 229-869-8592 mmcclure@gfc.state.ga.us
Southeast Region Chris Barnes 5645 Riggins Mill Rd. Dry Branch, GA 31020 (o) 478-751-3491 (c) 912-601-7093 cbarnes@gfc.state.ga.us
Program Coordinator Chip Bates 18899 US Hwy. 301 N. Statesboro, GA 30461 (o) 912-681-0490 (c) 912-536-7544 cbates@gfc.state.ga.us
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