Six Rivers “Dirty Dozen” Invasive Species
Cogongrass (Imperata cylindrica)
A relatively new patch of cogongrass recently found in Washington County.
Photo Credit: Mark Mauldin
Define Invasive Species: must have all of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define “Dirty Dozen” Species:
These are species that are well established within the CISMA and are considered, by members of the CISMA, to be one of the top 12 worst problems in our area.
Cogongrass is from southeast Asia.
It was accidentally introduced as an “escapee” from satsuma crates brought to Grand Bay, Alabama in 1912. It was later intentionally introduced into Mississippi in the 1920s as a forage crop and then to Florida in the 1930s for both forage and soil stabilization.
EDDMapS currently list 79,134 records of this plant. All are listed in the southeastern U.S. Most are in Florida and Alabama, but there are records from Mississippi, Louisiana, Texas, Georgia, North and South Carolina.
Within our CISMA there are 13,279 records. This is probably underreported.
Cogongrass is a perennial grass that can vary in color from a bright-light green when young to a brown-orange when older. It does die back in areas with cold winters and heavy frost and becomes brown. The leaves emerge from the ground in clumps and can reach four feet in height. The blades are 0.5-0.75 inches wide and the light-colored midline is off center. The blades are serrated along the edge. In the spring the grass produces large white colored fluffs of seeds extending above the leaves to be carried by the wind. There are numerous small seeds joined on long hairs of these structures. There is an extensive rhizome system beneath the ground that can contribute to short distance spread.
Issues and Impacts:
The plant spreads aggressively and has been found in ditches, along roadsides, in pastures, timberlands, golf courses, empty lots, and even on barrier islands. It spreads both by seed wind dispersal and rhizome fragmentation. The plant is known to be allelopathic, desiccating neighboring plants and moving in. It can form dense monocultures in many areas.
The serrated edges of the leaves make it undesirable as a livestock forage, a fact not detected until the plant was established. It can cover large areas of pasture making it unusable. In the winter the plant becomes brown and can burn very hot. Timberland that has been infested with cogongrass can burn too hot during prescribed burns actually killing the trees.
It is currently listed as one of the most invasive plants in the United States. It is a federal and state noxious weed, it is prohibited all across Florida and has a high invasion risk.
The key to controlling this plant is destroying the extensive rhizome system. Simple disking has been shown to be effective if you dig during the dry season, when the rhizomes can dry out, and if you disk deep enough to get all of the rhizomes. Though the rhizomes can be found as deep as four feet, most are within six inches and at least a six-inch disking is recommended.
Chemical treatments have had some success. Prometon (Pramitol), tebuthurion (Spike), and imazapyr have all had some success along roadsides and in ditches. However, the strength of these chemicals will impede new growth, or plantings of new plants, for up to six months. This can lead to erosion issues that are undesirable. Glyphosate has been somewhat successful, and its short soil life will allow the planting of new plants immediately. Due to this however, it may take multiple treatments over multiple years to keep cogongrass under control and it will kill other plants if sprayed during treatment.
Most recommend a mixture of burning, disking, and chemical treatment. Disking and burning should be conducted in the summer to remove thatch and all older and dead cogongrass. As new shoots emerge in late summer and early fall herbicides can then be used to kill the young plants. Studies and practice have found complete eradication is difficult. It is also recommended not to attempt any management while in seed (in spring). Tractors, mowers, etc. can collect the seeds and, when the mowers are moved to new locations, spread the problem. If all mowing/disking equipment can be cleaned after treatment – this is highly recommended.
For more information on this Dirty Dozen species, contact your local extension office.
Cogongrass, University of Florida IFAS Center for Aquatic and Invasive Plants
Imperata cylindrica. University of Florida IFAS Assessment.
Early Detection and Distribution Mapping System (EDDMapS)
Six Rivers CISMA
Wild Turkeys in Chufa planted in Gadsden County – Photo by Shep Eubanks UF IFAS
Wildlife management continues to be an area of growing interest on our local farms and ranches and has the potential to generate significant additional income to the farm enterprise. It is also an opportunity to practice good stewardship of the natural resources that we have in abundance here in the Panhandle. Each spring I get many phone calls from landowners wanting to know what they can plant to encourage wild turkeys to utilize their property more and to enhance the quality of their wild turkey habitat. Chufa is one such plant that wild turkeys love like most of us love ice cream and it is easy to grow and will provide feed for turkeys for several months.
What is chufa? Chufa is an African variety of the native nutsedge, which is a warm season perennial plant. However, chufa is not as aggressive as the native nutsedges and typically will not create problems with succeeding crops that you might plant after it. The actual foliage of the plant is not utilized by wildlife, but turkeys, hogs, ducks, and raccoons love the underground tubers that the plant produces. Each individual plant can produce 10 to 75 peanut kernel sized tubers (see photo 1) that wildlife utilize. These tubers are high in carbohydrates and protein, and they are also edible by humans, having a sweet taste similar to almonds or raw peanuts.
Photo 1. Chufa seed for planting – Photo by Shep Eubanks UF IFAS
Turkeys will usually begin to dig the chufas up in early fall as soon as the above ground leaves turn brown. In Florida, they will dig and eat the nuts from fall throughout the winter and into spring. (see photo 2 of turkeys feeding in a spring chufa patch)
Photo 2. Turkeys scratching up chufas – Photo by Shep Eubanks UF IFAS
If you are considering planting chufa there are several considerations to take into account. The chufa plant typically grows well anywhere that field corn can be grown. You should soil test the area you intend to plant and lime to a pH between 6.0 – 6.5. On most soils this requires 1 ton of lime per acre. Recommended planting dates are April 1st through June 30th in the panhandle area. Earlier plantings will provide higher yields, whereas later plantings typically will provide foraging for wildlife later into the following spring. To maximize use by turkeys into the spring I would recommend looking at planting in June. Chufa can be planted later than June 30th some years but remember that it takes the plant approximately 90 days to produce mature tubers and this must be accomplished prior to frost/cold weather. Plant the seed into a well prepared and fertilized seedbed. The seeding rate for chufa is 40 – 50 pounds per acre broadcast or 30 pounds per acre drilled on a 36 inch row spacing. Strive for a coverage of 3 or 4 seed per square foot. When broadcasting the seed, set your disk to cut about 4 inches deep. This will cover the seed to an approximate depth of 2 inches which is ideal for chufa. Normal fertilizer recommendations would be 200 pounds of 17-17-17 per acre or equivalent at planting. When the plants are 6 – 12 inches high (approximately 1 month old) you should top dress with 100 pounds of actual N per acre (300 pounds of ammonium nitrate) to maximize yields. With high costs of fertilizer this may not be as desirable, but yields will be smaller if fertilizer rates are reduced. For weed control options on chufa plantings consult with your local County Extension Agent for up-to-date recommendations.
Small plantings are feasible (less than ¼ acre) if wild hogs are not present. It has been my experience that best results are obtained with ½ acre or larger plantings. Chufa is a plant that will do a good job of reseeding itself, sometimes for several years. Reseeding can be accomplished by simply disking the area of the previous planting between April and the end of June and following fertilizer recommendations for the initial planting. For most locations it is advisable to move the chufa plot to a different location after the second crop to avoid problems with soil pests. (see photo 3 of typical planting).
Photo 3. Chufa planting – Photo by Shep Eubanks UF IFAS
If you have never planted chufas before for your turkeys, you may want to pull some up or disk a row up in the fall after the tops have died back. This will assist the turkeys in finding the plants if they have never encountered it before. Once they do find it you can expect to find tremendous areas of scratching. Quite often the plots will literally look like a mortar or bombing range where the turkeys dig down to get the chufas!
For more information consult with your local Extension Agent .
‘Bobwhites in Pine Savanna’ Workshop Set
For Jan. 30 in Marianna, Florida
The National Bobwhite Conservation Initiative (NBCI) and partners will host the Tri-State Bobwhite Symposium for professional land managers and landowners Thursday, January 30, 2020, in Marianna, FL.
It is the second Working Lands for Wildlife–Bobwhites in Pine Savanna workshop funded by the Natural Resources Conservation Service and is expected to draw attendees from three states. The program goal is to restore pine savanna on 82,000 acres across seven states using thinning, prescribed fire, and native grass restoration. Federal funding is available to landowners who choose to pursue pine savanna management on that designated landscape.
Bobwhite quail are popular with many hunters and management is trying to restore them.
“Private lands are a critical and necessary component for landscape-scale restoration of wild bobwhites, which is what NBCI is all about,” said NBCI Forestry Coordinator Steve Chapman. “Active management of pine forests on those lands, while still meeting landowner objectives, is a key NBCI strategy, and 82,000 managed acres will show the dividends of this approach.”
Dr. Jess McGuire, Quail Forever’s Working Lands for Wildlife bobwhite coordinator, added that “in order to achieve this level of restoration, wildlife professionals must be trained in the nuances of bobwhite management.”
The workshop will be from 9am–2pm at the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) office, located at 2741 Penn Avenue, Suite 3, Marianna, FL 32448. Preregistration by January 23 is required by contacting firstname.lastname@example.org or online at http://bit.ly/tristatequail.
Additional partners include Quail Forever, Florida Fish and Wildlife Conservation Commission, Tall Timbers Research Station and Land Conservancy, University of Florida Extension, and the Natural Resources Conservation Service.
Through multiple agreements, NBCI, in collaboration with Quail Forever and Warnell School of Forestry and Natural Resources/University of Georgia, will provide at least one of these workshops in each of the seven states identified in the project geography. Those states include Alabama, Florida, Georgia, New Jersey, North Carolina, South Carolina, and Virginia. Partners will also produce educational materials detailing management techniques and the results of intentional, targeted pine savanna management for bobwhites as part of the overall project.
Headquartered at the University of Tennessee’s Institute of Agriculture/Department of Forestry, Wildlife and Fisheries, NBCI is a science and habitat-based initiative of the National Bobwhite Technical Committee (NBTC) to elevate bobwhite quail recovery from an individual state-by-state proposition to a coordinated, range-wide leadership endeavor to restore wild bobwhites on a landscape scale. The committee is comprised of representatives of 25 state wildlife agencies, various academic research institutions and private conservation organizations. Support for NBCI is provided by the Federal Aid in Wildlife Restoration Program, state wildlife agencies, the Joe Crafton Family Endowment for Quail Initiatives, the University of Tennessee, Park Cities Quail and Roundstone Native Seed.
Young Longleaf Pine
All of Florida’s ecosystems contain pine trees. There are seven native species in the state; Sand, Slash, Spruce, Shortleaf, Loblolly, Longleaf, and Pond. Each species grows best in its particular environment. Pines are highly important to wildlife habitats as food and shelter. Several species are equally valuable to Florida’s economy. Slash, Loblolly, and Longleaf are cultivated and managed to provide useful products such as paper, industrial chemicals, and lumber. All pines are evergreens, meaning they keep foliage year-round. The leaves emerge from the axil of each scale leaf into long slender needles clustered together in bundles. Needles are produced at the growing tips of each branch and remain on the tree for several years before turning reddish-brown and falling off. The bundles are referred to as “fascicles”. The length and number of needles in each fascicle is one way to help identify the different pine species.
A handy rule of thumb is that pines starting with “S” have needles in twos, while pines starting with “L” have needles in threes. And slash pine, which starts with “SL” has needles in twos and threes. The pond pine is also a three-needled fascicle. Pay attention to their length and the number that are held in a fascicle. Because the numbers per fascicle may vary, be sure to check several fascicles to get an overall sense for the plant! Longleaf has the longest needle, measuring over 10 inches. While sand pine has the shortest needles at around 2 inches in length. Pine cones are also a means for identification. Typically the longer the needle, the bigger the cone. But, they also vary in attachment and “spinyness’.
Cone of Loblolly Pine, attached directly to the stem
The outer (dorsal) surface of each seed cone scale has a diamond-shaped bulge, or “umbo,” formed by the first year’s growth. The umbo may or may not be armored with a “prickle,” a sharp point but not quite a spine or thorn, at the tip. As the seed cone continues to grow and expand, the exposed area at the end of each scale grows as well. The larger diamond-shaped area around the umbo, formed in the second year of growth, is called the “apophysis.” The shapes of the prickle, umbo, and apophysis can be helpful in identification. The male and female cones are separate structures, but both are present on the same plant. Pollen is produced by male cones and is carried by the wind to female cones where it fertilizes the ovules. Seeds develop and mature inside the female cones (also called the seed cones) for two years, protected by a series of tightly overlapping woody scales. Some pines open their seed cones after two years to release the seeds, while other pines continue to keep their cones tightly closed past maturity and release seeds in response to the heat of a forest fire.
To learn more about Florida’s pines and helpful hint on identification go to:
Controlling competing vegetation and brown spot disease are two main reasons we prescribe burn young longleaf plantations:
- Longleaf pine seedlings do not like competing vegetation and will stay in the grass stage for years if vegetation is not controlled by fire, mowing or herbicides. Using improved containerized seedlings along with good vegetation management can release longleaf pines from the grass stage in 2-3 years.
- Longleaf pines are the only species of southern pines susceptible to brown spot needle blight. Seedlings are infected in the grass stage and can die from the disease. Prescribe burning is an effective method for controlling this fungus disease. Burning removes the infected needles and kills the spores. Brown spot can be identified by yellow bands on the needles, which eventually turn brown as shown below.
December thru March is the typical burn window for this activity. Older longleaf pine stands can be burned into late spring with the right weather conditions and understory. If turkey management is important to you, wait until nesting season is over to burn mature longleaf stands. We get better control of understory brush and hardwoods burning in the spring.
The link shown here shows an example of a control burn in 5 year old longleaf pine that is in the sampling stage. Good forest management practices have got these pines off to a good start. The key is not to damage the bud in the tip of pines or the newly formed candles in the spring.
*Make sure and get a burn permit from the local state forestry service before you light your fire.
“Timing of Prescribed Fire in Longleaf Pine” http://www.southernfireexchange.org/SFE_Publications/etc/Clemsonforfl32.pdf
“Prescribed Burning in Newly Planted Longleaf Pine.” (Alabama Guide Sheet No. AL 338 A)
Air potato vine. Photo by Scott Jackson
Air potato (Dioscores bulbifera) is a perennial, herbaceous self-twining vine that can grow over 60 feet in length, enabling it to climb over and smother many native plants. The Florida Exotic Plant Pest Council (FLEPPC) lists air potato as a Category 1 invasive plant, which means that it has disrupted natural communities and ecological functions by displacing native plant species.
In 2012, a leaf feeding beetle (Lilioceris cheni) was introduced into South Florida from China for biological control of air potato. Although it is too early to determine any potential long-term impacts, the initial results have been promising. The larvae and adults of the air potato leaf beetle feed on the leaf tissue and occasionally the bulbils. The damage to the growing tips of the plant have dramatically reduced its ability to cover native vegetation. Extensive damage to air potato was evident within three months after the first release. Additionally, testing by scientists at the USDA/ARS Invasive Plant Research Laboratory in Fort Lauderdale concluded that the beetle will not complete development on any other plant found in Florida.
Air potato beetle up close. Photo by Julie McConnell
The female air potato leaf beetle lays an average of 1,200 eggs, which develop into larvae in about four days. The young beetles skeletonize the air potato leaves for the next eight days and then pupate into foam-like cocoons. Clumps of cocoons fall to the ground and the adult beetles emerge 13 to 16 days later. There can be a new generation of air potato leaf beetle every month while the weather is warm. For the winter, the adults hide in leaf litter and wait for spring.
The question now is: “How well will they survive through a longer, colder Northwest Florida winter?”. USDA scientists, UF Extension agents and citizen scientists in Bay and Okaloosa County hope to find out. Earlier this month, June 2015, air potato leaf beetles from the Hayslip Biological Control and Research and Containment Laboratory in Ft. Pierce were released into areas containing air potato. They will be monitored over the next year. Look for an update this coming summer.