National Invasive Species Awareness Week: March 3rd – March 8th
March 10th: Palmer Amaranth (Palmer amaranth) & Nutria (Myocastor coypus):
Image courtesy of University of Illinois Extension
Palmer Amaranth: Palmer Amaranth, a type of pigweed, is invading the Southeast. It is a very troublesome weed for us because it is fast growing, produces a lot of seed and easily develops herbicide resistance. Palmer is a summer annual weed that can grow up to 10 feet tall. Each female plant can produce up to 500,000 seeds. Populations of this weed have developed resistance to 4 different classes of herbicides, including glyphosate or “Round-Up”. There are other types of pigweed in Florida, such as spiny and redroot pigweed, so you must be able to positively distinguish Palmer Amaranth from others.
Here are the main differences:
1. Petioles (or stalks joining leaves to the stem) are as long or longer than the leaf blades.
2. The plant has long terminal inflorescence (cluster of flowers on top of the stem).
3. They have prominent white veins on the lower surface of the leaves.
4. They have hairless leaves.
5. They are faster growing than other pigweeds.
If you have identified palmer amaranth in your field, treat with glyphosate. If the pigweed survives, then quickly hand-weed the female plants as soon as possible. Even if just a few plants survive this year, next year you could have thousands more. Palmer Amaranth is very difficult to control but by employing sound IPM principles it can be managed. Refer to http://edis.ifas.ufl.edu/ag346 for identification and control measures.
For more information contact the author Jennifer Bearden, Agriculture Extension Agent, 850-689-5850.
Photo Courtesy of US Fish & Wildlife National Digital Library
Nutria:This large rodent resembles a beaver but has a round tail. They are originally from South America and were brought to the United States for the fur business. Nutria are completely vegetarian and feed on both land and aquatic plants. Their small forelimbs are used to dig out roots and rhizomes and they can eat their own weight in plants each day. Feeding occurs anytime but is most often at dawn and dusk. From their initial release in Louisiana they have spread all over the Gulf coast. There are reports of them in the Chesapeake Bay area, Ohio, and along the Oregon coast. They become sexually mature very quickly (4-9 months) and have a short gestation period (130 days). Breeding year around a single female can produce 2.5 litters each year so in a short period of time high numbers of nutria can completely clear a densely vegetated area. Another problem with them is their ability to burrow into dikes and levees, making them weaker. Their occurrence in Florida has been spotty, with 45 individuals being recorded. There are records in all Florida panhandle counties except Bay.
For more information, contact the author Rick O’Connor, Sea Grant/Marine Sciences Agent 850-475-5230.
Mimosa Tree: When traveling down secluded roads, one always marvels at the beautiful fragrant puff-like flowers lining the right of way. Many people decide that they must have one for their yard. Unfortunately, obtaining one for landscaping purposes is a bad decision. This tree is a Mimosa, Albizia julibrissin, and is famous for the ability to thrive in disturbed areas and fix nitrogen. Mimosa was brought from China in the 1700 for use as an ornamental and remains popular today. Unfortunately it crowds out native vegetation by reducing sunlight and nutrients available and may clog small waterways with intense growth. What’s more, it produces numerous seed that can remain viable for many years and is capable of vegetative propagation. Fortunately, Mimosa may be controlled by a variety of techniques. Eliminating existing trees mechanically, such as with a power saw, will reduce future numbers substantially. Additionally, the application of a 25% solution of glyphosate or triclopyr herbicide to a freshly cut stump will prevent re-sprouting of cut trees. When applying herbicides, apply them only to the stump and not to surrounding areas. Remember to make the application within one minute of cutting the tree. Enjoy your invasive removal!
For more information, contact the author Matt Orwat, Horticulture Extension Agent 850-638-6180.
Video courtesy of UF/IFAS Center for Aquatic and Invasive Plants
Photo Courtesy of Universtiy of Florida
Eurasian Water Milfoil:Eurasian water milfoil is a submerged aquatic plant that can be found in northwest Florida in lakes, rivers, and coastal marshes. Water milfoil forms a dense mat of vegetation that can block sunlight and habitat for native plants. These mats can increase water temperatures and interfere with boat traffic, fish habitat, and native aquatic plant species. Eurasian milfoil was first documented in Florida in 1964. It was reportedly planted by aquarium plant dealers. It is still used today in the aquarium industry and obtained through suppliers and through internet sales. This plant is listed as a category II on the Florida Exotic Species Pest Plant Council List, which means it has the potential to overtake native submerged plant communities. The spread of Eurasian milfoil can be caused by the breaking of stems and roots, which can be carried by boats, engines and trailers to other lakes and coastal marshes. To help prevent spread of Eurasian water milfoil to Florida’s waters, always clean off your boat, motor and trailer at the ramp to avoid transporting vegetative stems to other areas. In addition, never release or dispose of aquarium plants or animals into local waterways.
For more information, contact the author Chris Verlinde, Marine Science Agent 850-623-3868.
National Invasive Species Awareness Week: March 3rd – March 8th
March 6th: Chinese Privet (Ligustrum sinense) & Alligator Weed (Alternanthera philoxeroides):
Video courtesy of Aquatic and Invasive Plant Identification Series by the UF/IFAS Center for Aquatic and Invasive Plants (http://plants.ifas.ufl.edu) and the Florida Fish and Wildlife Commission, Invasive Plant Management Section.
Chinese Privet: Chinese Privet is a non-native shrubby tree commonly found in forested areas in northern Florida. This eastern invader thrives in low-lying, wet areas near forest openings and fence rows. Other species of the Ligustrum genus are commonly grown in landscapes. Chinese Privet can be identified in the spring by its small white flowers which omit a foul odor. Birds easily spread this weed by feeding on and excreting the fruit which contain many seeds. Additionally, Chinese Privet can spread by underground plant structures called rhizomes which allow new shoots to sprout up from the ground from a mother plant. For control options of Chinese Privet, see http://www.gainvasives.org/pubs/gfcnew.pdf or contact your local extension agent.
For more information, contact the author Josh Thompson, Regional Agriculture/IPM Extension Agent 850-482-9620.
Alligator Weed:This highly invasive aquatic weed, which is a native of South America, was first discovered in Florida in 1894 and is believed to have been transmitted through ballast water. Alligator Weed is usually found as sprawling mats
Alligator Weed photo by Vic Ramey courtesy of UF/IFAS Center for Aquatic and Invasive Plants, University of Florida
across the surface of water. Although classified aquatic, it can be found along shorelines or dry land.
This plant is a category II invasive and also an aquatic weed. “This species is on the FL DACS Prohibited Aquatic Plant List – 5B-64.011. According to Florida Statute 369.25, No person shall import, transport, cultivate, collect, sell, or possess any noxious aquatic plant listed on the prohibited aquatic plant list established by the department without a permit issued by the Florida Department of Environmental Protection. See 5B-64.011 for more information.”
There are several biological controls of Alligator Weed, such as the Alligator weed Flea Beetle. For more information about this biological control and others, please see the following IFAS extension publication. https://edis.ifas.ufl.edu/in831 .
For more information, contact the author Matt Orwat, Horticulture Extension Agent 850-638-6180.
National Invasive Species Awareness Week: March 3rd – March 8th
March 4th: Cogongrass (Imperata cylindrica) & Hydrilla (Hydrilla verticillata):
Cogongrass Photo Credit: Chris Evans, Illionois Wildlife Action Plan, www.bugwood.org
Cogongrass: Cogongrass is one of the 10 worst weeds in the world. This grass is an aggressive grower and forms colonies causing loss of productive forest areas, severe degradation of habitat, and economic issues. Since its introduction in the 1900s, Cogongrass has spread to most of the counties in Florida. Reproduction occurs through seed production and the creeping rhizome system. This plant is prolific once established with the creation of a very dense rhizome system that retains water and releasing of allelopathic chemicals reducing competition from other plants. The main identifying characteristic is the off-center mid rib and its yellow green coloring.
Once this grass invades, it will quickly displace the native species and requires frequent and intensive controls. Early detection is best since a small infestation is easier and cheaper to treat. The larger infestations become more time intensive, expensive, and difficult. There are treatment options for these infestations, make sure that specific instructions are followed and treatment is repeated. For more information on the biology of this plant and various treatment options visit http://edis.ifas.ufl.edu/wg202. Also, by contacting your local UF/IFAS Extension office for assistance and information.
For more information contact the author Brooke Saari, Sea Grant Marine Science Extension Agent, 850-689-5850
Hydrilla:Hydrilla is a submerged plant that grows in dense mats up to the surface of freshwater habitats, including ponds, lakes, springs, and rivers. Growing at the rapid rate of an inch a day and up to 25 feet long, hydrilla shades out beneficial native plants and clogs waterways, preventing flood control, boating, shrimping and fishing. In dense populations, the plant can alter oxygen levels and water chemistry and survive in a wide variety of nutrient conditions, sunlight availability, and temperatures.
Hydrilla Photo Credit: Vic Ramey, UF
Originally found in Asia and introduced to Florida (likely through Tampa and Miami) in the 1950’s as part of the aquarium trade, hydrilla has become a very expensive problem for the state. Millions are spent annually on chemical and mechanical treatment simply to maintain the plant. Adding to the problem is the fact that it is still available commercially, even though it has been placed on the US Federal Noxious Weed List.
Methods of control include mechanical harvesters and chopping machines (although fragments of hydrilla left in the water can regrow), introduced insects and fish (particularly the Chinese grass carp), aquatic herbicides, and lake drawdowns. Hydrilla is often transported from one body of water to the other by unknowing boaters moving fragments of the plant left on boats, trailers, or live wells, so learning to identify the plant and cleaning boats before leaving the ramp are helpful in prevention. Visit the Extension Hydrilla IPM site for more helpful tips at: http://entomology.ifas.ufl.edu/hydrilla/index.shtml.
For more information contact the author Carrie Stevenson, Coastal Sustainability & Natural Resources Agent, 850-475-5230.
