Noxious Weeds

In 2004, the Plant Act was amended to include noxious weeds. Currently nine weeds are listed as regulated on the Mississippi Noxious Weed List (page 47).  Of the weeds listed the Bureau has active programs involving four of the weeds. Information about these weeds and current activities are listed below.

BENGHAL DAYFLOWER / TROPICAL SPIDERWORT SURVEY
Benghal Dayflower is a member of the dayflower family and is considered a creeping annual that becomes perennial depending on the growing conditions.  The weed produces aerial and subterranean flowers resulting in viable seeds below and above ground.  A single plant could produce approximately 1,200 seeds.  Benghal Dayflower is the only dayflower that produces subterranean flowers.

On August 8, 2006, Benghal Dayflower also known as Tropical Spiderwort, Commelina benghalensis, was found for the first time in Southeast Mississippi as part of the CAPS (Cooperative Agricultural Pest Survey) Noxious Weed Survey.  Benghal Dayflower is a federal noxious weed which is becoming an increasing problem in glyphosate resistant varieties of crops due to its relative tolerance of glyphosate.  Benghal Dayflower has been reported in Georgia, Florida, Alabama, Louisiana, Hawaii, and California.

As a result of the 2006 initial find, the Bureau of Plant Industry and USDA-APHIS-PPQ conducted extensive delimiting survey and found Benghal Dayflower in George and Jackson counties infesting 1,200 acres.  Infested sites include: pasture, cotton, peanut and road right-of-way

Benghal Dayflower can also reproduce vegetatively from cut stems.  Contaminated farm equipment and hay can spread Benghal Dayflower from field to field.

Due to the recent find, Benghal Dayflower has been added to the State’s Noxious Weed List.  A quarantine is now in effect on the positive fields in George and Jackson counties to suppress the further spread of the weed to neighboring fields and other regions of the State where glyphosate resistant crops are produced.  Equipment from other States that have Benghal Dayflower should be cleaned of soil and vegetation prior to shipment to Mississippi.  The Benghal Dayflower quarantine can be viewed at Rule 138 (page 49).   Open Benghal Dayflower Fact Sheet.

GIANT SALVINIA SURVEY
Giant Salvinia, Salvinia molesta, is a floating aquatic fern that is also listed on the federal noxious weed list. Giant Salvinia is native to South America and has been found in South Carolina, Texas, California, Arizona, Louisiana, Alabama, Georgia, Florida, and Mississippi.

Giant Salvinia grows very vigorously in favorable conditions doubling its size in 7 to 10 days. As the mats continue to grow it forms a thick layer of vegetation. In some areas of the world it has been documented the layer of vegetation to be more than 2 feet thick. Due to the great biomass produced by this plant, water bodies like ponds and lakes are rendered unusable.

The surface of the Giant Salvinia leaf has rows of hairs that are topped with four branches that are joined at the tip forming an “eggbeater” shape, giving it a plush appearance and repels water. Mature plants form root like structures can have “egg-shaped” spore cases. In the United States the spore cases are not known to be fertile. Giant Salvinia reproduces and overwinters vegetatively.

In 2004, Giant Salvinia was discovered near Hattiesburg, Mississippi on a 40-acre lake near the Leaf River. The Bureau of Plant Industry and the Mississippi Department of Wildlife and Fisheries have been providing assistance to the landowner in an effort to contain the weed to the lake with the application of herbicides.

The Bureau of Plant Industry obtained permits from USDA-APHIS-PPQ for the release of the Salvinia Weevil, Cyrtobagous salviniae as a biological control organism. Release of the weevil began in the fall of 2004 and spring of 2005. The release has been very successful in controlling 90% of the Giant Salvinia infestation in Forrest County.  Open Giant Salvinia Fact Sheet.

TROPICAL SODA APPLE SURVEY
Tropical Soda Apple (TSA) is a thorny perennial shrub that is native to South America. Mature TSA plants can grow to be 3 to 6 feet tall with ¾ inch thorn-like prickles on the leaves and stems. The leaves are broad and lobed like a fig leaf. TSA produces a ¾ to 1 ¼ inch diameter fruit that has watermelon like markings that turns yellow when it matures. Livestock and wildlife can spread TSA when the fruit are consumed. One TSA plant is capable of producing 200 or more fruit per year and a single fruit is capable of producing 180 to 420 seeds. Contaminated equipment, hay, seeds, composted manure, and sod are also a means of spreading the weed.

TSA is currently found in Florida, Alabama, Georgia, Louisiana, Texas, Tennessee, North Carolina, South Carolina, Pennsylvania and Mississippi. Today Florida has over one million acres infested with TSA. The total acreage in the other states is consistent with the total acreage Florida had 5 to 10 years ago. Due to the rapid spread of TSA it was placed on the Federal Noxious Weed List in 1994.

Bureau of Plant Industry and USDA-APHIS-PPQ personnel have conducted Surveys for TSA yearly to determine the extent of infestation in the State. Currently, TSA has been located mainly in pastures found in Amite, George, Greene, Lamar, Harrison and Pearl River Counties. The infestations range from slight to severe.

Starting n 2004 the Bureau has been providing assistance to USDA-APHIS-PPQ in applying herbicide in infested areas in an attempt to eradicate and prevent the spread of Tropical Soda Apple in Mississippi before the degree of infestation is overwelming. Over 38 sites have been documented with over 16,000 acres infested with this weed.  Open Tropical Soda Apple Fact Sheet.

COGONGRASS SURVEY
In October 1999, the Bureau began surveying for Cogongrass (Imperata cylindrical). Some experts consider it the seventh worst weed in the world. Cogongrass is a Federal Noxious Weed. It has an aggressive weedy habit and is not good animal forage. It is found in 64 counties in the state with the heaviest infestation in Southeast Mississippi. The Bureau of Plant Industry has a landowner assistance program which provides herbicide to the landowner who agrees to treat cogongrass as directed. Click for the Cogongrass Research Demonstration Participation Application.

PUBLICATIONS and SURVEYS
» Tropical Soda Fact Sheet
» Cogon Fact Sheet
» Benghal Dayflower Fact Sheet
» Giant Salvinia Fact Sheet

Fact sheets were published on Tropical Soda Apple and on control methods for Tropical Soda Apple.  These fact sheets were produced through the cooperative efforts of BPI, USDA-APHIS-PPQ, USDA-ARS and the Mississippi Cooperative Extension Service.

A regional fact sheet on Cogongrass was published in June 1999 through the cooperative efforts of BPI, USDA-APHIS-PPQ, USDA-ARS and the Mississippi Cooperative Extension Service.  The goal is to use this fact sheet as an educational and survey tool.