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Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Tribe: Phaseoleae
Genus: Pueraria
Species: P. lobata
Binomial name
Pueraria lobata
(Willd.) Ohwi

Kudzu (クズ or 葛 Kuzu?), Pueraria lobata (syn. P. montana, P. thunbergiana), (sometimes known as foot a night vine, mile a minute vine, Gat Gun, Ge Gan[1] and The vine that ate the South) is one of about 20 species in the genus Pueraria in the pea family Fabaceae, subfamily Faboideae. It is native to southern Japan and southeast China in eastern Asia. The name comes from the Japanese word for this plant, kuzu. The other species of Pueraria occur in southeast Asia, further south.


[edit] Uses

[edit] Soil improvement and preservation

Kudzu has been used as a form of erosion control and also to enhance the soil. As a legume, it increases the nitrogen in the soil via a symbiotic relationship with nitrogen-fixing bacteria in the soil.[2] Its deep taproots also transfer valuable minerals from the subsoil to the topsoil, thereby improving the topsoil. In the deforested section of the Central Amazon Basin in Brazil, it has been used to improve the soil pore-space in clay latosols and thus freeing even more water for plants than in the soil prior to deforestation.[3]

[edit] Animal feed

Kudzu can be used by grazing animals as it is high in quality as a forage and greatly enjoyed by livestock. It can be enjoyed up until frost and even slightly after. Kudzu hay typically has a 15–18% crude protein content and over 60% total digestible nutrient value. The quality of it decreases, however, as vine content increases relative to the leaf content. Kudzu also has low forage yields despite its great deal of growth, yielding around two to four tons of dry matter per acre annually. It is also difficult to bale due to its vining growth and its slowness in shedding water. This makes it necessary to place kudzu hay under sheltered protection after being baled. Kudzu is readily consumed by all types of grazing animals, yet frequent grazing over 3 to 4 years can ruin stands. Thus kudzu only serves well as a grazing crop on a temporary basis.[4]

[edit] Medicine

The Harvard Medical School is studying kudzu as a possible way to treat alcoholic cravings, by turning an extracted compound from the herb into a medical drug.[5] The mechanism for this is not yet established, but it may have to do with both alcohol metabolism and the reward circuits in the brain.

Kudzu also contains a number of useful isoflavones, including daidzein (an anti-inflammatory and antimicrobial agent), daidzin (a cancer preventive) and genistein (an antileukemic agent). Kudzu is a unique source of the isoflavone puerarin. Kudzu root compounds can affect neurotransmitters (including serotonin, GABA, and glutamate) and it has shown value in treating migraine and cluster headache.[6] It is recommended for allergies and diarrhea.[7]

Research in mice models suggests that Kudzu is beneficial for control of some post-menopausal symptoms such as hypertension and diabetes type II.[8]

In traditional Chinese medicine, where it is known as gé gēn (Chinese: 葛根), kudzu is considered one of the 50 fundamental herbs. It is used to treat tinnitus, vertigo, and Wei syndrome (superficial heat close to the surface).[citation needed]

[edit] Starch

The roots contain starch, which has traditionally been used as a food ingredient in East Asia.

[edit] Other uses

In the Southern United States, where the plant has been introduced with devastating environmental consequences,[9] kudzu is used to make soaps, lotions, jelly, and compost.[10] It has even been suggested that kudzu may become a valuable asset for the production of cellulosic ethanol.[11]

[edit] Problems

[edit] Ecological Invasion

Kudzu growing on trees

Kudzu was introduced from Japan into the United States in 1876 at the Philadelphia Centennial Exposition, where it was promoted as a forage crop and an ornamental plant. From 1935 to the early 1950s the Soil Conservation Service encouraged farmers in the Southeastern United States to plant kudzu to reduce soil erosion as above, and the Civilian Conservation Corps planted it widely for many years.

Kudzu growing on shrubs

However, it was subsequently discovered that the Southeastern US has near-perfect conditions for kudzu to grow out of control — hot, humid summers, frequent rainfall, temperate winters with few hard freezes (kudzu cannot tolerate low freezing temperatures that bring the frost line down through its entire root system, a rare occurrence in this region), and no natural predators. As such, the once-promoted plant was named a pest weed by the United States Department of Agriculture in 1953.

Infestation of Kudzu in the United States.

Kudzu is now common throughout most of the Southeastern United States, and has been found as far northeast as Paterson, New Jersey, in 30 Illinois counties including as far north as Evanston,[12] and as far south as Key West, Florida.[citation needed] It has also been found growing (rather inexplicably) in Clackamas County, Oregon in 2000. This is the first infestation west of Texas.[13] Kudzu has naturalized into about 20,000 to 30,000 square kilometers (7,700–12,000 sq mi) of land in the United States and costs around $500 million annually in lost cropland and control costs.[14]

During World War II, kudzu was introduced to Vanuatu by United States armed forces to serve as camouflage for equipment.[citation needed] It is now a major weed.

Kudzu is also becoming a problem in Northeastern Australia and has been seen in isolated spots in Northern Italy (Lago Maggiore).

Kudzu seedpods

The spread of kudzu is mainly by vegetative expansion by stolons (runners) that root at the nodes to form new plants and by rhizomes. Kudzu will also spread by seeds, which are contained in pods and mature in the autumn, although this is rarer. One or two viable seeds are produced per cluster of pods. These hard-coated seeds may not germinate for several years, which can result in the re-appearance of the species years after it was thought eradicated at a site.[citation needed]

[edit] Control

For successful long-term control of kudzu, it is not necessary to destroy the entire root system, which can be quite large and deep. It is only necessary to use some method to kill or remove the kudzu root crown[15] and all rooting runners. The root crown is a fibrous knob of tissue that sits on top of the root (rhizome). Crowns form from vine nodes that root to the ground, and range from pea-size to basketball-size.[15] The older the crown, the deeper they tend to be found in the ground because they are covered by sediment and plant debris over time. Nodes and crowns are the source of all kudzu vines, and roots cannot produce vines. If any portion of a root crown remains after attempted removal, the kudzu plant grows back.

Small kudzu crown severed from root using flexible pruning saw.

Mechanical methods of control involve cutting off crowns from roots, usually just below ground level. This immediately kills the plant. Cutting off vines is not sufficient for an immediate kill. It is necessary to destroy all removed crown material: Buried crowns can regenerate into healthy kudzu. Transporting crowns in soil removed from a kudzu infestation is one common way that kudzu "miraculously" spreads and shows up in unexpected locations.

Close mowing every week, regular heavy grazing for many successive years, or repeated cultivation may be effective, as this serves to deplete root reserves.[15] If done in the spring, cutting off vines must be repeated as regrowth appears to exhaust the plant's stored carbohydrate reserves. Cut kudzu can be fed to livestock, burned, or composted.

Late-season cutting should be followed up with immediate application of a systemic herbicide to the cut stems, to encourage transport of the herbicide into the root system. Repeated applications of several soil-active herbicides have been used effectively on large infestations in forestry situations.[15]

Kudzu infestation along the Kanawha River in West Virginia.

Prescribed burning is also used on old extensive infestations in order to remove vegetative cover and promote seed germination for removal or treatment. It is usually done to prepare for treatment of the root crowns.[16] Landscape equipment, such as a skid loader ("Bobcat"), can also remove biomass. While fire is not an effective way to kill kudzu,[15] equipment such as skid loaders can remove crowns and thereby kill kudzu with minimal disturbance of soil.[15]

Efforts are currently being organized by the U.S. Forest Service to search for biological control agents for kudzu. Several fungi are pathogenic to kudzu. Colletotrichum gloeosporioides is one tested example.[citation needed]

The city of Chattanooga, Tennessee has undertaken a trial program using goats and llamas that graze on the plant. The llamas serve double-duty as defense against predators due to their aggressive nature. Currently the goats are grazing along the Missionary Ridge area in the east of the city.[17]

[edit] See also

[edit] References

  1. ^ http://www.zooscape.com/cgi-bin/maitred/ZooRide/fountainheadgreen/questt100256/critiquet100256/trait106511
  2. ^ Amanda Allen (2000). "Kudzu in Appalachia". ASPI Technical Series TP 55. Appalachia -- Science in the Public Interest. http://www.a-spi.org/tp/tp55.htm. Retrieved on August 20 2007. 
  3. ^ Chauvel, A; Grimaldi, M; Tessier, D (1991). "Changes in soil pore-space distribution following deforestation and revegetation: An example from the Central Amazon Basin, Brazil.". Forest Ecology and Management. ProQuest. http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=2524557&q=kudzu+soil&uid=789920646&setcookie=yes. Retrieved on August 20 2007. 
  4. ^ John Everest, James Miller, Donald Ball, Mike Patterson (1999). "Kudzu in Alabama: History, Uses, and Control". Alabama Cooperative Extension System. http://www.aces.edu/pubs/docs/A/ANR-0065/. Retrieved on August 20 2007. 
  5. ^ Associated Press (2006). "Got a drinking problem? Try kudzu". MSNBC. http://www.msnbc.msn.com/id/7884540/. Retrieved on August 20 2007. 
  6. ^ "Kudzu". Med-owl.com. 2006. http://med-owl.com/clusterheadaches/tiki-index.php?page=Kudzu. Retrieved on August 20 2007. 
  7. ^ Duke J. The Green Pharmacy, The Ultimate Compendium of Natural Remedies from the World's Foremost Authority on Healing and Herbs. 1997. Pp. 57; 281-282; 310.
  8. ^ Grapes, Soy And Kudzu Blunt Some Menopausal Side Effects
  9. ^ Richard J. Blaustein (2001). "Kudzu's invasion into Southern United States life and culture" (PDF). United States Department of Agriculture. http://www.srs.fs.usda.gov/pubs/ja/ja_blaustein001.pdf. Retrieved on August 20 2007. 
  10. ^ Jeffrey Collins (2003). "If You Can’t Beat Kudzu, Join It". Off the Wall. Duke Energy Employee Advocate. http://www.dukeemployees.com/offthewall2.shtml. Retrieved on August 20 2007. 
  11. ^ Richard G. Lugar, R. James Woolsey. The New Petroleum. Foreign Affairs. 1999. Vol. 78, No 1. p. 88.
  12. ^ Molly McElroy (2005). "Fast-growing kudzu making inroads in Illinois, authorities warn". News Bureau, University of Illinois at Urbana-Champaign. http://www.news.uiuc.edu/NEWS/05/1020kudzu.html. Retrieved on April 28 2008. 
  13. ^ Oregon Department of Agriculture (2000). "Serious noxious weed found in Oregon for first time". Internet Archive, The. http://web.archive.org/web/20061108013727/http://www.oda.state.or.us/information/news/2000/kudzu.html. Retrieved on August 20 2007. 
  14. ^ "Cogon Grass Becoming Scourge of the South". Associated Press. October 20, 2003. http://www.treepower.org/cogongrass/nyt-cogongrass.html. Retrieved on 2008-12-07. 
  15. ^ a b c d e f "Kudzu Control Without Chemicals". kokudzu.com. 2007. http://kokudzu.com. Retrieved on August 20 2007. 
  16. ^ "Written Findings of the State Noxious Weed Control Board". Washington State Noxious Weed Control Board. 2007. http://www.nwcb.wa.gov/weed_info/Pueraria_lobata.html. Retrieved on August 20 2007. 
  17. ^ Bramlett, Betsy (2007-04-03). "Kudzu Goats And Friends Getting To Work On Missionary Ridge". The Chattanoogan. http://www.chattanoogan.com/articles/article_104814.asp. Retrieved on 2007-08-20. 

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