Kudzu (//; also called Japanese arrowroot) is a group of plants in the genus Pueraria, in the pea family Fabaceae, subfamily Faboideae. They are climbing, coiling, and trailing perennial vines native to much of eastern Asia, Southeast Asia, and some Pacific islands. The name is derived from the Japanese name for the plants, クズ or 葛 (kuzu).[note 1] Where these plants are naturalized, they can be invasive and are considered noxious weeds. The plant climbs over trees or shrubs and grows so rapidly that it kills them by heavy shading. The plant is edible, but often sprayed with herbicides.
Taxonomy and nomenclatureEdit
The name kudzu describes one or more species in the genus Pueraria that are closely related, and some of them are considered to be varieties rather than full species. The morphological differences between them are subtle; they can breed with each other, and introduced kudzu populations in the United States apparently have ancestry from more than one of the species. They are:
Origin in the United StatesEdit
Kudzu was introduced to the United States as an ornamental bush and an effortless and efficient shade producer at the Philadelphia Continental Exposition in 1876. In the 1930s and 1940s, the vine was rebranded as a way for farmers to stop soil erosion. Workers were paid $8 per acre to sow topsoil with the invasive vine. The cultivation covered over one million acres of kudzu.
Kudzu spreads by vegetative reproduction via 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 rare. One or two viable seeds are produced per cluster of pods. The hard-coated seeds can remain viable for several years, and will successfully germinate only when soil is persistently soggy for five to seven days, with temperatures above 20 °C (68 °F). Once germinated, saplings must be kept in a well-drained medium that retains high moisture. During this stage of growth, it is critical for kudzu to receive as much sunlight as possible. Kudzu saplings are sensitive to mechanical disturbance, and are damaged by chemical fertilizers. They do not tolerate long periods of shade, or high water tables.
Soil improvement and preservationEdit
Kudzu has been used as a form of erosion control as well as to enhance the soil. As a legume, it increases the nitrogen in the soil by a symbiotic relationship with nitrogen-fixing bacteria. 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 for improving the soil pore-space in clay latosols, thus freeing even more water for plants than in the soil prior to deforestation.
Kudzu can be used by grazing animals, as it is high in quality as a forage and palatable to livestock. It can be grazed until frost and even slightly after. Kudzu had been used in the southern United States specifically to feed goats on land that had limited resources. Kudzu hay typically has a 15–18% crude protein content and over 60% total digestible nutrient value. The quality of the leaves decreases, however, as vine content increases relative to the leaf content. Kudzu also has low forage yields despite its rate 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 three to four years can ruin stands. Thus, kudzu only serves well as a grazing crop on a temporary basis.
Kudzu fiber has long been used for fiber art and basketry. The long runners which propagate the kudzu fields and the larger vines which cover trees make excellent weaving material. Some basketmakers use the material green. Others use it after splitting it in half, allowing it to dry and then rehydrating it using hot water. Both traditional and contemporary basketry artists use kudzu.
Kudzu contains isoflavones, including puerarin (about 60% of the total isoflavones), daidzein, daidzin (structurally related to genistein), mirificin, and salvianolic acid, among numerous others identified. In traditional Chinese medicine, where it is known as gé gēn (gegen), kudzu is considered one of the 50 fundamental herbs thought to have therapeutic effects.
In traditional medicine, kudzu has been used as a remedy for alcoholism, hangover, measles, menopausal symptoms, diabetes mellitus, fever, common cold, and neck or eye pain. However, a 2007 study suggested that the use of the kudzu root is inappropriate as a hangover remedy due to increased acetaldehyde accumulation through mitochondrial aldehyde dehydrogenase inhibition. Kudzu has no benefit for treating cancer and is specifically contraindicated in people with estrogen receptor-positive breast cancer.
Food and beveragesEdit
The roots contain starch, which has traditionally been used as a food ingredient in East Asia. In Vietnam, the starch called bột sắn dây is flavoured with pomelo oil and then used as a drink in the summer. In Japan, the plant is known as kuzu and the starch named kuzuko. Kuzuko is used in dishes including kuzumochi, mizu manjū, and kuzuyu. It also serves as a thickener for sauces, and can substitute for cornstarch.
The flowers are used to make a jelly that tastes similar to grape jelly. Roots, flowers, and leaves of kudzu show antioxidant activity that suggests food uses. Nearby bee colonies may forage on kudzu nectar during droughts as a last resort, producing a low-viscosity red or purple honey that tastes of grape jelly or bubblegum.
Kudzu has also been used for centuries in East Asia to make herbal teas and tinctures. Kudzu powder is used in Japan to make an herbal tea called kuzuyu. Kakkonto (葛根湯, Mandarin Chinese: gěgēntāng, Japanese: kakkontō) is a herbal drink with its origin in traditional Chinese medicine. It is made from a mixture of ginger, cinnamon, Chinese peony, licorice, jujube, ephedra, and powder ground from the root of the kudzu plant, one of the 50 fundamental herbs. As the name, which translates literally to "kudzu infusion", implies, kudzu, or pueraria lobata, serves as the main ingredient. Together these plants are used to create a drink containing puerarin, daidzein, paenoflorin, cinnamic acid, glycyrrhizin, ephedrine and gingerol.
Kudzu fiber, known as ko-hemp, is used traditionally to make clothing and paper, and has also been investigated for industrial-scale use. The stems are traditionally used for basketry.
Ecological damage and rolesEdit
Kudzu's environmental and ecological damage results from acting through "interference competition", meaning it outcompetes other species for a resource. Kudzu competes with native flora for light, and acts to block their access to this vital resource by growing over them and shading them with its leaves. Native plants may then die as a result.
Changes in leaf litter associated with kudzu infestation results in changes to decomposition processes and a 28% reduction in stocks of soil carbon, with potential implications for processes involved in climate change.
Kudzu was introduced from Japan into the United States at the Japanese pavilion in the 1876 Centennial Exposition in Philadelphia. It is now common along roadsides and other disturbed areas throughout most of the southeastern United States as far north as rural areas of Pulaski County, Illinois. Estimates of its rate of spreading differ wildly; it has been described as spreading at the rate of 150,000 acres (610 km2) annually, although in 2015 the United States Forest Service estimated the rate to be only 2,500 acres per year.
Kudzu was discovered July 2009 in a patch 110 m (360 ft) wide and 30 m (98 ft) across, on a south-facing slope on the shore of Lake Erie near Leamington, Ontario, about 50 km (31 mi) southeast of Windsor. Leamington is located in the second-warmest growing region of Canada after south coastal British Columbia.
Ecologist Gerald Waldron made the Leamington find while walking along the beach. He recognized the kudzu instantly, having read about its destructive expansion in the southeastern United States.
In New Zealand, kudzu was declared an "unwanted organism" and was added to the Biosecurity New Zealand register in 2002.
For successful long-term control of kudzu, it is not necessary to destroy the underground system, which can be extremely large and deep. It is only necessary to use some method to kill or remove the kudzu root crown and all rooting runners. The root crown is a fibrous knob of tissue that sits on top of the roots. Crowns form from multiple vine nodes that root to the ground, and range from pea- to basketball-sized. The older the crowns, the deeper they tend to be found in the ground. 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 may grow back.
Mechanical methods of control involve cutting off crowns from roots, usually just below ground level. This immediately kills the plant. Cutting off the above-ground 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 unexpectedly spreads and shows up in various 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. If done in the spring, cutting off vines must be repeated. Regrowth appears to exhaust the plant's stored carbohydrate reserves. Cut kudzu can be fed to livestock, burned, or composted.
The city of Chattanooga, Tennessee, has undertaken a trial program using goats and llamas to graze on the plant. Similar efforts to reduce widespread nuisance kudzu growth have also been undertaken in the cities of Winston-Salem, North Carolina and Tallahassee, Florida.
Prescribed burning is also used on old extensive infestations to remove vegetative cover and promote seed germination for removal or treatment. While fire is not an effective way to kill kudzu, equipment, such as a skid loader, can later remove crowns and thereby kill kudzu with minimal disturbance of soil.
A systemic herbicide, for example, glyphosate, triclopyr, or picloram, can be applied directly on cut stems, which is an effective means of transporting the herbicide into the kudzu's extensive root system. Herbicides can be used after other methods of control, such as mowing, grazing, or burning, which can allow for an easier application of the chemical to the weakened plants. In large-scale forestry infestations, soil-active herbicides have been shown to be highly effective.
After initial herbicidal treatment, follow-up treatments and monitoring are usually necessary, depending on how long the kudzu has been growing in the area. It may require up to 10 years of supervision after the initial chemical placement to make sure the plant does not return.
Since 1998, the United States Department of Agriculture, Agricultural Research Service (ARS) has experimented with using the fungus Myrothecium verrucaria as a biologically based herbicide against kudzu. A diacetylverrucarol spray based on M. verrucaria works under a variety of conditions (including the absence of dew), causes minimal injury to many of the other woody plants in kudzu-infested habitats, and takes effect quickly enough that kudzu treated with it in the morning starts showing evidence of damage by midafternoon. Initial formulations of the herbicide produced toxic levels of other trichothecenes as byproducts, though the ARS discovered growing M. verrucaria in a fermenter on a liquid, instead of a solid, diet limited or eliminated the problem.
- Despite the English name, the Japanese word 葛 was always spelled くず in kana (kuzu in romanization) and pronounced [kɯzɯ]; it is the word 屑 ("scrap") that used to be spelled くづ (kudzu) and pronounced [kɯdzɯ]. Both words are now spelled くず (kuzu), and most speakers of Japanese no longer make the distinction between [zɯ] and [dzɯ] (a phonemic merger), so the two words are homonyms for them.
- "USDA PLANTS profile".
- "USDA GRIN Taxonomy".
- "kudzu". Merriam-Webster Dictionary. Retrieved 2017-10-05.
- Vance, Timothy J. (2008). The Sounds of Japanese. Cambridge University Press. pp. 85–6. ISBN 978-0-5216-1754-3.
- Labrune, Laurence (2012). The Phonology of Japanese. Oxford University Press. pp. 64–5. ISBN 978-0-19-954583-4.
- "くず". Daijirin. Weblio. Retrieved 2017-10-05.
- John Everest; James Miller; Donald Ball; Mike Patterson (1999). "Kudzu in Alabama: History, Uses, and Control". Alabama Cooperative Extension System. Archived from the original on 16 June 2012. Retrieved August 20, 2007.
- D. K. Jewett; C. J. Jiang; K. O. Britton; J. H. Sun; J. Tang (1 September 2003). "Characterizing Specimens of Kudzu and Related Taxa with RAPD's". Castanea. 68 (3): 254–260. ISSN 0008-7475. JSTOR 4034173.
- Sun, J H; Li, Z-C; Jewett, D K; Britton, K O; Ye, W H; Ge, X-J (2005). "Genetic diversity of Pueraria lobata (kudzu) and closely related taxa as revealed by inter-simple sequence repeat analysis". Weed Research. 45 (4): 255. doi:10.1111/j.1365-3180.2005.00462.x.
- Kudzu: The Vine that Ate the South; PorterBriggs.com http://porterbriggs.com/the-vine-that-ate-the-south/
- Amanda Allen (2000). "Kudzu in Appalachia". ASPI Technical Series TP 55. Appalachia -- Science in the Public Interest. Retrieved August 20, 2007.
- 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. 38 (3–4): 259–271. doi:10.1016/0378-1127(91)90147-N.
- Wang, F. R.; Zhang, Y; Yang, X. B.; Liu, C. X.; Yang, X. W.; Xu, W; Liu, J. X. (2017). "Rapid Determination of 30 Polyphenols in Tongmai Formula, a Combination of Puerariae Lobatae Radix, Salviae Miltiorrhizae Radix et Rhizoma, and Chuanxiong Rhizoma, via Liquid Chromatography-Tandem Mass Spectrometry". Molecules. 22 (4): 545. doi:10.3390/molecules22040545. PMID 28353641.
- "Kudzu". Memorial Sloan Kettering Cancer Center. 2017. Retrieved 28 June 2017.
- "Kudzu". Drugs.com. 2017. Retrieved 28 June 2017.
- Neil R. McGregor (2007). "Pueraria lobata (Kudzu root) hangover remedies and acetaldehyde-associated neoplasm risk". Alcohol. 41 (7): 469–478. doi:10.1016/j.alcohol.2007.07.009. PMID 17980785.
- Shurtleff, William; Aoyagi, Akiko (1977). The Book of Kudzu: A Culinary & Healing Guide. Soyinfo Center. p. 9. ISBN 978-0-394-42068-4. Retrieved 25 October 2013.
- Sandra Lynn Burney (2010). "Determination of antioxidant and total phenolic content of Pueraria lobata and evaluation of novel food products containing kudzu". Mississippi State University.
- Marchese, C. Marina; Flottum, Kim (2013). The Honey Connoisseur. Black Dog & Leventhal. ISBN 9781603763325.
- Doug Stewart (30 September 2000). "Kudzu: Love It or Run". Smithsonian Magazine.
- Huang, Hsi-Ya; Hsieh, You-Zung (1997). "Determination of puerarin, daidzein, paeoniflorin, cinnamic acid, glycyrrhizin, ephedrine, and -gingerol in Ge-gen-tang by micellar electrokinetic chromatography". Analytica Chimica Acta. 351 (1–3): 49–55. doi:10.1016/S0003-2670(97)00349-8.
- "Merriam-Webster Dictionary".
- Larry W. Mitich (Jan–Mar 2000). "Kudzu (Pueraria lobata (Willd.) Ohwi)". Weed Technology. 14 (1): 231–235. doi:10.1614/0890-037X(2000)014[0231:KPLWO]2.0.CO;2. JSTOR 3988532.
- Robert D. Tanner; S. Shahid Hussain; Lindsey A. Hamilton; Frederick T. Wolf (October 1979). "Kudzu (Pueraria Lobata): Potential agricultural and industrial resource". Economic Botany. 33 (4): 400–412. doi:10.1007/BF02858336. ISSN 1874-9364.
- Sibel Uludag; Veara Loha; Ales Prokop; Robert D. Tanner (March 1996). "The effect of fermentation (retting) time and harvest time on kudzu (Pueraria lobata) fiber strength". Applied Biochemistry and Biotechnology. 57–58 (1): 75–84. doi:10.1007/BF02941690. ISSN 1559-0291.
- William Shurtleff; Akiko Aoyagi (1977). The book of kudzu: a culinary & healing guide. Soyinfo Center. ISBN 9780394420684.
- Richard G. Lugar, R. James Woolsey. The New Petroleum. Foreign Affairs. 1999. Vol. 78, No 1. p. 88.
- Jeffrey Collins (2003). "If You Can't Beat Kudzu, Join It". Off the Wall. Duke Energy Employee Advocate. Retrieved August 20, 2007.
- Cain, Michael L.; Bowman, William D.; Hacker, Sally D. (2011). Ecology. Sinauer Associates, Inc. p. 246.
- Tamura, Mioko; Tharayil, Nishanth (July 2014). "Plant litter chemistry and microbial priming regulate the accrual, composition and stability of soil carbon in invaded ecosystems". New Phytologist. 203 (1): 110–124. doi:10.1111/nph.12795. PMID 24720813.
- "SPECIES: Pueraria montana var. lobata". US Forest Service - United States Department of Agriculture. Retrieved 29 September 2015.
- "Controlling Kudzu With Naturally Occurring Fungus". ScienceDaily. July 20, 2009. Retrieved 2009-07-20.
- Bill Finch (September 2015). "Legend of the Green Monster". Smithsonian Magazine. Vol. 46 no. 5. p. 19.
- "Kudzu: Invasion of the killer vines or a tempest in a teapot?". Chatham-Kent Daily Post. September 27, 2009. Retrieved 2010-04-20.
- Wingrove, Josh (24 September 2009). "'Vine that ate the South' has landed in the Great White North". The Globe and Mail. Retrieved 14 October 2013.
- Walker, Timothy (2013). Plant Conservation: Why it matters and how it works. Timber Press. p. 157. ISBN 160469260X.
- Gill, George (1 August 2002). "Kudzu vine an unwanted organism" (PDF). Biosecurity. Wellington: MAF Biosecurity Authority (37). ISSN 1174-4618.
- "Kudzu Control Without Chemicals". kokudzu.com. 2007. Retrieved August 20, 2007.
- Bramlett, Betsy (2010-08-31). "Winston-Salem Using Goats To Attack Problem Kudzu Vines". Wxii12.com. Archived from the original on 2012-03-06. Retrieved 2010-09-08.
- Neofotis, Peter. "Kudzu (Pueraria montana)". Introduced Species Summary Project. Columbia University. Retrieved 17 September 2011.
- "Written Findings of the State Noxious Weed Control Board". Washington State Noxious Weed Control Board. 2007. Archived from the original on 27 September 2011. Retrieved August 20, 2007.
- Southeast Exotic Pest Plant Council Invasive Plant Manual
- Missouri Department of Conservation - Kudzu
- National Park Service - Kudzu
- Bugwood Network (Center for Invasive Species and Ecosystem Health)
- Matt Nespeca (August 2007). "Kudzu Control Methods and Strategies" (PDF). kokudzu.com.
|Wikimedia Commons has media related to Kudzu.|
- "Species Profile - Kudzu (Pueraria montana var. lobata)". National Invasive Species Information Center, United States National Agricultural Library.
- "Kudzu Vine - One of Ontario's Most Unwanted Invasive Plant Species" (PDF). Ontario Invasive Plant Council. Archived from the original (PDF) on 29 December 2015.
- T. L. Copley and Luke A. Forrest (1953). Kudzu in Rotation with Corn and Small Grain. NCSU College of Agriculture and Life Sciences.