Kudzu (//; also called Japanese arrowroot or Chinese arrowroot) is a group of climbing, coiling, and trailing perennial vines native to much of East Asia, Southeast Asia, and some Pacific islands, but invasive in many parts of the world, primarily North America. The vine densely climbs over other plants and trees and grows so rapidly that it smothers and kills them by heavily blocking sunlight. The plants are in the genus Pueraria, in the pea family Fabaceae, subfamily Faboideae. The name is derived from the Japanese name for the plant East Asian arrowroot (Pueraria montana var. lobata), クズ or 葛 (kuzu).[note 1] Where these plants are naturalized, they can be invasive and are considered noxious weeds. 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:
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Kudzu spreads by vegetative reproduction via stolons (runners) that root at the nodes to form new plants and by rhizomes. Kudzu also spreads 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 can successfully germinate only when soil is persistently soggy for 5-7 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, kudzu must 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 and 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 22-23% crude protein content and over 60% total digestible nutrient value. The quality of the leaves decreases 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. Fresh kudzu is readily consumed by all types of grazing animals, but frequent grazing over three to four years can ruin even established 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.
Phytochemicals and usesEdit
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, although there is no high-quality clinical research to indicate it has any activity or therapeutic use in humans. Adverse effects may occur if kudzu is taken by people with hormone-sensitive cancer or those taking tamoxifen, antidiabetic medications, or methotrexate.
The roots contain starch, which has traditionally been used as a food ingredient in East and Southeast 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 (Chinese and Japanese: 葛根湯; pinyin: gégēntāng; rōmaji: kakkontō; "Kudzu Root Soup") is a herbal drink with its origin in traditional Chinese medicine, intended for patients with a group of symptoms and signs including fever, headache, neck stiffness, no perspiration, and in some cases, diarrhea. It is made from a mixture containing the main ingredient, dried kudzu roots, and sliced fresh ginger, cinnamon twigs, Chinese peony, licorice, jujubes, and ephedra. Together these plants are used to create a drink containing puerarin, daidzein, paenoflorin, cinnamic acid, glycyrrhizin, ephedrine and gingerol.
Ecological damage and rolesEdit
Kudzu's environmental and ecological damage results from its outcompeting 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. 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. 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.
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, destroying the underground system, which can be extremely large and deep, is not necessary. Only killing or removing the kudzu root crown and all rooting runners is needed. 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. Destroying all removed crown material is necessary. 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 new 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.
In the United States, the city of Chattanooga, Tennessee undertook a trial program in 2010 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. Up to 10 years of supervision may be needed 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 diet (instead of a solid) 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".
- "Pueraria montana var. lobata". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 11 December 2017.
- 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 20 August 2007.
- "kudzu". Merriam-Webster Dictionary. Retrieved 5 October 2017.
- 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 5 October 2017.
- 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.
- Amanda Allen (2000). "Kudzu in Appalachia". ASPI Technical Series TP 55. Appalachia -- Science in the Public Interest. Archived from the original on 28 September 2007. Retrieved 20 August 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" (PDF). Forest Ecology and Management. 38 (3–4): 259–271. doi:10.1016/0378-1127(91)90147-N.
- William Shurtleff; Akiko Aoyagi (1977). The book of kudzu: a culinary & healing guide. Soyinfo Center. ISBN 9780394420684.
- 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. PMC 6154678. PMID 28353641.
- "Kudzu". Drugs.com. 2017. Retrieved 28 June 2017.
- "Kudzu". Memorial Sloan Kettering Cancer Center. 2017. Retrieved 28 June 2017.
- 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 (January–March 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.
- 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 20 August 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.
- Kudzu: The Vine that Ate the South; PorterBriggs.com http://porterbriggs.com/the-vine-that-ate-the-south/
- "SPECIES: Pueraria montana var. lobata". US Forest Service - United States Department of Agriculture. Retrieved 29 September 2015.
- "Controlling Kudzu With Naturally Occurring Fungus". ScienceDaily. 20 July 2009. Retrieved 20 July 2009.
- 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. 27 September 2009. Retrieved 20 April 2010.
- 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 978-1604692600.
- Gigon, A.; Pron, S.; Buholzer, S. (2014). "Ecology and distribution of the Southeast Asian invasive liana Kudzu, Pueraria lobata (Fabaceae), in Southern Switzerland". Eppo Bulletin. 44 (3): 490–501. doi:10.1111/epp.12172.
- Gill, George (1 August 2002). "Kudzu vine an unwanted organism" (PDF). Biosecurity (37). ISSN 1174-4618.
- "Kudzu Control Without Chemicals". kokudzu.com. 2007. Retrieved 20 August 2007.
- Bramlett, Betsy (31 August 2010). "Winston-Salem Using Goats To Attack Problem Kudzu Vines". Wxii12.com. Archived from the original on 6 March 2012. Retrieved 8 September 2010.
- 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 20 August 2007.
- Southeast Exotic Pest Plant Council Invasive Plant Manual
- Missouri Department of Conservation - Kudzu Archived 26 May 2011 at the Wayback Machine
- National Park Service - Kudzu
- "Bugwood Network (Center for Invasive Species and Ecosystem Health)". Archived from the original on 8 March 2013. Retrieved 27 November 2009.
- 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.
- T. L. Copley; Luke A. Forrest (1953). Kudzu in Rotation with Corn and Small Grain. NCSU College of Agriculture and Life Sciences.