Kudzu

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 the subspecies of P. montana 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 subspecies. They are: • P. montana • Pueraria montana var. chinensis (Ohwi) Sanjappa & Pradeep (= P. chinensis) • Pueraria montana var. lobata (Willd.) Sanjappa & Pradeep (= P. lobata) • Pueraria montana var. thomsonii (Benth.) Wiersema ex D.B. Ward (= P. thomsonii) • P. edulis • P. phaseoloides – proposed to be moved to Neustanthus Various other species in Pueraria sensu stricto are also known as "kudzu" with an adjective, but they are not as widely cultivated or introduced. ==Ecology==

Kudzu has been referred to as "quasi-wild" due to its long history of cultivation, selective breeding into various cultivars, and subsequent return to wild conditions. Some researchers suggest that humans are the main predator of kudzu in its native range, and that human use and cultivation of kudzu both contributes to its success as an invasive species and is a form of biological control for kudzu. ==Propagation==

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). '' flowers 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. Kudzu is able to withstand environments ranging from sunny to shady upon reaching its mature stage; however, forest edges with greater light availability are optimal. ==Invasive species==

, Georgia 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., NYWhen kudzu invades an ecosystem, it makes the leaf litter more labile, thereby lessening the carbon sequestration ability of the soil. Americas Kudzu is an infamous weed in the United States, as far north as rural areas of Pulaski County, Illinois, and along the East Coast in sparser populations as north as the New York City Metropolitan Area and Boston, Massachusetts. The vine has become a sore point in Southern US culture. Estimates of its rate of spreading differ wildly; it has been described as spreading at the rate of annually in 2009, although in 2015 the United States Forest Service estimated the rate to be only per year. A small patch of kudzu was discovered in 2009 in Leamington, Ontario, the second-warmest growing region of Canada after south coastal British Columbia., Kudzu was introduced from Japan into the United States at the Japanese pavilion in the 1876 Centennial Exposition in Philadelphia. It remained a garden plant until the Dust Bowl era (1930s–1940s), when the vine was marketed as a way for farmers to stop soil erosion. The new Soil Conservation Service grew seventy million kudzu seedlings and paid $8 an acre () to anyone who would sow the vine. Road and rail builders planted kudzu to stabilize steep slopes. Farmer and journalist Channing Cope, dubbed "kudzu kid" in a 1949 Time profile, popularised it in the South as a fix for eroded soils. He started the Kudzu Club of America, which, by 1943, had 20,000 members. The club aimed to plant across the South. Once Soil Service payments ended, much of the kudzu was destroyed as farmers turned the land over to more profitable uses. The Soil Conservation Service stopped promoting kudzu altogether by the 1950s. This means that this species cannot be imported, cultivated, transported, commercialized, planted, or intentionally released into the environment anywhere in the European Union. There are only some kudzu populations in certain regions of Italy and Switzerland. In Switzerland it occurs almost exclusively in Ticino, where it has been found in the wild since at least 1956. Most outbreaks are concentrated around Lake Lugano and Lake Maggiore, where the climate (hot summers and mild winters) encourages its growth. However, outbreaks in peripheral areas such as the Onsernone Valley and Lower Leventina are likely due to the illegal disposal of plant waste. A plan is currently in place to reduce and eventually eradicate the kudzu population in Ticino. Other regions During World War II, kudzu was introduced to Vanuatu and Fiji by United States Armed Forces to serve as camouflage for equipment and has become a major weed. In Australia, Kudzu is also becoming a problem in Queensland, Northern Territory and New South Wales. In New Zealand, kudzu was declared an "unwanted organism" and was added to the Biosecurity New Zealand register in 2002. ==Control==

Crown removal Destroying the full underground system, which can be extremely large and deep, is not necessary for successful long-term control of kudzu. Killing or removing the kudzu root crown and all rooting runners is sufficient. 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 age of the crowns is correlated to how deep they are 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 still 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. and Tallahassee, Florida. Norfolk Southern, an American railroad company, has used goats to control kudzu at its Inman Yard in Atlanta. Prescribed burning is 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, Herbicide A systemic herbicide, for example, glyphosate, triclopyr, 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. Fungi Since 1998, the United States' Agricultural Research Service has experimented with using the fungus Myrothecium verrucaria as a biologically based herbicide against kudzu. ==Uses==

Soil improvement and preservation 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. Animal feed 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. Food 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 Korea, the plant root is made into chikcha (칡차; "arrowroot tea"), used in traditional medicine, and processed starch used for culinary purposes such as primary ingredient for naengmyeon (칡냉면). 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 be a substitute for cornstarch. '', a Japanese pudding The flowers are used to make a jelly that tastes similar to grape jelly. 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. Fiber ’s reconstructed main keep are made using kuzufu (woven kudzu cloth) Kudzu fiber, known as ko-hemp, is traditionally used to make clothing and paper, and has also been investigated for industrial-scale use. Kudzu fiber is a bast fiber similar to hemp and linen and has been used for clothing in China for at least 6,000 years and in Japan for at least 1,500 years. In ancient China, kudzu was one of three main clothing and textile materials, with silk and ramie being the other two. Basketry 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 uses 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 gě 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. Kudzu powder is used in Japan to make an herbal tea called kuzuyu. Kakkonto () is a herbal drink with its origin in traditional Chinese medicine, intended for people with various mild illnesses such as headache. Puerarin which is the main clinical extract from kudzu root, has been used to improve blood flow, reduce chest pain, and support recovery in cardiovascular and cerebrovascular conditions. Other uses It may become a valuable asset for the production of cellulosic ethanol. In the Southern United States, kudzu is used to make soaps, lotions, and compost. ==See also==