Friday, December 31, 2010

Kudzu

Kudzu (Pueraria lobata or P. montana) is a vine that is part of the pea family, Fabaceae, introduced to the United States from Asia in the late 1800s. Farmers in the southeastern states planted the vine because of its fast growth with a plan to reduce soil erosion and possibly use it as animal feed. The vine also belongs to the legume family, which includes plants that capture nitrogen at the plant root and make it available for the plant’s use; this process is called nitrogen fixation. Kudzu, however, does not control erosion. Instead it bursts into growth so prolific that it engulfs every stationary thing in its path. Those early farmers probably soon discovered that without constant cutting, the vine overgrew yards, gardens, trees, orchards, stream banks, hillsides, and even abandoned houses and farm equipment. In 2005 Georgia farmer Jason Millsaps told National Geographic, “I’ve measured a foot a day [of kudzu growth]. It’s a never-ending battle to keep it back.” Kudzu remains a very big problem in U.S. agriculture, and universities have set up project teams to work solely on the task of solving the kudzu problem.

Source of Information : Green Technology Conservation Protecting Our Plant Resources
Kudzu is one example of an aggressive invasive plant, nonnative to the United States. The vine has spread from its origins to the rest of the southeastern states, from Florida north to Maryland and west to Texas. Some farmers have nicknamed it “the vine that ate the South.” At the current rate of global warming, scientists predict kudzu will spread to Michigan in about 30 years. The University of Arkansas agricultural research station offers on its Web site the following: “The joke goes that you should fertilize kudzu in a dry year with motor oil because lubricating the undersides of the leaves reduces the chance of sparks as it races across the ground.” This fast growth explains why many invasive plants threaten the surroundings they enter; nature simply cannot adapt fast enough to repel them.

Aggressive plants may be the most harmful of all invasive species because they disrupt the foundation of ecosystems. Aggressive invaders kill or dislodge native photosynthetic plants that support a community of herbivores, carnivores, and predators in addition to microbes and invertebrates Kudzu also blocks sunlight from reaching soil organisms, overwhelms tree trunks and leaves, and can literally choke any woodland it overruns.

Kudzu removal is difficult for the following five reasons: (1) it creates deep and extensive root systems; (2) it grows back within days of cutting; (3) kudzu has no natural enemies outside Asia; (4) its seeds disperse easily, carried by wind, water, and animals; and (5) the herbicides active against kudzu also kill many native plants. Entomologist David Orr of North Carolina State University told the New York Times in 1998, “It takes a 55-gallon drum of herbicide to kill just one acre, and even then you don’t really kill it.” Protection against kudzu invasion may require a combination of new technologies and a certain amount of cleverness.

New techniques meant to save pristine forests from kudzu attack may soon employ caterpillars called soybean loopers, which have been engineered in laboratories to devour kudzu leaves as they do soybean plants. Though this research has been conducted since the mid-1990s, research has yet to find the right approach for looper-destruction of the thousands of square miles of kudzu infestation. Another approach under study involves a fungus named Colletotrichum gloeosporioides, which causes a deadly infection in kudzu after the fungus has been grown and strengthened in a laboratory. These and other biological means of fighting kudzu must come onto the scene quickly in order to help agriculture threatened by invasion.

Meanwhile, research into kudzu’s valuable properties has taken shape. Perhaps kudzu can be made into a food source or serve as a sustainable answer to deforestation. Botanists have explored kudzu’s use in pulp and papermaking, for example. University of Toronto botanist Rowan Gage told CBC News in Canada in 2007, “If you can develop it as a commodity, kudzu can pay for its own control.” Kudzu’s commercial use may be a long way off, but the fact that kudzu has caught the attention of people in Canada attests to the vine’s ability to grow and invade. Solutions from any sector of research will be helpful.

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