http://www.ppws.vt.edu/scott/weed_id/cypes.htm
2.4 Reproduction
Yellow nutsedge does produce seed; however, reproduction by seed is of minimal importance in most areas in comparison to vegetative spread. The species spreads primarily by tubers, rhizomes, and corn-like basal bulbs.
Tubers planted to soil depths of 80 cm produced new plants. Tubers survive soil temperatures as cold as -5oC and require a period of chilling to break dormancy and germinate. Tubers germinate when soil temperatures remain above 6oC. Under field conditions, tubers typically survive approximately 3-4 years.
Yellow nutsedge is considered one of the world's worst weeds. Well adapted to irrigated agriculture, yellow nutsedge is particularly problematic in row crops because it competes with crops for water, light, and nutrients, thereby reducing crop yield. It has also been known to spoil the quality of some crops. In some areas, yellow nutsedge tubers have been known to grow into potato tubers causing them to be graded as culls. They may also pass through shelled lima beans, requiring costly hand sorting. It addition, there has been some suggestion that this species may produce chemicals that are toxic to crops.
2.5 Economic Importance
Yellow nutsedge is closely related to chufa (Cyperus esculentus variety sativus); some taxonomists treat them as the same species. In parts of Africa, Europe and Asia, chufa is grown for its edible tubers. The tubers contain protein, carbohydrates, sugars, and lots of oil and fiber. The chufa nut is good for human health, containing high levels of iron and potassium, and no sodium. The Spanish produce a drink called "horchata" made out of the nuts (tubers) of the yellow nutsedge. The popularity of this drink has recently extended to other countries such as France, Great Britain, and Argentina. Chufa tubers are ground into flour, as well as being used to produce a cold drink (horchata), a coffee substitute, vegetable oil, and cellulose.
In the United States, the primary use of chufa as a crop is to attract and feed game, particularly wild turkeys. Turkeys love chufa tubers; as natural scratchers, once discovering a plot of chufa, they will return again and again, all winter long, or until spring arrives and other food is readily available.
Chufa tubers have been planted so that pigs could be turned into the fields to fatten and improve the taste of pork. In the United States, chufa tubers have been used as hog feed, pastured in the field in states such as Florida, Georgia, and Alabama.
Tubers of chufa have also been identified as valuable food for waterfowl and cranes. Ducks dive for them when wetland fields are flooded. Chufa is also used in seed mixes for wetland restoration, mitigation, and erosion control.
Currently, yellow nutsedge is merely regarded as another obnoxious weed; however, historically, its small tuberous rhizomes were used both as food and medicine by the Native Americans. Even today the Egyptians cultivate a native species of Cyperus in moist soils or sandy shores for their edible tubers. These are called "tiger nuts" and are first fried, and then soaked in water. Reportedly, the taste is similar to hazelnuts. It was another species (C. papyrus) that the Egyptians used to make paper, sails, cloth. mats, ropes, or plaited into sandals.
In the Peruvian Amazon, reportedly there is a native species of Cyperus used widely by tribal women as a natural contraceptive. This property has been attributed to a certain mold that grows on the root of the Amazonian species that has oxytoxic (abortive) properties similar to Ergot, a fungus that grows on rye.
In Maradi state, eastern Niger, C. esculentus is cultivated for export to Nigeria. Revenues from this weed exceed those from the typical cash crops such as cowpea and groundnut. The tubers of C. esculentus may be consumed raw, roasted, or ground.
Nowadays, chufa is cultivated in Northern Nigeria and Ghana, where it is made into a sweet meat, and Togo, where it is used uncooked as a side dish. These countries, and others as the Ivory Coast, export 2300 tons of tubers every year to Spain. The chufa is also a representative crop of the Spanish Mediterranean region, where tubers are used to make a beverage called horchata or horchata de chufas. The milky-looking aqueous extract of chufa has a pleasant and characteristic flavor of vanilla and almonds.
Chufa is potentially a commercial source of high-oleic acid vegetable oil and high-carbohydrate tuber cakes. Some authors believe that tuber oil could be exploited in the same way as olive oil.
Chinese researchers have measured the physical and fuel properties of oil extracted from the chufa, and concluded that the physical properties are similar to those of other vegetable oils. They have suggested that this oil may also be used as biodiesel fuel.
http://threeissues.sdsu.edu/three_issues_coquillofacts02.html
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3 comments:
Yellow Nut Sedge is an invasive species.
In your yard, while harmless where these are growing and offering special mid-summer beauty.
I actually like them in my yard; they are pretty plants. I was just surprised that you would be so proud of such a low-quality, invasive species in the WPWP. They are a detriment to other, more desireable cyperus and carex species.
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