Eichhornia crassipes

From Wikipedia, the free encyclopedia
For other plants known as "water hyacinth", see Eichhornia.
Common water hyacinth
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Commelinales
Family: Pontederiaceae
Genus: Eichhornia
Species: E. crassipes
Binomial name
Eichhornia crassipes
(Mart.) Solms

Eichhornia crassipes, commonly known as (common) water hyacinth, is an aquatic plant native to the Amazon basin, and is often considered a highly problematic invasive species outside its native range.

Description

Water hyacinth is a free-floating perennial aquatic plant(or hydrophyte) native to tropical and sub-tropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter in height. The leaves are 10–20 cm across, and float above the water surface. They have long, spongy and bulbous stalks. The feathery, freely hanging roots are purple-black. An erect stalk supports a single spike of 8-15 conspicuously attractive flowers, mostly lavender to pink in colour with six petals. When not in bloom, water hyacinth may be mistaken for frog's-bit (Limnobium spongia).

One of the fastest growing plants known, water hyacinth reproduces primarily by way of runners or stolons, which eventually form daughter plants. Each plant can produce thousands of seeds each year, and these seeds can remain viable for more than 28 years.[1] The common water hyacinth (Eichhornia crassipes) are vigorous growers known to double their population in two weeks.

Habitat and ecology

Its habitat ranges from tropical desert to subtropical or warm temperate desert to rainforest zones. It tolerates annual precipitations of 8.2 dm to 27.0 dm (mean of 8 cases = 15.8 dm), annual temperatures from 21.1°C to 27.2°C (mean of 5 cases = 24.9°C), and its pH tolerance is estimated at 5.0 to 7.5. It does not tolerate water temperatures >34°C. Leaves are killed by frost and salt water, the latter trait being used to kill some of it by floating rafts of the cut weed to the sea. Water hyacinths do not grow when the average salinity is greater than 15% that of sea water. In brackish water, its leaves show epinasty and chlorosis, and eventually die.[2]

Because of E. crassipes invasiveness, several biological control agents have been released to control it, including two weevils, Neochetina bruchi Hustache (Coleoptera: Curculionidae) and Neochetina eichhorniae Warner (Coleoptera: Curculionidae), and the moth Niphograpta albiguttalis (Warren) (Lepidoptera: Pyralidae).[3] Neochetina eichhorniae causes "a substantial reduction in water hyacinth production" (in Louisiana); it reduces plant height, weight, root length, and makes the plant produce fewer daughter plants. N. eichhorniae was introduced from Argentina to Florida in 1972.[4]

Azotobacter chroococcum, an N-fixing bacteria, is probably concentrated around the bases of the petioles. But the bacteria do not fix nitrogen unless the plant is suffering extreme N-deficiency.[5]

Fresh plants contain prickly crystals.[2] This plant is reported to contain HCN, alkaloid, and triterpenoid, and may induce itching.[6] Plants sprayed with 2,4-D may accumulate lethal doses of nitrates,[7] as well as various other nocive elements in polluted environments. See further down.

Invasive species

Water hyacinth has been widely introduced in North America, Asia, Australia, Africa and New Zealand. They can be found in large water areas such as Louisiana, or in the Kerala Backwaters in India. In many areas it is an important and pernicious invasive species. In New Zealand it is listed on the National Pest Plant Accord which prevents it from being propagated, distributed or sold.

First introduced to North America in 1884, an estimated 50 kilograms per square metre of hyacinth once choked Florida's waterways,[8] although the problem there has since been mitigated.[citation needed] When not controlled, water hyacinth will cover lakes and ponds entirely; this dramatically impacts water flow, blocks sunlight from reaching native aquatic plants, and starves the water of oxygen, often killing fish (or turtles). The plants also create a prime habitat for mosquitos[citation needed], the classic vectors of disease, and a species of snail known to host a parasitic flatworm which causes schistosomiasis (snail fever)[citation needed]. Directly blamed for starving subsistence farmers in Papua New Guinea[citation needed], water hyacinth remains a major problem where effective control programs are not in place. Water hyacinth is often problematic in man-made ponds if uncontrolled, but can also provide a food source for gold fish, keep water clean [9] [10] and help to provide oxygen[citation needed] to man-made ponds.

Water hyacinth often invades bodies of water that have been impacted by human activities[citation needed]. For example, the plants can unbalance natural lifecycles in artificial reservoirs or in eutrophied lakes that receive large amounts of nutrients.

Eichhornia crassipes, the Common water hyacinth, has become an invasive plant species on Lake Victoria in Africa after it was introduced into the area in the 1980s[citation needed].

Africa
See also: Water hyacinth in Lake Victoria

The plant was introduced by Belgian colonists to Rwanda to beautify their holdings and then advanced by natural means to Lake Victoria where it was first sighted in 1988.[11] There, without any natural enemies, it has become an ecological plague, suffocating the lake, diminishing the fish reservoir, and hurting the local economies. It impedes access to Kisumu and other harbors.

The water hyacinth has also appeared to the north in Ethiopia, where it was first reported in 1965 at the Koka Reservoir and in the Awash River, where the Ethiopian Electric Light and Power Authority has managed to bring it under moderate control at the considerable cost of human labor. Other infestations in Ethiopia include many bodies of water in the Gambela Region, the Blue Nile from just below Lake Tana into Sudan, and Lake Ellen near Alem Tena.[12]

Control

Water hyacinth can be controlled using three methods:

Chemical Control

The application of herbicides for controlling water hyacinth has been carried out for many years and it has been found that there is a good success rate when dealing with small infestations. A main concern when using herbicides is the environmental and health related effects, especially where people collect water for drinking and washing.

Physical Control

Physical control is performed by land based machines such as bucket cranes, draglines, or boorm or by water based machinery such as aquatic weed harvester, dredges, or vegetation shredders. Mechanical removal is seen as the best short-term solution to the proliferation of the plant. A project on Lake Victoria in Africa used various pieces of equipment to chop, collect, and dispose of 1500 hectares of water hyacinth in a 12 month period. It is however costly and requires the use of both land and water vehicles, but it took many years for the lake to become in poor condition and reclamation will be a continual process.

Biological Control
In 2010 the insect Megamelus scutellaris was released by the Agricultural Research Service as a biological control for the invasive species Eichhornia crassipes, more commonly known as waterhyacinth.
In 2010 the insect Megamelus scutellaris was released by the Agricultural Research Service as a biological control for the invasive species Eichhornia crassipes, more commonly known as waterhyacinth. (United States Department of Agriculture, Agricultural Research Service, )

As chemical and mechanical removal is often too expensive and ineffective, researchers have turned to biological control agents to deal with water hyacinth. The effort began in the 1970s when USDA researchers released three species of weevil known to feed on water hyacinth into the United States, Neochetina bruchi, N. eichhorniae, and the water hyacinth borer Sameodes albiguttalis. Although meeting with limited success, the weevils have since been released in more than 20 other countries. However, the most effective control method remains the control of excessive nutrients and prevention of the spread of this species.

May 2010 the USDA’s Agricultural Research Service released Megamelus scutellaris as a biological control insect for the invasive waterhyacinth species. Megamelus scutellaris is a small planthopper insect native to Argentina. Researchers have been studying the effects of the biological control agent in extensive host-range studies since 2006 and concluded that the insect is highly host-specific and will not pose a threat to any other plant population other than the targeted water hyacinth. Researchers also hope that the biological control will be more resilient than existing biological controls to the herbicides that are already in place to combat the invasive water hyacinth.

Uses

Bioenergy

Because of its extremely high rate of development, Eichhornia crassipes is an excellent source of biomass. One hectare of standing crop thus produce more than 70,000 m3 of biogas.[13] According to Curtis and Duke, one kg of dry matter can yield 370 liters of biogas, giving a heating value of 22,000 kJ/m3 (580 Btu/ft3) compared to pure methane (895 Btu/ft3)[14]

Wolverton and McDonald report only 0.2 m3 methane per kg, indicating requirements of 350 MT biomass/ha to attain the 70,000 m3 yield projected by the National Academy of Sciences (Washington).[15] Ueki and Kobayashi mention more than 200 MT/ha/yr.[16] Reddy and Tucker found an experimental maximum of more than a half ton per day.[17] Bengali farmers collect and pile up these plants to dry at the onset of the cold season; they then use the dry water hyacinths as fuel. They then use the ashes as fertilizer. In India, a ton of dried water hyacinth yield circa 50 liters ethanol and 200 kg residual fiber (7,700 Btu). Bacterial fermentation of one ton yields 26,500 cu ft gas (600 Btu) with 51.6% methane, 25.4% hydrogen, 22.1% CO2, and 1.2% oxygen. Gasification of one ton dry matter by air and steam at high temperatures (800°) gives circa 40,000 ft3 (circa 1,100 m3) natural gas (143 Btu/cu ft) containing 16.6% H3, 4.8% methane, 21.7% CO, 4.1% CO2, and 52.8% N. The high moisture content of water hyacinth, adding so much to handling costs, tends to limit commercial ventures.,[15][18] A continuous, hydraulic production system could be designed, which would provide a better utilization of capital investments than in conventional agriculture, which is essentially a batch operation.,[2][19]

The labour involved in harvesting water hyacinth can be greatly reduced by locating collection sites and processors on impoundments that take advantage of prevailing winds. Wastewater treatment systems could also favourably be added to this operation. The harvested biomass would then be converted to ethanol, natural gas, hydrogen and/or gaseous nitrogen, and fertilizer. The resulting byproducts of water and fertilizer can both be used to irrigate nearby cropland.[2]

Phytoremediation, waste water treatment

The roots of Eichhornia crassipes naturally absorb pollutants, including lead, mercury, and strontium-90, as well as some organic compounds believed to be carcinogenic, in concentrations 10,000 times that in the surrounding water.[20] Water hyacinths can be cultivated for waste water treatment.[2]

Edibility

The plant is used as a carotene-rich table vegetable in Taiwan. Javanese sometimes cook and eat the green parts and inflorescence.[2]

Medicinal use

In Kedah (Java), the flowers are used for medicating the skin of horses.[2] The species is a "tonic.",[21][22]

Other uses

In East Africa, water hyacinths from Lake Victoria are used to make furniture, handbags and rope.[23] The plant is also used as animal feed and organic fertilizer although there is controversy stemming from the high alkaline pH value of the fertilizer.[24] Though a study found water hyacinths of very limited use for paper production,[25] they are nonetheless being used for paper production on a small scale.

Gallery

  • Floating

  • Flowers

  • A pond covered with water hyacinth

  • Inflated petiole

References

  1. ↑ Sullivan, Paul R. and Wood, Rod. 2012. Water hyacinth, Eichhornia crassipes (Mart.) Solms, seed longevity and the implications for management. 18th Australasian Weeds Conference. Melbourne: Conference Proceedings CD.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Eichhornia crassipes, in Handbook of Energy Crops. By J. Duke. Available only online. An excellent source of information on numerous plants.
  3. ↑ Julien, M.H., and Griffiths, M.W. (1998), Biological Control of Weeds: A World Catalogue of Agents and their Target Weeds (4th ed.), Oxon, UK: CABI Publishing, CAB International.
  4. ↑ Suppressing water hyacinth with an imported weevil. By R.A. Goyer and J.D. Stark. 1981. La. Agr. 24(4):4-5. Cited in Handbook of Energy Crops. By J. Duke.
  5. ↑ Water hyacinth: a plant with prolific bioproductivity and photosynthesis. By S. Matai and D.K. Bagchi. 1980. pp. 144-148 in: Gnanam, A., Krishnaswamy, S., and Kahn, J.S. (eds.), Proc. Internat. Symp. on Biol. Applications of Solar Energy. MacMillan Co. of India, Madras. Cited in Handbook of Energy Crops. By J. Duke.
  6. ↑ Medicinal plants of east and southeast Asia. By L.M Perry. 1980. MIT Press, Cambridge. Cited in Handbook of Energy Crops. By J. Duke (Available only online. An excellent source of information on numerous plants.)
  7. ↑ Tropical feeds. Feed information summaries and nutritive values. By B. Gohl. 1981. FAO Animal Production and Health Series 12. FAO, Rome. Cited in Handbook of Energy Crops. By J. Duke.
  8. ↑ "A Troublesome "Water Weed"". Popular science monthly: 429. January 1898. Retrieved 13 May 2013. 
  9. ↑ J. Todd, B. Josephson, The design of living technologies for waste treatment / Ecological Engineering 6 (1996) 109-136
  10. ↑ Water Hyacinth For Nutrient Removal, Orange County Water Conservation Department Orlando, Florida, http://www.apms.org/japm/vol06/v6p27.pdf |accessdate=31 July 2013
  11. ↑ Die grüne Pest. By Thilo Thielke. Spiegel (de) 2/9/2008, accessed 2/9/2008.
  12. ↑ Rezene Fessehaie, "Water Hyacinth (Eichhornia crassipes): A Review of its Weed Status in Ethiopia", Arem., 6 (2005): 105-111.
  13. ↑ Making aquatic weeds useful. National Academy of Sciences (or N.A.S.), Washington, DC. 1976.
  14. ↑ An assessment of land biomass and energy potential for the Republic of Panama. By C.R. Curtis and J.A. Duke. 1982. vol. 3. Institute of Energy Conversion. Univ. Delaware.
  15. ↑ 15.0 15.1 Energy from vascular plant wastewater treatment systems - Eichhornia crassipes, Spirodela lemna, Hydrocotyle ranunculoides, Pueraria lobata, biomass harvested for fuel production. By B.C. Wolverton and R.C. McDonald. 1981. Econ. Bot. 35(2):224-232. Cited in Handbook of Energy Crops. By J. Duke.
  16. ↑ Cultivation of new biomass resources. K. Ueki and T. Kobayashi. 1981. In “Energy Develop. in Japan”, 3(3):285-300. Cited in Handbook of Energy Crops. By J. Duke.
  17. ↑ Productivity and nutrient uptake of water hyacinth Eichhornia crassipes. K.R. Reddy and J.C. Tucker. 1983. 1. Effect of nitrogenous source. Econ. Bot. 37(2):237-247. Cited in Handbook of Energy Crops. By J. Duke.
  18. ↑ The wealth of India. By the C.S.I.R., or Council of Scientific and Industrial Research. 1948-1976. 11 vols. New Delhi. Cited in Handbook of Energy Crops. By J. Duke.
  19. ↑ Energy from fresh and brackish water aquatic plants. By J.R. Benemann. 1981. pp. 99-121. In: Klass, D.L. (ed.), Biomass as a non-fossil fuel source. ACS Symposium Series 144. ACS. Washington. 564 p. Cited in Handbook of Energy Crops. By J. Duke.
  20. ↑ BioScience 26(3): 224. 1976.
  21. ↑ Medicinal plants of the world. By J.A. Duke and K.K Wain. 1981. Computer index with more than 85,000 entries. 3 vols.
  22. ↑ Oudhia P.(2001).Traditional medicinal knowledge about a noxious weed, jal kumbhi (Eichhornia crassipes), in Chhattisgarh (India). AQUAPHYTE. 21(2). Winter 2001.
  23. ↑ Patricia Aguilo et al, "Attracting Investment to Kisumu: Opportunities and Challenges", Columbia University
  24. ↑ Global Invasive Species Database
  25. ↑ W.J. Nolad, D.W. Kirmse, The Papermaking Properties of Waterhyacinth, Journal of Aquatic Plant Management (JAPM) Vol 12 (May 1974), pp 90-97

External links

Wikimedia Commons has media related to Eichhornia crassipes.
This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.