Essay On Waterhyacinth

Waterhyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a native of the tropical South America, is considered to be one of the most serious aquatic weeds (Holms et al., 1977). It has spread throughout tropical countries causing widespread problems to millions of users of water aquaticbodies and water its resources. It causeings severe problems related to itsthe use and management of fresh water resources (Gopal, 1987; Center, 1994). It has a tremendous socio-economic impact on aquatic ecosystem causing global annual loss of more than US$ 100 million to hydroelectricity generation, irrigation schemes, fisheries, water transport, etc (Shabana, 2005). Several control mechanisms including manual, mechanical, chemical and biological

2011). In its native land, waterhyacinth is attacked by a large complex of natural enemies including several arthropod agents and fungi (Bennett and Zwolfor, 1968; Bennett, 1970, 1972; Corodo, 1996, 1998). But in its range of introduction, in absence of control agents, waterhyacinth also flourishes as many other weedsmajestically. Thus the need and subsequent search for indigenous control agents continues for weed scientists. The biological control agents have provided excellent control of waterhyacinth in many locations around the world including India (Center, 1994, Coetzee et al. 2011). Biological control of weeds using insects and pathogens have gained considerable importance over last five decades as they are ecologically eco- friendly, host specific and effective means of weed control. Among various biological control agents, several various phytopathogenic fungi have been found to workeffective against the weed (Charudattan, 2001). Various studies on the isolation, identification and pathogenicity of fungi associated with the waterhyacinth in its native range, as well as in several water hyacinthwaterhyacinth infested areas of the world (Freeman et