A SIMPLE METHOD TO CONTROL WATER HYACINTH

(Eichornnia crassipes), A COMMON AQUATIC WEED *Nayeem UUah Khan, **Jayarama Reddy, ***P K Shetty and ****

Mathews P Raj *#104,h cross Opp. DayanandaSagar College, K S Layout, Bangalore 560078

** Priya Residency apartments, 7th main, Puttenahalli, 7th phase, JP Nagar, Bangalore 560078

***#386, Krishna, 4th cross, 1st block, R. T Nagar, Bangalore-560032

****#86,1st main road, 9th cross (Upstairs), Chamarajpet, Bangalore-560018

PREAMBLE

Water hyacinth, Eichornnia crassipes, a free floating aquatic weed of South American origin, ranks among the top ten weeds worldwide. Chemical herbicides have been used in many areas, but they are suitable only if water is not used for drinking and the weed stand is high. It is considered the water hyacinth is the most common aquatic weed which is causing an enormous damage to the lakes in Bangalore city. A biological control program of water hyacinth was undertaken in Southern Benin between 1991 and 1993. It consisted of the release of three natural enemies, two weevil species and one moth that feed exclusively on water hyacinth (De Groote. et al, 2003). A study on the cyanide phytoremediation by water hyacinths (Eichornnia crassipes) was done by Mathias et al (2007). In 1995 the weevils Neochetina eichorniae and JV. bruchi were introduced separately in China from USA and Argentina to control water hyacinth (Ding et al, 2001). Release of the water hyacinth mite, O. terebrantis which confines to water hyacinth were initiated in 1986 at Bangalore, Kamataka (Singh, S.P, (2004) with little success. The above research indicates that there is a need for the development of an environmentally safe method of controlling and managing the weed. The present invention has the following aims and objectives.

OBJECTIVES

1. To devise a simple cost effect method for control of water hyacinth.

2. To devise a method to monitor environmental safety.

COMPLETE SPECIFICATION

The growth of the weed Eichornnia crassipes is monitored by physical observation, the spraying of salt leads to etiolation of the leaves, etiolation is followed by loss of chlorophyll (the leaves turn yellow), drying is indicated by browning and necrosis (death of tissue). The plant is grown in plastic trays measuring (75cmX36cmX12cm), containing natural pond waters collected from local ponds where the weed is found. The plant is sprayed with different salt concentrations and the setup is left for a few days, Growth is measured by fresh weight (biomass), there is initial increase in biomass after salt solutions of various concentrations are sprayed there is a decrease in biomass. The minimum lethal dose is thus determined to be 0.1 M.

REFERENCES

1. De Groote, H., O. Ajuonua, S. Attignona, R. Djessoub and P. Neuenschwander. 2003 Economic impact of biological control of water hyacinth in Southern Benin. Ecological Economics. 45(1): 105-117.

2. Ding JQ, Wang R, and Fu WD (2001) Water Hyacinth in China: Its Distribution, Problems and Control Status. In: Mien MH, Hill MP, Center TD, et al., editors. Biological and Integrated Control of Water Hyacinth, Eichhornia Crassipes; ACIAR Proceedings 102; Canberra, Australian. 2001. Pages. 29-32.

3. Mathias Ebel, Michael W.H. Evangelou, Andreas Schaeffer. 2007. Cyanide phytoremediation by water hyacinths {Eichornnia crassipes). Chemosphere Volume 66, Issue 5, January 2007, Pages 816-823.

4. Singh, S.P, (2004). Biological Control of Water Hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae). Some success stories in classical biological control in India. APARI Publication, Bangkok, Thailand. Pages. 12-16.

WE CLAIM

1. The method used is the cheapest (Cost per area of the pond).

2. Easy and simple to use.

3. The entire method is environmentally safe.