Water Hyacinth: A Useful Plant to Improve Rural Economy

Abstract

Aquatic plants have created havoc all over the world. Natural aquatic plants population to some extent is healthy for any aquatic ecosystem as it serves as fish feed, plays an important role in nutrient cycling, purifies the water, controls unwanted algal growth and supports fauna including birds. Unwanted growth of aquatic plants especially some seriously invasive species like water hyacinth and Salvinia has caused a loss of billions of US$ all over the world. It affects the supply of drinking water and water hyacinth (Eichhornia crassipes) has proved to be a persistent and expensive aquatic weed problem costing millions of dollars to control and unaccounted millions of dollars more to the damage to the environment, irrigation systems and crops. It was first introduced as an ornamental plant in India in 1896 from Brazil. Water hyacinth has posed ecological and economical problems in several countries. This weed poses problem especially in tropical and subtropical countries where environmental conditions provide a year round growing period. The natural loss of water from the water surface by evaporation is thought to increase through transpiration from the leaves of water hyacinth by at least 40–50%. The dense growth of water hyacinth obstructs water flow in irrigation channels, interferes with navigation and hydroelectric power generation. The flow of water is reduced by 40–95% and roughness coefficient increases from 0.024 to 0.055 in irrigation channel. Water hyacinth interferes with the seed germination and seedling establishment in paddy, resulting in heavy economic losses to the tune of up to 24 million dollars. The oxygen-depleting load of one hectare of water hyacinth mat is equivalent to that of the sewage created by 80 persons. Over the years, various control methods have been studied and tried including chemical, biological and mechanical means but with no lasting success. The simplest way to control this weed is to harvest it and utilize it for useful products. Utilization of plant will improve rural economy and also solve the problem of management of this weed in India.