ombine the fastest growing water-borne weed in the world with the "Venice of the East" and the outcome was inevitable. Introduced as an ornamental plant nearly 100 years ago, the water hyacinth quickly filled the extensive waterways of Thailand. Know in Thailand as pak tok cha wa or "java weed," it doubles its biomass in less than two weeks and will completely coat the surface of rivers, lakes and canals, crowding out native flora and fauna and clogging boat motors.

Other infested parts of the world have attempted to eliminate the nuisance with herbicides and insect predators. For decades, Thailand also adopted this approach, but the end result was invariably time-consuming removal and dumping of the weeds.

In the last few years, however, the water hyacinth is being viewed in a new light. Suhsuttijed Chantrasiri, researcher at Thailand Institute of Scientific and Technological Research (TISTR), explains. "The object of our research was how to use what we would normally waste." So along with the Thai Ministry of Science, Technology, and the Environment, TISTR worked hard to make alternate uses of the water hyacinth profitable. Several utilization programs began in 1992 and have recently transformed the image of the weed.

Decaying water hyacinth was found to be the perfect medium to cultivate valuable straw mushrooms (hed fang in Thai) and has been successful as an ingredient in a water-hyacinth-based fiber board for construction.

Because it rots in 15 days, it is an ideal component in fertilizer. Weed harvested from the Bangkok area is used in a new fertilizer factory to provide low cost organic fertilizer for farms. But the real success, both economically and in terms of eliminating the weed, lies in the field of wickerwork. Wicker items made from the stems have proved extremely popular in Germany and Japan, where environmentally friendly products are fashionable. Rural farmers can gain valuable extra income from wickerwork in the off-season. The success of wickerwork sales has in fact caused a shortage of water hyacinth and, incredibly, the weed must be brought in from other areas to maintain production levels.

While the aggressive weed is still far from being a cash crop and is still a pest in some regions, few would have guessed ten years ago that it could ever be in demand. In Chaninat Province, water hyacinth is actually being cultivated to produce the long stems that are best for wickerwork.

The success of the water hyacinth project has led researchers to examine vetiver grass, or ya fak, another fast-growing weed once thought to be of no value, but which now appears to have potential applications in handicraft.

Meanwhile, other uses for the water hyacinth are also being studied. "We are testing fermenting water hyacinth for butane gas production," Chantrasiri says, "also using it for 'green fuel'--water hyacinth compacted into cooking wood. It's a versatile plant."

The water hyacinth has witnessed an amazing and unexpected turnaround. While many invasive plants have given rise to some well-intentioned, but ultimately inconsequential ideas for their use, it is a rare weed indeed that can eventually lay claim to being in high demand as a raw material.

(Photograph by Ron Morris)

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