Alive For Go-Ahead Men : A Delhi Press Magazine

Noxious weeds, both aquatic and terrestrial, that flourish with unchecked abundance, pose a serious threat to the well-being of both humans and cattle. However, human ingenuity has paved the way for successfully harnessing many of the troublesome weeds for improving the quality of man’s life.

For instance, the fast-growing, much-detested, water-hyacinth, known as a “champion coloniser of the plant world,” is now being exploited to generate bio-gas, purify water, and treat effluents, as well as for producing utility items, including paper, hard-board and cattle-feed.

Incidentally, the potential of water-hyacinth as an agent for purifying waste-water, was first noticed by researchers at the National Space Technology Laboratory (NSTL) in Louisiana, USA, way back in 1976, while looking for an efficient lifesupport system in outer space.

Further, in conjunction with a water-hyacinth-based waste-water treatment system, it is also possible to recover valuable minerals from the waste as the weed has the property of absorbing heavy metals. In many countries of Asia-Pacific region, water-hyacinth is used to treat wastewater and industrial effluent.

The potential of water-hyacinth as an agent to purify tannery effluents has also been demonstrated in pilotprojects carried out in India and other parts of the world. Water-hyacinth has also been used effectively to absorb chemical, heavy metals and organic compounds, including pesticides from an aquatic eco-system.

However, the promise of waterhyacinth as a potential source of biogas, eclipses all its other properties in view of the rapidly-escalating energy crisis. Water-hyacinth-based bio-gas is being projected as a promising substitute for natural gas.

Researchers at the NSTL demonstrated that 314 litres of bio-gas can be produced from 1 kg of dried waterhyacinth mass. As it is, this aquatic weed is converted into bio-gas by capitalising on nature’s process – decay by anaerobic bacteria found in the warmer zones of the world.

The gas so generated can be used for cooking, lighting and operating appliances. The high-nutrient compost, left behind in the digester, is rich in nitrogen, potash and phosphorous.

On another front, water-hyacinth is also used in producing paper, hardboard, as well as animal-feed.

So much for the manifold uses of this problematic weed. Now about Lantana.

Not long ago, lantana was considered a harmful weed, found thriving on the forest floors, posing a serious threat to plantation forestry. It is now being widely used to make a wide range of aesthetically-designed furniture to suit every taste and pocket.

Lustrous lantana

Known in Kannada language as Belligida or Silver Plant, lantana was introduced into India by the British colonial rulers as an ornamental plant, in early 19th century. However, it turned out be a menacing weed, threatening all vegetation in its vicinity.

A group of tribals in southern Karnataka, including Medaras, Koravas and Soligas, who used to be dependent on forest produce for their survival, have now taken to turning lantana into beautiful furniture. It is being made into chairs, diningtables, racks, cots and baskets.

This furniture has a ready market in cities such as Bangalore and Mysore. In fact, anything that can be crafted out of bamboo-cane, can also be made from lantana. The rapid disappearance of bamboo stocks has threatened the very livelihood of tribals dependent on bamboo for making both ends meet.

Now, lantana has emerged as their saviour and life-sustaining force. Prior to this, the Dehradun-based Himalayan Environmental Studies and Conservation Organisation (HESC) had actually promoted the use of lantana for making furniture.

Thanks to the initiative by the Bangalore-based Ashoka Trust for Research in Ecology and Environment (ATREE), tribals in M.M.Hills, B.R.Hills, Nagarhole and other adjoining areas, were trained to make furniture from lantana. In fact, simple and cost-effective techniques devised to treat strips of lantana, allowing them to be used in much the same way as cane, attracted the tribals to lantana as a potential bamboo-substitute for crafting furniture.

Over 60 products, ranging from baskets to office furniture, are being designed and crafted out of lantana.

Many destitute women, too, have taken to crafting lantana furniture. According to sources in ATREE, cost-wise, lantana furniture is much cheaper than cane furniture. Not surprisingly then, many offices, business centres and individual households in Bangalore are taking to lantana furniture.

Lucrative sea-weeds

On another front, rustic women in Langaleswar village, off Ganjam coast in Orissa, have floated self-help groups to promote the cultivation of sea-weed, whose extracts are used in toothpaste, ice-cream, textile-printing, cosmetics, teeth-filling, tissueculture and packaging. Sea-weed is also a major ingredient used in the food-processing industry. It is used as a thickening agent in products such as chocolates and custard powder.

Moreover, it is also considered a rich source of certain vitamins and minerals. Currently, about 60 womenfolk in this coastal hamlet of Orissa are actively involved in sea-weed cultivation.

Central Salt and Marine Chemicals Research Institute (CSMCRI) at Bhavnagar and Central Marine Fisheries Research Institute (CMFRI) at Kochi, have developed culture technique for some of the commercially important sea-weed species.

Similarly, in the shallow waters of Mandapam coast, in the Gulf of Mannar along Tamil Nadu’s Rameswaram coast, one can see hundreds of bamboo rafts floating. These rafts carrying sea-weeds are left to float in the calm Gulf waters by around 700 cultivators, who make a living by growing and selling sea-weed.

Normally, each raft, carrying about 60 kg of sea-weed, gets ready for harvesting after 45 days. Here, too, the cultivators have floated self-help groups to cultivate and market the sea-weed.

According to one of the cultivators, the investment on sea-weed cultivation can be recovered in a year’s time. Many fishermen, who no longer find fishing lucrative on account of the rapidly-declining fish catch, are taking to sea-weed cultivation. However, sea-weed cultivation in India is still in its infancy. South-East Asian countries have made major strides in cultivating and marketing sea-weed.

Through a well-conceived strategy of cultivation and an efficient marketing mechanism, sea-weed could be a major money-spinner for India. There is a huge and captive market for seaweed, which India can easily tap.

Experience says that sea-weed can easily be sold in both the domestic and overseas markets. Moreover, seaweed cultivation, in distinct contrast to aqua-cultural prawn cultivation, is an ecologically benign operation.