Exotic floating waterweeds are now a serious problem in Africa, and indeed throughout the tropical world. Three floating weeds cause most of the problems: the water hyacinth (Eichhornia crassipes), the water fern (Salvinia molesta) and the water lettuce (Pistia stratiotes). These weeds are native to the Amazon basin, where they rarely cause any problems. However, outside their natural habitat, and freed from the controlling influence of their natural enemies, their unchecked growth leads to thick mats of vegetation on rivers, lakes and lagoons (Science and Technology News, Published by the Commonwealth Science Council, Number 21, December 1991).  

Waterweeds create serious problems. Infestations cause deterioration of water quality, reduce fish populations, clog irrigation and drainage schemes, and hinder or prevent navigation. Rural fishing communities can be seriously affected. Hydroelectric facilities can become clogged and forced to shut down. In some cases fishing and transport become impossible. Floating weeds also create a favorable environment for the breeding of the vectors of insect-borne disease and bilharzias (Science and Technology News, Published by the Commonwealth Science Council, Number 21, December 1991).  

How Did the Water Hyacinth Arrive in Africa?

Soon after the plant was first recorded, it was taken to Europe for detailed scientific description and because the flowers are attractive. It was also taken to the US in the 19^th century, and in the late 19^th century it was introduced to Egypt. At about the same time it was introduced into Japan, Indonesia And Australia, and a few years later it was introduced to South Africa. So in the space of a few years the plant was transported to many parts of the world, and there is no doubt that the intentional movement by humans has led to its worldwide distribution. Once present in an area, the water hyacinth spreads with further help from people, and also by water currents carrying plant seeds (Water Hyacinth, A threat to Malawi’s rivers and Lakes, Answers to Commonly Asked Question, CAB International Africa Regional Center, Nairobi, Kenya).  

The water hyacinth has been present in Zimbabwe, Mozambique and Angola for about sixty years, in the Congo River since 1952, in the White Nile since about 1956 and Senegal since 1963. In the 1980s it appeared in the West Africa coastal lagoon through which it spread rapidly, and at the same time it was discovered in the lakes of Eastern Africa, including Lake Victoria. Thus the weed is now found in much of sub-Saharan Africa (Water Hyacinth, A threat to Malawi’s rivers and Lakes, Answers to Commonly Asked Question, CAB International Africa Regional Center, Nairobi, Kenya).  

When Did the Water Hyacinth Arrive in Malawi?

Reports by local fishermen indicate that the water hyacinth appeared in the southern part of the Shire River in about 1968. Communities in the area have suggested that floods may have brought the weed from Mozambique where it has certainly stayed for much longer. Since then it has spread northward and is now present throughout the Shire river system including Lake Malombe. It has been reported in Lilongwe, Malawi’s administrative capital, the Linthipe and Bua Rivers and some parts of the southern end of Lake Malawi (Water Hyacinth, A threat to Malawi’s rivers and Lakes, Answers to Commonly Asked Question, CAB International Africa Regional Center, Nairobi, Kenya).  

Why is the Water Hyacinth One of the World’s Worst Weeds?

Several features of the biology of the water hyacinth contribute to its status as one of the world’s worst waterweeds. Chief among these is its enormous potential for growth and production of huge quantities of biomass. Growth varies considerably with conditions and nutrient availability, but some reports estimate that it can double its mass in one or two weeks. Although the water hyacinth normally floats on water, it can survive on mud when levels are low, enabling it to persist through dry seasons. It can survive a wide range of temperatures, wide range of nutrient levels in the water and a wide range of acidity and alkalinity, which enables it to colonize many habitats (Water Hyacinth, A threat to Malawi’s rivers and Lakes, Answers to Commonly Asked Question, CAB International Africa Regional Center, Nairobi, Kenya).  

The presence of the water hyacinth reduces water flow causing suspended particles to be precipitated, thereby increasing silt. Other than that the water hyacinth reduces the effective capacity of reservoirs, as the sheer volume of water is displaced. The weed also causes water loss, as evaporation from leaves is up to 13 times the rate of evaporation from clear water. It is estimated that up to 10 percent of the annual flow of the Nile River is lost in this way. The list of problems that result from the presence of the water hyacinth is therefore endless. Some organisms appear to be encouraged by the presence of the water hyacinth, but unfortunately they include several that are damaging to human health. It is reported that crocodiles and snakes are common in water hyacinth infested areas and the breeding conditions of mosquitoes, which transmit malaria, encephalitis, and filariasis, are improved by its presence (Water Hyacinth, A threat to Malawi’s rivers and Lakes, Answers to Commonly Asked Question, CAB International Africa Regional Center, Nairobi, Kenya). 

The Weed Brings Prosperity to Malawi

While the water hyacinth is creating chaos on many southern Africa rivers, women in Malawi are celebrating its existence. Several groups of women are currently using the water hyacinth to sterilize the substrate required to grow the edible fungi Oyster mushroom. Mushroom growing dates back as far as 1998, when a group of women started the venture in Malawi’s commercial capital of Blantyre. Mushroom selling has become a lucrative business and many people are now growing it as it continues to spread countrywide. 

The Enterprise Development and Training Agency (EDETA) has supplied the farmers with the technical expertise in successful mushroom growing. So far with funding from OXFAM, United Nations Development Programme (UNDP) and under the Enterprise development and employment creation in the Ministry of Commerce and industry, EDETA now boasts of 23 groups in its project area. The groups are actively involved in mushroom growing at present. Supplementary funding has also been sourced from the Community Partnership in Sustainable Natural Resource Management in Malawi (COMPASS) for a group of women in Chiwembe Township, in Blantyre. According to EDETA, significant progress has been registered in these groups.  

Emmanuel Mlaka, Executive Director of EDETA says, “The idea behind the establishment of the groups is to promote alternative livelihood strategies. These measures are aimed at enhancing income-oriented approaches to environmental conservation. Many Malawians are living in dire poverty compared to other sub-Saharan countries. The per capita income in Malawi is much lower than in other sub-Saharan countries.”

Mushroom Growing Solves Weed Problem

People in the village know that cutting down trees is not good. But the problem is that the average person has no other alternative to survive. You don’t tell someone, ‘don’t cut the tree it will help you in five years to come’. The people need alternatives in life now and that’s what EDETA is doing,” he said. 

Why alternative livelihood strategies? In mushroom growing, the deadly water weed -the water hyacinth- is a very good substrate for mushroom growing. Good substrate has a high nitrogen content and the water hyacinth, because of the green coloring matter available, has proved to be an ideal material for production. Mlaka says ½ metric tone of the water hyacinth is needed per shelter per cycle of mushroom growing. 

The water hyacinth has the potential to regenerate and multiply faster; there is the need, therefore, to have more groups to utilize the weed. EDETA intends to institute three times the numbers of groups currently available by the end of this year. This will automatically affect the rate of vegetative growth by the weed. “The rate and speed of growth will be hampered as the number of those using the weed will almost triple,” he said. 

The Madalitso Entrepreneurs women group in Chiwembe benefited from a COMPASS grant of close to US$2000. The group is currently involved in active mushroom growing. The group has a total membership of 11 of which 91 percent are women. The women collect the water hyacinth that has colonized the Chiwembe dam as an alternative substrate for sporophore production of Oyster mushrooms. The group harvest according to COMPASS generated an initial supplementary cash income of K57,313.00, an equivalent of $856.00. The production is likely to skyrocket with time and hence more income is likely to be generated. 

Grace Malani, a retired Banker and now a resident of Machijiri Township in Blantyre, is one of the women involved. Grace started growing mushrooms in 2000 and it has proved very beneficial for her. “I got the technical expertise from EDETA. I have already made sales of close to MK18,000.00,” she said. “Since mushroom growing doesn’t involve traveling like other businesses, it is good for me,” Malani said. When asked about the way forward for mushrooms, she said that there is a need for those in the spore-making (seed production) phase to concentrate a lot in order to give growers the best. Mushroom seeds are produced at Chancellor College, a constituent college of the University of Malawi. 

A Profitable Business

The species of mushroom being promoted for production is scientifically known as Pleurotus sajor-caju. This is easy to grow using simple adopted technologies and does not require large pieces of land. The development of mushrooms is in line with the government policy of diversification of the country’s production base. 

Mushrooms are savory and have a high protein content closely related to animal protein. Mushrooms are widely used as an ingredient in a number of products such as soup and prepared meals in homes, hotels and specialized institutions. They are in high demand in Malawi and abroad. According to EDETA, domestic production of mushrooms has been estimated at 6.5 tons a year. This is too insufficient to meet the demand that annually stands at 80 metric tones a year (according to import statistics) the supply gap is satisfied by monthly imports from abroad. 

Other species of mushroom also on the production list include Genodarme lucidum, an edible mushroom used in boosting medicinal immunity, especially for cancer. Gendarme has the capacity to grow on live trees. EDETA intends to work closely with the department of forestry and wildlife in order to propagate this phenomenon. This will help to conserve other species of trees that are wantonly being cut down. Agaricus bisporous, or the button head mushroom, is another species also being promoted for production by EDETA. 

Figures obtained from EDETA indicate that mushroom growing is a lucrative business. The sales for nine groups in three months, according to EDETA, amounted to MK115, 000.00, an equivalent of $1,822.99. Since most of the materials are locally found, mushroom growing is economically viable. The presence of the water hyacinth is therefore a blessing in disguise. Despite being the worst water weed, local people are able to extract from it benefits for there livelihoods. EDETA intends to diversify strategies to benefit a cross section of the Malawi communities. 

Malawi Export Promotion Council research has identified mushrooms as a potential export product. In 1999, the global market value for edible mushrooms was estimated to be $17-30 billion, while that of medicinal mushrooms and their products for the same year was $6 billion. There is therefore the need for developing the mushroom industry, looking at the high demand globally. The presence of the water hyacinth therefore assures the growers of a readily available sterilizer for the substrate, especially due to the booming market. 

EDETA therefore intends to keep exploring more ways of utilizing the weed. At present, plans are underway to exchange information with an agricultural institution in Kenya. Research there has proved that dairy cattle that feed on the water hyacinth produce more milk, which can either be used for sale or for domestic use. 

The Water Hyacinth Saves Malawi’s Forests

In a related development, women in the Ndirande, one of the largest squatter areas in Blantyre, are producing briquettes using the water hyacinth. Briquettes have proved to be a substitute for charcoal and firewood. They have proven effective in mitigating the rampant deforestation. Already, Ndirande Mountain has suffered massive wanton tree cutting despite being a forest reserve.  

In Ndirande Township, over 270 women have received financial assistance from COMPASS as a grant to facilitate briquettes production. A committee of 17 members coordinates production units in three sections of Ndirande (Makata, Matope and Gamulani). 

The briquettes are also made from using waste paper. The paper is collected from offices and industrial sites. The activity assists in the control of waste management in the city. To make briquettes, the raw material is soaked, pounded and compressed into cylindrical blocks. The blocks are then dried up before being used to provide fuel for heating. 

Patricia Ndeula, one of the senior members and chair of the Briquettes group says, “The group started in 1998. COMPASS funded us with MK775, 000.00. With the grant money received, we bought two pressers and constructed a shade. Raw material like paper and saw dust were also included in the budget,” she said. When asked about how beneficial the briquettes business is she said, “There is a ready market for briquettes in Ndirande. Furthermore, a leading textile industry has shown interest in buying the briquettes in bulk quantities for industrial use,” Ndeula said. However she was quick to say that the challenge being faced by the group is the lack of finances so that group can reach other parts of the country with this technology. Ndeula also lamented the fact that the group’s shade was gutted with fire, and was quick to say that future expansion of the group activities will be determined by finances. 

Recent findings have proved that briquettes generate adequate calories for cooking. Women are able to cook any food including beans. Practical experience has shown that women cook beans with a maximum of eight briquettes and this translates into a cost of MK14-MK16 - about 13 cents - compared to approximately MK20-MK24 - about 25 cents - when charcoal is used. Briquettes have therefore proven to be far more effective as a source of energy. The presence of the water hyacinth therefore makes it sustainable to produce briquettes, since fuel wood is hard to come by. The technology in briquettes is simple, requires low maintenance and uses locally available material, says COMPASS.

Sources: 

• COMPASS, proceedings of a Water Hyacinth Workshop, Internal Report 5,2000

• Science and Technology News, Published by the Commonwealth Science Council, Number 21, December, 1991

• Water Hyacinth, A Threat to Malawi Rivers and lakes, CAB International, Africa Regional Center, Nairobi, Kenya

Charles Mkoka is an independent Malawian environmental writer with much experience in environmental issues. He has worked in the field of environment and natural resources since 1996, after graduating from the Malawi Natural Resources College. Apart from being a writer, he is also a wildlife educator, specialist and guide. You can reach him at: mkokach@yahoo.com. 

 

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