Strategies for Water Hyacinth Control

Report of a Panel of Experts Meeting, 11-14 September, 1995, Fort Lauderdale, Florida USA

Edited by: R. Charudattan, Ricardo Labrada, Ted D. Center, Christine Kelly -Begazo

Food and Agricultural Organization of the United Nations, Rome 1996

TABLE OF CONTENTS

Introduction International Expert Consultation on Strategies for Water Hyacinth: Control: Background and Jusfification Labrada, R. Charudattan, and T.D. Center

Status of Water Hyacinth in Developing Countries R. Labrada

Region A - West Africa: Benin, Ghana, and West Africa

Biological Control of Water Hyacinth in Benin, West Africa P. Neuenschwander, O. Ajuonu, and V. Schade

Integrated Control of Aquatic Weeds in Ghana K.A.A. de Graft Johnson

The Water Hyacinth Problem in West Afiica and Proposals for Control Strategies A.H. Pieterse, A. Mangane, M. Traori, G. van de Klashorst, and P.J. van Rijn

Region B - East and Southern Africa: Malawi, South Africa, and Uganda

The Water Hyacinth Problem in Malawi and Foreseen Methods of Control P.J. Terry

An Integrated Water Hyacinth Control Program on the Vaal River, in a CooL High Altitude Area in South Africa C.J. Cffliers, P.L. Campbell, D. Naude, and S. Neser

Water Hyacinth: its Problems and the Means of Control in Uganda F.L. Orach-Meza Region C - Austrtalia

An Outline of Water Hyacynth Control in Australia A.D. Wright

Region D - North America: Mexico and USA

Water Hyacinth Problems in Mexico and Practised Methods for Control E. Gutienrez Lopez, I;L Huerto DelgadiHo, and M. Martinez Jiminez

Operational Aspects of Cherffical, Mechanical and Biological Control of Water Hyacinth in the United States W.T. HaBer

Water Hyacinth Control Program in USA Al. F. Cofrancesco

Biological Control of Water Hyacinth in the United States T.D. Center

Special Section: New and Additional Agents for Biological Control and Steps in Implementing Integrated Management Programs

Recommendations for Finding and Prioritizing New Agents for Biocontrol of Water Hyacinth IELA. H.A. Cordo

Pathogens for Biological Control of Water Hyacinth R.Charudattan

Steps in Implementing integrated Management programs Against Water Hyacinth S. Ne ser

Conclusions and Recommendations of the Expert Panel: Intergrated Control of Water Hyacinth in Developing Countries with Emphasis on Biological Control

List of Participants

Introduction International Expert Consultation on Strategies for Water Hyacinm Control:

R. Labrada, R. Charudattan, and T.D. Center

'Food and Agriculture Organization of the United Nations (FAO), Rome, Italy, PIant Pathology Department, Center for Aquatic Plants, Institute of Food and Agricultural Sciences, University of Florida, and3USDA-ARS Aquatic Plant Control Research Laboratory, Fort Lauderdale, Florida

One of the major problems in water bodies of the tropics and sub-tropics is the floating aquatic weed water hyacinth Eichhornia crassipes, which is considered to have originated from the Amazon and has dissen-dnated very quickly in various tropical and sub-tropical countries of Latin America and the Caribbean, Africa, Southeast Asia and the Pacific.

The level of reproduction of water hyacinth is very high in countries where the plant has recently been introduced. The explosive growth rate of the weed is due, to a large extent, to the eutrophication in water bodies. In addition, the absence of natural enemies of the plant contributes to the rapid growth of this weed.

It is well known that biological control is one of the most successful methods to control water hyacinth. The method, practised for example successfiffly in Australia through the regular release of the weevils Neocheam eichhormae and N. bruchi, and the moth Smneodes albiguttalis, has been recently adopted in some countries of Latin America and Africa and it is expected to have the same impact as in Australia. However, in many countries the water bodies present very heavy infestations in different sites (fish landing areas, docks, hydroelectric power stations, rivers and dams), and there is a general consensus that other short-term control measures should also be implemented to reduce the weed stands and also to benefit the growth of natural enemies for successful biological control.

Among the short-term control measures there are physical (mechanical and manual) removal and chemical control. AD have serious constraints for implementation in water bodies of developing countries of the tropical and sub-tropical regions.

Mechanical removal requires the purchase of harvesters, many of them too costly for most of developing countries. Manual removal requires a large labour force, and Governments of the developing world do not always have the means to pay for this operation.

Chemical control through the use of certain herbicides such as 2,4-D or glyphosate, seems to be an economically feasible option in some countries, but not in others with less economic development. In additior4 in many countries public opinion is strongly against the use of chemicals in water, which is used for drinking purposes.

FAO, taldng into consideration the seriousness of the problem and the need to develop a strategy for integrated water hyacinth control, has decided to organize, in close cooperation with USDA and University of Florida, the present expert technical consultation.

Expected Outputs

1. Suitable guidelines for water hyacinth control in developing countries of the tropical and sub-tropical regions. These guidelines should clearly indicate the strategy for implementing available control methods.

2. An updated status report of biological control of water hyacinth (natural enemies and methods for rearing and release available) giving relevant advice on ways for its rapid implementation and success in countries of the developing world.

Participants

Outstanding specialists on water hyacinth control from countries and/or institutions (such as CSIEFLO, Australia; IITA, Benin; Royal KIT, Amsterdam, The Netherlands; Long Ashton Research Station, University of Bristol and I[IBC, UK) and several others from the University of Florida and USDA will actively participate in this meeting. Some other specialists from selected ongoing projects on water hyacinth control have also been invited, whose participation may give the necessary background to discussions and debates. These are specialists from Uganda (Lake Victoria), Ghana and Mexico who work closely on water hyacinth control.