Water hyacinth [Eichhornia crassipes (Mart.) Solms] is a noxious aquatic weed in rice fields. Farmers are compelled to erect barricades to prevent these weeds from entering their fields through irrigation canals. Mechanical removal and chemical methods are advocated, but, for one reason or another, none of the methods proved successful in controlling the weed. In recent years, biological control has received great attention.
Bowers (1986) described a procedure for field application of Collego, a water-suspendible dried spore preparation of the fungus Colletotrichum gloeosporioides f. sp. aeschynomene for the control of Northern jointvetch in rice and soybean fields. Abbot Laboratories-USA developed an experimental formulation of Cercospora rodmanii (named ABG-5003) against E. crassipes (Te Beest 1991).