Competitive interaction between two weeds: water hyacinth (Eichhornia crassipes [Mart.] Solms.) and alligator weed (Alternanthera philoxeroides [Mart.] Griseb).

Experiments were conducted to determine the competitive interaction between alligator weed (Alternanthera philoxeroides) and water hyacinth (Eichhornia crassipes). The treatments comprised: pure alligator weed (150 segments in a tankful of water); pure water hyacinth (30 bulbs in a tankful of water); and mixture of water hyacinth (15 bulbs) and alligator weed (50 segments). Comparative data on plant characteristics as influenced by alligator weed-water hyacinth interaction are also tabulated. The effect of alligator weed leachates on water hyacinth was also studied. Pure water hyacinth and alligator weeds were also maintained in separate cement tanks for 15 days, which served as sources of leachate. Plant height, number of leaves, number of branches and fresh weight of water hyacinth were lowest with the application of alligator weed leachate.