Population dynamics of water hyacinth (Eichhornia crassipes)

Water hyancinth (Eichhornia crassipes (Mart.) Solms) is a perennial, herbaceous, aquatic weed of the family ontederiaceas. Water hyacinth is considered as a serious pest in many part of the world in the tropical and sub-tropical regions due to its prolific growth affecting water resources adversely by blocking canals and pumps in irrigation projects; interfering with hydroelectricity production; wasting water in evapotranspiration; hindering boat traffic; increasing waterborne disease; interfering with fishing and culturel; and clogging rivers and channels so that drainage is impossible and floods results. A dynamic numerical model was developed to simulate the growth dynamics and production of water hyacinth. Two state variables, shoots and roots, were considered to illustrate the growth of the water hyacinth. The net growth of the shoots was imperative effects of photosynthesis, repiration, mortality and allocation for root growth. Biomass data reported in literature was used calibrate the model. Model parameters were allowed to vary as a result of acclimation, following experimental data reported in literature. Model simulations show a good agreement with observed data with asimilar biomass temporal dynamics.