The ecology of weeds and the impact of management on channels in MWEA irrigation scheme, Kenya

The growth of weeds in irrigation channels poses significant problems to the managers of such systems, impeding flow and encouraging siltation. Additional problems include health hazards, e.g. schistosomiasis and malaria. This research project aims to describe the plant communities which cause such problems in the Mwea Irrigation Scheme (MIS) , Kenya, and to investigate the factors which dictate their presence in relation to appropriate management. The environmental setting of the MIS is described with an emphasis on crop production (75-80% of Kenya's rice) and the functioning of the irrigation scheme which is supplied by water from the Thiba and Nyamindi rivers. The weed management programme is under the works Department of National Irrigation Board and the farmers who operate a year round schedule of maintenance. [Continues.]