Rice is the second most important cereal crop in Tanzania after maize and the majority of rice farmers depend on it both for food and as a cash crop. However, highly competitive annual and perennial wild rice species have been identified as one of the important constraints to rice production on lowlands in southern Tanzania. In addition to competing with the crop, these weed species are the only known alternative hosts for African Rice Gall Midge (ARGM) and are important hosts for Rice Yellow Mottle Virus (RYMV), both of which are major pests of rice in sub-Saharan Africa. Therefore, the Department For International Development from the United Kingdom (UK DFID) developed technologies and promotional materials for optimising the use of herbicides and fertilizer for the control of annual wild rice (Oryza punctata on irrigated land) and perennial wild rice (O. longistaminata) on rainfed fields in Tanzania.