RESUMEN
The influence of agricultural wastewater effluents dumped to the Nile water at Minia [Upper Egypt] on phytoplankton distribution, diversity, succession and standing crop was monthly evaluated in a comprehensive study for one year. Autumn harboured the highest standing crop at all sites. Bacillariophyta contributed the highest percentage composition. Chlorophyta and Cyanophyta rated second and third in the order of dominance, Euglenophyta was poorly represented however, some members of the three groups tended to form blooms at certain times. The agricultural runoff induced gross changes in physico chemical characteristics of the Nile water and community structure of phytoplankton populations. Species of high occurrence being densely encountered at all sites were excelled by: Tabellaria fenestrata. Cyclotella bandanica, Cocconeis caespidata and Microcystis aeruginosa