Surveillance of potential pathogenic fungi associated with water hyacinth in Lake Kainji, Nigeria

The entire Kainji Lake and the riverine areas upstream of Yauri were surveyed monthly between February and May 2002 with a motorboat to make full inspection of fungi-infested water hyacinth plants. Various parts of water hyacinth plant showing symptoms of fungal infection were collected, dried between paper towels, labeled, treated and planted onto growth agar media in petri dishes sealed with parafilm. All isolates were characterised for identification. On some older plants with larger leaves were found sporulating Myrothecium roridum. On the smaller plants with purple flecking lesions were isolates of Alternaria eichhorniae of, which were necrotic patches surrounded by chlorotic halos. The presence of A. eichhorniae in Nigeria indicates a great promise as its choice in most African environment by the International Mycoherbicide Programme for Eichhornia crassipes Control in Africa (IMPECCA) for development into a mycoherbicide. Other fungal pathogens isolated included Rhizoctonia solani, Acremonium zonatum and Cercospora piaropi