Controlling water hyacinth infestation in Lake Tana using Fungal pathogen from Laboratory level upto pilot scale

Abstract

ABSTRACTWater hyacinth (Eichhornia crassipes) is one of the most dangerous aquatic weeds for Lake Tana and other water body in Ethiopia. To reduce its invasion biological, chemical and physical control methods can be used. Use of natural biological enemies of the weed to discourage its propagation is one of the best recommended options by scientfic society. Among them, there are more fungi naturally a pathogen for water hyacinth and other plants. To use those patogenes to manage water hyacinth infestation in Lake Tana infected plant material by fungi were collected from three weredas (Amba Gyorgese, Dabat and Debarke) around Gondar at 20 Peasant associations (PAs) since Novmber 2015. The collection was done from infected Faba bean leaves and roots. All isolated fungus was attempted to infect the collected healthy water hyacinth in laboratory and green house. Among isolated fungus species Rhizoctonia solani, Aspergillus flatus, Tricothcium roseum, Fusarium spp and Aspergillus niger fungi show high moderate disease severity on the healthy water hyacinth at temporarey green house and laboratory. Disease severity scale was recorded using modified NAHEMA et al. (200). By following those experiments to show its efficiency, the effective pathogens on laboratory and green house were released to 16 m2 open ponds since September 2016, in University of Gondar. In this study, we have recorded scientific data that shows the fungi were high potencial to attack healthy water hyacinth at above 26 oc and at less than 25 % humidity. From this research also we have observed the most infected water hyacinth by fungi have not produced flower and it can not re generate by seed in the next propagation sesaon.Finally, before directly release the fungi on Lake Tana its impacts were studied in the Goregora, at Kuame Michel kebela for a year in open ponds and in controlled wet land areas that not linked to the Lake by taking some common aquatic plants and fish from the Lake. Fortunatelly, those fungi have not impact on aquatic plant like Echinochloa and Cyperus papyrus grass, water quality and fish.