Controlling Water Hyacinth in Lake Tana Using Biological Method at Green House and Pond Level

Abstract

Water hyacinth (Eichhornia crassipes) is one of the most dangerous aquatic weeds for Lake Tana. To minimize invasion; biological, chemical and physical control methods can be used. Biological control based on the use of natural enemies of the weed to discourage its development was the best option. Plant pathogenic associated with naturally infected Faba bean by fungus was conducted at different sites with the objective of study the pathogen city indigenous fungi on water hyacinth to manage its spread on Lake Tana. Infected fungus plant samples were collected from three weredas (Amba Gyorgese, Dabat and Debarke) around Gondar at 20 Peasant association (PAs), The collection were done for infected Faba bean leaves and roots and isolated using Potato Dextrose Agar medium. Highest disease incidence per plant was recorded in water hyacinth plants using Using Modified Naseema et al. (2001) disease severity rating scale by inoculated with Rhizoctonia solani spp. Aspergillus flavus, Tricothcium roseum, Fusarium spp and Aspergillus niger show high moderate disease severity and tissue death at green house and pond level. Those fungus were released on September 2016 to prepared open pond at 16m2 and water hyacinth was started severely attacked on November 2016, its disease incidence was 55% at 23˚C and humidity 39%, in December 2016 its disease incidence was 58.4% at humidity 31% and 23˚C, in January 2017 disease incidence was 65% at 26˚C and humidity 25% and in Feb 2017 not record disease incidence because all leaves are attacked and dry and Disease severity was 100%.However, in April 2017 due to the climate conditions becomes cold and rain the dried water hyacinth started make new shoot and at this time the disease severity was 90%. Some species of Fungi found in Faba bean leaf and root can eradicate the healthy water hyacinth at above 26˚C and at less than 25% Humidity.