Management of water hyacinth (Eichhornia crassipes [Mart.] Solms) using bioagents in the Rift Valley of Ethiopia

Abstract

Management of water hyacinth (Eichhornia crassipes[This thesis presents a study on management of water hyacinth (Eichhornia crassipes [Mart.] Solms) using insects and fungal pathogens as bioagents. The main goal was to develop an effective biocontrol strategy for water hyacinth in the Rift Valley of Ethiopia. To this end, a field survey was conducted to assess the agro-ecological distribution of water hyacinth and of native fungal pathogens found in association with water hyacinth. We also performed laboratory and lath house experiments on (i) pathogenicity and host specificity of the fungal pathogens; (ii) adaptability, life table, efficacy and host specificity of the two Neochetina weevils; and (iii) the synergetic effects of integrated use of Neochetina weevils and fungal pathogen as bioagents. Survey results indicated that the weed is distributed in the Rift Valley water bodies located in low, mid and high altitude. The survey results also identified 25 fungal species found in association with water hyacinth that belonged to nine genera. Among the isolates, Alternaria alternata, A. tenuissima, and Alternaria spp. hold promise as possible bioagents of water hyacinth.Laboratory study on life cycle and development of Neochetina weevils indicated the two weevils took shorter generation time in Ethiopia than in Argentina but relatively similar to Kenya and Uganda. In Ethiopia, the two weevils produced four generations per year indicating their successful establishment. Feeding by adult weevils and tunneling by larvae significantly impacted the vigour and reproduction of water hyacinth plants. A herbivory loads of three pairs of N. bruchi and two pairs of N. eichhorniae showed the highest level of leaf damage and defoliated petioles. The study also reinforced that the two weevils are sufficiently host-specific. Finally, a study on integrated use of Neochetina weevils and an indigenous plant pathogen revealed that the two Neochetina weevils and the fungus A. alternata were together able to reduce the vegetative growth and fresh weight of water hyacinth plants considerably.This study recommends integrated use of fungal species and the two weevils to control water hyacinth. Implications of the findings are also discussed in the context of integrated water hyacinth management using the native fungal pathogens and the two weevils.

Socioeconomic effects of water hyacinth (Echhornia Crassipes) in Lake Tana, North Western Ethiopia

“…More than 70% of interviewed farmers' crop fields were infested by the weed in 2014/15 and 2016/17 cropping seasons. It is similar with the findings of [27]. According to [27], the crops production of close to 70% of farmers was affected by water hyacinth in the Rift Valley of Ethiopia.…”

“…It is similar with the findings of [27]. According to [27], the crops production of close to 70% of farmers was affected by water hyacinth in the Rift Valley of Ethiopia. Farmers were asked to level the intensity of water hyacinth infestation on their crop fields.…”

Occurrence, Diversity and Potential of Fungal Pathogens Associated with Water Hyacinth (Eichhornia crassipes [Mart.] Solms) for Sustainable Biological Management in Ethiopia: A Review

“…The effect of water hyacinth on the farming activities was observed along River Tano and Tano Lagoon, Ghana [25]. Crop production is the main source of food and means of income generation of the people living in the Lake Tana area though the infestation of water hyacinth in has affected crop production of 70% of interviewed farmers during 2014/15 and 2016/17 cropping seasons Likewise, the crops production of close to 70% of farmers was affected by water hyacinth in the Rift Valley of Ethiopia [34].…”

Pembentukan Biogas pada Media Eceng Gondok dengan Starter Kotoran Ternak

“…Eceng gondok (Eichhornia crassipes) adalah jenis tumbuhan air yang perkembangannya sangat cepat (Jones et al, 2018); (Mekuriaw et al, 2018); (Gebregiorgis, 2017); (Isebe, 2016), sehingga tergolong sebagai gulma yang invasive (Koutika & Rainey, 2015). Pada kondisi yang menguntungkan, eceng gondok dapat mencapai laju pertumbuhan 17,5 metric ton per hektar per hari dan memiliki pertumbuhan yang ekstrem, yakni mampu memproduksi bio massa 2 ton per are (0,4 hektar).…”