Eshetu Bekele
VSU Parthenium Project- Ethiopia
International Workshop on Bioogical Control and
Management of Parthenium hysterophorus
Addis Ababa, Ethiopia July 14-17, 2014
 Address most of the adverse effects on
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Crops and pastures
Livestock health and products
Social
Natural ecosystems
 Include appropriate impact assessment plan and
parameters
 Quantify the economic benefits that could be
obtained by managing the weed
 Evaluating pre-release baseline conditions
▪ Provides benchmarks against which effectiveness of the
bioagent can be later evaluated
 Monitoring establishment and spread of the
bioagents
▪ This is an indicator of the ultimate success of any
biological control program
 Measuring actual impacts
▪ This actually measures the ultimate success or failure of
the biological control program
 Photo points
▪ Comparison of a series of photographs taken from a
fixed reference points
▪ Periodically on release and non-release plots
 Stakeholder survey
▪ Comparative surveys of perceptions of managers,
farmers DAs, etc
▪ A questionnaire to assess their opinions before and
after release
 Comparing sites or plots with and without the
bioagents:
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Abundance of parthenium
Abundance of bioagents
Extent of damage
Response of the associated plant community
 Correlative studies:
▪ Correlation between weed performance and agent
density or damage severity
 Agent exclusion experiments:
▪ Comparison of protected plots (using pesticides or
cages) with plots with the bioagents.
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On parthenium: before/during release & end of
seasons
 NP, NF, Ht, BM, SB
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On bioagent: fortnightly after release & end of
seasons (at & beyond the release points)
 NA, NP, NL, NE per plant
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Extent of damage: during the season
 NDP, PLAD, visual score (0-5)
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Associated plant communities
 Spp., abundance, and % coverage
 Data should be taken from a unit area
 Example:
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0.5 x 0.5m quadrant
It should be replicated
Appropriate statistical models should be
selected
 Example: One way or two way ANOVA followed by a
Tukey test (Dhileepan, 2003)
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Ultimate goal of biological control of
parthenium is
 improvement in crop and pasture yields and qualities.
 Recovery of native species
 Reduce the socioeconomic Impacts
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But, it may take several years to measure
such real impact
Requires continuous monitoring & data
collection
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Superimposing zonal crop yield data on
parthenium distribution map, three major
crops identified in potential release areas
 Teff
 Sorghum and
 Maize
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Yields vary significantly within zones
District (wereda) level yields could be better
Thus, means of the last 5 seasons used
 Impact of biological control of parthenium
on human health,
livestock health and product qualities,
net savings/incomes generated
 Determined using well structured
questionnaires.
 Analyzed with appropriate statistical procedures
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The impact of managing parthenium by bioagents
can be evaluated from different perspectives:
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the establishment and effectiveness of the bioagents ,
significant reduction in parthenium populations
subsequent increase in crop/pasture yields & quality,
Improvements in livestock health and quality of their
products,
 rehabilitation of other plant communities in the
ecosystem, and
 the additional economic benefits farmers could get from
reduced weeding costs and labor.