Assessment of environmental pollution by residues of copper fungicides used on coffee in Arusha Region, Tanzania
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Date
2012
Authors
Journal Title
Journal ISSN
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Publisher
Sokoine University of Agriculture
Abstract
Bean bruchids Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boheman) are
the main storage pests of beans in Africa. Farmers in Tanzania have been using different
pesticidal plants which were not uniform from different locations for many years to reduce
damage in their produce. Laboratory studies were carried out to investigate the
effectiveness of nine botanical extracts in controlling the two bruchid species. The study
included plant species from Iringa, Kilimanjaro, Mbeya and Morogoro Regions. The
insecticidal materials were extracted from Eucalyptus citriodora, Vernonia amygdalina,
Telfairia
pedata,
Chenopodium
ambrosioides.
Neorautanenia
mitis.
Dolichos
kilimandscharicus. Gnidia kraussiana, Zanha africana and Schinus mode. Powders of
these plants were tested under the laboratory conditions, where doses commonly used by
farmers were tested to identify plant species with superior characteristics. The experiment
was set in a Completely Randomised Design to determine the optimum doses of five
selected pesticidal plant formulations that can be recommended for protecting beans
against bruchids. The effectiveness of the extracts was compared with Actellic Super Dust,
a synthetic chemical commonly used for control of bean bruchids. The results show that,
all plant species were potential in controlling A. obtectus. Two plant species namely N.
mitis and C. ambrosioides, performed similar to synthetic Actellic Super Dust followed by
Z. africana at the highest tested concentration (600 g/100 kg) to A. obtectus and Z.
subfasciatus. Out of nine plant formulations evaluated on Z. subfasciatus only three were
statistically different in their effectiveness compared to untreated beans. The study shows
that C. ambrosioides and N. mitis have higher efficacy comparable to Actellic Super Dust
followed by Z. africana. Hence, the plants can be used efficiently as the recommended
insecticidal plants. However, further study is recommended to assess the insecticidal
plants role in seed deterioration during storage, shelflife, pesticidal plant combination and
toxicity to mammals.
Description
Dissertation
Keywords
Environmental pollution, Copper fungicides, Arumeru districts, Arusha Region, Tanzania, Environmental pollution