Comparative Assessment of Some Storage Technologies Used for Cowpea Storage in the Nadowli District of the Upper West Region of Ghana
Loading...
Date
2012-06-21
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Pest infestation is the major storage problem in cowpea (Vigna unguiculata) storage around the
world. The principal postharvest pest of cowpea in Ghana is the cowpea weevil (Callosobruchus
maculatus). The main objective of the study was to evaluate the common storage methods used
in the Nadowli District and their effectiveness in maintaining the quality of cowpea beans during
storage. A survey was conducted to identify the major storage technologies and problems in the
district. Four storage structures: barns, polypropylene sacks, earthen pots and triple bags and 3
protectants (wood ash, phostoxin, monthly solarisation) with a control were used to store
‘ormondoh’ cowpea variety. There were monthly data collections on cowpea samples taken from
each treatment set up and assessed for quality for three months. Parameters that were determined
were percentage weight loss, percentage damage, germination percentage, taste and colour
change. Monthly solarisations of beans on all the storage structures proved to be more
efficacious by killing all stages of the weevil. Also, triple bags using Purdue Improved Cowpea
Storage sacks which use hermetic principle was also more effective when combined with the
control or either of ash and phostoxin. The interactions between ash and storage in pots, barns
and polypropylene sacks offered lower protection and recorded a high level of damage and loss
of other quality parameters. Phostoxin fumigation on polypropylene sack and pot recorded a
reduction in grain quality as the storage period increased because the structures were not entirely
airtight. The untreated control of the barn, polypropylene sack and pot were highly ineffective in
keeping cowpea grain quality. There were losses in taste and colour for all the controls for the
various storages technologies with the exception of those kept in the triple bags. Monthly
solarisation of cowpea in storage structures did not record any taste or colour change. The study
has shown that the use of triple bag treatment with the protectants were more effective in
controlling the cowpea weevil (Callosobruchus maculatus) which feeding activities cause loss in
grain quality. Monthly solarisation in all the interventions should be the method of choice in the
absence of triple bags in the district.
Description
A Thesis Submitted to the School Of Research and Graduate
Studies, Kwame Nkrumah University of Science and
Technology, in Partial Fulfilment of the requirements for
the Degree of Master of Science in Postharvest Technology.