Reducing Postharvest Losses
In the OIC Member Countries
36
Table 9: Causes of postharvest losses of pulses at different stages
Activity/stage Type of loss Contribution to
postharvest loss
(%)
Harvesting Losses due to shattering and/or attack by rodents, birds and
other pests
4
Threshing Improper threshing and field handling 6
Drying Improper drying leading to moulds 4
Transporting Quantitative losses due late or inefficient transportation 2
Primary processing Poor handling, sorting and packaging 4
Storage Inefficient storage leading to quantitative and quality losses 20
Secondary processing Poor processing practices 60
Source: based on information from Jeswani and Baldev (1990)
Innovations can make a difference in postharvest losses. As indicated above, Affagnon et al.
(2014) reviewed 213 postharvest studies in SSA. The countries covered were: Benin, Ghana,
Kenya, Malawi, Mozambique and Tanzania. The main oilseed covered was groundnuts and the
pulses were cowpeas and common beans. The estimated physical quantitative losses – without
and with adoption of loss-reduction technologies are summarised below:
 Oilseeds (e.g. groundnuts): the estimated average annual postharvest loss is 10%. This
estimate does not take account of potential quality-related economic losses. For instance,
the level of Aflatoxin infestation in groundnuts in Ghana is estimated by Anim-Somuah et
al. (2013) to be over 70%. However, owing the fact that groundnuts produced in Ghana is
largely marketed locally this does not affect the crop. However, as reported by Nakhumwa
(2015) Malawi lost access to lucrative European markets largely because of high levels of
Aflatoxin infestation.
 Pulses (e.g. cowpeas and dry beans): estimated postharvest losses ranges between 14
and 24% by volume. However, this can potentially be reduced to between 2 to 3% if
appropriate mitigation strategies are adopted. Coincidentally, postharvest losses for
cereals in SSA which can be as high as 26% can be reduced to about 6% with appropriate
postharvest handling and technologies.
Loss-reducing pre- and postharvest handling techniques and technologies
Evidence from various sources indicate that adoption of the practices and technologies
outlined below can significantly reduce postharvest losses in oilseeds and pulses:
 Pre-harvest practices include planting suitable varieties and at the recommended seed
rates per hectare. For instance, there is evidence from Malawi indicating that most
smallholder groundnuts farmers plant at rates of about 47 kilograms per hectare instead
of the recommended rate of 80 kilograms per hectare. Consequently, the lower plant
population limits natural ground cover by the leaves and therefore increases vulnerability
to pests such as Aphids and diseases like Rosette virus disease which lead to losses
(Simtowe et al. 2010).
 Harvesting: timing is crucial, especially where unanticipated rainfall during the harvest
season makes field drying of crops difficult. The harvesting technology can also affect level
of losses in the field. It can also affect the speed of harvest and therefore the level of losses
due to attack by rodents, insects and birds.
 Postharvest drying allows crops to store better. It is important that storage occurs in the
right environment – for instance in well-aerated cribs or on clean surfaces from which
livestock are excluded. This will not only reduce quantitative losses but also minimise