Reducing Postharvest Losses
In the OIC Member Countries
23
5.81
8.85
23.43
38.86
6.55
18.5
Harv
Thre
Dryi
Stor
Tran
Milli
6.90
7.60
24.05
27.54
33.90
Harvesting
Threshing
Drying
Storage
Transport
Milling
Central and south-eastern Asia
Estimated % postharvest weight loss = 13%
China
Estimated % postharvest weight loss =
14.8%
Figure 6: Comparison of the proportion of rice postharvest losses occurring at different
activity stages
Sources: Calverley (1994) cited in Grolleaud (2002); IDRC (1987-1989)
Opinions differ regards whether mechanising processes would reduce the quantity of rice lost
PH, although it is recognised that mechanisation usually brings time and labour savings, but
can be financially costly to access, with insufficient skills for operating equipment PHL could
increase (Grolleaud, 2002). In Indonesia rice is still traditionally threshed using the slow and
labour intensive method of beating the rice stems with bamboo sticks which leads to high
losses (Riady et al., 2015). Although rice threshing machines are available, they are typically
expensive, rarely work optimally with power supply often a problem. For example, milling
losses in Indonesia reduced when milling machinery was introduced, but as the machinery
aged this gain declined (e.g. mechanised rice-milling ratio for paddy declined from 70% to
60% as machines aged) (Simatupang & Timmer, 2008). IRRI researchers’ estimates of
comparative losses in traditional and mechanised PH rice chains suggest a wide range of loss
can occur with both traditional and mechanised process.
Two comprehensive studies of paddy losses in Indonesia in 1986/7 and 1994/5 suggested
total harvest and postharvest losses were ~21%, with 15% occurring during harvesting and
threshing (Maksum, 2002 cited in Simatupang and Timmer, 2008). Earlier work in Indonesia
highlighted the links between the labour organisation system used and harvesting losses, and
the technology for threshing losses. The largest losses (18.6%) occurred with open-access
harvesting and the slapping paddy threshing system, and the lowest (5.9%) with labour-group
(or trader-harvester) harvesting and mechanical threshing (Hasanuddin et al., 2002). A much
earlier Indonesian study reported the harvest loss with the open-access system reaching a
massive 42.5% of total yield loss, owing to stamping-down, dropping and left-over losses, as
well as transportation losses between field and home (Utami and Ihalauw, 1973).
In Bangladesh, two studies thirty years apart compared PHL along the rice chain and between
different stakeholders. The 2010 farmer level data came from a survey of 944 marginal, small,
medium and large farmers. In contrast to the Indonesian study, these studies (as did the
Central and south-east Asian studies) found the largest rice PHL occurred by farmers are
during storage and drying. Although, in Bangladesh rice is often produced in 3 seasons each
year with PHL differing by season and location. Processors incur more rice PHL during milling
than drying or parboiling, and wholesaler and retailer rice PHL occur mainly during storage
and transport .