Reducing Postharvest Losses
In the OIC Member Countries
26
Table 5: Overview of study findings on wheat postharvest weight losses in Pakistan
Postharvest
losses (%)
Storage
losses
(%)
Comments Authors
15.3 - Aggregate weight loss during the postharvest operations;
Threshing and winnowing losses of 1.5-1.7%; farmer level
PHL 1.10-1.69%; market level PHL4.6-7.3%; public sector 3.6-
6.2%; terminal level 1.9%
Chaudhary, 1980
22.7 9.5 13.2% loss during harvesting and threshing, 9.5% loss during
storage
Ahmad & Afzal, 1984
2.7% loss during harvesting when ears are left in the field in
Punjab, but this varies by variety
2.19% loss left on threshing floors from tractor Phalla type of
threshing, 2.1% from bullock threshing, 1.4% from
mechanical threshing. Mean threshing loss 1.5% in Punjab.
Grain Storage
Research Laboratory
(GSRL), 1994
- 3.5-25 Storage losses country-wide survey Irshad & Baloch,
1985
- 1.4-8.2 Storage losses during 4 months storage in house type
godowns
Mohammad, 1986
- 2-9 Storage weight losses during 6-7 months storage Khan, 1986
- 4 and 7 Storage weight losses at farm-level (4%) and in the public
sector (7%)
Baloch, 1986
- 20 Storage weight loss during 6 months lab storage with Khapra
beetle
Ahmedani et al.,
2011
- 2-2.5 Storage weight losses in public sector stores GSRL, 1994
- 4-20 Public sector storage losses due to rodents Hafiz and Hussain,
1961; Hussain, 1966
- 0.2-1 Public sector storage losses due to rodents Roberts, 1981;
Ahmed and Brook,
1986a, b; Ahmed et
al., 1995
- 23 Losses due to rodents in go-down warehouses Micas, 1976
- 1-5 Losses due to rodents in go-downs Shafi, 1986
Rodents are also a major source of postharvest grain loss at household level, in small grain
markets and in public and private sector grain stores. A study of godowns at TPX (~3km from
Karachi Kemari Port) analysing the stomach contents of the different rodent species trapped in
the godowns found that insects were a main food item along with rice and a preferred source
of protein (Lathiya et al., 2008). Another study of rodents in grain shops in wholesale markets
in Punjab, estimated an average year-round population of 40 rats per grain shop (Ahmed et al.,
1995). These rats cause annual losses of 740 kg/shop/year, with 185 kg/shop/year due to rat
consumption, and 555 kg/shop/year due to spillage and contamination. Given there are 5,500
shops in the major and minor markets throughout Punjab, the aggregate losses in them due to
rodents in the Province reach ~4,000mt annually, or 0.3% of the 1.225 million MT of grain
moved through the markets each year.
Pakistan has a grading system for wheat based on fair average quality (FAQ) which includes
specific tolerance for the presence of non-edible matter, other food grains, damaged kernels,
and weevils (CIDA, 1980). Issues with wheat grain needing to be washed before milling, but
not then being re-dried down to the required moisture content, which enables the miller to
ship out the ‘required content of flour,’ but due to the high moisture content the keeping
qualities of the flour are reduced.
Due to the massive trade in wheat, supplies and losses in one country can affect other
countries. Pakistan exports several hundred thousand tonnes of wheat flour to Afghanistan