The potential of hermetic bags for storage of maize in sub-Saharan African countries. Summary of study findings. Read the study: https://cgspace.cgiar.org/bitstream/handle/10568/106250/WP291.pdf

1. CCAFS Case: Hermetic Bags
The potential of hermetic Bags for storage of Maize in sub-
Saharan African countries
2019, Bert Dijkink, Jan Broeze
Wageningen Food & Biobased Research
This work is implemented as part of the Consultative Group on International Agricultural Research (CGIAR) Research
Program on Climate Change, Agriculture and Food Security (CCAFS), which is carried out with support from CGIAR
Fund Donors and through bilateral funding agreements.

2. Hermetic Bags for Maize storage : Introduction CCAFS
2
 The use of Hermetic Bags in sub-Sahara-Africa is studied as
one of the 4 cases in this CAFFS project.
 The goal of the CCAFS project is to the evaluated different
interventions in the food chain on the effect on Green House
Gas (GHG) emissions and food security.
 Other cases:
● Cassava processing: Mobile factory in Mozambique to improve
processing yields compared to traditional processing and avoid
spoilage by long transport times to central factories.
● Milk chain: Evaluating different cold chain opportunities in Ethiopia.
● Tomatoes: Reduction of post harvest losses by changes in transport.

3. Hermetic Bags for Maize storage: Introduction
3
 Insects infestation causes a larges part of the Post-harvest losses
(PHL) of staple crops in the Sub Sahara region. Especially for
smallholder farmers.
 Hermetic storage in the form as steel silo’s, plastic drums of plastic
bags is an promising improvement to reduce PHL by insects.
 In this case the field data of several studies are combined to get a
realistic figure on the reduction of PHL using hermetic bags for Maize.
Furthermore the (economical) drivers to use this kind a bags by the
farmer are taken into account
Maize Weevil on Maize
(Goergen IITA 2017)

4. Hermetic Bags for Maize storage: Introduction
4
 The effectiveness of the reduction of storage loss of a hermetic
storage system is reducing the O2 and increasing the CO2 Levels
 Thereby controlling the activity and the number of life insects in
the product.
Njoroge et al 2017

5. Hermetic Bags for Maize storage: Introduction
5
 In this case the effect of the introduction of Hermetic BAGS for
the storage of Maize is studied.
● Literature from field trails are combined to get a realistic
view on the expected reduction and spread in weight loss
during storage.
● Calculation of the effect on the GHG emissions of the
different storage methods.
● Calculation of the expected penalty due to of quality loss
during storage.
● The farmer economic prospects in different countries using
the different of storage methods.

6. Hermetic Bags for Maize storage: field trails
6
 Effect of Hermetic bags and the use of pesticides on losses in
small farm storage of Maize.
Likhayo, Bruce et al.
(2016), Ndegwa, De
Groote et al. (2016),
Mlambo, Mvumi et al.
(2017), Ng’ang’a, Mutungi
et al. (2016), Baoua,
Amadou et al. (2014)
Conclusion:
Large scattering of the measured values. Hermetic bags are very effective

7. Hermetic Bags for Maize storage: net GHG effects
7
 Effect of Hermetic bags and the use of pesticides on GHG
emission per kg Maize during storage of batches of 90kg
Average values, bars 95%
confidential limits
Conclusion: the GHG emissions associated to producing the packaging is
small compared to reduction of the GHG emission through loss reductions.

8. Hermetic Bags for Maize storage: quality
8
 Quality change during on farm storage of maize which effect the
market prices
Percentages are calculated from averages measurements with standard
deviations from literature on damaged grains during storage.

9. Hermetic Bags for Maize: Market Prices
9
 Seasonally price fluctuation
● Storage enables selling when the price is high
● Market price fluctuation differs per country: Uganda harvest twice a year,
Malawi has a high seasonal gap and Zambia a low seasonal gap;
hence in a market like Malawi the bags are most profitable.

10. Hermetic Bags for Maize: Cost Prices
10
 Parameters for the cost price calculations
● PICS bag is chosen as most economical and good available Hermetic bag

11. ● Bold cost price lower as market price, green cheapest option for that period
● The Best storage option depends on the on the seasonal GAP
Hermetic Bags for Maize: cost price
11
 Cost price of Maize during storage in different countries
compared with the market price.
standard
bags
pesticides
hermetic
bag
standard
bags
pesticides
hermetic
bag
standard
bags
pesticides
hermetic
bag
0 $0,27 $0,27 $0,28 $0,28 $0,26 $0,26 $0,26 $0,27 $0,30 $0,30 $0,31 $0,31
65 $0,29 $0,28 $0,29 $0,28 $0,28 $0,26 $0,27 $0,27 $0,28 $0,31 $0,32 $0,31
127 $0,33 $0,29 $0,30 $0,28 $0,29 $0,28 $0,28 $0,27 $0,29 $0,32 $0,33 $0,31
187 $0,30 $0,32 $0,30 $0,28 $0,29 $0,30 $0,29 $0,27 $0,29 $0,35 $0,34 $0,31
247 $0,27 $0,35 $0,31 $0,28 $0,34 $0,34 $0,30 $0,27 $0,33 $0,39 $0,35 $0,31
Uganda Malawi Zambia
market price
per kg
costprice stored grain per kg market price
per kg
costprice stored grain per kg market price
per kg
costprice stored grain per kgstorage (days)

12. Hermetic Bags for Maize: Prices
12
Expected profit of stored Maize on the market
Lifetime
Hermetic
bag:
3 seasons
Lifetime
Hermetic
bag:
1 season
standard
bags
pesticides
hermetic
bag
standard
bags
pesticides
hermetic
bag
standard
bags
pesticides
hermetic
bag
0 -1% -4% -5% -1% -4% -5% -1% -3% -4%
65 -1% 3% 7% -1% 4% 8% -15% -11% -8%
127 -1% 9% 22% -11% -2% 8% -23% -15% -6%
187 -15% -7% 7% -13% -4% 10% -27% -20% -8%
247 -35% -22% -7% -14% 4% 23% -29% -14% 2%
storage
(days)
Uganda Malawi Zambia
Conclusions:
 Due to higher grain quality, hermetic bags can increase farmers income
 The profit is very dependent on the life time of the hermetic bag
standard
bags
pesticides
hermetic
bag
standard
bags
pesticides
hermetic
bag
standard
bags
pesticides
hermetic
bag
0 -1% -4% -14% -1% -4% -15% -1% -3% -13%
65 -1% 3% -2% -1% 4% -2% -15% -11% -16%
127 -1% 9% 12% -11% -2% -2% -23% -15% -15%
187 -15% -7% -3% -13% -4% 0% -27% -20% -17%
247 -35% -22% -17% -14% 4% 13% -29% -14% -7%
storage
(days)
Uganda Malawi Zambia

13. Hermetic Bags for Maize storage: Conclusions
13
 Hermetic bags are very efficient for the reduction of PHL of
Maize by insects at longer storage times.
 The GHG emission of the production of Hermetic bags is very
small compare to the GHG reduction by preventing PHL.
 Also the quality of the maize is preserved much better as for the
standard bag of the use of Pesticides.
 The drivers for a farmer to use hermetic bags can depends also
on many other factors:
● Seasonal price fluctuation
● Storage time
● Price penalties due to
quality loss
● Need for cash
● Experience with his own harvest
● The price of the Hermetic bag
● Life time of the Hermetic bag