GrainPro SuperGrainbags are double layer bags consist of a gas-proof inner bag placed inside a much tougher open weave polypropylene (PP) bag for protection against physical damage. After filling they are tied shut with string or in some case may be closed with a gas-tight zip. The bags are gas-tight (hermetic) so that some weeks after bing filled with grain and tightly closed, a modified atmosphere is created that will kill insect pests. The double bags usually have a capacity of 50 or 100kg. At least two types of double bags are available on the market.
Storage Period: 3-24 months
Capacity: 50kg - 100kg
Lifespan: 1 year - 3 year
Initial cost: US$ 40 - 100
Cost per tonne per year: US$ 13.33 - 100
CEREALS - Maize (Uganda, West Africa); Sorghum (Uganda, West Africa); Millet (Uganda, West Africa); Fonio (West Africa); Milled rice (SE Asia)
PULSES - Cowpea (West Africa, Uganda); Groundnut (West Africa); Soya (West Africa);
BEVERAGE CROP - Coffee (Ethiopia, SE Asia)
Inner bags is plastic sheet constructed in three layers (a laminate), polyethylene outside layers and a special oxygen barrier in the middle. The outer bag is usually woven polypropylene.
GrainPro, The Philippines
2-3 harvests (Uganda), 2 years (Zimbabwe), 1 +year (Kenya), variations in lifespan depend care in handling and on attack by rodents or LGB (Prostephanus truncatus). In Kenya the tougher IV-R variant is still susceptible to LGB attack. In Vietnam, a seed producer had used bags for 6 seasons with an seasonal loss of around 8% due to poor handling, damage.
Marketing and promotions:
Since 2004, the International Rice Reseach Institute has promoted them for rice, maize and coffee storage. There has been wider promotion by GrainPro but they have not provided details. In Zimbabwe, 2014 onwards (through development agents); In Uganda, Mar 2014-May 2015 (during UN World Food Programme storage trials)
Success and nature of marketing:
No M&E of the promotion campaigns has been done, so there is limited understanding of how successful promotions have been. The marketing or promotion has been through demonstrations at shows, farmer meetings and other agricultural events but is not felt to be sufficient to break into the smallholder market where the greatest demand is likely to be. In Uganda, with a 70% subsidy by World Food Programme, 31,872 SuperGrainbags were distributed (in bundles of 4 per farmer).
Training as part of the campaign:
Most demonstrations have been accompanied by some training. When initially launched, the International Rice Research Institute did a lot of practical training with first adopters and NARES partners. Including on: safe storage conditions, grain – surrounding air relationships, MC, how to set up a grain cocoon, how to seal it and to check that it is sealed, principle of hermetic storage, how to measure moisture content. In the World Food Programme's recent Ugandan storage trials and promotions, a 1-day training workshop covered improved postharvest management techniques and practical applications of new handling and storage equipment. This was followed-up by on-farm refresher training and correct positioning of new household storage technologies.
Degree of adoption:
Adoption is currently low, setting up the last mile delivery supply chain is challenging. Margins are extremely low, and a distributor might only sell a few bags to each farmer. In Zimbabwe it was only introduced in 2014 (to farmers in 10 districts). Apparently, doing well for storing coffee in Ethiopia. In Uganda, UN World Food Programme provided it at 70% subsidised and distributed 31,872 bags across the four regions of Tororo, Soroti, Gulu and Mbarara. Regional sales figures were not provided.
Reason for adoption:
- Maintains moisture content of the stored grain
- Kills insects without pesticides
- Doubles the life of farmers’ seeds
- Gives around 10% higher head rice in 6-8 months of storage
- It is relatively inexpensive
Weaknesses of this store:
- Easily punctured, thin walls are susceptible to boring insects and rodents, then require pesticides in order to be effective for storage
- A “knowledge intensive” technology, sealing is essential
- High price compared to ordinary plastic bags without the hermetic properties, and more expensive that PICS bags plus you have to additionally purchase the polypropylene bag
- Distribution network needed
- Environmental issues arising from the bags having a short life usage and the ensuing large number of plastic bags becoming waste
- PICS bags are more resistant to insect penetration from outside as they have three rather than two layers
Barriers to adoption:
- Limited lifespan due to its vulnerability to rodent and LGB damage
- Cost is too high currently (presumably high as it is being imported into many countries)
- Requires a distribution network
- Lack of marketing
- Users not being able to differentiate between hermetic bag and non-hermetic PE/PP bag which is only a fraction of the price
- Needs to be purchased, as it can’t be self-made unlike a woven basket
- Government policies that farmers should not use own seeds
- Awareness creation, training
- Building lasting supply chains
- Piggyback on cell phone card system for distribution network
- Need for input credit system
- Working with government to change some extension messages.
- Reduce import tax on materials, and increase demand to reduce the cost of importation
Use by institutions:
In community grain stores. Also, seed producers, especially for storing smaller amounts of high quality seeds. Inventory storage systems in Myanmar
Once punctured can be used in 'ordinary grain storage (i.e. not hermetic). Finds other uses in patching leaking roofs (Kenya), and as containers to hold captured crickets (Cambodia).
What to like:
Hermetic, controls moisture and insects without pesticides, cheap compared to household metal silos, grain effectively protected from theft since stored in house (but this reduces living space).
What to dislike:
Weak so limited lifespan, prone to LGB damage and possible rodent damage rendering the technology non-hermetic. Inability to repair after being damaged, not easily reusable. Need for distribution network, not based on being able to construct oneself; need for purchase. Environmental disposal issues. The tie cable provided can tear the bag. Not known whether these bags can maintain their integrity and characteristics in extremely high temperatures.