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LOGO IITA. Purdue Improved Cowpea Storage (PICS) – Potential for Application in West Africa?. Kerstin Hell, Kukom Edoh Ognakossan and Ousmane Coulibaly. Traditional storage system.
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LOGO IITA Purdue Improved Cowpea Storage (PICS) – Potential for Application in West Africa? Kerstin Hell, Kukom Edoh OgnakossanandOusmane Coulibaly
Traditional storage system • Environmental conditions, traditional farming methods, improper grain drying and storage practices facilitate quality reduction and insect infestation in African Post-harvest systems • Grain losses due to Insects in West-Africa • >30% in maize stores infested with Prostephanustruncatus • 10-12 % in maize infested withSitophiluszeamais • Several African staple commodities are affected by high losses due to insects – maize, millet, groundnut, rice, sorghum and processed yam and cassava products • Post-harvest Loss Network determined losses for cereals of 17.4% to 14.3% (2003 till 2008)
Hermetic storage trials at IITA-Benin • Testing of IRRI Superbags(‘09) and PICS-Bags (‘09) for control of P. truncatus & S. zeamaison maize • Testing of PICS Bags for control of insects in maize (’10 & ’12) and cassava chips (’11 & ‘12) • Destructive sampling • Moisture content, insect species, grain losses, holes on bags, CO2 and O2 levels • Cost/benefit analysis to determine financial profitability PICS bag
Mortality rate (%) of insectsin IRRI Super bag (ISB) on maize Mean (± SE) within a column (row) followed by the same uppercase letter (lowercase) are not significantly different from each other at 5% probability level
Mortality rate (%) of insectsin IRRI Super bag and PICS on maize Mean (± SE) within a column (row) followed by the same uppercase letter (lowercase) are not significantly different from each other at 5% probability level
Effect of PICS & IRRI Bag on maize post-harvest pest after 3- and 6-month • Pest densities were significantly reduced in hermetic bags compared to control polypropylene Bags (PPB) (P=0.018) • In control bag insect densities increased significantly with storage time (P < 0.0001) • In hermetic storage, P. truncatuswas found ONLY when maize was artificially infested whereas in the control it all bags had this species
Effects of PICS & IRRI Bags on maize grain losses after 3- and 6-months • Losses were significantly lower in PICS & IRRI-bags . • No increase of losses in PICS & IRRI with storage. • In polypropylene bags losses increased with storage time reaching nearly 18%.
Financial benefits of PICS Maize prices in three localmarkets Maize prices in three local markets If bags would be reused for a second storage season the benefit/cost ratio would increase to 3.7, 5.0 and 6.3 Benefit Cost Ratio of the use of PICS bags
Efficacy of PICS on cassava chips • Number of P. truncatuswas not significantly different between treatments • Losses were beyond economical levels, exceeding 8% after 6 months of storage • Oxygen levels in both treatments reached 18.69% and 19.12% after 8 months of storage.
What have we learned? • Hermetic storage technology effective for maize, • In regions with high levels of P. truncatus(more than 1 Pt per kg) precaution about technology • High moisture content of grains in PICS bags can reduce germinability and lead to quality loss • Bags are penetrated from inside to outside • Technology not effective for traditional cassava and yam chips
What R&D is missing • Need for low-cost energy efficient dryers to improve grain drying to avoid mycotoxins & moisture meters • Potentially increase effectiveness of PICS bags by including another technology to reduce insect attack (oils, natural substances, ???) • Test PICS bags for other commodities and include further quality parameters (nutrition, processing characteristics, toxins) • All stakeholders need to address the persistent high post-harvest losses (advocacy)