Effectiveness and economics of hermetic bags for maize storage: Results of a randomized controlled trial in Kenya

Maize is an important seasonal crop and year-round food staple in Africa. On-farm storage is therefore needed, but it suffers from storage pests. To study the effectiveness and economics of a new storage method, hermetic bags, a randomized controlled trial was organized in Kenya with 300 farmers in the treatment group using hermetic bags and 300 in the control group using conventional farmer practices. A subsample of 224 farmers was visited three times during the 2012-2013 major storage season: at baseline and after two and four months. Grain samples were taken and insect infestation, damage and weight loss observed. Results show that hermetic bags were highly effective in controlling storage insect pests: after four months, grain damage was 14% in the control and only 4% in the treatment; weight loss due to insect pests was 1.7% among control farmers, but only 0.4% in the treatment group. Economic analysis shows that hermetic bags become potentially profitable, under basic price and loss assumptions, if farmers use hermetic bags for storage for at least four months per season, and if the bags last for at least four seasons.