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Based on the first and second phases of Kopernik’s Grain Storage Solution experiments, Kopernik found that storing grain in hermetically-sealed plastic drums at full capacity (meaning filled to the top) – and keeping them sealed (without opening the container during the storage period to take out grain as needed) – was so far the most effective way to keep the weevils out. However, the research also showed that this solution might not be optimal as hermetically sealed plastic drums are costly and farmers are likely to need to access the grain more frequently than once every six months.

To address these challenges, in the third phase of the experiment, we applied food grade Diatomaceous Earth (DE)1, a natural insecticide, to the three storage solutions: the current method of a woven plastic sack, a hermetic plastic bag, and a hermetically-sealed plastic drum. From May to October, we have been opening the storage containers every month to check for weevils and found none in all three storage methods. It was only in the sixth month that we found a small number of weevils in all three containers.