Storing seeds in the tropics can often be difficult; with high temperatures and humid conditions, seeds lose their ability to germinate quickly. Many techniques for seed storage exist, from the high-tech standards of gene banks to simple methods used by villagers for saving their own seeds. All have their strengths and weaknesses, but when balancing costs and resources, which methods are really the most effective? This article highlights research conducted by ECHO Asia regarding the use of vacuum sealing, using a simple bicycle tire pump, for tropical seed storage under resource-constrained settings.
The three key factors that determine the rate of seed deterioration in storage are: oxygen pressure (amount of oxygen with the seeds in storage), seed moisture content, and temperature (Roberts, 1973). An increase in any of these factors will lower the storage life of the seeds, and as a general rule any increase of 1% moisture content or 10° F (5.6° C) in storage will halve the storage life of the seeds (Bewley and Black, 1985). Each factor contributes to seed decay in specific ways, and minimizing these conditions is critical to effective seed storage. Vacuum sealing is a relatively low-cost method that requires few inputs after an initial investment. Sealing helps conserve seed quality by minimizing oxygen presence and exposure to ambient humidity, thereby keeping seed moisture content low.