COMPARISON OF APPROPRIATE TROPICAL SEED STORAGE TECHNIQUES FOR GERMPLASM CONSERVATION IN MOUNTAINOUS SUB-TROPICAL CLIMATES WITH RESOURCE CONSTRAINTS

Changes in seed viability over 12 months of low-input storage conditions were monitored on five diverse seed species grown in the tropics: amaranth (Amaranthus cruentus), lablab bean (Lablab purpureus), moringa (Moringa oleifera), pumpkin (Cucurbita moschata) and tomato (Solanum lycopersicum). Because the costs of maintaining low-temperature storage can be prohibitively expensive in developing countries, this study explored alternatives to low-temperature storage at the Educational Concerns for Hunger Organization (ECHO) Asia Impact Center Seed Bank in Northern Thailand. Specifically, this research compared the effects of vacuum sealing and refrigeration on stored seed viability in both laboratory and field settings. While seed species was an influential factor in determining seed longevity, the relative importance of vacuum sealing and refrigeration differed for the dependent variables of seed moisture content, germination rate, mean time to 50% germination and field emergence. Although the combination of vacuum sealing and refrigeration was most effective at conserving seed quality as measured by each of these variables, the storage of seeds in vacuum-sealed packages at ambient temperatures was more effective than unsealed but refrigerated packets at conserving low moisture content and high germination and field emergence rates across species. This suggests that for resource-constrained seed banks in the tropics, vacuum sealing with or without refrigeration may represent a viable alternative to other expensive and energy-intensive storage techniques.