A comparative study on the effects of moisture content and temperature on storability of an orthodox and a semi-recalcitrant tropical forest tree seed

The effects of moisture and temperature on Intsia palembanica (orthodox) and Swietenia macrophylla (semi-recalcitrant) were investigated. The critical moisture content of I. palembanica and S. macrophylla were 4-6% and 15% respectively. Evaluation of the temperature effects suggests that I. palembanica, like many orthodox seeds were able to survive in subfreezing temperature of -20 degrees C with no reduction in germination after 2 weeks. However, after 4 weeks of storage, lower temperatures between -20 degrees C and 0 degrees C showed slight but significant reduction in germination compared with higher temperatures. For the semi-recalcitrant species, S. macrophylla, higher storage temperatures between ambient and 20 degrees C were significantly better than lower temperatures, especially of -20 degrees C and 0 degrees C. For I. palembanica, higher moistures between 8 and 10% were better, but temperatures between -20 degrees C and 5 degrees C had no effect. For S. macrophylla, higher moisture and temperature of 25% and 15 degrees C were best for seed storage.