SEED SCIENCE AND TECHNOLOGY, cilt.35, sa.1, ss.165-175, 2007 (SCI-Expanded)
This work was carried out to determine whether hermetic storage at ultra-dry Moisture contents (in equilibrium with about 13% r.h. at 20 degrees C) would provide better survival compared with those seeds stored at 5 +/- 1 % moisture contents (dry). Seeds of pepper, aubergine, winter squash. summer squash, bean, cowpea, okra, melon, onion, leek, cabbage, radish, lettuce were stored hermetically for five years in four environments (dry and ultra-dry storage moisture contents combined factorially with temperatures of 20 degrees C or -20 degrees C) and viability (assessed by radicle protrusion in germination test) was estimated at six months intervals. No loss in viability was detected during this period in okra, melon. bean, winter squash, summer squash, cowpea, radish, cabbage at 20 degrees C and -20 degrees C with either moisture content. Significant loss in viability Occurred at 20 degrees C in pepper, onion, lettuce and leek. however, this loss was more rapid in dry (5.1-6.2% moisture content) than Ultra-dry (3.7-3.9% moisture content) seeds. In contrast, dry seeds of aubergine in the final sample had a higher final viability than the ultra-dry seeds at both temperatures: this is possibly due to the afterripening effect. Results indicate that seeds of the eight species (okra, melon, bean, winter squash, summer squash, cowpea. radish, cabbage) survived irrespective of moisture content at both temperatures. However, storage at -20 degrees C rather than 20 degrees C is beneficial to seed survival and drying seeds in equilibrium with about 13 %. r.h. provides greater longevity than 5.1-6.3% moisture content in pepper, leek, lettuce and onion.