EFFECT OF HIGH PRESSURE ON GERMINATION OF SEEDS (MEDICAGO SATIVA AND MELILOTUS ALBA).
An increase in percentage germination is obtained with seeds of Medicago sativa exposed for 1 to 10 minutes at 2000 atmospheres hydraulic pressure at 20 degrees C., dried, and germinated after 30 days; and from seeds of Melilotus alba under the same conditions of pressure, when exposed for 5 to 30 minutes, dried, and germinated 30 days later. Exposures to 500 atmospheres pressure was less advantageous for germination; the vitality of seeds normally germinating was more rapidly destroyed than the hard impermeable seeds rendered permeable by the pressure treatment. At 0 degrees C., it required approximately 2(1/2) times the exposure to 2000 atmospheres for seeds of Medicago sativa, and approximately 5 times the exposure for seeds of Melilotus alba, as it did at 20 degrees C.
Davies
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Laboratory of General Physiology, Harvard University, Cambridge.