UNFREEZABLE AND FREEZABLE WATER EQUILIBRIUM IN PLANT TISSUES AS INFLUENCED BY SUB-ZERO TEMPERATURES

It is commonly accepted that with bioeolloidal systems there is a definite temperature at which all of the freezable water will be frozen (7, 11, 6, and others). This temperature has been arbitrarily selected as about -18° to 20° C. In studying one phase of a problem on winter hardiness in red clover roots, it was desirable to determine the amount of unf reezable water in these tissues. Thus an opportunity was afforded to test the preceding hypothesis with regard to this tissue by determining the amount of water which does not freeze at temperatures of -10° to -50° C. Potato tubers were also included in the study.