Factors Influencing Freezing of Supercooled Water in Tender Plants

Cary, J.W. and Mayland, H.F. (1970) Factors Influencing Freezing of Supercooled Water in Tender Plants. Agronomy Journal. 62(6):715-719.

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Abstract

Seedlings of beans (Phaseolus vulgaris), corn (Zea mays),
and tomatoes (Lycopersicon esculentum) were grown in
the greenhouse and then exposed to controlled freezing
conditions in a growth chamber. Variables were adjusted
to determine the influence of plant water potential, freezing
time, and external dew formation on the seedlings'
susceptibility to frost injury. Freezing, detected visually
and by release of latent heat, progressed rapidly throughout
plants with high water potential and was always lethal.
Spreading of the ice phase was impeded in plants with
low water potential. In this case, the freezing injury appeared
as spots on the leaves which gradually enlarged
to encompass the entire leaf as the exposure continued.
In general, the plant water supercooled before freezing.
Supercooled water within the plant appeared to be internally
nucleated if the leaf temperature remained above
the atmospheric dewpoint temperature. Under these conditions
root temperature, plant water energy, and duration
of the freezing period all influenced the stability of the
supercooled water. On the other hand, external inoculation
prevailed when the freezing temperatures were accompanied
by condensation of water from the air and
subsequent formation of ice crystals on the leaves. One
important exception was noted when ice on corn seedling
leaves failed to nucleate the supercooled internal plant
water with a potential of —18 bars.

Item Type:	Article
NWISRL Publication Number:	0174
Subjects:	Mass Import - unclassified
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:51
Last Modified:	07 Mar 2017 22:58
Item ID:	191
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/191