The present study indicated that S. tuberosum var. Jersey
Royal could supercool to temperatures as low as -6ºC during in-vitro
frost tests, whereas in the field freezing occurred at immediate
sub-zero temperatures (between 0 and -1ºC). The microbial flora
upon the early. sown S. tuberosum var. Jersey Royal did not contain
INA bacterial species active at warm sub-zero temperatures. Plants
inoculated with a strain of Ps. syringae (84:27) containing type 1
active nuclei readily froze at -2 to -3ºC. Applications of leaf
surface water applied to plants during in-vitro frost tests resulted
in nucleation temperatures comparable to those measured in the
field. Applications of leaf surface water initiated freezing in
whole plants during in-vitro frost tests at temperatures warmer than
those caused by Ps. syringae (84:27). Thus field frost kill and ice
nucleation in the presence of leaf surface water occurred at
temperatures warmer than type 1 INA bacterial nucleation
temperatures.
Exogenous foliar applications of ethylene glycol applied in
the presence of leaf surface water led to enhanced supercooling and
frost avoidance during in-vitro frost tests and during field frost
events. It was concluded that modifying the formation and freezing
of leaf surface water would be more likely to provide a frost
control strategy applicable to the field crop than frost control
through manipulation of phylloplane microorganisms.
Date of Award | 1993 |
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Original language | English |
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Awarding Institution | |
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THE ROLE OF ICE NUCLEATION ACTIVE BACTERIA IN FROST DAMAGE TO EARLY SOWN Solanum tuberosum var. JERSEY ROYAL
Le Grice, P. (Author). 1993
Student thesis: PhD