Tab A - Page 42 
most of the growing season. This implies an Ice nucleatlon frequency of 
approximately one Ice nucleus per 100 INA* bacteria cells on potato In the 
field and resembles the nucleatlon frequency for a strain of £. s_. syrlnqae at 
-5° C measured under greenhouse conditions. Measured nucleatlon frequency of a 
strain of E. herblcola at -5° C under greenhouse conditions. In contrast, was 
only one active Ice nucleus per 1000 cells approximately. (W) 
If the field test Is successful, the bacteria that have had their 
ice-nucleation genes removed will colonize plants first and prevent the 
naturally-occurring INA + from colonizing and becoming established on the 
plants, thereby protecting them from frost damage. The modified bacteria will 
be no more competitive, and probably less so, than their natural ly-occurrlng 
INA + counterparts because they are adapted only to the target crop for the 
experiment. It is believed that INA + bacteria are more competitive than INA" 
bacteria because of their ability to induce frost damage and obtain nutrients 
through lesions caused by the frost damage. Because of this comparative 
lack of competitiveness and the small numbers of the modified bacteria In 
relation to the naturally occurring, ubiquitous bacteria, there Is no 
significant risk that the modified bacteria will have an adverse effect upon 
existing epiphytic populations. 
5.3.5 Insect Populations 
Mechanisms of frost hardiness in Insects closely parallel those in plants 
(Asahlna, 1966; Salt, 1961). Frost Injury can be avoided in those Insects that 
tolerate Ice formation within their tissues or that escape all Ice formation by 
supercooling (Asahlna, 1966; Salt, 1961, 1962; Salt and Kumlc, 1961; 
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