Tab A - Page 28 
uncertain In most cases. Disease caused by pathogenic P. s. syrlnqae strains 
on many woody and herbaceous plants is rare in California and probably occurred 
only after predisposition by frost injury. 
All strains used In the experiment will be isolated from the surfaces of 
healthy plants, not from any disease lesions. Or. Lindow has screened a 
collection of such P_. s_. svrinoae isolates for pathogenicity towards oats, 
barley, corn, tomato, wheat, citrus, almond and three cultlvars of beans. 
Most Isolates were not pathogenic on any of these hosts while others showed 
different specificity patterns. None of the isolates was pathogenic on all 
hosts that were tested. Only strains shown not to be pathogenic to any of 
these crops will be used for the proposed field trials. The use of 
non-virulent non-toxin-producing strains (see paragraphs 4 and 5 below), in a 
location where there are no susceptible crops will protect crop plants 
surrounding the test site. (I) Amorg £. syrinaae strains known to cause plant 
disease, no correlation exists as to ice phenotype. INA + are just as likely to 
cause disease as are INA", especially those that cause diseases of cereal 
grains. Bacterial plant diseases are rare or absent In the Tulelake Basin 
because the dry, high desert climate is not conducive to development of 
bacterial diseases. 
3. Epiphytic Biology 
£. s_. syrlnqae colonizes the leaf surfaces of host and non-host plants in 
what has been called "resident phase." According to several reports, isolates 
from resident phase populations are usually specific, with respect to 
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