Final answer:
The use of low pressure, hand-held sprayers with nozzles for applying the bacteria was not a precaution; rather it's a method of application. Protective clothing, monitoring samples, and a soil buffer zone were actual precautions implemented.
Step-by-step explanation:
In the case of the field-testing of genetically engineered (GE) ice-minus strains of Pseudomonas syringae, several precautions were taken. However, one precaution that was not implemented during the field-testing was the use of low pressure, hand-held sprayers with nozzles for applying the bacteria.
This methodology does not inherently involve a precautionary measure but is a means of application.
Precautionary measures which were in place included the wearing of protective clothing by applicators from head to toe.
Obtaining monitoring samples both inside and outside the test plot at the time of spraying and for an extended period post-application, and ensuring a contained field trial within a set acreage bordered by a bare soil buffer zone to prevent unintended spread.