Freeze damage and the presence of pathogens in the orchard can apparently be linked. George Sundin and Nikki Rothwell at the Michigan State University Extension, Department of Plant, Soil and Microbial Sciences published at article entitled, “ Bacterial canker, ice nucleation, frost injury and blossom blast in sweet cherries”, outlining how in this example, a bacterial pathogen worked in tandem with frost events to cause or further damage in a prunus species.
The phenomenon occurs when bacterial cells act as nucleation sites within the flowers. The presence of the bacteria facilitates freezing which in turn allows the plant tissue to be damaged, and thus permits the pathogen to invade the plant tissue more effectively. An ingenious, if insidious maneuver. How effective the process is depends upon the temperature (the cooler it is, the less bacterial cells are necessary to cause freeze damage). The bacterium acts, in a way as a catalyst.