Survival for 2-5 years is possible even if these surfaces are exposed to freezing temperatures. In addition, volunteer potatoes may also harbor the pathogen. The bacterium enters the tuber through wounds. One of the most common times for infection to occur is when tubers are being cut for seed. A cutting knife which comes into contact with an infected tuber can spread the bacterium to the next 20-100 seed pieces.
Infection can also occur at planting when a picker planter is used.
Once in the ground, chewing insects such as the Colorado potato beetle and flea beetle, sucking insects have been reported to spread the disease. The bacterium can also be disseminated in irrigation water. Potato is the only host that is naturally infected although the bacterium can colonized sugar beet roots without causing the disease. Other solanaceous crops such as tomato and eggplant have been successfully inoculated in the lab but the disease does not occur on these hosts in nature. While tubers most often become infected at or before planting, symptoms do not develop until after mid-season.