Aerial Stem Rot

Infected stems become slimy and are a paler green color.

Causal Agent:

Pectobacterium atrosepticum, Pectobacterium carotovora supsp.carotovora, Dickeya spp.


Bacteria that cause aerial stem rot are nearly everywhere in the environment. They are moved in irrigation water, in aerosols, and on insects. Crop debris and soil are often sources of these bacteria. Disease development is favored by dense canopies, warm weather, and long periods of leaf wetness. Bacterial reproduction can be very rapid under warm moist conditions.


Bacterial aerial stem rot occurs everywhere potatoes are grown.


The critical issue: limit optimal growing conditions for the bacteria.
Minimize long periods of leaf wetness.
Avoid overly dense canopies.
Carefully manage irrigation, especially avoiding excess irrigation during hot weather; plants cannot use as much water in very hot weather and excess moisture encourages bacterial growth.

Further Reading:

Pacific Northwest Pest Management Handbook

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Insects, Diseases, Nematodes, & Beneficial Organisms

Find out more information about insects, diseases, nematodes, and beneficial organisms for Potatoes.

About The Northwest Potato Research Consortium

In February 2012 the state potato commissions in Washington, Idaho, and Oregon officially launched a new cooperative effort in research. The aim of this initiative is to increase cooperation and efficiency of the research programs funded by the three potato commissions that total about $1.5 million annually. It will also work toward comprehensive research results reporting process that aims to get useful information to the growers and industry members who need it. This website is a big part of that effort. Research results, integrated pest management guidance, and production information of many kinds will be presented here. For feedback or suggestions on this site, please contact Andy Jensen, Manager of the Consortium.

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