Pectobacterium carotovorum subsp. carotovorum infects young plants in nurseries (figures 1 and 2) causing a wet and black rot of seedlings at the soil line which gives the name “ black leg” or “soft rot” to the disease.

 

In the later growing season, the bacteria may penetrate the stem through topping wounds and cause a stem rot (figure 3, “hollow stalk”). 

 

It may also occur during curing causing damage similar to the damage caused by Pectobacterium chrysanthemi. The infected leaves develop a wet and black appearance as the rot spreads through the petiole and gradually progresses to the ribs and the inter-veinal tissues (figure 4).

 

Some of the information on the worldwide distribution of the disease is obtained from surveys conducted by CORESTA (Cooperation Centre for Scientific Research Relative to Tobacco). The reliability of the information is not confirmed in all countries.

Last change : 09/12/13