Biology, epidemiology
 

The biology of Sphingomonas suberifaciens understood is not well .


- Conservation

This bacterium can be kept for several years in the soil, especially on plant debris. Indeed, it is maintained for at least 3 years in the soil without the presence of salads. It has a fairly narrow host range, mostly belonging to the asteraceae family (chicory, wild lettuce, Sonchus oleraceus, etc.). It can also be found on the roots of various plants that could allow it to persist in a plot (bean, tomato, melon, barley ...). This bacterium is part of their rhizoflora, but without always inducing apparent symptoms on their roots.


- Penetration

The first stages of its infectious process are unknown.


- Dissemination

It takes place through water, agricultural tools polluted by contaminated soil ...


- Conditions favorable to its development

The expression of this bacteriosis is favorably influenced by the application of excessive nitrogenous manures. The dose provided and the nature of the fertilizer are of some importance. The nitrate forms would be more conducive to "Corky root" than the ammoniacal forms. Heavy and asphyxiating soils, and / or overly irrigated, especially with furrows and the rise in temperature, predispose plants to this bacterial blight. Lettuce growing in light soils can also be affected if overwatered.

Temperature also influences the development of this bacteria. This is optimum at 31 ° C, but it is relatively good from 10 ° C. It stops above 36 ° C.