Main symptoms

As its species name suggests, it causes alterations developing around the periphery of the limbus. Quite quickly, the affected areas show a few spots that turn brown, black and necrosis. Subsequently, the tissues may dry out and take on a paler color and a papery appearance. If conditions are very humid, an oily, black rot invades the leaves (Figure 1). Some secondary veins sometimes appear darker.

During particularly humid periods, the bacteria are able to reach the collar and the stem; it is then associated with a soft and olive rot of the marrow, comparable to that caused by Pectobacterium carotovorum subsp. carotovorum (called "Butt rot" by the Anglo-Saxons, figure 2).

Pseudomonas marginalis pv. marginalis would produce damage during transport and storage of lettuce stored in poor conditions, especially thermal, sometimes in association with Pectobacterium carotovorum subsp. carotovorum .