Symptoms present on both young seedlings and adult plants.
Rapid wilting of young leaves at the hottest times of the day, often reversible at first during the night; they come on suddenly and become permanent (Figures 1-2. Leaflets and leaves eventually dry out like whole plants at term.
In less favorable conditions: slowed growth of plants, leaf epinasty, emission of adventitious root outlines on the stem, yellowing of lower leaves, etc.
Yellowish to brown more or less dark coloring of the vessels observable in the roots, taproot and stem (figures 3 and 4). The marrow and cortex may show moist, brown lesions.
Signs : perform a "water glass test" to reveal the presence of bacteria in the vessels. To do this, take a stem fragment from the lower levels of the stem, immerse it in a glass of water: white mucous wisps made up of billions of bacteria appear within 5 minutes (figure 5).