Final diagnosis


Thanatephorus cucumeris (Rhizoctonia solani, rhizoctone brun)

Altération marron, bien délimitée, sèche d'aspect. <b><i>Thanatephorus cucumeris</i></b> (<b><i>Rhizoctonia solani</i></b>, rhizoctone brun, damping-off)
A brownish canker, rather dry and well defined, surrounds the base of these tomato plants. <i> <b> Rhizoctonia solani, Thanatephorus cucumeris </b> </i> (<i> Rhizoctonia </i> basal stem canker)
<b><i>Rhizoctonia solani</i></b> (damping-off, <i>Rhizoctonia</i> root rot, basal stem canker)
The brown and branched mycelia of <b> <i> Rhizoctonia solani </i> </b> are clearly visible on this root (damping-off, <i> Rhizoctonia </i> root rot, basal stem canker)
Rhizoctonia3
Rhizoctonia2
A more or less dense felting covers a wet and brown lesion that has developed on this portion of the stem. <i> <b> Thanatephorus cucumeris </b> </i>
Rhizoctonia1
More classic lesions from an attack of <b> <i> Thanatephorus cucumeris </i> </b> (<b> <i> Rhizoctonia solani </i> </b>) are observed on this green fruit. Rather limited, brown to beige, they have a few concentric patterns. A few small canker sores are also noted.
These three mature fruits testify to the diversity of lesions induced by <b> <i> Rhizoctonia solani </i> </b> (<b> <i> Thanatephorus cucumeris </i> </b>) on tomato.
On this fruit we can observe both small beige canker lesions and a large spot consisting of brown concentric rings, alternating with lighter rings. <b> <i> Rhizoctonia solani </i> </b> (<b> <i> Thanatephorus cucumeris </i> </b>)
Rhizoctonia4
A brown mycelium progresses to the surface of damaged tissue. <b> <i> Thanatephorus cucumeris, Rhizoctonia solani </i> </b> (Brown Rhizoctonia, <i> Rhizoctonia </i> basal stem canker)
Barrel-shaped structures can be seen on the mycelium; they are considered to be blank sclerotia. <b> <i> Thanatephorus cucumeris, Rhizoctonia solani </i> </b> (Rhizoctonia, damping-off, rot fruit)
Rhizoctonia5
Rare basidia, often bearing 4 basidiospores, can be seen on the white hymenium partially covering affected organs and soil. <b> <i> Thanatephorus cucumeris </i> </b>