Final diagnosis


Thielaviopsis basicola (Chalara elegans, Black root rot)

Various soil-borne parasitic microorganisms, by altering the root system of lettuce, disrupt their growth. This is the case of the curly chicory located on the left, the root system of which is strongly attacked by <b> <i> Thielaviopsis basicola </i> </b> (<i> Chalara elegans </i>, "black root rot ").
These 4 curly chicories, more or less attacked by <i> <b> Thielaviopsis basicola </b> </i> (<i> Chalara elegans </i>, "black root rot"), show very different sizes, this despite a plantation carried out on the same date.
Their root system is more or less altered, which explains the poor growth of plants. <b> <i> Thielaviopsis basicola </i> </b> (<i> Chalara elegans </i>, "black root rot")
<i> <b> Thielaviopsis basicola </b> </i> (<i> Chalara elegans </i>) is also responsible for a dark brown to black rot affecting many roots; this alteration is at the origin of the Anglo-Saxon name of the disease: "black root rot".
Wet and brown alterations are also visible. Deep tissue rotting causes the roots to break when the plants are pulled up. <i> <b> Thielaviopsis basicola </b> </i> (<i> Chalara elegans </i>, "black root rot")
The root symptoms are quite varied. There are corky and cracked sleeves. <b> <i> Thielaviopsis basicola </i> </b> (<i> Chalara elegans </i>, "black root rot")
The brown and chain chlamydospores of <b> <i> Thielaviopsis basicola </i> </b> (<i> Chalara elegans </i>, "black root rot") are prominent on this root.