Ink disease: possible confusion

If an observer is to determine whether a chestnut tree is affected by blight, it is essential to observe one or more of the symptoms that characterise the disease. Unfortunately, these are not specific and can be caused by various other biotic and abiotic causes:

Symptoms

Elements for ink diagnosis

Elements for other diagnoses

Shoot wilting and/or mortality

Generalized dieback

Observation of root or collar necrosis.

No rhizomorphs.

Canker disease: sectorial mortality, subcortical mycelium, orange fruiting bodies.

Nutritional deficiency, water stress: no necrosis

Armillaria: root infections, subcortical rhizomorphs

Defoliation

Leaves reduced

Cynips: galls and leaf deformation

Black discharge

Cortical necroses observed under the discharge after stripping.

 Galleries of wood-eating insects: no necrosis

 Frost: splitting of the wood

Root necroses

Infected or destroyed fine roots, infected taproot or large roots sometimes up to the collar.

 Armillaria: rhizomorphs

Trunk necroses

Trunk necroses are caused by root necroses

 Javart: lesions not related to the roots

Last change : 11/30/21
  • Authors :
  • C Robin (INRA)
  • T Allery (INRAE)