Which root rot is identified by gray to cinnamon mycelium on bark at the root collar and on roots, with advice to regenerate with tolerant species and wider spacing?

Which root rot is identified by gray to cinnamon mycelium on bark at the root collar and on roots, with advice to regenerate with tolerant species and wider spacing?

• A. Armillaria
• B. Laminated root rot
• C. Black stain root disease
• D. Dwarf mistletoe

Answer: (B)

Recognizing root rot in the field comes down to the signs you can see on roots and at the root collar. The gray to cinnamon mycelium seen on the bark at the root collar and on the roots is characteristic of Laminated root rot. This disease forms layered, laminated wood tissue as the fungus colonizes and decays the roots, giving that distinct color and texture you can observe on the roots and root collar. Because the infection can persist in the root system and spread through stands, a common management approach is to regenerate with species that are tolerant to the disease and to increase spacing so young trees have less contact with infected roots and can grow in healthier conditions. Other diseases show different indicators: Armillaria typically has white-to-tan, fan-like mycelium under bark and rhizomorphs; black stain root disease causes dark staining within the sapwood; dwarf mistletoe is a parasitic plant with canopy and growth form symptoms rather than a root-rot signature.

Recognizing root rot in the field comes down to the signs you can see on roots and at the root collar. The gray to cinnamon mycelium seen on the bark at the root collar and on the roots is characteristic of Laminated root rot. This disease forms layered, laminated wood tissue as the fungus colonizes and decays the roots, giving that distinct color and texture you can observe on the roots and root collar. Because the infection can persist in the root system and spread through stands, a common management approach is to regenerate with species that are tolerant to the disease and to increase spacing so young trees have less contact with infected roots and can grow in healthier conditions. Other diseases show different indicators: Armillaria typically has white-to-tan, fan-like mycelium under bark and rhizomorphs; black stain root disease causes dark staining within the sapwood; dwarf mistletoe is a parasitic plant with canopy and growth form symptoms rather than a root-rot signature.