Armillaria root rot

Armillaria root rot, also known as shoestring root rot, is caused by a number of Armillaria species, most notably Armillaria mellea and Armillaria gallica. It is also known as the honey toadstool or bootlace fungus, is a widespread and often destructive disease that can affect an extremely wide range of plants.

The disease is a rare disease of blueberries in the United States, but it can cause serious damage where it occurs.

They are most commonly found in forests and natural areas where they infect a variety of trees and shrubs. Therefore, the disease is most common in newly established blueberry fields that are planted on land recently cleared of native vegetation.

Armillaria survives as mycelium and rhizomorphs on old roots and stumps. The fungus spreads between bushes by root-to-root contact and can also survive on wood chip mulches.

What are the symptoms? Infected plants are low in vigor and may appear to be suffering from a nutrient deficiency.

Leaves are small and chlorotic, and branches wilt suddenly. The entire plant may be affected or only individual canes may exhibit symptoms of the disease. Plants decline slowly over several years or die within a short time. Occasionally, after an infected tree has died, honey-coloured clusters of toadstools grow from the base of the tree.
Armillaria root rot