Management of Armillaria melea Root Rot Disease Research & FAQ

Armillaria melea Root Rot Disease FAQ

What is Armillaria mellea?

Armillaria mellea, commonly known as honey fungus, is a fungal pathogen that causes root rot in a wide range of woody and perennial plants. It is a soil-borne fungus that infects the roots of plants, eventually causing them to decay and die. Armillaria mellea is found throughout the world and can cause significant damage to forests, orchards, and other woody plantations. The fungus produces characteristic honey-colored mushrooms in the late summer and autumn, which can help with identification. Armillaria mellea is a difficult disease to control once it becomes established, but preventive measures such as good sanitation practices and avoiding planting susceptible species in infected soil can help reduce the risk of infection.

What causes Armillaria root rot?

Armillaria root rot is caused by a fungal pathogen known as Armillaria mellea. The fungus can infect a wide range of woody and perennial plants by colonizing their roots and causing them to decay. The fungus spreads through rhizomorphs, which are root-like structures that grow through the soil and can infect new plants. Armillaria mellea can also spread through spores produced by the characteristic honey-colored mushrooms that it produces in the late summer and autumn. The fungus can persist in the soil for many years, even in the absence of a host plant, making it difficult to control once it becomes established. Factors such as poor soil drainage, damage to the root system, and stress on the plant can increase the likelihood of infection. Once infected, the plant's ability to absorb water and nutrients is compromised, leading to yellowing leaves, wilting, and eventual death.

What are some examples of plant species that are known to be resistant to Armillaria root rot?

Plant species know to have some natural resistance to Armillaria root rot are: 

1. Bald cypress (Taxodium distichum)
2. Eastern red cedar (Juniperus virginiana)
3. Ginkgo (Ginkgo biloba)
4. Japanese yew (Taxus cuspidata)
5. Northern white cedar (Thuja occidentalis)
6. Redwood (Sequoia sempervirens)
7. River birch (Betula nigra)
8. Sassafras (Sassafras albidum)
9. Southern magnolia (Magnolia grandiflora)

However, it's important to note that while these plants may be more resistant to Armillaria root rot than others, no plant species is completely immune to the disease. Good cultural practices and preventive measures can also help reduce the risk of infection.

How do you fix Armillaria root rot?

To control the spread of Armillaria root rot disease, it is important to take prompt and effective action. One approach is to physically remove the infected bark and roots, taking care to burn them to prevent further spread of the disease. Any cuts made during this process should be painted with a plastic paint to protect the plant from further infection. Additionally, it is recommended to leave the crown and roots uncovered and avoid replacing the soil during cultivation, as exposing the roots and crown to air can help kill the Armillaria fungus.

In cases where the disease has severely affected a plant, it may be necessary to remove the entire tree, including the roots, and burn the affected materials to prevent further spread of the fungus. Preventive measures such as avoiding planting susceptible species in infected soil and practicing good sanitation can also help reduce the risk of Armillaria root rot disease. Regular monitoring and prompt action can help prevent significant damage to crops and forests caused by Armillaria mellea.

References: 

1. Evaluation of some important woody plant species against wood destroying activity of honey

fungus

Rahele Soltantoyeh*¹, Alireza Dalili2

, Ali Borhani2

1Damghan Islamic Azad University,Damghan, Iran

2Agricultural and Natural Resources Research Center of Mazandaran, P.O. Box 48175-556, Sari, Iran

*Corresponding author: rahelehsoltani55@gmail.com

http://www.cropj.com/toyeh_8_6_2014_881_886.pdf 

2.