Brown Root Rot Disease
1. What is Brown Root Rot disease?
Brown Root Rot disease (BRRD) is caused by the aggressive fungal pathogen Phellinus noxius, a white rot fungus that could result in rapid health and structural deterioration of trees and may lead to tree failure.
2. How does Brown Root Rot disease spread?
- BRRD disease can be spread through root contact, contaminated soil, ground water, surface water, and even through the air.
- The public are strongly advised to stay away from known infected trees as contaminated soil on shoes can also spread the disease.
3. Impact of Brown Root Rot disease infection
- It is an international disease prevalent in tropical and sub-tropical regions with no effective cure. There have been numerous claims of cures or effective management, but once the tree is infected, it cannot be cured.
- BRRD disease can lead to swift deterioration in health of the tree, causing eventual decay and irreversible structural damage to tree roots, posing a serious threat to public safety.
- BRRD disease has devastating impact on our landscape. Once a site is infected, it must be completely disinfected.
4. Management Approach
- A multi-pronged approach combining preventive and management tactics is being adopted by the Greening, Landscape and Tree Management Section (GLTMS) to safeguard our urban forest assets.
- The GLTMS has promulgated the "Guidelines on Brown Root Rot Disease" in which a referral mechanism of suspected cases is adopted to actively report trees suspected of BRRD disease infection, and arrange verification, limit the spread and carry out necessary removal of the tree as appropriate for the subject site conditions.
- An operation manual on the removal of BRRD disease infected tree will be issued to advocate the proper removal and follow-up procedures of BRRD disease infected tree.
- Once an infected site is known, the focus is to save the surrounding landscape and nearby vegetation.
- International best practice and policy position is to limit the spread to other trees and remove the infected tree as soon as practicable, including other plants within the infection area and the root system of the infected tree.
- The site should be properly disinfected and replanting of trees at the same site is not recommended unless it is proven to be rid of disease pathogen.
5. Way Forward
- The GLTMS has been collaborating with research institutions to conduct fungal surveys, diagnosis and preventive studies on aspects such as BRRD disease resistant species and cure.
- Research projects and exchange of views with overseas experts can enhance our understanding of the disease, which could help build a more holistic, active and successful management approach in the future.
- To positively build capacity and raise overall professional knowledge and standards in the industry will be the key towards better management of BRRD disease.
Fact Sheet on Brown Root Rot Disease