- Lead scientist
- Dr Liz Beal
- Start date
- 2003
- End date
- 2009
- Keywords
temperature, pH, moisture, organic matter, Armilllaria, honey fungus, abiotic, humidity, rhizomorph
- Benefits to gardeners
The project aims to provide gardeners with better advice for dealing with Armillaria root rot problems related to the current changing climate conditions.
- The problem
Armillaria sp. is the most frequently identified fungus causing plant death in British gardens by the plant pathology department at RHS Garden Wisley.
The majority of cases are caused by A. mellea, however A. gallica is often found and occasionally A. ostoyae and A. cepistipes. Previous research has demonstrated that A. gallica is able to kill live plants but only those that are stressed by other factors, for example overcrowding or drought.
With potential changes in climate, plants may suffer stress and therefore become more susceptible to a wider range of Armillaria species.
- Approach
Temperature effects on survival of rhizomorphs were carried out using 2cm lengths of rhizomorphs grown up from hazel inoculum plugs. These inocula were placed into petri dishes containing horticultural grit. The variables were: level of moisture during heating (wet/dry), duration of heat (2hrs/12hrs), and the type of inoculum.
Initial results show temperature appears to have more of an influence on A. gallica and A. mellea survival rates than humidity. At 50oC no A.mellea or A. gallica survived.
To study the effect of pH and soil moisture on survival a standard loam will be used. The inoculum used is hazel plugs infected with Armillaria species.
For the pH experiment the pH will be adjusted at either 5, 6, 7 or 8. The trays will be kept moist so the water content is 50% of field capacity.
For the soil moisture experiment the moisture content will be kept at 10%, 30%, 50%, 70%, 90% or 100% of field capacity. The rhizomorphs will be harvested and measured after three months in both experiments.
- Further information
Advice on honey fungus
Read about the studies on the pathogenicity of Armillaria spp
Read about the identification of Armillaria spp using molecular methods
Read about the behaviour of severed rhizomorphs of Armillaria mellea and A. gallica in growing media
Read the Armillaria survey
Read about the growth and behaviour of Armillaria in mulches
- References
Pérez Sierra A (2003) Systematics, diagnostics and epidemiology of the fungal genus Armillaria. PhD thesis, University of London