Mycologg: a new accelerated test method for wood durability above ground
If not properly handled, selected and protected, wood will be degraded by bacteria, fungi and also insects. In order to ensure service life, durability tests are needed. Most accelerated laboratory tests on wood durability are focused either on fungi attacks or the uptake of moisture. Accelerated field tests in ground contact are of limited use since they could be difficult to reproduce and are sensitive to the characteristics of the soil in which the wood is placed. In addition, the results cannot be directly transferred to wood in use above ground because such wood is subjected to different set of conditions. The Mycologg is a new accelerated test method for estimating the durability of wood in above ground applications. The Mycologg allows the test panels to be subjected to the discolouring fungi and different RH (relative humidity) cycles simultaneously. Every 30 min, the temperature, the RH, and the moisture content in each test panel are measured and saved in special software. This allows for a constant update of the moisture patterns during a fungi attack. A trial was made with Scots pine (Pinus sylvestris) heartwood samples, where fungal growth after 6, 8 and 10 weeks in the Mycologg were compared to weather exposure of duplicate samples after 12, 16, and 26 months. The results showed that 10 weeks into the Mycologg accelerated test method corresponds well to real-time weather exposure with respect to fungal discolouration.
Improvements of monitoring the effects of soil organisms on wood in ground contact
The germination of fungous spores in relation to controlled humidity
Water, either liquid or vapor, has long been recognized as essential to the germination of spores of most pathogenic fungi. Furthermore, high atmospheric humidities are known to favor the initiation of plants by fungus pathogens and the subsequent development of epiphytotics of plant diseases. However, fully convincing experimental data on the relation of high relative humidities to the germination of spores of most phytopathogenic fungi have been lacking, because of the difficulties of controlling the experimental conditions with such accuracy as to preclude the possible intervention of minute amounts of liquid water. The investigation reported herein was undertaken (1) to develop an accurate method for spore germination at high relative humidities, and (2) to determine the relation of relative humidity to the germination of spores of certain phytopathogenic fungi.