2025/04/04 by Burgdorf, Nicole, Straßer, Ludwig, Mager, Enno +1
#Acer pseudoplatanus #Bavaria #airborne conidiospores #endophyte #pathogen
paper · doi:10.5073/jfk.2025.02.07
Outbreaks of sooty bark disease in sycamore (Acer pseudoplatanus L.), caused by Cryptostroma corticale, get more frequent in Central Europe. The disease leads to individual and stand wise mortality of sycamore in many regions. In Bavaria, sooty bark disease has been observed in sycamores mainly in the dry-warm region around Würzburg. However, the fungus is widely distributed as an endophyte in regions without symptomatic findings. According to our results, outbreaks of the disease become more frequent, when endophytic colonisation in the lower trunk area increases. Trees with sooty bark disease are fragile due to white rot and dehydration of the wood. Therefore, cutting down should be done mechanised, not motor-manual. During felling by harvester spore dispersal is increased for that moment: We found a 48-fold increase compared to the time before and after felling. For timber utilisation it should be taken into account that C. corticale can develop as a saprophyte in felled, previously asymptomatic sycamore logs. While observing felled trees without external symptoms of the disease, a first building of spore layers was found after three to four months of storage. After three years, a second development of spores in older annual rings has been detected. However, on felled logs the initial formation of spore layers on the outer annual ring under the bark can be suppressed by debarking.