Winter survival of Phytophthora alni subsp. alni in aerial tissues of black alder
K. Černý, V. Strnadováhttps://doi.org/10.17221/11/2012-JFSCitation:Černý K., Strnadová V. (2012): Winter survival of Phytophthora alni subsp. alni in aerial tissues of black alder . J. For. Sci., 58: 328-336.
The winter survival of the invasive pathogen Phytophthora alni subsp. alni in black alder stems was studied in the bankside alder stand of the Moravská Dyje River in southern Bohemia after two very different winter seasons: cold in 2008/2009, with the average temperature of –1.96°C, and extremely mild in 2006/2007, with the average temperature of 2.54°C. The difference in these two winters resembles the expected potential climate change in Central Europe in this century. After the cold winter of 2008/2009, the pathogen survived in only 13.91% of the samples, with the average survival rate of 2.70%. The pathogen survived the mild winter much better and was successfully isolated from 86.09% of the samples, with the average survival rate of 25.52%. Moreover, the total thickness of the covering tissues (outer + inner bark) and exposure to the most heated southwestern quadrant of stem girth positively affected the pathogen survival. Winter freezing seems to be an important environmental factor regulating the pathogen survival in alder stems and disease severity.Keywords:
Phytophthora alni; winter survival; black alder; temperature; Phytophthora alder disease