Update on the situation of Citrus bark cracking viroid in Germany
In Germany Citrus bark cracking viroid (CBCVd - EPPO A2 List) was first reported from two hop fields (Humulus lupulus) in Bavaria in July 2019 (EPPO RS 2019/165). Official surveys were conducted to determine the extent of the outbreak and official measures taken.
In 2019, CBCVd was found in 12 hop gardens (production sites) of three producers in Bavaria. A major survey was conducted in 2020 in 672 hop gardens located in ten administrative districts, and CBCVd was found in two districts in 27 hop gardens belonging to 7 producers (including 15 fields from the three producers who already had infected fields in 2019), covering a total of 93.6 ha. The infection level varied strongly between the infected fields, from one infected plant per field up to nearly 100 percent of plants being infected. It was shown that the spread of the disease was linked to the movement of infected plants and the sharing of machinery.
The survey in 2021 found infections at two further hop producers. In total CBCVd was found in 32 hop gardens covering an area of 92 ha (in 2019-2021, some hop plots were cleared resulting in a decrease of 5 ha of the infested area).
It is considered that CBCVd has been present in Bavaria for at least seven years and that eradication is no longer possible. Containment measures are applied and include: removal and destruction of infected plants (including the roots), prohibition to use hop residues from the whole production site to produce biogas, prohibition to share machinery from an infected place of production, prohibition to sell hop planting material from an infected place of production.
The pest status of Citrus bark cracking viroid in Germany is officially declared as: Present, under containment.
Sources
NPPO of Germany (2022-01) Citrus bark cracking viroid – Update of an infestation on plants of Humulus lupulus (hop) in Bavaria. https://pflanzengesundheit.julius-kuehn.de/index.php?menuid=86&downloadid=3162&reporeid=223