5.6 CBCVd-Monitoring 2020

5.6 CBCVd-Monitoring 2020

Sponsor: Bayerische Landesanstalt für Landwirtschaft, Institut für Pflanzenbau und Pflanzenzüchtung (Bavarian State Research Center for Agriculture, Institute for Plant Production and Plant Breeding) Financing: Bayerisches Staatsministerium für Ernährung, Landwirtschaft und Forsten (StMELF) (The Bavarian State Ministry for Food, Agriculture and Forestry) Erzeugergemeinschaft HVG (Hop Producers Group) Project Management: S. Euringer, Dr. D. Kaemmerer (IPS 4b)

Team: IPZ 5b, IPZ 5a, IPS 4b, IPS 2c Sampling Period: 06.2020 to 09.2020

In the 2020 crop year, CBCVd monitoring was carried out in all German cultivation areas. The implementation and intensity of the measures were adapted to the size of the cultivation area and to local conditions. No infestation was found in Spalt, Tettnang, Elbe-Saale. The results of the Bavarian CBCVd Monitoring 2020 are presented below. Table 5.3: Classification of CBCVd-Monitoring, 2020

Classification of CBCVd-Monitoring, 2020 Monitoring of cultivation regions with infestations

HVG Biogas monitoring Voluntary Monitoring (HVG) Plots of newly infested farms (2020) Sum Plots Samples Farms Risk-based 422 Grid 117 ~ 1760

Sum 539 65 195 ~ 15 ~ 45 ~ 40 ~ 300

~ 656 ~ 2300 ~ 400

Table 5.4: Classification of CBCVd-Monitoring, 2020

Farms Infected Region Infection Detected [Year] Severity of Infection 5 Hallertau Central 2019 Low to very high 1 Hallertau South 1 2020 High 1 Hallertau South 2 2020 Low

The following findings were generated by CBCVd-Monitoring in 2020:

• Despite a risk-based approach and a massive effort, “only” four additional farms in three infested areas could be identified → Hallertau is not (yet) contaminated! • The severity of the infestation in the farms affected ranges from low to high • Within a farm, the spread (without a mitigation concept) can progress very quickly

• There is less transmission between neighboring fields from two different farms (requirement: no shared use of machines; no exchange of planting material) • High uncertainty in plots that tested negative but belonged to infested farms • There is evidence that infections with CBCVd have existed for years in the Hallertau cultivation region • Heterogeneous conditions (soil, cultivation, variety) make visual assessments more difficult. Therefore, laboratory tests are mandatory.

Outlook 2021

• Development and implementation of the CBCVd criteria for a clean pass • Monitoring will continue in 2021 and 2022

The Hop Research Center Hüll (LfL IPZ) is supported financially and in terms of its personnel by StMELF, LfL IPS, GfH e.V. and the producer group HVG e.G. Other research activities and official audits are only marginally affected.