The Eucalyptus Pine Pathogen Interactions (EPPI) team has been undertaking a large-scale greenhouse trial running for a third consecutive year since 2020. The experiment consists of 205 Eucalyptus grandis x Eucalyptus urophylla backcross to E. grandis clones, produced by SAPPI-South Africa . For this year’s round of the experiment, 3030 ramets belonging to 202 of the clones, planted in January 2021 were inoculated with a fungal canker pathogen, Chrysoporthe austroafricana . In the forest plantation, the pathogen enters the trees through wounds. We conducted the inoculations from 5-9 December 2022. This will be followed by stem sampling for RNA-sequencing and phenotyping, which will be conducted in early 2023. EPPI team members and volunteers from the wider FABI participated in the trial. This experiment is part of a grand effort of disease resistance mapping in the economically important forest tree species Eucalyptus . We aim to identify DNA markers associated with resistance against this canker pathogen and to understand the underlying resistance mechanisms.