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.