Successful establishment of epiphytotics of Puccinia punctiformis for biological control of Cirsium arvense

- Rosettes of C. arvense were inoculated in the fall with telia-bearing leaves.
- Rosettes inoculations were done in Greece, New Zealand, Russia, and the USA.
- Conditions were favorable for teliospore germination in the fall in all fields.
- Systemically diseased shoots resulted from inoculations in all 13 field sites.
- Rosettes in the fall are the infection court for basidiospore infection.