Nature of winters, Poplar habit
Alternate (conifer) host
Overwintering mode for rust
Spring base level of inoculum
Rate of seasonal build-up of inoculum
Impact on host
Cool to cold Poplar deciduous
Present
Teliospores
Very low
Very slow
Mild
Cool to cold Poplar deciduous
Absent
Urediniospore survival (facultative)
Very low
Slow to very slow
Mild
Mild Poplar deciduous
Present or absent
Urediniospores or teliospores
Low
Slow
Mild
Mild, poplar deciduous or semi-deciduous Immaterial Continued production of urediniospores High Very rapid Very adverse