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Broom Rust

Gymnosporangium libocedri

16 host plants

Last updated

Data Coverage 3 of 6 dimensions
Causal Agent
Host Plants
Symptoms
Management
GDD Threshold
Regional Notes

Bright orange or brown fuzzy pustules appear on leaf undersides, indicating this fungal disease requires two different plant species to complete its entire life cycle. The disease spreads readily by wind-borne spores traveling from alternate hosts to susceptible plants. Remove nearby alternate hosts or susceptible plants to interrupt the disease cycle. Improve air circulation and avoid overhead watering that spreads spores.

Remove and destroy cedar brooms before spring. Remove alternate hosts from around the planting. Identify and manage the alternate host if one exists. Remove heavily infected tissue and clean up fallen debris. Preventive fungicide applications before the infection window offer the best chemical control.

Quick Reference

Causal Agent
Gymnosporangium libocedri
Host Plants
16

Management

Cultural Controls

  • Remove and destroy cedar brooms before spring.
  • Remove alternate hosts from around the planting.
  • Separating hosts by 0.5 to 2 miles has been recommended.
  • Avoid overhead irrigation that wets foliage for extended periods of time.

Host Plants (16)