Yellow Rust
Phragmidium rubi-idaei
14 host plants · Fungal
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Red raspberry leaves show yellow-to-orange spots in spring and early summer with orange spore pustules on leaf undersides. Phragmidium rubi fungus overwinters on trapped old leaves. Fruit dies before maturing if infection is early. Remove old canes immediately after harvest. Strip leaves from primocanes before tying. New races now infect previously resistant cultivars like 'Meeker' and 'Willamette'.
Burying fallen leaves, old cane stubs, and refuse before new leaves appear will help eliminate inoculum sources. In home gardens, destroy fallen leaves and other refuse.
Quick Reference
Management
Spring through early fall (March-October in western Washington). New cane growth is most susceptible (March-May). Uredinia and teliospores develop on foliage through summer and fall (June-October). (Source: PNW Plant Disease Management Handbook)
Cool, moist spring weather (≥50°F) with leaf wetness favors teliospore germination and basidiospore infection on new Rubus growth. Urediniospore infection cycles continue through late spring and summer in cool, wet conditions. (Source: PNW Plant Disease Management Handbook)
Cultural Controls
- Burying fallen leaves, old cane stubs, and refuse before new leaves appear will help eliminate inoculum sources.
- In home gardens, destroy fallen leaves and other refuse.
- Remove and burn old fruiting canes as soon after harvest as possible, cutting flush with the ground.
- Cultivate as soon as weather permits.
- Strip leaves from primocanes before tying.
- Postpone trellising primocanes until leaves drop off.