Yellow rust is a fungal disease of the leaves and succulent tissues of red raspberries. Leaf infections occur in the spring, causing a yellowish to orange spotting on the upper surfaces. On the lower surface of the leaf in positions corresponding to the yellow spots, orange to pale yellow rust pustules appear in mid-summer. By fall, these pustules turn dark brown to black. Severe infections may result in premature drop of leaves, which may reduce yields and weaken plants. Fruit may fail to mature. Infected canes may be brittle and break off easily. The fungus overwinters as spores, primarily on debris and on the bark of previously infected plants. Wild caneberries including blackcap and salmonberry may also be infected.

Management Options

Non-Chemical Management

Plant resistant varieties such as 'Canby', 'Newburgh', 'Puyallup', and 'Sumner'.
Space plantings, prune, and train to provide good air circulation and reduce humidity.
Cultivate in fall or spring to cover fallen leaves, cane stubs, and other plant debris.
Clean up fallen leaves and plant debris. Destroy or discard (do not compost) diseased materials.
Prune out old fruiting canes and all dead or damaged canes after harvest. Make cuts flush with the ground, without leaving stubs.
Train canes after leaf drop or strip leaves before tying.

Select non-chemical management options as your first choice!

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides

Apply dormant or delayed dormant lime sulfur or copper products

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

Bonide Liquid Copper Fungicide Conc/Organic Gardening
Active ingredient: copper octanoate | EPA reg no: 67702-2-4
Lilly Miller Sulfur Dust Fungicide/Insecticide Dust or Spray
Active ingredient: sulfur | EPA reg no: 802-16
Soap-Shield Flowable Liquid Copper Fungicide [Organic]
Active ingredient: copper octanoate | EPA reg no: 67702-2-56872
Spectracide IMMUNOX Multi-Purpose Fungicide Spray Conc
Active ingredient: myclobutanil | EPA reg no: 9688-123-8845
This list may not include all products registered for this use.

Images

+ Show larger images


Caption: Raspberry rust Photo by: R.S. Byther
Caption: Raspberry rust Photo by: R.S. Byther
Caption: Raspberry rust on fruit Photo by: R.S. Byther

WSU Extension

Hortsense