Plant Disease Management Handbook

Cause Marssonina sp. are fungi that have been reported from all states; M. kriegeriana was reported from Washington, and M. rubiginosa has been reported from Idaho. These fungi overwinter on fallen leaves and in twig lesions. The disease is widespread and common, especially in moist spring weather.

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Crown Gall Disease of Nursery Crops

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Poplar (Populus spp.) - Canker

Willow (Salix spp.) - Twig Blight (Scab)

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Lilac (Syringa spp.) - Bacterial Blight

Cause Wheat streak mosaic virus, a potyvirus vectored by an eriophyid mite, Aceria tulipae. The virus attacks and overwinters in wheat, oat, barley, and rye, and a large number of wild grass genera including Bromus (cheatgrass), Hordeum, Lolium, Agropyron, and Poa.

Cause A virus, wheat soilborne mosaic virus, transmitted by a soilborne fungus-like organism, Polymyxa graminis. In 1993, the disease was first found west of the Rocky Mountains, in Washington and in Columbia County, Oregon. The disease tends to be in wetter areas of the field, following the distribution of its fungal vector.

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Wheat (Triticum aestivum) - Common Root Rot (Seedling Blight)

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Fungicide Effectiveness as Seed Treatments for Cereal Diseases

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Barberry (Berberis spp.) - Rusts

Cause Fungi cause four different snow mold diseases including Typhula ishikariensis and T.