Plant Disease Management Handbook

Cause Phytophthora spp., fungal-like organisms that thrive in water saturated soil and/or poor drainage conditions. Several different species have been identified throughout the world on Aucuba. The organism infects at the tips, middle and junctions of lateral root branches. Entire roots become necrotic as the pathogen colonizes the tissue. Depending on the species, the pathogen may continue up into the stems causing the plant to collapse and die.

Cause Leaf spots of Aucuba have been a common problem sent into the OSU Plant Clinic. A wide variety of fungi have been isolated and many have been considered secondary invaders (such as Pestalotia sp.) to abiotic issues such as sunburn. The fungi Colleotrichum gloesporeiodes and a Phomopsis sp. have been found by the OSU Plant Clinic and reported from WA.


Note: These are shade loving plants that do not tolerate full sun even for part of the day.

Cause The fungus, Rhizoctonia spp., has been found on Astragalus in Oregon. Rhizoctonia spp. occurs in Oregon on other crops and may incite disease on numerous other crops including arugula, beets, snap bean, clover, peppermint, and brassicas. This fungus also causes damping-off of a wide range of plant species. It overwinters in soil as durable, long-lived structures known as sclerotia, but can also survive in association with infected plant debris.

Plant Viruses: Dead or Alive?

Copper-based Bactericides and Fungicides

Cause Wisteria vein mosaic virus has been reported from Washington and observed in Oregon. The disease has been observed in nurseries and home landscapes. As a potyvirus, an aphid is expected to be a vector of this disease. Vegetative propagation of infected plants, however, will easily spread the disease.