Plant Disease Management Handbook

By M. Nampijja, S. Crane, L. du Toit, and C. Ocamb

Bacterial leaf spot caused by Pseudomonas syringae pv. aptata in red beet crops. A) Severe, coalesced lesions on a leaf. B) Bacterial leaf spot symptoms on leaves and seed stalks (black arrow) in a table beet seed crop. C) Bacterial leaf spot symptoms on beet seedlings. D) Dark black, water-soaked lesions on a beet leaf following a rainstorm. Photo credited to M. Nampijja, S. Crane, and L. du Toit, Washington State University.
Bacterial leaf spot caused by Pseudomonas syringae pv. aptata in red beet crops. A) Severe, coalesced lesions on a leaf. B) Bacterial leaf spot symptoms on leaves and seed stalks (black arrow) in a table beet seed crop. C) Bacterial leaf spot symptoms on beet seedlings. D) Dark black, water-soaked lesions on a beet leaf following a rainstorm. Photo credited to M. Nampijja, S. Crane, and L. du Toit, Washington State University.

Bacterial leaf spot caused by Pseudomonas syringae pv. aptata in red beet crops. A) Severe, coalesced lesions on a leaf. B) Bacterial leaf spot symptoms on leaves and seed stalks (black arrow) in a table beet seed crop. C) Bacterial leaf spot symptoms on beet seedlings. D) Dark black, water-soaked lesions on a beet leaf following a rainstorm.

Photo credited to M. Nampijja, S. Crane, and L. du Toit, Washington State University.

Fasciation

Ribbon type fasciation of Coast Redwood (Sequoia sempervirens).

OSU Plant Clinic image, 2008.

Small plantlets at the bottom of a potted plant

Leafy gall caused by the bacteria Rhodococcus fascians showing multiple buds that only partially expand.

OSU Plant Clinic image, 2008.

Ribbon type fasciation of this petunia stem.

OSU Plant Clinic image, 2009.

Ribbon type fasciation of 'Berkeley' blueberry.

OSU Plant Clinic image, 2010.

Ribbon type fasciation of Sedum.

OSU Plant Clinic image, 2008.

Flatened stem of this Linaria plant is called fasciation.

Jay W. Pscheidt, 2008.

Ribbon type fasciation of 'Rome' apple.

Jay W. Pscheidt, 1990's.

Strange looking top of sugar beet plant

Ribbon type fasciation of sugar beet.

OSU Extension Plant Pathology image collection, 1975.  

Ribbon type fasciation of Douglas-fir.

OSU Extension Plant Pathology image collection, 1980.  

Fasciation of Shasta Daisy.

Jay W. Pscheidt, 2020.

See:

Tomato (Solanum lycopersicum)- Fusarium Crown and Root Rot

Tomato (Solanum lycopersicum) - Tomato Varietal Resistance to Fusarium Wilt and/or Crown and Root Rot

Discoloration of the vascular system exposed in cross section (top) and along the stem (bottom) of the same tomato plant.

OSU Plant Clinic image, 2017.

Discoloration of the vascular system exposed along the stem (left) and in cross section (right) of the same tomato plant.

OSU Plant Clinic image, 2017.

Slide is labeled Tomato Fusarium Wilt.

Barry J. Jacobsen

(Includes arugula, broccoli, broccoli raab, Brussels sprouts, cabbage, cauliflower, Chinese broccoli, Chinese cabbage, collard, kohlrabi, kale, mustard, radish other than daikon, rape, rutabaga, and turnip)

See:

Tanoak (Notholithocarpus densiflorus) - Sudden Oak Death

Rhododendron - Ramorum Leaf Blight and Shoot Dieback

See:

Cherry (Prunus spp.) - Nematode, Dagger

Cherry (Prunus spp.) - Nematode, Root-lesion

By K. Frost and C. M. Ocamb

Cause Potato virus Y (PVY) is a mechanically- and aphid-transmitted disease. PVY can reduce yields of most potato varieties, particularly in the high-yielding, long-growing season of the Columbia Basin. In addition to yield reduction, specific strains of PVY can cause reductions in tuber quality.

Potato tuber showing early necrotic ring due to PVY.

Photo by Ken Frost, 2016.

Potato tuber showing necrosis due to PVY.

Photo by Ken Frost, 2019.

Veinal necrosis symptoms of PVY on potato leaflets.

Photo by Ken Frost, 2017.

Cause The fungus Sphaerulina populicola (formerly Septoria populicola) has been reported in the PNW following comprehensive surveys of native Populus trichocarpa (black cottonwood) and commercial plantations. This species only causes a leaf spot disease on native and hybrid poplars and rarely causes significant adverse impact on tree growth and survival.

Necrotic spots of Septoria populicola on leaves develop within 3-4 weeks of leaf expansion.

Kelsey Sondreli, 2020.

Spots may be circular to angular, appear grey to silver or become yellow to brown, and may coalesce to include large portions of the leaf including the petiole. These spots were due to Septoria populicola.

Kelsey Sondreli, 2020.

Cankers due to Septoria musiva are elongate, often depressed, dark brown or black but may include lighter brown or tan areas.

Kelsey Sondreli, 2020.

Stems may be constricted at the canker or appear swollen due to the production of callus.

Kelsey Sondreli, 2020.

Leaf infection by Septoria musiva may extend down the petiole and into the stem.

Kelsey Sondreli, 2020.

Leaf spots due to Septoria musiva (shown here) are similar to those produced by S. populicola.

Kelsey Sondreli, 2020.

Cause The result of fruit (or young leaves) being exposed to direct sunlight, especially under periods of high temperatures and high relative humidty. Fruit that are rapidly exposed to sunlight due to defoliation by biotic pathogens are very susceptible to sunburn.

Fruit develop sunken, light-brown to white colored areas where they are exposed to direct sunlight.

Melodie Putnam, 2000.