|Swisher Grimm, Kylie
|WATERS, TIM - Washington State University Extension Service
|WOHLEB, CARRIE - Washington State University Extension Service
Submitted to: Potato Country USA
Publication Type: Trade Journal
Publication Acceptance Date: 4/1/2019
Publication Date: 4/30/2019
Citation: Swisher Grimm, K.D., Waters, T., Wohleb, C. 2019. Columbia Basin mystery disease Studies on the recent mysterious foliar damage seen in potato across the Columbia Basin. Potato Country USA. 35:24-26.2019.
Interpretive Summary: During the 2017 and 2018 growing season, mysterious foliar damage was seen in potatoes across the Columbia Basin of Washington and Oregon, prompting an investigation into the cause of the symptoms. Researchers at the USDA-ARS Temperate Tree Fruit and Vegetable Research Unit in Prosser, Washington, along with Washington State University scientists, were tasked with investigating whether a pathogen could cause the symptoms to develop. Here, molecular diagnostics to detect common pathogens, and greenhouse grafting of diseased tissue to healthy potatoes did not identify a causal agent of the pathogen. These results suggest that something else, such as environment factors or pest pressure, is the likely cause of the mysterious foliar damage seen in 2017 and 2018 potatoes.
Technical Abstract: In 2017 and 2018, disease-like symptoms were prevalent in potato foliage across the Columbia Basin of Washington and Oregon, appearing in July to early August and persisting throughout the season. Symptoms included leaf distortion with crinkled, warped leaves often found with small holes, purpling of upper terminal leaves, and stem damage seen as blisters and necrotic lesions. The widespread nature of these disease-like symptoms in the Columbia Basin prompted researchers at the USDA-ARS Temperate Tree Fruit and Vegetable Research Unit in Prosser, Washington, and Washington State University, to determine if a pathogen could be causing these symptoms. Foliar tissue and tubers were collected from different cultivars across the Columbia Basin in 2017 and 2018 for analysis. Molecular diagnostics and greenhouse grafting of diseased tissue were performed simultaneously in an effort to identify a cause of these symptoms. The cause of the symptoms was not found to be pathogenic in nature.