|SELSTEDT, RACHEL - NORTH DAKOTA STATE UNIVERSITY|
|WESTRA, ALAN - IDAHO CROP IMPROVEMENT ASSOCIATION, INC.|
|NOLTE, PHIL - UNIVERSITY OF IDAHO|
|DUELLMAN, KASIA - UNIVERSITY OF IDAHO|
|YELLAREDDYGARI, S.K.R. - NORTH DAKOTA STATE UNIVERSITY|
|GUDMESTAD, NEIL - NORTH DAKOTA STATE UNIVERSITY|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2019
Publication Date: 6/22/2019
Citation: Whitworth, J.L., Selstedt, R.A., Westra, A.A., Nolte, P., Duellman, K., Yellareddygari, S., Gudmestad, N.C. 2019. Symptom expression of mainstream and specialty potato cultivars to bacterial ring rot (Clavibacter sepedonicus) and evaluation of in-field detection. American Journal of Potato Research. 96:427-444. https://doi.org/10.1007/s12230-019-09730-x.
Interpretive Summary: Bacterial ring rot (BRR) causes rot in the vascular ring of potato tubers. Nearby affected tubers in storage can also rot, leading to substantial loss. Equipment and facilities that are exposed to the ring rot bacteria can serve as a source of new infections in the following years. The ability to detect BRR in the field prior to harvest allows a grower to make management decisions before storage plans are formulated. Many new cultivars and advanced breeding lines, including specialty types have not been screened for BRR symptoms . This work examines 28 cultivars and breeding lines infected with the ring rot bacteria and grown in North Dakota and Idaho. Samples collected prior to harvest showed that the bacteria can be reliably detected. Field symptoms were observed as early as 91 days in Idaho and 55 days after planting in North Dakota.
Technical Abstract: Bacterial ring rot caused by Clavibacter sepedonicus is a zero-tolerance disease in seed potato certification and can cause crop loss and substantial economic damage for affected growers. To address symptom expression and time of expression, 28 cultivars and advanced breeding lines were inoculated with C. sepedonicus and grown in North Dakota and Idaho. Cultivars included russet, chip, and specialty types. Foliar ratings were taken, and first symptoms were observed as early as 91 days after planting in Idaho and 55 days in North Dakota. Symptom characteristics were noted for each cultivar. This information is useful to growers and certification officials. Samples of stems, petioles, stolons, and tubers were also collected at different pre-harvest intervals to determine if C. sepedonicus can be reliably detected in the lab. The ability to detect C. sepedonicus before harvest allows an affected grower to make harvest and management decisions that limit damage caused by bacterial ring rot.