|RASHED, ARASH - UNIVERSITY OF IDAHO|
|PAETZOLD, LI - TEXAS A&M UNIVERSITY|
|WOODELL, LYNN - UNIVERSITY OF IDAHO|
|OLSEN, NORA - UNIVERSITY OF IDAHO|
|WORKNEH, FEKEDE - TEXAS A&M UNIVERSITY|
|RASHIDI, MAHNAZ - UNIVERSITY OF IDAHO|
|WENNINGER, ERIK - UNIVERSITY OF IDAHO|
|RUSH, CHARLES - TEXAS A&M UNIVERSITY|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2015
Publication Date: 7/15/2015
Citation: Rashed, A., Wallis, C.M., Paetzold, L., Woodell, L., Olsen, N., Workneh, F., Rashidi, M., Wenninger, E., Rush, C. 2015. Candidatus Liberibacter solanacearum' development in Russet Norkotah under commercial storage conditions. Meeting Proceedings. p. 13-17.
Interpretive Summary: Zebra chip disease in the Pacific Northwest generally develops from late-season inoculations of the causal agent, ‘Candidatus Liberibacter solanacearum’ (Lso), by potato psyllid vectors. Therefore, many potato plants will be inoculated just prior to harvest resulting in asymptomatic tubers becoming accepted by processors which are then stored. The formation of zebra chip disease and associated changes in tuber physiology were monitored in late-season infected potatoes to assess the risk of disease development in stored potatoes. Following removal from cold storage, 41% of tubers exposed to infections by psyllid vectors four days prior to harvesting tested positive for Lso. Therefore, psyllid vectors must be managed until harvest to avoid asymptomatic Lso-infections that could result in zebra chip symptoms developing in storage.
Technical Abstract: ‘Candidatus Liberibacter solanacearum’ (Lso) is the causal agent of zebra chip (ZC) disease in potato. Following the recent appearance of ZC in the Pacific Northwest region of the US, where waves of the vector arrive towards late-summer and early fall and tubers are stored for future marketing, emphasis has been placed on late-season infections. The importance of the-late season infections is that the asymptomatic tubers at harvest can potentially develop ZC post-harvest and during storage. The present study evaluated effects of vector density and time of infection on post-harvest disease development. In all infestation treatments, Lso continued to multiply and interact with the infected tubers after harvest and during storage. When placed at room temperature following cold storage, 41% of the tubers collected from plants infested 4 days before harvest tested positive for Lso. This indicates that Lso may arrive into the tuber tissue as early as four days after infestation by the bacteriliferous vectors, and highlights the importance of vector management until harvest.