Zebra chip development during storage: cause for concern?

Authors: Wallis, Christopher; RASHED, ARASH - University Of Idaho

Submitted to: Spudman
Publication Type: Trade Journal
Publication Acceptance Date: 3/20/2018
Publication Date: 7/1/2018
Citation: Wallis, C.M., Rashed, A. 2018. Zebra chip development during storage: cause for concern?. Spudman. 56:26-27.

Interpretive Summary: Tubers infected with the zebra chip pathogen ‘Candidatus Liberibacter solanacearum’ may be asymptomatic when placed in cold storage but develop symptoms before consumer purchase. Thus, two studies were performed to examine the likelihood of this occurrence, and determined that as long as infections were prevented at least ten days prior to harvest, asymptomatic tubers were unlikely to develop zebra chip symptoms that would be observed by end consumers. As a result, best management for potato growers is to maintain psyllid vector management up to ten days before harvest.

Technical Abstract: Zebra chip disease is associated with infections by ‘Candidatus Liberibacter solanacearum’ (Lso), a bacterium spread by the potato psyllid Bactericera cockerelli. A major concern of the potato industry is the likelihood that Lso could cause asymptomatic infections prior to placement of tubers in cold storage, with undesired zebra chip symptoms developing before consumer purchase. Thus, two studies were performed to observe zebra chip symptom development in stored, Lso-infected tubers. At least half of tubers infected greater than ten days before harvest did develop zebra chip symptoms after removal from storage. However, tubers infected later did not develop significant symptoms. Therefore, these results suggest psyllid control should continue up to ten days prior to harvest to prevent asymptomatic tubers becoming symptomatic before consumer reception.