ARS | Publication request: Similarities and Differences Between Sugar-end and Stem-end Chip Defects

Submitted to: Proceedings Wisconsin Annual Potato Meetings
Publication Type: Abstract Only
Publication Acceptance Date: January 25, 2010
Publication Date: February 2, 2010
Citation: Wang, Y., Bussan, A.J., Bethke, P.C. 2010. Similarities and Differences Between Sugar-end and Stem-end Chip Defects [abstract]. Proceedings Wisconsin Annual Potato Meetings. 23:49-51.

Technical Abstract: Sugar-end defect and stem-end chip defect are quality defects of processing potatoes that cause losses to potato growers on an annual basis. Both defects are characterized by darkening of fried potato products near the tuber stem end. Sugar ends are most commonly observed in processing russet potatoes used for the manufacture of French fries, and stem ends are a serious concern in round white potatoes used for chip production. The environmental and biochemical causes of sugar-end defects are understood relatively well. The same is not true for stem-end chip defect, and we have undertaken research to identify the causes of stem-end chip defect. Our research has shown that there are similarities and distinct differences between these two quality defects. A general summary of these will be presented as this provides a useful framework for discussing the nature of stem-end defects. Particular emphasis will be given to water stress early in the growing season as a reliable trigger for sugar-end production that has little effect on stem-end occurrence or severity. The tight association of stem-end defects with vascular discoloration will be highlighted, and hypotheses for stem-end defect formation that incorporate this observation will be proposed.