ARS | Publication request: Causes of stem end chip defect in chipping potatoes

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2011
Publication Date: August 6, 2011
Citation: Bethke, P.C., Wang, Y., Bussan, A.J. 2011. Causes of stem end chip defect in chipping potatoes [abstract]. American Society of Plant Biologists Annual Meeting. Available: http://abstracts.aspb.org/pb2011/public/P01/P01011.html.

Technical Abstract: Stem-end chip defect (SECD) is a serious tuber quality concern that affects chipping potatoes. This defect is characterized by dark-colored vascular tissues and adjacent cortical tissues at the tuber stem-end of potato chips after frying. Chips with SECD are unappealing to consumers and raw product may be rejected at processing plants if SECD exceeds specifications. A multi-year research project has investigated the potential causes for SECD using controlled-environment greenhouses in the UW Biotron and field plots at Hancock Agricultural Research Station. Our Biotron data indicate that moderate environmental stresses including soil moisture deficit and high daytime temperature (30°C), either alone or in combination, as well as immaturity at harvest, had little affect on the percentage of severe SECD. Immaturity at harvest greatly affects tuber bud-end and stem-end sucrose contents at harvest, with sucrose being significantly greater (p <0.01) in tubers harvested from immature rather than mature plants. Vine maturity at harvest slightly changed the percentage of tubers that had severe defects by only 2%. More severe SECD corresponded with higher rates of vacuolar acid invertase activity. Defects in chips cut through the stem attachment point were common in field plots at Hancock in 2010 at harvest and in storage, as they were throughout the upper Midwest during that year. Defect incidence differed between cultivars and for three of four cultivars in these small-scale trials, defect severity decreased slowly during storage at 13°C.