Submitted to: Idaho Potato School
Publication Type: Abstract Only
Publication Acceptance Date: January 27, 1995
Publication Date: N/A
Technical Abstract: The periderm of potato tuber consists of skin (phellem) and biologically related adjoining cell layers. It is critically important that potato tuber periderm be mature at harvest to withstand digging and handling operations without damage. Tubers with immature periderm are easily skinned/scuffed, cut and bruised because the skin is tender and loosely attached to the tuber. This susceptibility to damage results in costly disease, blemish defects and shrinkage. Although there are several factors associated with periderm maturation, the most important is the development of good skin-set; i.e. tightly bonding the skin of the potato to underlying cell layers after cessation of tuber growth. Generally, russeted potatoes develop skin-set quickest and red skinned varieties slowest. We have identified the cellular changes responsible for skin-set. However, we do not know why there are varietal differences in skin-set development; it may ybe partially related to differences in the amount of water vapor released through the undamaged skin prior to skin-set. Weight and thickness of potato skin stabilizes to relatively consistent levels as part of periderm maturation, but this occurs well before skin-set develops and before vines are killed. Currently, the only practical approach to hasten skin-set involves chemically killing potato vines. We have made significant progress in developing a technique to objectively measure skin-set for use in breeding screening, assessing cultural practices and determining if potatoes are sufficiently mature for harvest. Although we have identified the cellular changes associated with skin-set development, we must now determine how to manipulate these changes for more rapid skin-set to reduce disease, blemish defects and shrinkage in all types of potatoes.