Comparison of Skin-set and Periderm Maturation in ‘Red Norland’ Potatoes Grown in Two Soil Types in Wisconsin

Abstract

Skin-set is a necessary prerequisite for potato storability, but there is little published information on the effect of cultural conditions on the development of skin-set. The phellogen layer acts as a lateral meristem for the peri- derm and while active, fracture of its thin radial walls leads directly to skinning injury during harvest and handling into storage. During maturation of the periderm, these radial walls thicken. Red-skinned cultivars are often grown in muck soils in Wisconsin to improve skin condition and color. We tested skin-set and phellogen radial wall thickness for 'Red Norland' tubers grown on either loamy sand or muck soils in central Wisconsin. Skin-set varied between years and soil types, but there was no consistent effect of soil type on skin-set. Phellogen radial walls in Red Norland tubers doubled in thickness between bulking and vine-kill, but did not change in the three week period following vine- kill even when skin-set improved. Physiological processes other than cell wall thickening must be responsible skin-set during the three weeks following vine death.