BREEDING PROGRESS FOR POTATO-CHIP QUALITY IN NORTH-AMERICAN CULTIVARS

Forty-four potato cultivars, released in the period between 1876 and t he present were grown concurrently in field trials, stored simultaneou sly in three different environments, then evaluated for chip quality. They represented cultivars historically used and/or bred for potato ch ip production. Quality factors measured were tuber solids, chip color, reducing sugar levels, sucrose levels, and percent of defect-free chi ps. Tuber solids tended to increase in the late period cultivars, but trends were erratic. The release of Lenape marked the beginning of an increase in tuber solids that has continued to the present. There was a significant trend for lower reducing sugars and better chip color th at corresponded to increasingly later cultivar release dates. Since ab out 1960, progress toward lower reducing sugars and better chip color has been constant, regardless of whether tubers were stored at 4.4 C, stored at 4.4 C and reconditioned, or stored at 10 C. Late period cult ivars tended to have a greater percentage of defect-free chips in comp arison to those released earlier, with most of the improvement coming during the last few years. This study provided evidence that potato br eeders have made significant progress in developing cultivars with goo d chip quality. Evidence was also found that Lenape was a landmark cul tivar and has been an important contributor to the observed breeding p rogress.