EFFECTS AND INTERACTION OF SOME MANAGEMENT FACTORS ON THE GLYCOALKALOID CONTENT OF POTATO TUBERS

Abstract

Glycoalkaloids are a naturally occurring steroidal alkaloid of potatoes exhibiting human toxicity at levels > 30 mg/100 of tuber fresh weight. It has been documented that genotype and environment have a large impact on tuber levels within a potato crop. The impact on glycoalkaloid content was determined for four management variables including variety grown, N fertilizer rate, storage temperature, and length of storage period. In 1989 and 1990, three varieties (Russet Burbank, Norchip, and Gemchip) were planted in plots with three rates of applied N fertilizer (0, 168, and 336 kgh·m-1). Harvested tubers were stored at 4.4 or 10.0C. Tuber samples were obtained 1 month before harvest, at harvest, and then 3 and 9 months after harvest and analyzed for glycoalkaloid content. All four management variables had a significant (P = 0.05) effect on tuber glycoalkaloid content, but only length of storage period had a greater influence than the natural environmental effect as measured by the difference between years. There were significant year the trial was conducted × N fertilizer rate, year × variety, length of storage × variety, and N rate × variety interactions. The interactions were analyzed and explored.