Differences in sugars,chip color,specific gravity and yield of selected potato cultivars grown in michigan

Six cultivars, Atlantic, Eramosa, Kanona, Norchip, Onaway and Saginaw Gold and four selections, MS 700-70, MS 700-83 (Spartan Pearl), MS 716-15 and W-855 (Snowden), were analyzed for sucrose, glucose, chip color, specific gravity and yield at 98 and 138 days in 1988 and 1989, t evaluate their performance to Michigan growing conditions. The average yield of these cultivars at the two harvests for 1988 and 1989 was 46.9 and 54.7 t/ha and 43.1 and 52.3 t/ha, respectively. Eramosa and Onaway were the earliest maturing varieties with low specific gravity, high glucose content and processed into dark colored chips. The glucose and sucrose contents of the remaining eight cultivars at each harvest date were low and produced acceptable chips. The specific gravity of Atlantic, MS 700-70, MS 716-15 and W-855 was in the range of 1.079–1.088 and for Norchip, Kanona and Saginaw Gold the range was 1.071–1.076. The date of harvest, variety and year of production had significant effect (p > 0.01) on yield. The specific gravity, glucose content and chip color were significantly influenced by variety and year of production. The correlation between chip colorvs glucose (r= -0.842, p = 0.000) and harvest datevs yield (r= -0.572, p = 0.000) was also significant.