Variation in specific gravity of potato tubers

Specific gravity of tubers from the Irish Cobbler, Kennebec, Norgold Russet, Norland, Red Pontiac, Russet Burbank, Snowflake, and Viking varieties grown at 2 locations over 3 years were determined by the brine solution method. The usual differences in specific gravity were noted between varieties and locations. There was a narrow range in specific gravity of individual tubers within lots of Norland and Russet Burbank, and a wide range within lots of Kennebec and Snowflake, with the remaining varieties intermediate. Low variation of tubers within a variety as measured by standard deviation did not indicate low or high specific gravity. Varieties with low variation tended to remain low from one year to the next.