beet vs sugar beet

beet

noun
  • A beetroot, a swollen root of such a plant. 

  • Beta vulgaris, a plant with a swollen root which is eaten or used to make sugar. 

sugar beet

noun
  • A type of beet whose root contains a high concentration of sucrose. 

  • darling; sweetheart 

How often have the words beet and sugar beet occurred in a corpus of books? (source: Google Ngram Viewer )