According to Official Guinness Records,
The longest beetroot measures 7.956 m (26 ft 1.22 in) and was grown by Joe Atherton (UK), as verified at the UK National Giant Vegetables Championship, in Malvern, UK, on 23 September 2016.Joe is a veteran of giant vegetables, also holding records for the Longest carrot and Longest radish.
For a complete list of 2016 records, please visit 2016 Guinness Records in United Kingdom.