Grower Joe Atherton said he was "delighted" to break the world record, with a turnip measuring 4.064m.
The Ministry of Justice said 20 prisoners were involved in the disturbance at HMP Long Lartin in Worcestershire.
Donations will go to St Richard's Hospice to help fund the millions needed for end of life care.
The human remains were found in a septic tank in Kempsey earlier this month.
West Mercia Police said they received reports of bones being found earlier this month during the routine emptying of a septic tank.
Miss Lamplugh disappeared in 1986 aged 25.
Officers say the remains are not thought to be related to the ongoing search for missing estate agent Suzy Lamplugh.
Desmond Wooding was found dead last month at his home in Droitwich.
Police are appealing for witnesses after the incident at St Andrews Parish Church Cemetery on Pershore Road in Evesham.
The event in Worcestershire begins today and runs until Sunday.