Mr Carruthers said about 90 farmers entered about 120 winter crops between Shannon, about 20km southwest of Middlemarch, and Clarendon, about 10km northeast of Milton.
Judges scrutinised the crops considering factors such as yield, consistency and cleanliness, relative to the environment.
A prizegiving and auction will be held at Wingatui Racecourse on Friday.
Recipients of proceeds from the competition include the Otago Rescue Helicopter Trust, Otago Community Hospice, Otago Rural Support Trust and the Louise Davie Charitable Trust.
The competition is organised by the Taieri Lions Club and Taieri Rotary Club.