A special general meeting will now be held at the Waihemo Lodge, Palmerston on September 2.
Former president Telford Kinaston, of Dunback, who remains on the committee, said the situation was "dire".
The show was popular, but more committee members were urgently needed, he said.
Two of the outgoing committee members had offered to assist at the show, which is held on the first Saturday in February.
Nevin Gibb, of Palmerston, who resigned after two years as president, said the workload was not too heavy for committee members and helpers on show day,About 2500 people attended this year's show, and there were 3500 at last year's event.