In 1986, permanent power was added to 60 sites, providing a welcome facility for exhibitors, but the event's vulnerability to bad weather was emphasised when it was pounded by Cyclone Bola in March 1988.
Over time, the field days outgrew the Jaycees and the event's administrating committee of volunteers became an incorporated society registered with the Charities Commission, reinvesting back into the rural sector with annual community grants for scholarships and research.
In 2006, the land where the Northland Field Days is held now was purchased by the society and the event moved from the racecourse to its present site in 2009.
Logger sports competitions have always been a big crowd-pleaser at the field days and will be enhanced on Saturday by a digger fitted with a grapple demonstrating how logging trucks are loaded.
Other sporting attractions include a tractor pull contest, lawnmower racing, a quad bike competition and dog trials.
There will be sheep races, Big Fun Events which amuse youngsters for hours, and live auctions at 1pm daily at the Tru Test sites 232 and 234 where Radio Hauraki will be promoting a "Win your weight in meat" competition.
A "Hang the gate" competition for men and women will also be held at the Farmlands sites 148 and 150.
Field days visitors 12 and over will be able to do laser clay shooting without the danger of live ammunition and the Honeycroft Pioneers' Colonial Cottage will provide a glimpse of life in the past.
Along with the many attractions listed in the 60-page programme, field days' "streets" will be crammed with trade exhibitors and opportunities to eat, such as at the TMX Graphics Food Hall where tunes from the Joe Carbery Trio will help the tucker and drinks go down.
The event has been dubbed "New Zealand's friendliest field days" and society president Lew Duggan emphasised this aspect with a message in the programme saying it was the perfect opportunity for town and country to unite, share and promote the wonderful lifestyle sectors on offer and support primary industries.
The field days' site will be open from 9am-4.30pm daily until Saturday.