Jacob Price and Patrick Foley-Smith (both 17) won the title, formerly called TeenAg, ahead of schoolmates Ben Chambers (17) and Taylor Bird (16).
However, the third-placed team of Jason Harford and Archie Chisholm, also from the same school, had to be content with the bronze medal.
Compere Te Radar said the number of Geraldine High School pupils who took part was ''sensational'', as were the skills they showed.
''In all my years doing this event, I have never seen so many of the top teams coming from one school.''
''I'm excited we won, but I'm pretty nervous to be heading to the grand final,'' Patrick said.
''It was a great demonstration of how fast technology is changing in the industry.''
The AgriKidsNZ event for primary and intermediate pupils was won by Ashburton Intermediate School trio Hamish Paton, Isla Connelly-Whyte, and Charlie Scammell.
They competed against 120 others in a series of eight modules at the North Otago A&P Show.
Competition co-ordinator Jake Lonergan said the aim was to get children excited about opportunities in the primary industries.
The team of Ruby Giera, Lachlan Rooney, and James Clark from Mt Somers Springburn School was second, followed by Waitaki Valley School's Itaia Chapman, Tamati Dennison, and Maddy Phillips.
All three teams qualified for the national final.