A few National MPs were also there but did not speak.
Myrtle the tractor's owner Bob Appleton declared Ardern a "tax hungry socialist". He had decorated Myrtle with placards including "fart red for Labour" and "Jacinda and the Mob thinks food grows in supermarkets".
One man held up a sign stating "She's a pretty communist" on one side. The other side said "bring back Buck and Winston".
It would have come as a surprise to Winston Peters to discover he'd been away. When he arrived soon after the rally began, few noticed him.
"He's too short," they laughed. "Can't see him."
"I can't control the placards that farmers want to bring," organiser and Federated Farmers Waikato President Andrew McGiven said afterwards.
He had used his speech to say farmers were becoming the punching bags of the election and pleaded for townies to show some understanding of the farmers' role: "New Zealand is too small for a rural-urban divide."
But it was after the official bits were over and the farmers headed off for the march component of the rally - "up the road to the RSA for a beer" - that things got raucous. The self-appointed guardian of the regions leaped on to the stage, grabbing the megaphone. Peters stood there in his pin-striped suit in front of a massive cow udder in the rain and railed on about National's secret plan to charge for water through local government and Treaty settlements.
There were boos and heckling. But when Myrtle's engine cranked up in front of him it drowned him out.
"Tell him to turn it off," Peters yelled more than once.
Instead, Myrtle revved up and bucketed through the crowd to the road, running over one of Peters' supporters' toes in the process.
If Peters wanted any further hints about why his vote was disappearing in the squash between National and Labour, he got it in farmer Scott Smyth.
Peters had pulled up in a bus with "the straight talk express" written on it. Smyth thought Peters meant it.
He asked if Peters would insist Labour took taxes on farmers off the table if he ended up in government with them. Peters responded to that by saying he'd been milking cows before Smyth was born.
Smyth wasn't giving in.
"I'm not against you, mate," he said "but that was a just a bit harsh".
Others shouted "who are you going with? You're going with Labour aren't you? You won't get any votes here."
Peters might have thought only the chardonnay-drinking, pinky finger-pointing media wanted the answers to such questions. Yesterday he discovered the farmers did too.