If you thought rugby was withering at the grassroots, take a trip out to the lush fields of Pukekohe this week.

There you will see the game in its purest form - schoolboy rugby - and it is alive and kicking, between the goalposts.

The Roller Mills tournament is a 76-year-old tradition to bring out the best in under-13 rugby talent from Ahipara to Taupo.

And it's not just the kids running their hearts out on the field who make the event so rich. It is the volunteers who give up their week to run it in this modern age of professionalism, and the parents, who take it all so seriously.

Among the 2500-strong crowd, there are dads and grandads who played Roller Mills as boys.

Mothers, kitted out in the union's colours, screech with ear-splitting clarity such instructions as "Take out their legs".

Sometimes in their fervour they lose sight of the white sidelines and venture on to the paddock. One zealous mum had to be ordered off the field during Sunday's opening day.

Waikato parents bring their cowbells, but their clanging is drowned by the thunderous beat of Aucklanders banging support on Polynesian drums.

Ian Spraggon has been bringing teams to the Roller Mills almost every August school holidays since 1965. He calls it the Ranfurly Shield of primary school rugby.

And the Bay of Plenty coach, the principal of Bellevue School in Tauranga, reckons there is no tougher tournament in New Zealand.

"These kids are playing six games of rugby in seven days - and the All Blacks complain about playing too much rugby," he laughs.

"Yet every boy who plays in this tournament cherishes the memory.

"Even if the kids never go on to play representative rugby again, they will always have the Roller Mills to call back on. They will tell their grandchildren what year and where they played and the All Blacks they played against."

The Meads brothers, Colin and Stan, played for King Country as children - their names appear on the Roller Mills roll of honour alongside Don Clarke, Beegee Williams, Grant Fox and Kiwi league stars Dean Bell and Tawera Nikau.

The history and esteem of being chosen for the Roller Mills is not lost on 12-year-old boys.

Or girls for that matter. As an impressionable second former, I remember being in awe of boys in my class trying to sweat and starve the weight off in the week before the tournament, desperate to get below the magical 55kg mark. It was that serious.

The weigh-in still is. The windows of the clubrooms are blacked out with sheets when the boys ceremoniously step on the scales.

If they are a fraction over 55kg, they can strip off their clothing piece by piece until they sneak under.

Schoolboy rugby is a much more professional game today. Where once the only accessories were elastic garters to hold socks up, today's gangly youths are heavily disguised under headgear, shoulder pads and gaudy-coloured mouthguards.

There are other signs that the professionals influence the way our kids now play. When King Country shattered home side Counties-Manukau on the first day, 50-15, their try-scorers pointed towards the heavens as they dived theatrically under the posts.

Back in 1924, the Roller Mills was better known in the wheat fields, not on the rugby fields. That was the year flour manufacturer Northern Roller Milling Company presented a trophy for schoolboy rugby in Greater Auckland.

Although now a stockfeed company, NRM has returned, coming to the rescue of the tournament - which last year was in jeopardy of collapsing without a major sponsor.

It costs $25,000 to run the week-long tournament. That includes lunch for the players - most of whom are billeted with local families - and a day out at the pool and bowling alley when they have a bye.

Only $12,800 of that comes from sponsorship. The organising committee, all volunteers, "beg, steal and raffle" to raise the rest.

"This is real rugby," says Spraggon.

"People think the game is all professional, but this tournament is run by people who give all their time and effort free."

Before the first whistle was blown on Sunday, the boys stood for a minute's silence to honour those killed in a tragedy on the other side of the world.

As monumental as the threat of war is, the biggest thing in their lives right now is a game. And that's the way it should be.