Plant and Food scientists have declared they will create a revolution in orchard growing systems - before they have worked out exactly how they will do it.
Havelock North-based crop physiologists Stuart Tustin, Ken Breen and Ben van Hooijdonk say the theoretical potential is there to double orchard yields.
"We've been giving a lot of thought to this - about breaking out into a step change up to a new level of production," Dr Tustin said.
"I've been working here for 30 years and the whole time we have worked on the enhancement of fruit quality and efficiencies. Not since the '50s and '60s, with our forebears like Dr Don McKenzie, have we worked specifically on ramping up productivity.
"We take Mckenzie's advances for granted now and he is revered, but at the time it was enormously difficult for him as he tried to invoke a step change that was a whole lot of fundamental changes, compared to what people were accustomed to.
"Our thinking is the time has arrived for the next change.
"McKenzie's innovations took yields from 30-40 tonnes per ha to up to 100 tonnes per ha of export quality fruit. Our desk top model and concepts take us into the potential range off 140-200 tonnes per ha. Our minimum target is 140 tonnes per ha."
Mr Breen said the the improvement was vital for the industry.
"The very best orchard systems we are using now, while they are very efficient, are still difficult for a viable business," he said.
"There is a very small margin and a lot of things play a role in whether it's going to be plus or minus. The exchange rate seems to have a major impact on profit or loss and there seems to be nothing we can do about it. But if you look at other sectors they have managed to get their businesses viable."
Dr Tustin said the primary production driver will be harnessing more of the available sunlight.
"The most efficient agronomic crops, and pastures, typically utilise 90 per cent or more of the available sun energy. Our very best high-density planting systems peak around 60 per cent."
He said the problem was not shading of leaves but gaps among the trees, which meant sun was falling on unproductive areas by missing the tree entirely.
"There is a huge energy capture gap, 50 per cent of what we have now compared with the theoretical biological upper limit.
"On light interception models that is a realistic target. We don't know how far beyond that we can go but we think there is probably more."
He said just as important as new planting systems was the need to keep costs down.
"The industry needs new production systems that will serve growers into the next 50-60 years so we are determined to stick to self-imposed constraints of keeping costs down at current levels or less and protecting natural capital - the integrity of the land resource or improve it.
"Current constraints for costs of capital - the sheer cost of redevelopment into high density orchards as we do them now is about $60,000 per ha plus operating costs. The margin of return on that is so small and precarious.
"So we have to contain costs at the level they currently are - the whole purpose of the project is to create real profit margins beyond the influence of exchange rate fluctuations on the business viability.
"Another caveat is the quality of the fruit must at least be maintained, preferably improved further."
Dr Hooijdonk said another driver for change was the likelihood of increasing mechanisation in orchards.
"Our bio engineering people say current trees are too complex for automation, especially for robotics, so our future trees need to be much simpler."
Existing mechanisation could be made redundant.
"We are talking about a different organisation of trees in the orchard - the current use of large equipment such as tractors will not be possible. All the equipment will probably look different.
"Most growers associate their tractors with pest and disease control but if you look at where controls are headed they are moving away from spray regimes.
"All the new controls are not here yet, but if we design our trees differently all kinds of spray technologies won't be needed."
But they are not entirely reinventing the wheel. They plan to incorporate emerging techniques, providing they boost production and keep a lid on costs. Their current research using artificial spur extinction for precision crop load management is a good example - it is now possible to achieve more precise crop loads and return bloom without chemical thinners.
They are coy about what the next-generation orchard will look like.
"We are sure where we are going to start with trials but we don't want to disclose too much," Dr Tustin said.
The planting density is envisaged to remain at current levels of about 2000 trees per ha and there will be multiple stems per tree - a major deviation from the current design.
"We will fall on our face many times and we have to be prepared to be laughed at a lot - a lot - but we don't mind because our ideas are as different as McKenzie's were in the '60s. We are going to turn the system on its head.
"We are confident we can do it - we are staking our reputation on it."