Our apple orchards are getting a makeover, thanks to Hawke's Bay Plant and Food scientists, who have developed systems that grow up to twice as many apples per hectare over traditional methods.
The secret? To design orchards that capture more sunlight through closer rows of trees that don't cast as much shade on themselves.
Plant & Food Principal Scientist Stuart Tustin said traditional orchards were inefficient at utilising sunshine.
"We knew there was potential because more than 40 per cent of the sun energy available through a season was not currently being used by current orchard designs," he said.
"So we were interested to see if we could redesign the orchard to capture more energy, which should translate into more productivity.
"Typically very good orchards in our country are producing between 80 and 100 tonnes per hectare.
"The project is in its seventh year. None of our trees are completely mature but so far progress has been encouraging. When our trees are fully mature we are hoping – and our date is projecting - that we will be somewhere in that range between 160 and 200 tonnes per hectare."
Two-dimensional trees have been around for several years but the trial's tree shape has brought further gains in addition to closer rows.
The longer an apple is on a tree in the new system, the bigger the gain, so varieties that ripen later in the season can achieve double the harvest. The late-season larger varieties such as Envy and Fuji would most probably enjoy the greatest production boost.
The trial used varying orchard configurations and they have settled on 2m row spacing as optimum.
Not only has the quantity of the fruit in the trial increased, so has the quality. Plant & Food Senior Scientist Ben van Hooijdonk said fruit size, colour, and taste were superior. Also picking fruit at optimum ripeness was easier.
"Generally we do take a large proportion of the fruit in the first and second pick, which suggests that our maturation is much more even in our colour development - much better than our traditional systems," he said.
Tustin said there was no eureka moment in the trial, with it steadily reflecting long-held theories. But the results have been seen as too good to be true by some.
"We've got lots of critics, we've got lots of doubters – scientifically as well is in industry – and we enjoy that environment. We let the data speak for itself."
The trees, with multiple upright shoots, could provide further cost savings by enabling future technologies of robotic picking, pruning and spraying.
"These planar systems have been designed for automation and robotic picking," van Hooijdonk said.
"Through the design to optimise sunlight at the beginning of the FOPS (Future Orchard Planting System) programme we consulted bioengineers and there was discussion around what tree architecture we would need to not only improve yields and quality, but for future focus, ensure that we have orchards that are amenable to automation and robotics."
With trees in the trial still not fully mature, there are potentially more gains to be made in the move away from the traditional three-dimensional tree, which is constantly casting shade on itself.
The apple industry is well on its way with two-dimensional trees, so the gains from the trial should be easier to implement. But full adaptation, assuming uptake, is at least several years away according to New Zealand Apple and Pears chief executive Alan Pollard.
"At the moment, we're regenerating probably 10 per cent of our orchards per annum. So it's going to take a little while to get all of our orchards on the same sort of two-dimensional structure," he said.
The primary funder of the apple trial is the New Zealand Ministry of Business, Innovation and Employment.
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