Robots and super orchards

New Zealand’s pipfruit and kiwifruit crops are amongst the most productive globally; however, with a growing population, a sustainable future means being able to produce the same or more food on existing land.

Over the past five decades, the productivity of New Zealand’s pipfruit has been achieved using only 55-60% of available light within existing tree arrangements and there have been few advances to planting systems aimed at increasing productivity beyond the current potential.

“According to research, finding a way to increase light utilisation had the potential to double the yield of some fruit crops without losing quality,” says Dr Stuart Tustin, Plant & Food Research Principal Scientist, Fruit Crops Physiology.

The Future Orchard Planting Systems (FOPS) research programme — funded by the Ministry of Business, Innovation and Employment (MBIE) and New Zealand Apples & Pears Incorporated — was set up to develop novel orchard systems to raise productivity. To achieve this goal scientists designed ways to increase light interception by an additional 25% and enable more even light distribution, to ensure uniform fruit quality and ripening.

Drawing on their understanding of tree physiology and developmental biology, scientists at Plant & Food Research redesigned orchard systems into narrow, minimally branched, two-dimensional canopies that reduce shading.

“What we are attempting with the new design is to use light energy that is otherwise wasted, and to use the natural growth habit of trees to enhance production,” says Tustin.

In the FOPS arrangement, trees are planted with rows only one and a half to two metres apart, compared with the traditional four-metre spacing. The scientists were also mindful that the new system should be simpler to operate, more efficient with labour, and no more costly for growers to maintain.

“Everything in FOPS is simpler and more accessible,” says Tustin.

The FOPS blocks at Glenmore Orchard in Hawke’s Bay are now in their third leaf. For owners, Glenn Riddell and wife Ingrid, it was the simplicity of the architecture that appealed most because it makes working on trees easier. The narrower rows are also conducive to the use of platforms, which Riddell says “takes a lot of the effort” out of picking. Increasing productivity was only third on their list of reasons to implement FOPS.

“Standardising the canopies makes it much faster to train people with thinning and pruning. Previously, it could take two to three seasons to properly train, but with FOPS it can be done in a day,” Riddell says.

Gary Wellwood, Global Variety Development Manager, Apples, at T&G Global, says simpler canopies, unlike three-dimensional canopies, improve the outcome when using new digital technologies for counting and sizing.

“In three-dimensional orchards it’s hard to count fruit, as the technology is trying to guess what can’t be seen. But in two-dimensional canopies a large percentage of fruit can be seen, so it’s just a simple image capture,” Wellwood says.

Six years into trials, FOPS has demonstrated significant increases in apple production with higher yields than from conventional planting, while maintaining, or even improving, fruit quality. Light interception has increased to a maximum of 80%, which is over 20% more light interception than any other intensive apple orchard planting system in New Zealand, or internationally. In the Hawke’s Bay trial, six-year-old trees have yielded around twice the average of mature conventional orchards and the trees still have two years to mature, making further increases likely.

In addition to its potential for boosting apple production in New Zealand, the FOPS apple plantings provide a model for other crops and are guiding new growing techniques for summerfruit and kiwifruit. Early trials with FOPS plantings of sweet cherry trees have more than doubled the yield potential of conventionally planted trees. MBIE and Prevar are also co-funding a FOPS project for the Piqa^® brand fruit.

“In Plant & Food Research trials, FOPS has improved fruit quality, uniformity and is also likely to improve productivity of new fruit cultivars developed by Plant & Food Research, such as Piqa^®Boo^® pear,” says researcher Dr Ben van Hooijdonk.

In many orchards, labour shortages are a recurring issue. FOPS, with its two-dimensional canopies, has the potential to enable semi-automated and robotic picking, helping to mitigate labour shortages and improve labour efficiency.

Demonstrating some of the benefits of a two-dimensional canopy system, in 2019 T&G Global achieved a world-first commercial robotic apple harvest using an “on the job” robot to harvest two-dimensional orchards in Hawke’s Bay. The robot, designed by Abundant Robotics, is designed to protect both trees and fruit from damage and uses sensory computer vision to scan the trees for ripe apples.