
SNAP-E orchard systems
Design planting systems that are simple, narrow, accessible, productive, and enduring. By Anna Mouton.
“Orchard systems are not about what we know right now,” said horticultural consultant Craig Hornblow. “Every time we plant a tree, we’re planting with the belief that it will be there for another 20 years. We must think about our needs looking forward.”
Hornblow is a founding member of AgFirst in New Zealand. He has nearly four decades of experience in horticulture and specialises in high-density apple orchards.
New Zealand’s land and labour are expensive, and farms are expanding. Growers must manage bigger areas and more people. “The days are gone when you knew each tree and how you pruned it last year,” said Hornblow.
Like South Africa, New Zealand’s apple production is export-driven, and markets are 4–6 weeks away.
“We need to produce high-quality fruit,” said Hornblow. “We need to target fruit that pays — the upper quartile of growers contains those that focus on fruit that makes money.”
He explained the SNAP-E framework for thinking about orchard systems. The acronym stands for simple, narrow, accessible, productive, and enduring.
Simple
“We need to think about the tree growth and form when developing orchards,” said Hornblow. “What do we want that tree to look like in 3–5 years?”
Simple trees allow focused and objective management. “We must move from three-dimensional to two-dimensional trees,” he emphasised. “We absolutely need to think in terms of two-dimensional canopies.”
He showed several options for achieving two-dimensional canopies. One is the formal horizontal system developed in Plant and Food Research’s FOPS (Future Orchard Production System) research programme. Growers could also adopt a multi-leader vertical system.
“The systems can be formal or informal,” said Hornblow. “There’s a big debate around that because there’s a cost to training branches in a formal system. But two-dimensional formal is my reality — that’s where we create a very systematic, simple approach to achieving a narrow canopy.”
Narrow
Narrow canopies improve light distribution and facilitate mechanisation. “In many of the systems I work with, the canopy is only 20–30 centimetres deep on one side,” he said. He presented an image taken in midseason of an 11-year-old canopy. The maximum canopy width in this mature orchard is only 35–40 centimetres.
Hornblow explained the importance of windows in allowing light transmission throughout the canopy. In formal systems, windows between horizontal branches trained on wires are easy to maintain. “The windows are almost locked in,” he noted.
However, in informal systems, the structure is more random, and growers must create rules to manage wood and maintain windows. Hornblow warned against allowing canopies — and their windows — to close when pushing yields in informal and vertical systems.
Interventions such as leaf-blowing can also help keep canopies open. Narrow canopies are well-suited to actions such as leaf-blowing and mechanical pruning. Both can boost light exposure and red colour development close to harvest.
Accessible
“When using platforms or managing people, you don’t want a tree that’s more than an arm’s length in depth,” said Hornblow, “because otherwise people must move around and into the tree. So, we need to think about accessibility in terms of our labour efficiency.”
He described how New Zealand growers embraced platforms in the wake of labour shortages brought on by the COVID-19 pandemic. Narrow canopies enable platforms to improve labour efficiencies.
Labour efficiency is not only about cost, Hornblow explained. When growers plant only one or two cultivars, they have peak labour demands, and harvest efficiency becomes critical. Many manual orchard practices, such as hand-thinning and harvesting, are also physically demanding.
“We’re definitely seeing picker-efficiency gains in our two-dimensional orchards due to the placement and accessibility of the fruit,” said Hornblow. “When the pickers step on a ladder, they already know which fruit they will pick because they can see it.”
He noted that labour-efficient canopies will also be ready for digital and mechanical tools as they become available.
Productive
Hornblow contrasted the kilometres of fruiting wood per hectare for different orchard systems: 20–35 for three-dimensional trees compared with 42 for FOPS or V-systems. As it is possible to produce an average of 2.7 kilograms of fruit per metre on FOPS or V-systems, these systems should yield 90–110 tonnes annually.
“We maxed out on just over 135 tonnes of large-fruited cultivars on some V-systems this year,” said Hornblow. “On our two-dimensional system, there’s an orchard just approaching 100 tonnes this year.”
While high annual yields matter, he stressed the crucial role of early yields in orchard profitability. “We’re spending a lot of money. We can’t wait till year 10 to get this magical maximum yield,” he said. “We need good early production.”
Enduring
Growers should expect every orchard to last 20–30 years, reckons Hornblow. Rootstock selection should factor in likely disease pressure and environmental conditions that could compromise tree survival, especially as rootstocks may eventually be grafted to new scions.
“Sometimes the rootstock, the structure and the hail net might survive two or three different scions,” said Hornblow. “So, we must think about all those aspects to create an orchard that will still be standing.”
He reminded the audience that an orchard planted at 4 x 1.2 metres today may be technologically irrelevant 15 years from now. The challenge is understanding which systems will pass the test of time with flying colours and which will be prematurely obsolete.
The SNAP-E framework is helpful when making the consequential long-term choice of an orchard system. Nonetheless, Hornblow acknowledged a fifth factor that ultimately decides the success of any orchard.
“When you travel the world and look at these orchard systems, you find that everyone has an opinion — growers can stand in an orchard and debate pruning for three days,” he joked. “But at the end of the day, the best orchard system is the one that the orchard manager believes in.”
Watch Hornblow’s presentation on the Hortgro YouTube channel.