Rockit apples are like other apples in that they’re grown on trees but then the team at the Hawke’s Bay company behind the miniature apples have taken their own path. 

A little larger than a golf ball, Rockit apples are marketed globally as healthy snacks and sold in recyclable plastic tubes. In some markets, a tube of five perfectly formed Rockit apples sells for $US10.

Now Rockit is forging another new path by being an early adopter of the Future Orchard Production Systems (FOPS) created by Plant and Food Research.

FOPS is essentially a system of harvesting light and ensuring the light is evenly distributed within the tree canopy to maximise fruit production. Tree spacing and pruning are both intensive, with trees grown in a vertical 2D shape. Row spacing in the FOPS plantings¹ by Plant and Research in Havelock North was narrowed from the traditional 3 m or 3.5 m rows to 1.5 m and 2 m and raised the utilisation of incoming light energy from a typical 60 to 65 percent to close to 90 per cent use efficiency.

As Todd Blackman, Havelock Sector Orchard Manager for Rockit Management Services (RMS), explains, the initiative to move into FOPS came from the investors who buy the land and trees which are then managed by RMS. 

“The concern, at that early stage, was that FOPS hadn’t been implemented commercially at the scale being proposed. They were trials with five rows of trees here and there.”

With input from Plant and Food researchers, the RMS team adapted some aspects of FOPS to establish the first 11.5 ha block during the winter of 2020. They used two planting systems. The first has 1600 Rockit trees, on CG202 rootstock, per hectare with 3 m tree spacing and 2.2 m row spacing. The second has Rockit grafted on M9 stock with 2.4 m tree spacing and 2.2 m rows, giving around 1800 trees per ha.

“We opted for the 2.2 m rows which fit a narrower model of mower pulled by our existing tractors,” says Todd. “We adjusted the booms on our sprayers. We plan to grow the trees to a height of 3.5 m before we think shading starts to be an issue.”

When the first Rockit FOPS orchard went in, it doubled the worldwide area in FOPS plantings. Now, there is around 45 ha of Rockit grown on FOPS, which Todd estimates as being about 80 percent of the FOPS apples in the world.

“Yes, we were early adopters and we’re seeing the productivity improvements already.”

Rockit orchards, being a single variety, have other varieties spread throughout the orchard to help with cross-pollination. Last season, on the two-year-old FOPS trees, a lack of pollination impacted yield. The trees flowered a little later than usual, missing peak cross-pollination.

Todd says: “They produced 10 t/ha last season, but now, in year three, we have around 30 t/ha on the blocks with smaller trees and up to 45 t/ha on the blocks with bigger trees that are the same age but on a different root stock so more vigorous. To put that in perspective, we’ve got some eight-year-old Rockit trees grown in the typical 3D spindle structure doing about 35 t/ha, although I will note that these weren’t looked after as well as they could have been in their early years.”

From his earlier scepticism, Todd now thinks it’s achievable for the Rockit FOPS trees to produce as much as 100 t/ha when in full production.

There are challenges in establishing a highly productive FOPS orchard and the Rockit team is paying close attention to every detail.

“It’s very labour intensive in the first two years,” Todd explains, “when most of the vertical 2D tree training takes place. Training for a standard 3D tree starts in years two and three, and may carry on for another four or five years.”

Todd highlights the importance of setting the trees up correctly in the vertical 2D shape, technically called planar cordon, with the establishment of two horizontal branches from which ten verticals grow upright.

“The tree is primarily growing upwards, the way it wants. After those first two years, pruning is much easier. Up to a third of the wood of a traditional spindle tree might cut out in any one year whereas we’re taking only five percent, maybe ten percent, off a FOPS tree.”

Todd says he can teach someone how to prune a FOPS tree in one or two days. “With a standard 3D tree, it could take me a year, sometimes longer, to get a pruner to the same skill level. Ultimately FOPS will make some of our orchard jobs more systematic and allow us to use less skilled labour.”

The RMS team is in regular contact with Plant and Food about existing and new FOPS plantings, many hectares of which are being planned. They also participate the FOPS Sustainable Farming Fund (SFF) group with quarterly meetings and regular industry field days. FOPS is being used successfully for pears as well as stonefruit in the same SFF group.

Two Fruitfed Supplies personnel from the Hastings branch actively support Rockit. Technical Horticultural Representative (THR) Richard Griffiths has worked with RMS since its inception and is a Rockit grower in his own right. THR Hannah Greaves also assists across the wider Hawke’s Bay plantings of Rockit apples.

“As a Rockit grower himself, Richard’s knowledge with Rockit is hugely helpful. Growing a Rockit apple is all about perfection. You can’t hide any defects in the tube when on sale. Rockit is a slightly challenging apple to grow, impacted by diseases like russet and needing to ensure the shape, size, colour and cosmetic appearance are as close to perfect as we can get.”

For a tiny apple, the returns possible with Rockit apples are significant using a typical 3D tree orchard system. While Todd can’t share exact figures anticipated from the FOPS blocks, he says the returns are projected to be significantly better. 

“That’s why we’ve put in the attention to detail needed to grow great Rockit trees in the FOPS system with the right people doing the right job at the right time.”

¹Article reference: https://www.plantandfood.com/en-nz/article/the-future-orchard.