Future Orchard Systems

The ‘Future Orchard Planting Systems’ project has been running for nearly 2 years of an intended 6 years. The project has both government funding from MBIE and funding from Prevar, Pipfruit NZ, Zespri and Summer Fruit NZ. The project makes for complex management but the stakeholders have good relationships.

The project is looking at apples, apricots, cherries and an ‘interspecific pear’ (a new pear variety from Prevar, combining the best of European and Asian pear qualities). Cherry trials started in Central Otago a year ago, a little behind the other trials.

New Zealand already has some of the highest yields for apple production per hectare in the world. The economist driven ‘World Apple Report’ puts NZ yields at an average 60 tonnes per ha – the best 20% here in NZ are doing 80-110 tonnes per ha. So why do we need to do better?

Market demand for New Zealand quality apples is expanding quickly in Asia, driven by lifestyle changes there. The markets are larger than New Zealand can practically supply, especially with its other diverse markets both traditional and emerging (EU and UK, USA, Middle East and Americas). New Zealand provides only a small part of the total apple exports in the world.

Published findings by Plant & Food Research in the early 2000s showed these higher yield conventional orchards are able to use only 55-60% of available sunshine over a season. Calculations that model capture of 90% of radiation in the season’s growing months (between 1^st Sept to end of May) showed the promise of the biological ‘upper limits’ of possible yields in our NZ fruit growing environments was around 170 tonnes/ha.

Dr. Stuart Tustin, Science Group Leader – Fruit Crops Physiology at Plant & Food says “So the big gnarly question was how do we go from 55% to 90%?

They wanted a system that didn’t require more trees due to expense (a tree being about $15 and are currently planted at around 2,000-3,000 required per ha). We are interested in more leaves and apples – not more wood”.

Conventional high intensity orchards presently plant rows 3.5 – 5 metres apart and the trees 1.5m apart. The trees are trained into tall spindle (slim conical Christmas tree shape) shapes. In the Netherlands attempts were made to increase yields by planting more trees in this manner but this resulted in crowding and shading, along with tractor access issues and was deemed a failure in the 1980’s.

PFR researchers saw they needed to bring tree rows closer as the key to increasing light interception, but they also needed to reorganize branching and leaf distribution to capture additional sun without creating shade. Access also remains a vital practical consideration to operate these Future Orchards.

It is important that the quality of the apples be maintained and if possible, increased. And many quality characteristics in apples – red colour coverage, fruit crispness, sugar and acid content, flavour, taste and size of fruit – all depend on adequate light on the fruit itself during the season. So looking to increase the capture of the sun should be a win-win for yield and quality.

The PFR trial has commenced with a number of plots testing 4 key varieties Jazz, Envy, Royal Gala and Fuji:

Prototype 1: Vertical (trees grown in nursery to develop 2 main stems/branches)

1. Trees rows are planted 1.5metres from each other with the actual trees being 3 metres apart. The trees have 2 main cordon limbs from the trunk along the row direction with secondary fruiting stems trained upwards on a trellis (2 Dimensional planar canopy).  This spacing is pushing capacity and spatial considerations to the limits in order to find out the upper limit of light interception.

2. Tree rows are planted 2m apart and trees 3m apart with 2 main branches and all secondary branches trained upwards.

3. The control is trees of the same variety planted next to the trials in standard orchard arrangement as Tall Spindle conical tree at 3.5 m row spacing x 1.5 m spacing between trees

Stuart stresses that these systems are very different and quite claustrophobic for growers used to conventional orchard systems.

To date the results are promising, with these trees requiring less pruning work and picking also being easier, due to the narrow flat canopy of the branches with well-exposed easily seen fruit within arms reach.

Prototype 2: ’Narrow V’ (Trees grafted and grown in nursery for 1 year with 2 main branches closer to ground and bent/trained to slope slightly upwards).

1. The trees are planted in 2m apart rows/trees 3m apart. Trees are trained to grow up a narrow V shape on the frame.

At this stage the trees are only in their second growing season with fruiting wood yet to develop, however they have reported rapid growth in this system. Stuart says they do require work in terms of training so he’s already hoping the vertical system might prove the better.

One improvement already noted by the research is to make the grafts somewhat higher than in this trial to enable the main cordon structure of the trees to be about 0.8 m above ground, a better access for fruit at comfortable working height and to avoid splash contamination from the soil.

Stuart says the new systems “will change everything dramatically – they’re a whole system change” and likely therefore to require re-design of some orchard equipment etc. But this may enable reduced horsepower machinery which could reduce the energy footprint of the orchard systems – a sustainability measure that is important for the future

The setup has also taken into consideration the total costs – they’re working to assure costs are similar to setups of current orchard systems in order to assure bigger yields actually return real profits.

Testing involves calculating the light intercepted by the trees in summer. They calculate and compare with existing data and existing orchards. As fruiting wood develops, apple yields will also be better tested.

Presently only about 30% of current NZ orchards are using the modern intensive tall spindle systems. Many orchards are still using older systems with larger trees and more vigorous rootstocks – these are mainly the older mature orchards 20+ years old. So part of the programme is looking to assure there will be a good take up of results. Partner Pipfruit NZ, has set up Technical Advisory Groups to harness the interest and contribution of leading people and ‘early adopters’ – growers/profitable innovators and marketers. There are around 20 people in 2 groups in Hawkes Bay and Nelson.

The groups meet 3-4 times a year at the research sites and follow the progress of trial plots. Groups are set up so people are encouraged to speak freely to say anything. Stuart says “They see things from a really practical point of view that we don’t always see”. 

“It’s about what is possible in our country, in New Zealand. What is possible for us in terms of productivity and how do we utilize our land, water and in particular sunshine to get the best results we can”.