A multi leader ‘quad stem’ tree with four leaders has been adopted by a Goulburn Valley pome fruit grower as a way of improving fruit quality and consistency now, and also setting up the orchard for the future.

Manager of Plunkett Orchards, Jason Shields says the orchard has been gradually changing over to the fruiting wall system on each of its 2200 trees to harness the efficiencies of mechanisation and simplify orchard management.

He has found numerous advantages in the single plane ‘fruiting wall’ design, from simplifying orchard management tasks like pruning, thinning and picking to better quality fruit from more uniform ripening and improved fruit colour.

All the fruit on the fruiting wall is even and consistent in colour and ripeness. 

Long term, he says reduced labour costs and better marketability will offset any up-front costs in mechanisation and any minor yield penalties from the single plane design.

Mr Shields said while the initial cost of a double leader tree works out at about 25% more expensive, it replaces four conventional trees, and this also results in a saving in royalties.

Double leader nursery trees are trained to produce four leaders and Mr Shields finds getting trees at this stage enables them to grow more consistently and be a year in front compared to cutting a tree down to match Tatura other V shaped trellis systems.

Plunkett Orchards are set up on a 3m row width with a 1.5m tree spacing. This produces a dense fruiting wall system which has the advantages of better light penetration and ease of access to the tree for management and picking.

“You can get at both sides of the tree to utilise all mechanical aids and when you are spraying you reach every branch and achieve better coverage,” Mr Shields said.

“With a V system you can only get to the outside and all the growth where we want to defoliate, or prune is on the inside and has to be done by hand. One person can get across a lot of area with a machine that it used to require a big bulk of people to do.”

Mr Shields has gradually introduced mechanisation to all orchard operations, from self-propelled orchard platforms to mechanical pruning and thinning equipment and says the labour savings are obvious with the simplified tree architecture.

“Because you don’t have that excess layer of branches and foliage you can go through the orchard with a defoliator or a saw and lighten up the tree and cover 2ha a day with one person, compared to about 0.1ha day by hand.”

“We may be compromising yield by 10–15% compared to a V structure but you can get greater efficiencies from harvesting platforms and tractors that more than offset the lost yields per ha.

“We’re not there to set record yields. We aim to grow better fruit at a cost-effective price to get the best return on investment.

“Some growers might be achieving 15t more per hectare but it’s costing them more per bin to do that. Our solution is to just plant 20% more trees over a wider area as our cost structure is lower, so we can get better return which is also easy and simple to manage.”

Mr Shields said the four-leader system was used to control tree vigour and set up the tree for productive fruiting. “With one leader you get around 1m growth year. With two leaders the growth is more like 60cm, three leaders 40cm and four leaders even less, which is a form of vigour control.

“We aim to keep it narrow and simple with nothing longer than ‘secateur length’ (i.e. 20cm) so we can easily manage the tree throughout the year, and it makes picking that much easier.

“Fourth leaf trees are the oldest crop we have on this system. The light penetration is better, we get good light from both sides and in the first week of harvest we picked at 100% colour.

“All the fruit on the fruiting wall is even and consistent. There’s not apples in the sun in some spots and apples in shade in others, we have a nice even canopy.”

This helps Plunkett Orchards meet market demand for quality, quantity and consistency of specification which also simplifies packhouse operations.

A fruiting wall at Plunkett Orchards after mechanical pruning. 

“We train people and then send them into strip pick the fruit. With this system it’s very easy to train them to do the work. This tree design sets it up for mechanical harvesting. You don’t end up with a dense tree at the bottom and thin at top, you have a nice consistent fruiting wall top and bottom.

“That wall of fruit also lends itself to any type of mechanisation, like work platforms or even automation like robotics when it comes.

“After harvest, we mechanically pre-prune to set the wall to the length of the shoots we want. The sickle bar pruner does make some ugly cuts. But then the pruner can see what’s left and if it’s too big they can more easily cut it back to form small fruiting units with nice buds to grow fruit.”

Mr Shields said mechanisation was a ‘game changer’ when it comes to simplifying a whole range of labour-intensive orchard operations and in achieving better fruit quality.

“We use a pneumatic air shear nozzle fitted to one of our Red Pulse machines that shears the leaves off to expose the fruit to enhance light penetration and the colour of the fruit.

“We are eliminating a lot of variables. It enables us to open up our workforce. We no longer need just big strong people carrying a picking bag up and down a ladder. Small and nimble pickers, including more females are able to pick and might be better than someone who rushes and damages the fruit in traditional picking systems.”

But it’s not just picking where aids like specialised harvest platforms are improving the overall efficiency of operations. Mr Shields said they’re nearly more efficient in non-picking times.

“We’re using machines like our Revo Piuma harvest platforms all the time – probably 45 weeks all up, including a 12–16-week harvest window across our Pink Lady’s, Granny Smith’s and Royal Gala apples and also our pears. Then there’s all winter, pruning and tree training and then thinning.

“We run 12 machines ourselves and have totally retrofitted our four farms to a system where we can run the machines and there’s now only one block left on a vase system. And if we set the farm up ready for mechanisation now, it’s ready for robots in the future.

“We’ve retrofitted every other system that we’ve replanted in the last 20 years to make it work. We now use all our mechanical aids in every system we have that is trellised.

“Sometimes we have to sacrifice a bit of yield to make the canopy narrower or lower, but we don’t need to be reliant on such highly skilled labour and get into a bidding war with contractors.

“We make the whole orchard system simple, so we can employ anyone and we’re not fighting over the same people to get our crop off. Not only that but the so-called ‘better’ pickers might be rough on fruit.

“We don’t want them to work ‘fast’ as such, but with a harvest platform, they can’t be slow either as it all flows swiftly and evenly. Everything is in front of you whether picking or pruning. You don’t have to think or reach or climb to do it, the trees are set up so it’s all there within easy reach off the platform.”

Mr Shields estimates his costs per bin are about 40% lower than traditional picking systems, but said some growers were concerned about costs or sitting out waiting to see the next ‘big thing’ such as robotics.

“I’ve had growers ask me about mechanisation and say it is expensive, but then turning around and letting their crop drop on the ground because can’t get pickers, so how much has it really cost them when you consider the lost income and inefficiencies of hand labour?

“I think in two- or three-years’ time they’ll be back to buy a machine as they won’t have any pickers to pick it,” he said.