Next generation macadamia plantation

New macadamia orchard looks forward to the future

On Farm
Grafted macadamia trees going into alluvial soil over beach sand at Wardell where Salts Spray Farm manager Robbie Commens says floodplain production potential is driving investment in this crop.

Grafted macadamia trees going into alluvial soil over beach sand at Wardell where Salts Spray Farm manager Robbie Commens says floodplain production potential is driving investment in this crop.

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Macadamia production is moving beyond boutique by using techniques pioneered in almonds and walnuts.

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Money for macadamias is at an all time high and marketers say the bouyant optimism will continue, considering countries like India have yet to get a taste for the Aussie rainforest nut.

To capitalise on this opportunity new trees are going into the ground at record pace, with a three to five year waiting period for grafted varieties ready for transplanting.

Matthew and Jenny Durack have invested in 200 hectares of sugar cane floodplain country between river and beach at Wardell and have called their emerging venture Salt Spray Farms, and in collaboration with Robbie Commens developed a new macadamia orchard management company 2 Tonne Enterprises, named for their yield goal of two tonnes of saleable kernel per hectare. They are confident the farm is tracking that way, with tree growth data showing the trunk girth tripling in size over the past two very dry years.

Mr Commens was keen to highlight the diversification potential for macadamias on NSW floodplains for existing growers, stating that the orchard crop did not require large hectares to deliver strong returns. Macadamias take four years to produce a crop and pay back their input after a decade but at today's prices the net annual return can be $200,000 for 20ha at 1t/ha (SK/Ha). Mr Commens believes that this unique trait means that macadamias can complement rather than compete with other floodplain crops, particularly those that do require large hectares and scale like sugar cane or beans.

"Growers with 50 or 100ha could diversify a modest area into macadamias, and retain the majority of their farm with their current broad acre crops. Reducing their orchard development costs, maintaining cash flow, improving their capital value and providing risk management for their family property into the future"

To get the good yield requires knowledge, which includes data, and to inspire that program Mr Durack brings to the table a wealth of experience as manager and then owner of Stahman Farms before it was sold to Canadian investors PSP. With that experience he understands the need to incorporate aspects like integrated pest management to create a sustainable enterprise, for mutual benefit ecologically and economically.

He found a suitable manager in Mr Commens, who in his time as production manager with the Australian Macadamia Society was named 2013 Horticulture Australia Young Leader of the Year for helping increase average per-hectare production by more than 15pc. He later coordinated the joint development of the industry book on integrated orchard management and has been fortunate enough to put into practice many of the lessons learnt while touring more than 500 plantations from the Nambucca Valley to Bundaberg, Qld.

The Wardell plantation is called Salt Spray because of its proximity to the beach (500m from the ocean). A freshwater lens 1-1.5m below the surface lying beneath floodplain topsoil is thin - typically just 250mm deep over clay or sand. this arrangement is the key to growing nut trees here although that asset was acutely tested during last year's brittle drought. As a result the farm is planning to trial a 20ha block with irrigation lines to each tree that can also supply soluble fertiliser and lime but Mr Commens is hoping the remainder of the plantation can go continue to prosper without - after all that is the benefit of floodplain farming.

" The unique aspect of the floodplain orchard farming system is that we have this huge resource of fresh groundwater sitting just below the surface, and with that the trees have a smaller root ball which helps limit the size of the canopy (root:shoot ratio) whilst rarely going into moisture stress (because the roots tap into the high water table) which combines to create higher production from smaller trees," he says.

When trees need an occasional watering the job has been made more efficient with a combination of Trimble GPS navigation, into which every tree is mapped, and some clever work in electronics to allow a watering trailer to automatically deliver eight to 10 litres to the root zone of each tree. The same technology is used to apply foliar spray.

In fact the whole farm is mapped in three dimensions which initially allowed accurate drainage on slopes with just one per cent fall in the rows.

Terrific gains have been made in the industry by adopting integrated pest management, using diverse pasture in the inter-rows to harbour the good bugs which retreat to the canopy of trees after a side throwing slasher moves through the area.

Owner Mr Durack experienced the commercial benefits from moving away from a reactive spray based pest management system to a fully Integrated Pest Management (IPM) program while owner manager of Trewalla pecan orchard at Biniguy near Moree. He was keen to utilise the same approach on the new commercial scaled macadamia orchard in Wardell.

Pollination pattern

An important area of innovation is the way two varieties of macadamia trees have been planted, with one row of 344 variety followed by the next row planted with 246, another old Hawaiian variety, planted in every third spot. The resulting patterns enables each tree to have direct line of sight to another variety to maximise pollination.

"In my time with the Australian Macadamia Society (AMS) I saw well managed farms with only one variety producing average yields while less capably managed farms shotgun planted with different varieties and were winning awards for their yield," said Mr Commens. And this was supported by research data that New Zealand based entomologist Dr Brad Howlett identified from recent research trials on macadamia pollination across the Australian industry.

Unlike Almonds or Pistachios Macadamia trees do not need another variety to produce nuts however research indicates that cross pollination can increase yield by as much as 15-20pc. While small scale trials have produced this increase, no one has yet trialed this thinking on macadamias on a large scale until now.

"Bees don't fly down rows by variety, the research suggests they come in and work an area and then return to the hive," said Mr Commens. "We planned our orchard layout to compliment this pollinator characteristic, and have made it is easy as possible for the pollinators (native bees and honeybees) to transfer pollen from one variety to another. Basically, we realised we couldn't change their flight paths, so we placed the different airports directly around each other to help get the same result."

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