Although Australia has had a macadamia nut industry for some fifty years it is only recently that the pest control problems in mature orchards have been an issue for growers. In the past, it was common to plant as many trees as could possibly be squeezed onto a block for the best possible returns with a ‘more trees – more value’ approach.
But as the trees have grown older and taller with denser canopies thoughts about row and plant spacings are changing due to problems with pest control, especially in the top of tall canopies.
Similarly, growers are still learning about best practices for managing pests and disease such as lace moth, weevils and husk rot, the latter affecting the nuts as they grow and often leading to heavy losses of the nuts.
Mark Smith is a macadamia grower near Alstonville in northern NSW and the changing character of growing practices, including spray techniques and machinery options, have been interesting him for some time.
He says that, with a macadamia plantation of about eighteen hectares, he is not a large grower but nevertheless it is his main enterprise.
Mark’s trees are over thirty years old and he acquired the property some three or four years after it was originally planted, reflecting the common layout of the time.
“The challenge I faced was getting sprays up into the canopy and especially this season as the industry is facing a pretty sound outlook so strong nut production is an objective at a time of likely good returns”.
Mark sought to replace his original air blast sprayer used for over twenty years with a better performing option and thought he saw what he wanted at the Primex Field Day at Casino NSW earlier in the year.
His persistence led him to local Silvan dealer Ongmac in Lismore where a new Silvan Cannon Jet Sprayer with a 2000 litre capacity spray tank was ordered and has recently been delivered and calibrated by Silvan Regional Sales Manager Ian Davison.
Mark says he was about two weeks late in getting the Silvan sprayer going and the Spring season spray period for lace wing and weevils had already arrived but he was quickly impressed by the results.
He adds, “I wanted to get the spray mist well into the canopy”.
Silvan spraying product specialist David Carr says “as macadamia trees grow taller and broader with age growers need a sprayer with increased air speed and a more directed spray plume than standard air assist units have traditionally provided.
“The Silvan Cannon Jet Sprayer fulfils this objective with a 450mm twin turbine fan that delivers medium volumes of air at a significantly increased speed and directed by the Cannon’s chute up into the tallest canopy of the trees.
“With hydraulic adjustment of the chute angle the airstream can be easily directed into the densest part of the tree where the coverage is essential for maximum pest and disease control.
“The Silvan Cannon Jet is also fitted with adjustable cannon-type nozzles in the top of the chute with three nozzles in a removable panel on the side of the chute for coverage of the lower foliage.
“The adjustable cannon nozzles form a narrow stream of spray which is carried in the airstream from the fan into the canopy.
“Mounted on a 500 litre linkage tank or on trailed spray units from 2000 or 3500 litre tank capacity Silvan’s Cannon Jet Sprayers can be powered by tractors from 80 hp” David Carr adds.
Mark Smith says his spring spraying season can often extend into the early summer months depending on the disease pressure but he feels he is well equipped for whatever the season ahead presents for macadamia growers.
For technical specifications of a Silvan Cannon Jet Sprayer to suit specific requirements email [email protected] or see the website silvan.com.au or call 1300 SILVAN (1300 745 826) for local dealer information.
Silvan representative Ian Davison with Mark Smith at the commissioning of Mark’s new Silvan Cannon Jet Sprayer.
The performance of the Silvan Cannon Jet Sprayer is designed to get spray mists fully into the larger and broader canopy of mature established macadamia trees.