Organic macadamias - a viable option
From the May 2008 edition of Agriculture Today.
In the Australian macadamia industry, production philosophies range from conventional systems with little or no integrated pest management, through to certified organic production systems.
Cath Ford of Rosebank in the Northern Rivers of NSW is produces certified organic macadamias.
Cath’s farm includes 7000 macadamia trees between six months and 30 years of age as well as 12,000 mature coffee plants which are also organically grown.
This enthusiasm for organic production seems to be rubbing off on the neighbours, with many of the adjoining macadamia farms either certified organic or in conversion.
Cath believes that growing macadamias organically is not only a fine example of a sustainable and environmentally friendly agricultural system, but economically viable as well.
The financial rewards are particularly evident in the midst of the present industry downturn; Cath’s certified organic product is fetching almost twice the farm-gate price of conventionally grown macadamias.
Cath collaborates with other organic macadamia growers by pooling nut consignments to improve the economics of contract batch processing.
The majority of their organic macadamia kernel is then exported to markets such as Japan.
Cultivar selection seems to be one of the most important decisions for organic growers, because susceptibility to pests and diseases varies so much.
Cultivars unsuited to organic production have thin shells, making them particularly prone to insect damage, or have nuts that remain on the tree late into the season, allowing infection of the follow on crop with the fungal disease husk spot.
Unfortunately, there are no biological controls available for fruit spotting bug, another of the major insect pests of macadamia, so organic growers must rely on sound cultivar selection and cultural practices that encourage natural enemies.
Biological control of one of the major insect pests, macadamia nut borer, is available through commercially reared parasitic wasps.
Cath believes that growers who used biological control for macadamia nut borer this season had an advantage over those reliant on pesticides, because excessively wet weather in the Northern Rivers hampered spraying.
