Plants are nourished by applications of rock dust, which is a quarry by-product that has seen an enormous increase in use recently. Boral Ltd. and Cemex Ltd. are two companies amongst a host of other quarries and value-adding agri-products companies that supply the rock dust/crusher dust. Unlike conventional applications of synthetic fertilisers, the dust provides long-term nutrition and as it has low water-solubility does not cause sudden and irreversible changes in plant physiology.

Chicken litter is also used to provide natural forms of phosphorous and organic matter. The chicken litter and rock dust are composted together with the micro-organisms in the chicken litter chelating the minerals in the rock dust to form a highly desirable fertiliser.

Fish emulsion, kelp, zinc sulphate, and borax are also used at appropriate times to enhance plant growth, health and crop yields.

The cost of fertilisers is significantly lower than that of most conventional orchards.

The area in which Wodonga Park is located has a relatively low incidence of attack from insects as the trees are in good health and generously fertilised with highly paramagnetic crusher dust and therefore not really prone to insect attack.

As the climate is cooler and the elevation (600m) higher than most macadamia nut producing areas (e.g. NSW North Coast) the shells are slightly thicker thereby naturally minimising damage by insects. The percentage of macadamias which are unsaleable (2003) was just 2.36% of the total harvest in a year when many other producers had problems with immature or damaged kernels.

Pest management involves the following strategies:

• The most important strategy is to have healthy plants as they are unattractive to insects. Plants grown with salt-based synthetic fertilisers have poor root development and an unhealthy canopy due to an osmotic imbalance and therefore attract insects and sustain damage. These trees show a high incidence of Phytophthora and other fungal & insect damage as water soluble fertilisers are taken up with irrigation water and not, as would normally be the case, through the roots releasing acids to make nutrients available. Wodonga Park trees are given highly mineralised fertilisers that do not create imbalances or stunt root development; release of beneficial insects to control populations of harmful species;

• application of yoghurt/molasses sprays to combat fungal attack and anthracnose (The latter can be a large economic burden if not properly managed);

• use of naturally occurring plant extracts (e.g. garlic) mixed with selected oils to control insects at critical times or when populations of insects necessitate its use;

• Biodynamic preparations such as silica-based 501 to control botrytis and fungal attack;

• Biodynamic potentised ash preparations to deter harmful insects;

• Prudent use of water and fertilisers to ensure that phytophthora does not become a problem (so far Wodonga Park is unaffected); and

• use of paramagnetic rock dust acts to deter insects.