Pest and disease control

Potential pathogens including Rhizoctonia spp., Fusarium spp. and Pythium spp. can destroy young plants. Although soil fumigation and chemical treatments are available, the majority of Australian growers prefer organic methods. Growers should be mindful that chemical treatments have the potential to leave residue on the roots, causing a reduction in market price. More importantly, natural therapies should not contain synthetic substances.

Intensive planting in a monoculture garden can leave plants weak and more susceptible to disease. Less-intensive plantings generally allow better air circulation and reduce the risk of foliar transfer of fungal problems.

With about 70% of gardens in virgin bush soil where beneficial fungi appears to provide the appropriate mycorrhizal action required for healthy growth, there is little evidence of fungal disease being a major hurdle in Australia. Similarly, forest-floor gardens have not yet experienced any problems with pests.

Trials in previously cultivated or grazed soils have not been as trouble free. Various treatments have been applied to infestations of reticulate slugs (Deroceras reticulatum), cockchafers (Adoryphorus couloni and Aphodius spp.), chevron cutworm (Diarsia intermixta) and corbies (Oncopera spp.), with mixed success. Rather than straw, "scratchy'' mulches such as rice hulls mixed with coarse sawdust can be a deterrent, especially for slugs.

Animals such as possums, rabbits, kangaroos, wallabies and wombats are deterred by fencing. Growers with severe possum attack find it necessary to protect all plantings with small-mesh wire enclosures or fully enclosed shade structures. Protecting ripe berries with netting prevents parrots from destroying seed production. Anchoring wire mesh firmly across the surface of planted areas prevents lyre bird problems.

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