Hazelnuts

Quite aside from providing almost one quarter of the wine in Australia, our region is renowned for its production of nuts, particularly walnuts, almonds and hazelnuts.

Hazelnuts are an emerging crop in Australia, and as commercial plantings become more popular it is important for growers to have an understanding of threats to production. Current Australian production is small and is estimated at 60 tonnes. Research undertaken by the NSW Department of Primary Industries suggests that major biological threats to hazelnut production include the Hazelnut aphid, Green peach aphid, White fringed weevil, Pachydissus sp. and Plum scale. The weevil Aades cultratus is also of concern, particularly causing damage to damage to mature plantings.

The Hazelnut aphid is a common pest in most hazelnut producing areas in Australia, and occurs with fluctuating populations. Damage is caused to the underside of young expanding leaves throughout spring to early summer and a final generation appears in autumn. Populations decrease with higher temperatures in mid-summer. The long-term effect of high aphid population has not been quantified, but reduction of nut size and fill has been reported. It’s recommended that to combat the aphid fertiliser should be avoided, as succulent young growth can encourage higher aphid populations. Water shoots should also be pruned out where possible.

Another threat to production comes with feathers. Bird damage to hazelnut orchards includes pruning of foliage and buds, ringbarking of trees, and cracking and eating of hazelnuts. Sulphur-crested cockatoos, galahs, little corellas and long-billed corellas are the main bird pests to the nut industry. Other species cause damage to growing tips, buds, and mature fruit. These include crows and ravens, and a variety of rosellas and parrots. In 2006 national survey by NSW Department of Primary Industries found bird damage was found higher in nuts than any other horticulture industry, with average reported bird damage found to be 22.5%. There are also further costs associated with management, and opportunity costs, where growers are reluctant to grow nuts because of bird damage.

Management of birds who damage crops is more complicated that just killing them. The NSW Department of Primary Industries recommends that growers:

• Identify the bird species that is causing the destruction.
• Estimate the damage caused to production.
• Consider legal, social and environmental issues.
• Develop the most appropriate bird management plan (e.g. scaring the birds via sound sight or movement, attracting birds of prey, netting, chemical deterrents, etc.)
• Decide when the most cost-effective time is to implement a pest management plan
• Monitoring and evaluating.

• Topics:

• Rural Roundup