Twenty reasons to consider planting walnut trees

Harold Adem, Department of Primary Industries Walnut Industries Development Manager and Bas van den Ende, Advanced Horticulture, Consultant

One of the ongoing challenges facing the tree fruit industry is for orchardists to operate profitably. Drought, high water prices, climate change, spring frosts and hail, high retail and export standards, high cost of production, the high Australian dollar leading to cheaper imports and more costly exports, cannery quotas and intake reductions of fruit are just some of the issues confronting orchardists.

History has shown that orchardists are enterprising and willing to trial crops other than the traditional apples, pears, peaches, plums and cherries. While some exotic crops, such as nashi pears and pomegranates may benefit the most tenacious of growers, orchardists might consider growing walnuts, which offer a multitude of benefits. For more than 150 years, walnuts have been grown successfully in southern Australia. Walnuts do not require pickers or a trellis system, are not prone to frost damage, do not need netting, are not perishable and do not need to be cool stored.

Here are twenty reasons why growing walnuts could be a positive endeavour:

1.	Present projections of costs and returns indicate that walnuts will have a positive cash flow five years after planting.
2.	The cost of trees is about the same as trees of any licensed fruit variety.
3.	Walnut trees are free-standing – no trellis is required. Staking young trees may be required in areas that are not protected from strong winds.
4.	Excellent varieties on precocity-inducing rootstocks are now available in Australia.
5.	Densities of between 500 (5mx4m) and 660 (5mx3m) trees/hectare are possible to induce early precocity and obtain high yields.
6.	The ‘central leader’ system of growing walnuts permits a uniform tree complexity, high light interception per hectare, and good light distribution throughout the canopy for sustained production.
7.	Medium to light-textured soils, such as the duplex soils in the Goulburn Valley are suitable and will provide some vigour control. Hilling-up of topsoil is required for surface drainage and good soil structure.
8.	Inducing branching, general vigour control, and maintaining fruitfulness similar to fruit trees has already been researched and can be implemented.
9.	Advice is available on how to manage a high density walnut planting and how to increase precocity without the use of a size-controlling rootstock.
10.	There is minimal risk of frost damage to flowers and nuts, because walnut trees bloom in late November.
11.	No honeybees are required, because walnuts are wind pollinated by polliniser trees.
12.	Walnuts are mechanically harvested and processed.
13.	A factory to process walnuts has been established in Violet Town in north-central Victoria.
14.	Mature walnut trees under micro-irrigation need approximately 6 megalitres of water per hectare.
15.	Pest and disease pressures of walnut trees are much less than for fruit trees.
16.	Walnuts are not affected by fruit fly quarantine regulations.
17.	Walnuts in shell have a long storage life.
18.	Walnuts have health and cosmetic properties.
19.	Walnuts have excellent export potential.
20.	The wood of walnut trees also has commercial value.

For more information, contact Harold Adem, Industry Development Manager, Australian Walnut Industry Association Inc., Department of Primary Industries Tatura Centre, Victoria, email: harold.adem@dpi.vic.gov.au or phone: (03) 5833 5218.