Chestnuts (Castanea sativa)

How well established is this crop?

This crop is a relatively new crop. It has been grown commercially for 5-10 years. Commercial returns, current growers and some level of regional based research may be available to help those new to this industry.

Background

Commercial chestnut orchards have been established in New Zealand for many years with nut exports being made to Japan, Australia and Singapore. As you cannot store Chestnuts like other nuts such as Hazelnuts, they are treated as a fresh perishable product. They have a shelf life and our season corresponds to the off season in the Northern Hemisphere.

New Zealand nuts are also perceived as being of a large size and excellent quality. As volumes increase growers are looking to develop a range of products instead of just exporting fresh nuts.

Climate

In general the more humid conditions found in the North Island produce a bigger tree and final nut. However humidity also increases the chance of getting root rot and other diseases in the tree.

Winter Chilling and Frosts

Frosts are generally not a concern to chestnut trees as they flower late in the spring. Care must be taken with early autumn frosts, as these can affect both foliage and fruit.

Rainfall and Irrigation

Chestnut trees do use a lot of water especially near harvest as they are filling out the nuts. In coastal Otago the natural rainfall may be enough. In the drier inland areas, supplementary irrigation may be needed.

Wind

Even though they are a tree, Chestnuts do benefit from shelter. Trees will even fruit in coastal Southland provided they are sheltered from the wind.

A good rule of thumb when designing shelter is to multiply the final height of the shelter by 10. Use that measurement as the distance you position your shelters apart. For example, when using a 6m high tree species for shelter, you will need shelters every 60m.

Make sure the shelters running east-west are deciduous. This will allow sunlight into the blocks in the winter. Position all shelters at right angles to the prevailing winds. Talk to your local nurserymen when deciding on the right tree type for your property. They may also be able to help with design.

Soil

Chestnuts like a light free draining soil. They will not tolerate periods of waterlogging.

Fertility

No specific research has been done on this crop in New Zealand but it is expected that good general fertility will lead to good nut yields

Weed Control

Weed control under trees is essential to allow nut pickup. Grass in the rows is usually mowed. Be very careful if you are thinking of grazing between the trees. Sheep will and do eat the bark from around trees. This kills the tree by ring-barking it.

Varieties

Most plantings currently in the ground in New Zealand consist of a range of local selections such as Waikato 1002, 1005 and 1015. See the contacts section at the end of this document to get in touch with the local member of the Tree Crops Association. They will have up to date information regarding varieties.

Pests and Diseases

The main disease of chestnut trees in New Zealand is caused by Phomopsis castanea. This causes nut rots of chestnut in both Australia and New Zealand. The pathogen is endophytic within otherwise healthy trees and the disease is less of a problem in some regions of New Zealand than in others. Otago trees appear free of this disease at present.

Layout

Usual spacing is around 5m x 5m, although some growers are using a wider spacing of 8m x 8m

General Management

After planting there is a range of task required on a Chestnut block. This includes mowing, weeding, spraying, irrigation, fertiliser applications and maintenance pruning.

Harvest

Because most plantings are on a reasonably small scale, nuts are harvested form the ground manually. A pair of gloves to prevent being pricked is all that is required. After harvest the nuts must be chilled for fresh sale or processed, dried etc reasonably quickly.

Equipment

Basic gardening equipment such as a mower, weed sprayer etc is all that is needed for most chestnut plantings.

Returns

A grower reported recently that returns for his crop were around $2.80/kg in-shell.

Adding value by drying, crumbing or making into other value added products will significantly add to the income.



Contacts

The New Zealand Chestnut Council can be reached on this link http://www.nzcc.org.nz/

Local growers of Chestnuts will be able to be contacted through www.treecrops.org.nz

Kiwi Chestnut Cooperative 07 8263 648
Growing Today Magazine January 2005 Edition

Trees can be sourced from
Linda Gardener, Quality Tree Company Phone 03 344 1977:
Allenton Nurseries Ltd, Number 6RD, Ashburton, 03 308 5875