Apples and Pears (Malus domestica, Pyrus communis)

Braeburn apples displayed for sale
Braeburn apples displayed for sale
How well established is this crop?

This crop has been grown commercially in the region for at least 50 years. Commercial returns, current growers and some level of regional based research is available to help those new to this industry.

Background

Apples and Pears were one of the earliest of fruit varieties brought to New Zealand by European settlers. Since that time they have become one of the leading horticultural export earners from this country. Until 1992 all pipfruit sales were controlled by the Apple and Pear Marketing Board and more recently as ENZA. This was a grower owned body that was responsible for selling all of this countrys crop. In the last few years this changed and now anyone can export their own fruit. This has led to some cases of New Zealand sellers under-cutting other New Zealand sellers in the international market and a reduction in returns to some growers. Others are thriving. The industry is currently facing lower returns.

Winter Chilling and Frosts

Frosts do not directly affect the tree unless it is flowering. Flowering usually happens in the middle to end of October, a period that is characterised by frosts. The young fruit are susceptible to this frost and can all be killed if the temperature drops below 0 degrees C. Traditional methods of frost control such as smoke pots have been surpassed by over-head sprinkler frost fighting and now in some cases wind machines.

Rainfall and Irrigation

Irrigation is essential in apple and pear growing districts. Most growers use a combination of under-tree mini-sprinklers for irrigation, and overhead sprinklers for frost protection. Use 1 mini-sprinkler between 2 trees, with overheads spaced 20m apart and 20m between rows, which is every 4th row.

Wind

Even though apples and pears grow into large trees, they still benefit from some wind protection, especially when they are young. It reduces the chance of bruising on the fruit and reduces the drying effects of wind over the summer period.

Most blocks rely on natural tree shelters. 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 shelter trees that are 10m high you will need shelters 10m x 10 = every 100m.

Soil

Both apples and pears prefer a well drained soil with a good moisture holding capacity. Pears can tolerate slightly heavier soils if necessary but good drainage is important.

Fertility

Apples and pears require reasonable levels of soil fertility as they tend to be cropped quite hard. Regular soil and foliage tests will quickly identify any deficiencies and these can be easily corrected with the addition of fertiliser. Companies such as Hills Laboratories have a datasheet with the recommended soil and leaf nutrient levels for this crop. See the ‘Contacts’ section at the end of this datasheet.

Weed Control

Weed control in apple and pear blocks tends to be quite straightforward. When young trees are planted, plastic spray-guards are put around the trunks. This prevents rabbit damage and allows herbicides to be sprayed right up to the tree. Weeds growing up inside these guards are removed by hand. As the trees mature the bark on the trunk hardens and herbicides can be sprayed on them with no damage to the tree.

If growing organically, straw mulches, specialist low growing plants and mowing are used to control weed growth around the bottom of the trees.

Varieties

A large range of apple varieties are available to the new grower. Pacific Rose, Gala, Royal Gala and Fuji would be the most common in Otago. Braeburn is loosing support amongst local growers as it is prone to a flesh browning disorder, BBD (Braeburn Browning Disorder). This only affects Braeburn grown in Otago and seems to be caused by environmental conditions.

The most common pear varieties at the moment include Winter Nellis, Buerre bose. Doyerre de comice.

HortResearch has an active apple and pear breeding programme, and is producing new varieties that can be grown organically and are resistant/tolerant of a range of common pests and diseases.
New varieties such as Jaze are fiving growers good returns in a competitive marketplace.

Pests and Diseases

Apples and pears suffer from a range of insect and fungal pathogens. Research work in Otago has shown that these can be managed by either organic principles or using agrichemicals. The insects include leafrollers, codling moth, leaf curling midge, mites, and scale. Pears are also susceptible to pear slugs. The disease pathogens include black-spot, powdery mildew, fireblight and a range of storage rots.

Layout

Most apple and pear blocks are planted on a reasonably large scale and allow for tractor access between rows. This is usually 4.5 - 5.0m. Spacing within the row depends on which rootstock the trees are planted on. It could be anywhere from 1m for a plant on an M9 stock to 3.5m for a M793 stock. Rootstocks are always used in pipfruit orchards. Scion wood grafted onto a rootstock ensures all trees are genetically the same.

General Management

Ground preparation is the key to developing an apricot block. Irrigation installation and any drainage work is completed in the period before planting. Trees are delivered from the specialist nursery ‘bare-rooted' in bundles of approximately 10 trees. These are usually ‘heeled in’ meaning the roots are covered with soil or sawdust until they can be planted. Tree rows are usually ripped with a deep blade to free up the soil. Holes are dug and the trees planted, usually with the graft union pointing into the direction of the prevailing wind to give the tree more strength as it grows. Weed control using herbicides, mowing, spraying and irrigation are needed from this time. Some pruning and tree shaping is also done, generally in the winter. The traditional shape for a mature tree was the vase shape. However, more recently training the tree into a centre leader has become popular. It is important to seal the cuts made at pruning with a fungicide/bacterial spore killer as the trees are susceptible to infection through these wounds. Fruit is generally removed from the tree in the first two seasons to ensure as much vegetative growth as possible. After flowering the tree is generally thinned to a standard number of fruit. If this is not done the tree will produce a lot of small fruit.

Harvest

Harvesting commences when the starch in the fruit is converted to sugar. The levels of this depend on which variety is being grown. Picking is done by hand with care being taken not to bruise the fruit. They are placed in large bins in the orchard before being taken to the packhouse for processing.

Equipment

Because most blocks of apples and pears are planted on a reasonable scale, a tractor is required along with spray units, mowers, forks for transporting bins and maybe a truck to get fruit to a packhouse.

Returns

Returns are usually quoted on a 18kg box basis in the export market. However it does depend on the variety, the year and other factors such as the value of the New Zealand dollar.

Contacts

If you are thinking of growing apples or pears, talk to some local growers and look at the following website.

For fertility information www.hill-laboratories.com
www.hortnet.co.nz/publications/guides/fertmanual/pip.htm
www.nzpipfruit.co.nz
www.pgnzi.co.nz