Blueberries

Overview

The foundations for New Zealand’s fresh blueberry export industry were laid during the 1970s. Blueberry cultivars were imported from the United States for field evaluation by the Ministry of Agriculture and Fisheries. The best-performing cultivars were subsequently released for commercial production.

New Zealand-bred cultivars have lengthened the harvest season by up to six weeks. This has helped New Zealand producers to obtain premiums for early and late season fruit in the fresh export markets.

Blueberries are classified into three major commercial types according to their stature:

  • rabbiteye blueberry, Vaccinium virgatum is the tallest;
  • highbush blueberry, V. corymbosum, is intermediate size, and the most common; it includes southern highbush and northern highbush; and
  • lowbush blueberry, V. angustifolium, the smallest in size.

The two main types of blueberry grown in New Zealand are:

  • Highbush – native to the north-eastern areas of the United States. These make up most of the early plantings in New Zealand. They are the earliest berries to ripen, and with the addition of NZ-bred cultivars can start fruiting from mid-November and continue through to mid-February. This requires a mix of cultivars. The bushes are deciduous and can grow to six metres high if unpruned.
  • Rabbiteye – native to the south-eastern United States. The rabbiteye bush differs in several ways from the high bush: they are evergreen, more vigorous, and yields are usually higher. In New Zealand these, together with NZ-bred cultivars, make up the main producer of late season fruit, starting production early January and continuing to mid-April.

Around 700 hectares of blueberry crops are now grown in New Zealand, with about 25 commercial growers and another 50 part-time growers [1] producing around 3900 tonnes of blueberries in 2016.[2]

Worldwide production in 2014 was over 525,000 tonnes and valued at more than US$1 billion, with the United States and Canada being the main producers.

[1] ‘Jumbo blueberry to boost NZ industry by $8m in two years’, NZ Farmer, February 2017 (http://www.stuff.co.nz/business/farming/89250609/Jumbo-blueberry-to-boost-NZ-industry-by-8m-in-two-years)
[2] Fresh Facts 2016, Plant and Food Research (http://www.freshfacts.co.nz/files/freshfacts-2016.pdf)

Markets

Blueberries are known to possess a range of healthy properties. They contain higher antioxidant levels than just about every other fruit and vegetable. It appears the blue pigment, anthocyanin, is the major contributor to its high antioxidant levels.

Antioxidants prevent cell damage that occurs from everyday wear and tear. It is believed a diet high in antioxidants helps avoid such health problems as cancers and heart disease, as well as promoting good eyesight, urinary tract health and brain function.

Blueberries are available in a range of products including fresh fruit or frozen, fruit juice, powder, wine, jams, sauces, chutneys and of course muffins, with products available from growers, at grower markets, through supermarkets and retail outlets and online.

The majority of New Zealand blueberry value is derived from exports of fresh fruit or individually quick frozen (IQF) fruit at around $40 million compared with domestic sales of around $18 million [1].

The quantity of total blueberry exports (including fresh and IQF) has increased by 82 percent over the seven years to 2016. At the same time, the value of the exports increased by 114 percent. Fresh exports constitute approximately 80 percent of exports by weight, and IQF approximately 20 percent.

New Zealand’s distance from overseas markets mean that fresh blueberries need to be air-freighted, putting New Zealand at a price-disadvantage in those markets.

Predictions are that the export industry could be worth more than $60m by 2022. New Zealand’s top ten blueberry export markets for 2016 were:

[1] Fresh Facts 2016, Plant and Food Research

Production

When planning to establish a blueberry orchard, careful consideration needs to be paid to the selection of the site, the varieties of blueberry to plant, the source and quality of water available, harvesting, including the picking labour source, marketing and distribution channels.

Site selection and preparation

Blueberries require acid well-drained soils with an organic content of at least 3 percent and a pH of 4.0 to 5.5. The optimum pH is considered to be about 4.8. Soils with a natural pH of above 5.5 are difficult to adapt to blueberry growing and should be avoided. On the other hand, cultivated land that has been limed in the past may have an artificially high pH, which can be lowered by adding sulphur. As sulphur takes a considerable time to break down and adjust the pH, this should be done at least six months before planting.

Low-lying areas with a high water table are not recommended. Blueberries do not tolerate standing water or grow well in excessively wet areas.

Varieties

Blueberry types differ by way of their winter chilling requirement, fruiting season and deciduous or evergreen habit, thus it is important for growers to select species suited to their particular climate. Proper selection of varieties will have a large influence on the profitability of the blueberry operation.

Firstly, find out which cultivars are suited to local climate and winter chilling requirements, and then decide on the market being produced for.

Chill hours

Temperatures at or below 7°C are required to provide winter chilling.

  • Highbush blueberry varieties include southern highbush, which requires a moderate-to-low (below 700 hours) amount of winter chilling, and northern highbush, which requires a high winter chilling (over 1000 hours).
  • Rabbiteye varieties require a moderate amount of chilling (400–700 hours). Some of the variety releases from the Plant & Food Research blueberry breeding programme also require moderate to lower chilling.

Rabbiteye production in New Zealand has expanded in recent years, largely because of the ability of this species to crop late in the season (February–early April). Rabbiteye blueberries can be grown in most localities, but require temperatures of 20–25°C in late summer to fully ripen the berries. Rabbiteye plants require cross-pollination, so two or more varieties are required.

Bumblebees are considered the most efficient pollinators of blueberries.

Market selection

It is important to decide on the market that is going to be produced for. Local nurseries may be able to advise on this.

  • Early fresh market (November to mid-December, generally good export prices). Cultivars could include Nui, Reka, Sunset Blue, Puru, Misty, Oneal, Marinba and/or Early Blue.
  • Mid-season (mid-December to end of January, export/local fresh market/pick your own; lower prices. Easy to get pickers during school holidays). Cultivars could include Blue Crop, Duke, Toro, Dixi and/or Tifblue.
  • Mid-season process market (mid-December to end of January, low prices). Cultivars could include Jersey, Atlantic, Dixi and/or A9.
  • Late fresh market (February to mid-April, good export prices). Cultivars could include Elliot, Maru, Rahi, Powder Blue, Tifblue, Centurion, Southland, Ono, Delite, Whetu and/or Centra Blue.
Irrigation

Blueberry plants require 25–50 mm water per week during the growing season. Newly established plants have the most critical water needs and can be damaged by either over or under watering. Short periods (one to three weeks) without rain can stress plants severely. Trickle irrigation is the most common system that growers use. The recommended rate is 35–50 litres per plant per week. Water requirements increase as the plants age and grow and vary due to soil type, organic matter available and natural climate conditions.

Purchasing plants

Plants are usually ordered from nurseries during October to be propagated during the summer from softwood cuttings. These are supplied to the grower the following May to July as small plants in 25 x 25 pots (tubes). They need to be potted up into PB 5 planter bags or grown in beds the following summer before being planted out in the field the next autumn/winter. These are then considered to be two-year-old plants. Some nurseries will supply two-year-old plants if required.

Plant spacing

Highbush should be spaced up to 1.2 m apart within rows, and rabbiteye up to 2.0 m apart as they are more vigorous. Rows should be 3.0–3.6 m apart to allow room for mowers/sprayers to be used in a mature planting. Most highbush plants are self-fertile so can be planted up in larger blocks of a single cultivar. A density of 1.5 x 3.6 m provides for 1876 plants per hectare.

Production

After planting in the field as two-year-old plants, all the flower buds should be removed for the first two seasons to help the plants become established. The third season, the plant should be allowed to carry a small crop. Production will double every year until the plant reaches maturity, and will then be subject to the various seasonal influences. A mature block can produce in excess of 10,000 kg per hectare.

Timetable
  • 1st year – October order plants
  • 2nd year – May/June pick up plants, pot up or plant in beds during winter, make adjustments to soil in the orchard if required (pH, organic matter), drain as required
  • 3rd year – cultivate rows, plant out plants, install irrigation if required, remove fruit buds
  • 4th year – remove fruit buds
  • 5th year – remove most of the fruit buds to allow the plants to carry a small crop. Make arrangements to pack/market the produce.

Infrastructure

The amount of infrastructure required depends on the scale being sought, the area available and the degree of sophistication that will be implemented in the orchard.

A small operation may be set up on one or two hectares with mowing and spraying equipment and a shed for packing and selling to the local market and perhaps to an exporter. A large operation may be set up on 50 hectares, fully enclosed with bird netting, harvesting machinery, grading and packing facilities, with its own exporting arm.

Specialist harvest machinery may be needed. Harvesting machinery is often used to pick fruit destined for processing. Hand-picking fruit ensures top-quality fruit is selected, however labour can be one of the biggest cost centres.

Not all infrastructure is required immediately. Bird netting, harvesting and grading machinery may not be required until year three or four onwards, with more equipment required as fruiting reaches its peak.

 

Nitrogen Leaching: Unknown

Environment

Fertility

Blueberries are not a quick-growing plant, and have relatively low nutrient requirements. When adding fertilisers for nutrient deficiencies, formulations that also help with other soil properties can be used. For example, if the plants need nitrogen, the addition of ammonium sulphate or di-ammonium phosphate, will also make the soil more acidic – a useful side benefit. Slow-release fertilisers are the best, and a ‘less is best’ approach is good for new growers. Blueberries are very susceptible to over fertilising because of the position of the feeder roots near the soil surface.

No research is available for nitrogen leaching of a blueberry orchard, however it is not considered to be in the high range. Any land use change to a blueberry orchard planned for the Lake Rotorua catchment would need to be modelled for nitrogen leaching.

Frost tolerance

Winter frosts are usually no problem for established plants, but heavy, late-spring frosts can damage flowers and soft new growth, and early autumn frosts may damage the fruit of late-cropping varieties, so frost protection may need to be considered in more frost-prone areas.

Wind/shelter

In most areas, shelter is not a primary factor in successful blueberry production. It can in fact be detrimental, if the shelter shades the plants, or if it forms barriers that prevent air drainage and create frost pockets.

Sunshine hours

Blueberries need plenty of sunlight to help develop the maximum number of flower buds.

Rainfall

Having consistently optimum soil-moisture levels throughout the growing season is crucial to achieve maximum growth and yields. Drought and flood are both detrimental to this crop, so supplementary irrigation will be needed in most districts of New Zealand and extra drainage measures may be required in high-rainfall areas.

Soil

Before planting, a soil test should be carried out. Soil pH should lie between 4.0 and 5.2. Blueberries have shallow, surface feeding, fibrous roots and require the soil to be moist and free draining if they are to grow well. They also like an acidic soil, with a high proportion of organic matter.

Well-drained peat soils are ideal, but mineral soils such as sandy or silt loams are also suitable, provided peat moss or mulch is added during planting and on a regular basis afterwards. Heavy clay soils which crack in summer and become waterlogged in winter are generally not suitable for blueberries unless heavily amended with organic matter and sand.

Drainage

The shallow, fibrous root system is particularly sensitive to extreme fluctuations in soil-moisture levels. Water-logged soil encourages the root-rots and diseases to which blueberries are especially vulnerable, so efficient drainage is a must.

Weed control

Perennial weeds are a major problem in blueberry blocks and are best controlled before planting. Planting rows should be thoroughly worked (rotary hoed or similar) and weed free at the time of planting. A weed-free strip 1.2 m wide should be maintained, centred on the middle of the row at all times. Mulching with organic materials such as sawdust or pine bark is expensive but very beneficial. Mulching helps keep weeds under control and the soil moist and cool.

Pests and diseases

Blueberries are relatively free of pests and diseases. Leaf rollers, scale insects and grass-grub do affect the bushes but are easily controlled with insecticides. The main fungal disease is crown rot, caused by Phytophthora if the ground conditions are too wet.
Birds can be a problem. Bird-scaring devices give a measure of short-term control. Bird guard netting can be used or a completely netted enclosure constructed for long-term control.

Returns

Blueberry plantings are relatively expensive to establish when compared to short-term crops, but they remain productive for a long period of time, perhaps up to 50 years. Depending on the scale of the operation, establishment costs may be $50,000 per hectare or more.

Factors to consider include:

  • council consents
  • design issues/advice – block layout
  • equipment – some of the expenditure may be delayed until crops are yielding, or through the use of contractors
  • trellis design, posts and other structures
  • soil tests and fertilisers including start-up fertiliser for major soil amelioration, e.g. sulphur required as part of lowering pH for blueberry
  • pest and disease control, and weed control
  • irrigation, including design, pumps, main lines, laterals, sprinklers, drippers
  • netting, including posts – height, size, layout, wire, supports, bracing and style of netting
  • packing sheds, cooler facilities, storage facilities, transport
  • pollination.

 

Blueberry plants cost approximately $10 per plant. Used blueberry harvesters may be available from $50,000–100,000.
Returns depend on the final use of the fruit. Frozen product reaches $4–5/kg while fresh blueberries can return up to $15/kg. For an orchard producing at a peak of 10 tonnes per hectare with an 80/20 split between fresh and frozen, gross returns can reach $100,000–130,000 per hectare.

Useful Links

Blueberries NZ

Jan Bishell, Secretary
PO Box 13029, Hillcrest, Hamilton 3251
T: 07 856 6809
E: bishell@clear.net.nz
Website: http://blueberriesnz.co.nz

Information sources:

Tharfield Nurseries (http://www.tharfield.co.nz/crop.php?fruitid=23_Blueberry)
Blueberries – a 20th Century fruit is part of New Zealand’s expanding horticulture industry, Martech Consulting Group (http://martech.co.nz/images/13blueberry.pdf)
Infoshare, Statistics NZ (http://www.stats.govt.nz)
‘Jumbo blueberry to boost NZ industry by $8m in two years’, NZ Farmer, February 2017 (http://www.stuff.co.nz/business/farming/89250609/Jumbo-blueberry-to-boost-NZ-industry-by-8m-in-two-years)
Fresh Facts 2016, Plant and Food Research (http://www.freshfacts.co.nz/files/freshfacts-2016.pdf)
FAOSTAT, United Nations Food and Agricultural Organisation (http://www.fao.org/faostat/en/#data)