Blueberries
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| Berryfruit Variety Descriptions
Blueberries |
There are three main types of blueberries cultivated worldwide, `highbush', `lowbush' and `rabbiteye', each consisting of between 1-3 predominant species. Within each group there is a considerable number of varieties to choose from, reflecting 70 years of breeding effort that has taken place. Currently over 50 varieties of highbush, 15 varieties of rabbiteye, and several clones of lowbush, are in cultivation. In addition, some varieties are based on intermediate forms of these groups including the `half high' group (highbush x lowbush). Rabbiteye-highbush intermediates generally have not made good cultivars but have been used extensively in the improvement of highbush.
Highbush blueberry production is the most common, with two main species commercially cultivated, Vaccinium corymbosum and V. australe. In recent years the highbush group of blueberry species has needed to be separated into two groups based on geographical lines. `Northern highbush' denotes the group of species (V. corymbosum, V. australe) with a high winter chilling requirement and therefore are found in temperate regions of USA. `Southern highbush' species require fewer chilling hours and are often referred to as `low chill' highbush. These prosper in subtropical climates of south eastern USA and are the newest group of Vaccinium, having originated solely through breeding.
In New Zealand most blueberry production is based on `northern highbush' varieties. However, within the next 2-3 years it is likely that `southern highbush' varieties will be available for commercial production. These varieties, if grown in subtropical climates, may enable production to commence 2-3 weeks earlier than at present.
Lowbush blueberries are not grown in New Zealand but are found extensively throughout northern USA and southern Canada made up of clones of V. angustifolium or V. myrtilloides. Rabbiteye blueberry production, unlike highbush or lowbush, is based only on one species, V. ashei, common to south eastern USA where it is thought to have evolved from the natural hybridisation of several native Vaccinium species.
Rabbiteye production in New Zealand has expanded in recent years in response to this species ability to crop late in the season (February-early April). Rabbiteye can be grown in most localities throughout New Zealand, although commercial production is restricted to areas which have sufficient heat units in late summer and autumn, necessary to fully ripen the berries.
Most plants that are currently available from licensed blueberry nurseries are potted and are sold either in 5 cm tubes or in PB 5's (volume 5 litres). Tube lines should be grown on for a year by potting up to a PB5 or spend a year in a field nursery. On peat farms, growing on may not be necessary and tube lines can be directly set into the field, provided weeds are under control and the field is not prone to excessive wet or dry periods. It is important to note that only strong plants in tubes are suitable for direct field planting. Young plants are particularly sensitive to adverse conditions and large plant losses can occur within a short time of planting.
While planting material leaving the nurseries is true to type, care must be taken by growers to avoid accidental mix-ups resulting from subsequent transportation or handling. Even the most experienced growers will have difficulty distinguishing varieties especially when dealing with small dormant plants in tubes. Potted blueberries can be planted either in the autumn or early spring when roots are actively growing. Field grown stock is best planted between late winter and early spring before bud break. Avoid direct planting plants which have become badly pot bound.
Planting patterns differ for highbush and rabbiteye, largely reflecting pollination requirements. Rabbiteyes need cross pollination to set fruit and two rows of a single variety with pollinators on either side is best to obtain maximum yields. Highbush, on the other hand, are self fruitful and can successfully be planted in large blocks. Distances between rows are normally 2.6-3.0m apart depending on variety and equipment to be used. Distances between plants are listed under individual varieties.
On mineral soils, incorporate sawdust or similar material and mound plants with additional material. Do not allow sawdust to crust. If this occurs apply a layer of straw on top of sawdust. Beware Phytophthora root rot as blueberries are very sensitive. Rabbit eye types are more tolerant of marginal soil conditions but can be excessively vigorous. Summer pruning can help with the management of excess vigour. Plant spacings should normally provide eventual densities of about 1800 plants per hectare.
A page of colour plates allowing a visual comparison of some of the following varieties is available (Please note this is a large document with over 100K of graphics). Alternatively, clicking a colourised variety name in the list below will call a 40K image of that variety.
Type:
Rabbiteye
Season
Mid-February-early April
General description:
Released in 1978 by the North Carolina Agricultural Experiment Station and USDA. Parentage W4 x Callaway. An excellent cropper, producing large clusters of medium sized fruit (12-14 mm). Fruit is firm but a little on the dark side. Has a good balance between fruitfulness and vigour. Late flowering variety.
District suitability:
Recommended planting for Waikato northwards as it may have problems maturing fruit in cooler districts.
Type:
Northern Highbush
Season
Early, ripening with Nui and Reka
General description:
A heavy cropper, producing medium sized, medium blue fruit which maintains it's size throughout the cropping season. Fruit is firm and has a notable crisp texture. Plants have good vigour. Very popular commercial variety throughout the world.
District suitability:
Suitable for all districts from Waikato, south.
Type:
Southern Highbush
Season
Early
General description:
Bred in Florida to be suitable for mild subtropical climates. Berries are smaller than Misty or O'Neal, similar to Jersey in size. Flowers a little later than Misty and will need to be planted with a suitable pollinator for cross pollination purposes
District suitability:
Suitable for northern districts from Waikato, north.
Type:
Rabbiteye
Season:
Late February-mid April
General description:
Released by Ruakura Research Centre in 1990. Parentage Premier OP (TifBlue x Homebell). Excellent late cropper with large very typical rabbiteye fruit. Outstanding characteristic is the cropping performance through April in the Waikato district. Large dark blue berries have a gritty texture and an obvious calyx scar similar to Tifblue. Bushes have an upright growth habit with berries well exposed.
District suitability:
Recommended planting for Waikato northwards as it may have problems maturing fruit in cooler districts.
Cultural notes:
Berries have a poor flavour if picked too early. Fruit should be left on the bush for 7-10 days after turning blue. Bud thinning may be necessary in winter as this variety has a tendency to overcrop.
Type:
Southern Highbush
Season
Early
General description:
Bred in Florida is one of the second generation of southern highbush types and is considered a replacement for Sharpblue. Limited experience suggests excellent performance in terms of growth, crop yield and quality. Flowers early and will need to be planted with a suitable pollinator for cross pollination purposes (O'Neal or Marimba are likely candidates)
District suitability:
Suitable for northern districts from Waikato, north.
Type:
Northern highbush
Season:
Early, late November-early January.
General description:
Released by Ruakura Research Centre in 1985. Parentage E118 (Earliblue x Ashworth) x Bluecrop. Produces early crops of very large berries, most between 16-20 mm in diameter. Loose clusters of light blue fruit are borne on the outside of the canopy. Berries tend to be acidic during the early part of the season. Berries are firm with excellent keeping quality. Spreading leafy growth habit producing a smallish bush especially on mineral soils. Average yielding, tendency to be biennial.
District suitability:
Suitable for all districts from Waikato, south.
Cultural notes:
Slow establishment and responds to crop removal in the first two years after planting. Establishment can be difficult on mineral soils as it has a high requirement for organic matter. Recommended 1 metre plant spacing to maximise production on mineral soils.
Type:
Southern Highbush
Season
Early
General description:
Considered the best low chill variety from the North Carolina programme. Berries are large, sweet and relatively firm.
District suitability:
Suitable for northern districts from Waikato, north.
Type:
Rabbiteye
Season:
Late, late January-mid March.
General description:
Released in USA in 1978 by the North Carolina Agricultural experiment Station and USDA. Parentage Tifblue x Menditoo. Ripens with Tifblue. The most productive rabbiteye on the market. Produces large clusters of light blue fruit. Fruit size depends on the yield but most berries are between 11-13 mm in diameter. Berries are resistant to cracking and store well. Suitable for CA storage. Crops predominantly through February. As vigorous as Tifblue.
District suitability:
Suitable for all districts.
Cultural notes:
Crop second year after planting or crop two year old plants the season after planting to limit vigour. Limit nitrogen use particularly on peat soils. Has a tendency to overcrop necessitating fruit bud thinning during winter. May need support to hold fruiting canes up. Recommended plant spacing of 1.5-2 metres. Avoid high rates of nitrogen. Very susceptible to blast infection. Keep mulch materials which increase humidity away from the base of the bush and use copper preventative sprays in autumn.
Type:
Northern highbush
Season:
Early-mid, early December-early January.
General description:
Released by Ruakura Research Centre in 1985. Parentage E118 (Earliblue x Ashworth) x Bluecrop. Puru produces good crops of large light blue fruit with diameters ranging between 12-18 mm. Fruit is firm and is of comparable quality to Bluecrop. Excellent flavour and one that is popular with Japanese consumers. Has an upright growing habit and a tendency to crop again in the autumn. Moderate to heavy yielding.
District suitability:
Suitable for all districts from Waikato, south
Cultural notes:
Sets moderate numbers of fruit buds mostly on terminals. Careful pruning needed to maximise fruitful buds. Recommended spacing of 1.2-1.5 metres between plants.
Type:
Rabbiteye
Season:
Early February-late March (2 weeks after Powder Blue)
General description:
Released by Ruakura Research Centre in 1990. Parentage Premier OP (TifBlue x Homebell). A moderate cropper with outstanding fruit quality. Loose clusters of firm, very light blue fruit are borne within the canopy. Most notable feature is the keeping ability of fruit with good retention of fresh market quality after 4-6 weeks storage. Vigorous, upright growth habit. Berries are prone to splitting after heavy rain.
District suitability:
Recommended planting for North Island districts as it may have problems maturing fruit in cooler districts.
Cultural notes:
Allow to crop in the second season after planting to help control vigour. Summer pruning is needed to maximise bud set in the autumn.
Type:
Northern highbush.
Season:
Early, late November -late December.
General Description:
Released by Ruakura Research Centre in 1985. Parentage E118 (Earliblue x Ashworth) x Bluecrop. The most productive of the early fruited varieties released by Ruakura. Large loose clusters of medium sized berries (12-14 mm) reminiscent of Bluecrop. Berries tend to be darker than Puru or Nui but are firm and handle well. Suitable for CA storage or shipping. Flavour appeals to consumers. Outstanding plant vigour and adapted to mineral soils. Has an upright growth habit.
District suitability:
Suitable for all districts from Waikato, south.
Cultural notes:
It is necessary to thin fruit buds in winter as it has a tendency to overcrop. Recommended spacing of 1.2-1.5 metres between plants.
Type:
Northern Highbush
Season
Mid season (with Bluecrop)
General description:
A heavy cropper, producing large sized, medium blue fruit which has better flavour than Bluecrop. Fruit is borne in large clusters from a stocky plant similar to Nui. Expected to be a suitable replacement for Jersey.
District suitability:
Suitable for all districts from Waikato, south.
Cultural notes:
Recommended 1 metre plant spacing to maximise production on mineral soils.
Gloria Graydon, Ngaroto Nurseries, P.O. Box 428, Te Awamutu
Ph (07) 871 5668 (1 year tube plants)Tharfield Nursery, Te Puna Road, R D 6 Tauranga
Ph (07) 552 5802 Fax (07) 552 5131 (2 year old plants)Tissue culture stock is supplied through selected nurseries but ordered through NZ Berryfruit Propagators Ltd, P O Box 10050, Wellington Ph/Fax (04) 569 8263