Table of Contents
Rapp, K., S.K. Næss, and H.J. Swartz. 1993. Commercialization of the
cloudberry (Rubus chamaemorus L.) in Norway. p. 524-526. In: J. Janick
and J.E. Simon (eds.), New crops. Wiley, New York.
Commercialization of the Cloudberry (Rubus chamaemorus L.) in Norway
Kåre Rapp, S. Kristine Næss, and Harry Jan Swartz
- PLANT DESCRIPTION
- COMMERCIALIZATION PROSPECTS
- Fig. 1
The cloudberry, Rubus chamaemorus L., Rosaceae, is a small herbaceous
bramble common to peat bogs in the northern hemisphere (Fig. 1). The berry has
a strong musky flavor, quite distinct from that of any of the other bramble
crops, and is highly prized as a dessert berry in Scandinavia. Recently,
demand for the development of the cloudberry as a commercially viable crop has
increased in northern Norway where many districts are struggling to maintain a
The cloudberry is a circumpolar, subarctic species. It can be found as far
north as 78°30' N in Svalbard, Norway and its distribution extends south to
44°N in New Hampshire, U.S.A. (Resvoll 1929). It is a common plant in
northern Norway, and is also found in the highland areas and mountains farther
The cloudberry is a dioecious perennial herb. The plant spreads mainly by
means of an extensive rhizome system. Annual shoots consisting of from one to
four lobed leaves may terminate in a single staminate or pistillate flower.
Insect pollination is required for fruit set to occur in most places though
wind pollination may also contribute to fruit set in coastal windswept areas.
In Norway, the cloudberry begins ripening in the end of July or early August.
The berry, resembling a large amber raspberry, consists of from 5 to 25
drupelets. The cloudberry contains from 50 to over 150 mg ascorbic acid per
100 g fruit (Nordness and Werenskiold 1951; Heller 1981). It is also rich in
benzoic acid (Honkanen and Pyysalo 1976) and can therefore be easily stored for
several weeks or longer under normal refrigeration. For these reasons the
cloudberry was favored in the prevention of scurvy by Norwegian sailors and
North American Eskimos (Faegri 1970; Heller 1981).
Although the cloudberry is a common plant throughout northern Norway, the
Norwegians are unable to satisfy their domestic demand for the berry. In some
years, 200 to 300 tons of cloudberries are imported from Finland. The
cloudberry harvest in the wild is highly unpredictable due to the unstable
weather conditions prevailing in the beginning of June when the cloudberry
flowers. Early frost in August may also destroy the crop in some years. In
general, cloudberry yields from bog plants are very low, only averaging about
20 kg/ha. Domestication of the cloudberry would not only help fill the market
demand for the berry but would also provide an attractive crop for use in boggy
areas where little else of agricultural value can be grown. Several growers
organizations have now been formed in Norway and a consultant has been employed
at Holt Research Station, Tromsø, Norway (69°29'N) to study the
commercialization potential of the crop and set forth research priorities.
Bog management. A number of bog management practices have been
developed which can lead to greatly increased yields. Plowing furrows into a
bog with a spacing of from 1 to 5 m leads to an increase in cloudberry
proliferation and can reduce the incidence of spring freezes (Lid et al. 1961;
Østgard 1964; Makinen and Oikarinen 1974; Rapp 1982). Fertilization of
the bog with superphosphates or complete fertilizers (300 kg/ha) can increase
yields per hectare by an average of 50 kg when the fertilizer is placed at a
depth of 20 to 25 cm (Rapp 1989). Fertilizers applied to the surface of the
bog or at greater depths tend to benefit other bog species at the expense of
the cloudberry. In windswept areas, short fences may be useful in settling the
snow in the winter to delay the blossoming period and therefore avoid spring
frost injury. The use of windrows also leads to an increase in the activity of
pollinating insects and has increased yields (Østgard 1964).
Genotype improvement. A prerequisite for the success of any of these
bog management practices is the existence of a good stand of pistillate (fruit
bearing) plants. In most cloudberry producing bogs, less than 25% of the
flowering shoots are pistillate (Lid et al. 1967). Even among seedling
populations there is an overabundance of male plants (Rapp 1987). Current
research is aimed at the breeding of higher yielding pistillate or
hermaphrodite cultivars and the development of efficient propagation methods.
The development of cloudberry cultivars is well underway at the Holt Research
Station in northern Norway. Hundreds of seedlings from several different
environments have been screened for high flower production and large berry size
(Rapp 1988). Further performance evaluations have been made on promising
selections in square meter plots where their ability to spread and become
rapidly established can also be assessed. From these, two superior pistillate
clones (An 267 and If 542), and two superior staminate clones (An 30 and An
257), have now been selected for cultivar release.
The development of hermaphrodite cultivars is an important goal in the
domestication of the cloudberry. Occasionally, hermaphrodite flowers can be
found in the wild. Several plants bearing such flowers have been collected for
evaluation. Unfortunately, sex expression in these plants varies from year to
year and also from flower to flower within a clone. Plants with hermaphroditic
tendencies are currently being used as parents in the cloudberry breeding
program in an attempt to develop stable hermaphrodite cloudberry cultivars.
Several crosses between cloudberry and other Rubus species including a
hybrid blackberry, red raspberry clones, and several Asiatic ideobats have
produced plants with overall general chamaemorus morphology (thornless,
herbaceous, non-elongating) however, leaf pattern is definitely hybrid. The
blackberry x cloudberry cross is much more vigorous than other hybrids and
Rapid and good seed germination is important to the success of a cloudberry
breeding program. Normally cloudberry seed require 6 to 8 months cold
stratification before germinating and germination rates are often well below
50% (Rantala 1976). By removing the endocarp and seed coat from fresh
cloudberry seed, we have obtained in vitro germination rates of 75 to 85% four
weeks after culture initiation.
Plant propagation. The cloudberry is difficult to propagate relative to
other bramble species. Large turfs must be dug when collecting selections from
the wild to ensure transplant survival. Further propagation of the selection
can be made through the use of rhizome cuttings. The success rate with rhizome
cuttings has been greatly improved by increasing the length of the cutting from
about 7 cm to 15 to 20 cm. The best results have been obtained when the
rhizome cuttings are taken in May or August (Rapp 1986). Although the
cloudberry proliferates readily in tissue culture, explant rooting remains a
- Faegri, K. 1970. Norges planter (in Norwegian). J.V. Caappelens Press, Oslo,
- Heller, C.A. 1981. Wild edible and poisonous plants of Alaska. 8th ed.
Cooperative Extension Service, Univ. of Alaska, Fairbanks.
- Honkanen, E. and T. Pyysalo. 1976. The aroma of cloudberries (Rubus
chamaemorus L.). Z. Lebensm. Unters. Forsch. 160:393-400.
- Lid, J., O. Lie, and A. Løddesøl. 1961. Orienterende
forsøk med dyrking av molte. Medd. Det norske Myrselskap 59:1-26.
- Makinen, Y. and H. Oikarinen. 1974. Cultivation of cloudberry in
fennoscandia. Rpt. Kevo. Subarctic Res. 11:90-102.
- Nordness, E. and B.Q. Werenskiold. 1951. The variation of the ascorbic acid
content in raw and preserved cloudberries. Rubus chamaemorus L. Food
- Østgard, O. 1964. Molteundersøkelser i Nord-Norge. Forsk.
Fors. Landbr. 15:409-444.
- Rantala, E. 1976. Sexual reproduction in the cloudberry. Ann. Agr. Fenn.
- Rapp, K. 1982. Kultivering av moltemyr. In: Landbrukets Årbok 1981.
Tanum-Norli Press, Oslo, Norway.
- Rapp, K. 1986. Vegetativ oppformering av molte (Rubus chamaemorus L.).
Jord og Myr 10:1-11.
- Rapp, K. 1987. Om kjønnsfordeling of kjønnsdifferensiering hos
molte (Rubus chamaemorus L.). Jord og Myr 11:1-11.
- Rapp, K. 1988. Foredling i molte. Inf. SFL Holt 16:67-70.
- Rapp, K. 1989. Gjødsling til molte (Rubus chamaemorus L.) Jord
og Myr 14:109-129.
- Resvoll, T. 1929. Rubus chamaemorus L., a morphological-biological
study. Nyt Mag. Naturvit. 67:55-129.
||Fig. 1. The cloudberry.
Last update September 15, 1997