Plants 4 Bees :: Rosaceae :: Photo_Prunus_domesti

Prunus domestica

Scientific name	:	Prunus domestica
Synonyms	:	Prunus autumnalis
Common name	:	While the exact evolutionary origins of the European plum are lost in prehistoric time [18], the fruits which we cultivate today ironically probably have their more recent origins in southwestern Asia.
Description	:	The distinction between plums and prunes lies mainly in their sugar content. Prunes contain sufficient sugar that they can, without fermenting around the pit, be sun, or otherwise slowly dried, without removal of the pit. The plums and prunes share the same genus (Prunus) with almonds, apricots, peaches, and cherries. They lack the fuzziness of apricots and peaches (excluding nectarines) and also the furrowed stone of the apricots and many peaches. Unlike most cherries, the fruit is usually adorned with a bluish or whitish “bloom”. They produce solitary buds at the juncture of the leaf and the stem (axillary buds) rather than the three found in peaches and almonds. P. domestica is the familiar blue plum and prune that was long grown in Europe and now is popular in eastern North America and the Pacific Coast Region. The species is a relatively small tree that grows to 40ft in height but in orchards is usually restrained by pruning. The leaves are (2-4 in) long and at maturity are dull green above and pubescent beneath. The flowers are greenish white to white and 0.6 -1 inch across. Nectar is secreted by the receptacle tissue around the base of the style. In North America this is probably the most important species of the commercial plums and prunes. Cultivars include ‘Agen’, ‘Arctic’, ‘Bradshaw’, ‘Grand Duke’, ‘Green Gage’(=’Reine Claude’), ‘Italian Prune’, ‘Lombard’, ‘Stanley’, ‘Washington’. I would also place ‘French’ and ‘Shropshire’, often called Damson plums, in this group. I consider them here as a variety of P. domestica, but elsewhere they are sometimes considered a separate species (P. insititia).
Distribution	:	The map provided indicates the distribution of the species in an uncultivated state, as currently known by the U.S.D.A.[21]. The main areas of commercial production in the U. S. are the Pacific Coast, Michigan and New York. As a general rule, the garden plum is considered about as hardy as apple (zone 5)[23], but certain cultivars such as ‘Arctic’ can be grown north of this zone.
Blooming period	:	In Michigan the species generally blooms about the same time as apple and cherry, which in the Lansing area is late April, early May.
Importance	:	Most who have written about the importance of plums as a honey plant consider them to be mainly important for stimulating brood production[16, 11, and 15], but commonly also point out that at times surpluses have been obtained in California.
Honey potential	:	Crane[1] places P. domestica in her class 2 honey potential category (23-45 lbs/acre). She also provides sugar values that range from 0.13 to 1.47 mg/flower/day. Free[4] provides the information that plums produce from 0.80 to 3.40 mg nectar per day. No sugar values are given, however. McGregor[12] states that there appears to be as much as ten-fold variation in the amount of nectar produced by flowers of different cultivars.
Honey	:	Crane[1]makes the blanket statement about Malus, Pyrus and Prunus honey that it has a “light excellent delicate flavour and fine aroma”, and is said to “granulate quickly, with soft fine grain.”
Pollen	:	Ramsey provides the blanket statement that the pollen from the genus Prunus is an excellent protein source. Free[4], on the other hand, provides the information that plum pollen production is relatively low (0.39-1.96 mg pollen per flower). Of all fruits on which he reported (almond, apple, apricot, peach, pear, plum, and sweet cherry), only sweet cherry was lower.
Additional information	:	Pollination considerations There are three main groups of plums under cultivation in North America, the European plum (P. domestica), the Oriental plum (P. salicina) and several American plum species. P. domestica is a hexaploid species. I will also place the damson plum (Prunus domestica var. insititia), used primarily for jams and jellies, in this group since it is also hexaploid and crosses freely with the domestica group. The other two groups (the Oriental and American plums) are both diploid and for pollination purposes, are incompatible with the European plum, but can be used to pollinate each other and to produce hybrids that have been used to extend the geographic range of plum growing into climates that are colder than are suitable for either the European or Oriental plum. European plum cultivars range from being completely self-sterile to being nearly or completely self-fruitful. This issue is a little confusing because different researchers report different self-compatibility results for the same cultivars. The reasons for this are a little obscure, but there is a suggestion that a particular cultivar may exhibit different degrees of self-fruitfulness under the different climatic conditions under which the researchers performed their studies (perhaps a situation like “Bartlett” pear), but again not everyone agrees on this. Most authors [4, 12, and 14] agree that self-sterility is widespread in the species, but there are exceptions. The common cultivar, ‘Stanley’, for example, appears to be nearly or completely, self-fruitful. There are also cross-incompatible groups much as exist in sweet cherries. An individual flower can be open for as long as five days, and the stigma which is receptive at the time of opening can be receptive for as much as two days before pollen is released. A set of 15 – 20 percent results in a massive crops. Historically, honey bees have been considered to be the best pollinator species. Pollination of self-fertile cultivars appears to simply be a matter of moving pollen within a given flower from the anthers to the stigma. Because honey bees are better at this than the wind, the use of honey bees, even in self-fertile cultivars, appears to be advantageous. There also appears to be an advantage to using self-compatible or partly self-compatible cultivars as pollinizers for self-unfruitful cultivars [14]. In general most references recommend one strong colony per acre, and that the hives be distributed throughout the orchard, perhaps in groups of five or ten. If you are interested in pollination considerations, be sure to read the generalized comments on this subject in the sidebar article in the June, 2004 column.
Reference	:	1. Crane, E. The Flowers Honey Comes From. 1975. In: Honey--A Comprehensive Survey (E. Crane Ed.). Crane, Russak and Company, Inc. New York, NY. 2. Dirr, M. A. 1998. Manual of Woody Landscape Plants. Their Identification, Ornamental Characteristics, Culture, Propagation and Uses (Fifth Edition). Stipes Publishing L.L.C. Champaign, IL. 3. Fernald, M. L. 1970. Gray's Manual of Botany. 8th ed. D. Van Nostrand Co., New York, NY. 4. Free, J. 1993. Insect Pollination of Crops. Academic Press Limited. London 5. Hooper, T, and M. Taylor. 1988. The Beekeepers Garden. Alphabooks Ltd. London 6. Howes, E. N. 1979. Plants and Beekeeping. Faber and Faber. London. 7. Iezzoni, A. F. 1996. Sour Cherry Cultivars: Objectives and Methods of Fruit breeding and Characteristics of Principal Commercial Cultivars. In: Cherries--Crop Physiology, Production and Uses (Webster, A. D. and N. E. Looney Eds.) CAB International Wallingford, UK. 8. Iezzoni, A. F. 2005. Personal communication. 9. Liberty Hyde Bailey Hortorium staff. 1976. Hortus Third. Macmillan Publishing Co., Inc. New York. 10. Lovell, H. B. 1966. Honey Plants Manual. A Practical Field Handbook for Identifying honey Flora. A. I. Root Co. Medina, OH. 11. Lovell, J. H. 1926. Honey Plants of North America. A. I. Root Co. Medina, OH. 12. McGregor, S. E. 1976. Insect Pollination of Cultivated Crop Plants. Agricultural Handbook No 496, Agricultural Research Service. United States Department of Agriculture. Washington DC. This publication is being updated and is available on the web at: gears.tucson.ars.ag.gov/book. 13. Morton Arboretum staff. 1990. Woody Plants of The Morton Arboretum. A Handlist of Living Plants in the Outdoor Woody Plant Collections. The Morton Arboretum, Lisle, IL. 14. Nyéki, J. M. Soltész. 1996. Floral Biology of Temperate Zone Fruit Trees and Small Fruits. Akadémiai Kiadó, Budapest. 15. Pammel, L. H. and C. M. King Honey Plants of Iowa. Iowa Geological Survey Bulletin No. 7. Iowa Geological Survey, Des Moines, IO. 16. Pellett, F. C. 1978. American Honey Plants. Dadant and Sons, Hamilton, IL. 17. Ramsay, J. 1987. Plants for Beekeeping in Canada and the Northern USA: A Directory of Nectar and Pollen Sources Found in Canada and the Northern USA. International Bee Research Association. London. 18. Roberts, J. The Origins of Fruit and Vegetables. Universe Publishing. New York. 19. Scullen, H. A. and G. A. Vansell. 1942. Nectar and Pollen Plants of Oregon. Oregon Experiment Station Bulleton 412. Oregon State College, Corvallis 20. Thompson, M. 1996. Flowering, Pollination and Fruit Set. In: Cherries--Crop Physiology, Production and Uses (Webster, A. D. and N. E. Looney Eds.) CAB International Wallingford, UK. 21. USDA, NRCS. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA 22. Wilson, W. T., J. O. Moffett and H. D. Harrington. 1958. Nectar and Pollen Plants of Colorado. Colorado State University Experiment Station Bulletin 508-S. Fort Collins, CO. 23. Wyman, D. 1997. Wyman's Gardening Encyclopedia. Scribner, New York, NY.