Plants 4 Bees :: Rosaceae :: photo_Prunus_avium

Prunus avium

Scientific name	:	Prunus avium
Synonyms	:	Cerasus avium
Origin	:	Sweet cherry is probably native to the area from the southern shore of the Caspian Sea to the Balkan Peninsula and northern Africa and much of central Europe.
Description	:	The tree is somewhat pyramidal in shape and can attain a height of at least 70 feet if unpruned. The species is also sometimes grown on dwarfing root stock, in which case the trees are often grown in hedgerows and tree height is restrained to allow harvesting from the ground. The white flowers are arranged on short lateral spurs in clusters of 2 to 6 and are approximately 1 to 1.4 inch in diameter. The stigma is receptive when the flower opens, but the anthers often continue to open and release their pollen at least into the second day. The fruits range in size up to 1 inch in diameter, are bright or dark red to nearly black, but sometimes are also yellow. The leaves range from 1 to 6 inches in length, are smooth and hairless above with straight stiff hairs pressed close to the leaf (strigose) beneath. The petioles (leaf stems) often have reddish glands near the leaf.
Distribution	:	Deciduous cherries do not flourish in areas with long hot summers, but also are vulnerable to winter damage. Commercial growing areas, therefore, tend to be in northern states except where altitude or large bodies of water moderate temperatures[12]. The main sweet cherry producing states are Washington California and Oregon. The species is one of the hardiest of the cherries, and one standard text[ 9] considers it a zone 4 species. Where the species has escaped from cultivation, it is most commonly found in roadside thickets and on the borders of woods.
Blooming period	:	For much of the Eastern part of the United States, Fernald[3] provides a blooming date range of April and May. In the Lansing, Michigan area the species blooms from mid April into May. In the Pacific Northwest, it is late March and into April and in California it may be as much as a month earlier.
Importance	:	As a tree fruit nectar source, sweet cherry is often considered second only to apple. The sugar content of the nectar is greater than that of tart cherry[12].
Honey potential	:	Crane [1] reports the honey potential for P. avium, which she refers to as wild cherry, as being in her class 2 category, which has a range of 23 to 45 lbs/acre. She also reports a sugar value of 0.08 to 1.5 mg of sugar/flower/24 hrs.
Honey	:	Crane[1] describes the honey of Malus Pyrus and Prunus as being light with an “excellent delicate flavor and fine aroma”. She also provides the information that it “granulates quickly, with a soft fine grain”. Lovell[11], on the other hand claims that honey from P. virginianum (one of the native North American cherries) is bitter and tastes much like the pit of that species. Lovell[10] claims that honey from P. serotina (another American Cherry) is also bitter.
Additional information	:	There are ornamental cultivars of sweet cherry with double flowers, cut leaves and weeping branches. While they are quite common in Europe, they are much less so in North America. Hooper and Taylor[5] seem to suggest that the ornamental cherries are also attractive to bees, but that single flowered or semi-double flowered varieties should be chosen if the gardener wishes them to benefit bees. It is this author’s general feeling that standard flowers, once “worked over”, by the plant breeder to produce ornamental varieties, often are not as attractive to bees as their progenitors. Pollination considerations. Historically the majority of the cultivars of sweet cherry were self-sterile. In addition, there are cultivar groupings that are compatible and those that are incompatible. In situations where cultivars are chosen that fit this situation, a suitable compatible pollinator variety is essential. This is the situation in many orchards. The inheritance of self-sterility and cross-incompatibility in sweet cherry is fairly straightforward. There is a gene known as the “s” gene. It comes in a variety of forms, s1, s2, s3, etc (multiple alleles). There are a fair number of these different forms of essentially the same gene. If a tree is diploid , which is generally the case for sweet cherry, these genes will be present in paired combinations, that is, a tree could have an s1 and an s2 or an s2 and an s3, an s1 and an s3 etc. Pollen carries only one set of chromosomes and, therefore only one s gene. If a pollen grain contains an s gene that is the same as one of s genes of the tree, development of the pollen tube from that pollen grain is terminated prematurely and fertilization doesn’t occur. Through irradiation, we have developed “damaged s genes” that don’t react this way. Trees with these modified genes are at least partly self-fruitful. Because of the convenience self-fruitful cultivars provide, there has been a trend toward development of self-fruitful cultivars, and the necessity of having suitable pollinator varieties for cross-pollination probably will become less important than it has been historically. Even here though, insects, such as honey bees, are often useful in transferring pollen from the anthers to the stigma. The following recommendations for pollination are provided by a relatively recent text on cherry production[20]. Under reasonable foraging conditions, the number of strong hives (20 to 30 thousand bees per hive) should be 1.2 to 2 colonies per acre, spread throughout the orchard. Under poorer foraging conditions where the “window of pollination opportunity” often is quite short, this number should probably be increased to be certain that sufficient flowers have been pollinated in the limited time available. In addition to the direct estimation of the number of bees per hive, Thompson [Thompson] also suggests two other indicators that are often used to determine whether a foraging force is sufficient for good pollination. Under good foraging conditions (above 65oF and a wind less than 10 miles/hr), 100 bees returning to the hive in one minute is considered an indication of a strong hive. During optimal weather conditions one minute counts of 25-35 bees per 10 mature trees by trained observers as they slowly move around the trees is also recommended as an indicator that a sufficient foraging force is actively working the orchard. See also the side bar in the June 2005 issue of this column for additional general comments concerning pollination of tree fruits in the family Rosaceae.
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.