Garden strawberry

Garden strawberry
Garden strawberries grown hydroponically
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Rosaceae
Subfamily:	Rosoideae
Genus:	Fragaria
Species:	F. × ananassa
Binomial name
Fragaria × ananassa Duchesne

The garden strawberry is a common plant of the genus Fragaria cultivated worldwide for its aggregate accessory fruit, the (common) strawberry. The fruit is widely appreciated, mainly for its characteristic aroma but also for its bright red color, and it is consumed in large quantities, either fresh or in prepared foods such as preserves, fruit juice, pies, ice creams, and milk shakes. Artificial strawberry aroma is also widely used in all sorts of industrialized food products.

The garden strawberry was first bred in Brittany, France, in 1740 via a cross of Fragaria virginiana from eastern North America , which was noted for its flavor, and Fragaria chiloensis from Chile and Argentina brought by Amédée-François Frézier, which was noted for its large size.^[1]

Cultivars of Fragaria × ananassa have replaced, in commercial production, the woodland strawberry, which was the first strawberry species cultivated in the early 17th century.^[2]

The strawberry is, in technical terms, an aggregate accessory fruit, meaning that the fleshy part is derived not from the plant's ovaries (achenes) but from the receptacle that holds the ovaries.^[3] Each "seed" on the outside of the fruit is actually one of the ovaries of the flower, with a seed inside it. In both culinary and botanical terms, the entire thing is called a "fruit".

Cultivation

Fragaria × ananassa 'Gariguette,' a cultivar grown in southern France

Strawberry cultivars vary remarkably in size, color, flavor, shape, degree of fertility, season of ripening, liability to disease and constitution of plant.^[4] Some vary in foliage, and some vary materially in the relative development of their sexual organs. In most cases the flowers appear hermaphroditic in structure, but function as either male or female.^[5]

For purposes of commercial production, plants are propagated from runners and, in general, distributed as either bare root plants or plugs. Cultivation follows one of two general models, annual plasticulture^[6] or a perennial system of matted rows or mounds.^[7] A small amount of strawberries are also produced in greenhouses during the off season.^[8]

A garden using the plasticulture method

The bulk of modern commercial production uses the plasticulture system. In this method, raised beds are formed each year, fumigated, and covered with plastic to prevent weed growth and erosion. Plants, usually obtained from northern nurseries, are planted through holes punched in this covering, and irrigation tubing is run underneath. Runners are removed from the plants as they appear, to encourage the plants to put most of their energy into fruit development. At the end of the harvest season, the plastic is removed and the plants are plowed into the ground.^[6][9] Because strawberry plants more than a year or two old begin to decline in productivity and fruit quality, this system of replacing the plants each year allows for improved yields and denser plantings.^[6][9] However, because it requires a longer growing season to allow for establishment of the plants each year, and because of the increased costs in terms of forming and covering the mounds and purchasing plants each year, it is not always practical in all areas.^[9]

The other major method, which uses the same plants from year to year growing in rows or on mounds, is most common in colder climates.^[6][7] It has lower investment costs, and lower overall maintenance requirements.^[7] Yields are typically lower than in plasticulture.^[7]

A third method uses a compost sock. Plants grown in compost socks have been shown to produce significantly higher oxygen radical absorbance capacity (ORAC), flavonoids, anthocyanins, fructose, glucose, sucrose, malic acid, and citric acid than fruit produced in the black plastic mulch or matted row systems.^[10] Similar results in an earlier 2003 study conducted by the US Dept of Agriculture, at the Agricultural Research Service, in Beltsville Maryland, confirms how compost plays a role in the bioactive qualities of two strawberry cultivars.^[11]

Fragaria × ananassa 'Chandler,' a short-day commercial cultivar grown in California

Strawberries are often grouped according to their flowering habit.^[4][12] Traditionally, this has consisted of a division between "June-bearing" strawberries, which bear their fruit in the early summer and "ever-bearing" strawberries, which often bear several crops of fruit throughout the season.^[12] Research has shown recently that strawberries actually occur in three basic flowering habits: short-day, long-day, and day-neutral. These refer to the day-length sensitivity of the plant and the type of photoperiod that induces flower formation. Day-neutral cultivars produce flowers regardless of the photoperiod.^[13]

Strawberries may also be propagated by seed, though this is primarily a hobby activity, and is not widely practiced commercially. A few seed-propagated cultivars have been developed for home use, and research into growing from seed commercially is ongoing.^[14] Seeds (achenes) are acquired either via commercial seed suppliers, or by collecting and saving them from the fruit.

Strawberries can also be grown indoors in strawberry pots.

Manuring and harvesting

Most strawberry plants are now fed with artificial fertilizers, both before and after harvesting, and often before planting in plasticulture.^[15]

The harvesting and cleaning process has not changed substantially over time. The delicate strawberries are still harvested by hand.^[16] Grading and packing often occurs in the field, rather than in a processing facility.^[16] In large operations, strawberries are cleaned by means of water streams and shaking conveyor belts.^[17]

Pests

Around 200 species of pests are known to attack strawberries both directly and indirectly.^[18] These pests include slugs, moths, fruit flies, chafers, strawberry root weevils, strawberry thrips, strawberry sap beetles, strawberry crown moth, mites, aphids, and others.^[18][19]

A number of species of Lepidoptera feed on strawberry plants; for details see this list.

Diseases

Strawberry plants can fall victim to a number of diseases.^[20] The leaves may be attacked by powdery mildew, leaf spot (caused by the fungus Sphaerella fragariae), leaf blight (caused by the fungus Phomopsis obscurans), and by a variety of slime molds.^[20] The crown and roots may fall victim to red stele, verticillium wilt, black root rot, and nematodes.^[20] The fruits are subject to damage from gray mold, rhizopus rot, and leather rot.^[20] The plants can also develop disease from temperature extremes during winter.^[20] When watering your strawberries, be sure to water only the roots and not the leaves, as moisture on the leaves encourages growth of fungus. Ensure that the strawberries are placed in a windy area to prevent the fungus from occurring.

Production trends

Strawberry output in 2005

Agronomy

A diorama created from beeswax by Dr. Henry Brainerd Wright at the Louisiana State Exhibit Museum in Shreveport, Louisiana depicts strawberry harvesting. Strawberries are particularly grown in the southeastern portion of the state about Hammond.

Strawberries are an easy plant to grow, and can be grown almost anywhere in the world. The best thing to do is to buy a plant in early to middle spring. Place the plant preferably in full sun, and in somewhat sandy soil. Strawberries are a strong plant that will survive many conditions, but, during the time that the plant is forming fruit, it is important for it to get enough water. Strawberries can also be grown as a potted plant, and will still produce fruit.

A strawberry plant will send out shoots in an attempt to propagate a new plant, and, if left alone, it will be successful in doing so, but this shoot can be cut off, and placed wherever you wish to start a new plant.

Uses

In addition to being consumed fresh, strawberries can be frozen, made into preserves, as well as dried and used in such things as cereal bars. Strawberries are a popular addition to dairy products, as in strawberry-flavored ice cream, milkshakes, smoothies, and yogurts. Strawberries and Cream is a popular dessert, famously consumed at Wimbledon. Strawberry pie is also popular. Strawberries can be dipped in melted chocolate fondue as a healthier way to enjoy chocolate.^[22]

Strawberry pigment extract can be used as a natural acid/base indicator due to the different color of the conjugate acid and conjugate base of the pigment.^[23]

Nutrition

One cup (144 g) of strawberries contains approximately 45 calories (188 kJ) and is an excellent source of vitamin C and flavonoids.^[24][25][26]

Allergy

Some people experience an anaphylactoid reaction to the consumption of strawberries.^[27] The most common form of this reaction is oral allergy syndrome, but symptoms may also mimic hay fever or include dermatitis or hives, and, in severe cases, may cause breathing problems. Some research suggests that the allergen may be tied to a protein involved in the ripening of fruits, which was named Fra a1 (Fragaria allergen1). Homologous proteins are found in birch and apple, which suggests that people may develop cross-reactivity to all three species.

White-fruited strawberry cultivars, lacking Fra a1, may be an option for strawberry allergy sufferers. Since they lack a protein necessary for normal ripening, they do not produce the flavonoids that turn the mature berries of other cultivars red. They ripen but remain white, pale yellow or "golden", appearing like immature berries; this also has the advantage of making them less attractive to birds. A virtually allergen-free cultivar named 'Sofar' is available.^[28][29]

Gallery

Ready to eat Strawberries	Closeup of the surface of a strawberry shows achenes with style and stigma attached	Strawberry flowers and developing fruit	Halved strawberry showing internal structure
Ripe and unripe strawberries		Organic strawberry in Romania

See also

• California Strawberry Commission
• List of strawberry cultivars
• Musk Strawberry (hautbois strawberry)
• Fragaria vesca (alpine strawberry)
• Plant City, Florida (winter strawberry capital of the world)
• Fraise Tagada (strawberry-shaped candy popular in France)

References

External links

• F. ananassa data from GRIN Taxonomy Database
• How to grow strawberries
• University of California, Strawberry pest management guidelines
• California Strawberry Commission
• Strawberry Variety Monography vol.I°
• Strawberry Variety Monography vol.II°