Peach

This article is about the tree. For other uses, see Peach (disambiguation).

Peach
White nectarine (free stone) and cross section
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Rosaceae
Genus:	Prunus
Subgenus:	Amygdalus
Species:	P. persica
Binomial name
Prunus persica (L.) Batsch

Peaches (edible part)

Nutritional value per 100 g (3.5 oz)
Energy	165 kJ (39 kcal)
Carbohydrates	9.5 g
Sugars	8.4 g
Dietary fibre	1.5 g
Fat	0.3 g
Protein	0.9 g
Vitamins	Quantity %DV†
Vitamin A equiv.	2% 16 μg
Vitamin C	7% 6.6 mg
Minerals	Quantity %DV†
Iron	1% 0.25 mg
Potassium	6% 190 mg
†Percentages estimated using US recommendations for adults, except for potassium, which is estimated based on expert recommendation from the National Academies.

The peach (桃 in Chinese) (Prunus persica) is known as a species of Prunus native to China that bears an edible juicy fruit also called a peach. It is a deciduous tree growing to 5–10 m tall, belonging to the subfamily Prunoideae of the family Rosaceae. It is classified with the almond in the subgenus Amygdalus within the genus Prunus, distinguished from the other subgenera by the corrugated seed shell.

The leaves are lanceolate, 7–15 cm long (3-6 in), 2–3 cm broad, pinnately veined. The flowers are produced in early spring before the leaves; they are solitary or paired, 2.5–3 cm diameter, pink, with five petals. The fruit is a drupe, with a single large seed encased in what appears to be wood, but isn't (called the "stone" or "pit"), yellow or whitish flesh, a delicate aroma, and a skin that is either velvety (peaches) or smooth (nectarines) in different cultivars. The flesh is very delicate and easily bruised in some cultivars, but is fairly firm in some commercial cultivars, especially when green. The seed is red-brown, oval shaped and approximately 1.3-2 cm long. Peaches, along with cherries, plums and apricots, are stone fruits (drupes). The tree is small, and up to 15 ft tall.

The scientific name persica, along with the word "peach" itself and its cognates in many European languages, derives from an early European belief that peaches were native to Persia (now Iran). The modern botanical consensus is that they originate in China, and were introduced to Persia and the Mediterranean region along the Silk Road before Christian times. Cultivated peaches are divided into clingstones and freestones, depending on whether the flesh sticks to the stone or not; both can have either white or yellow flesh. Peaches with white flesh typically are very sweet with little acidity, while yellow-fleshed peaches typically have an acidic tang coupled with sweetness, though this also varies greatly. Both colours often have some red on their skin. Low-acid white-fleshed peaches are the most popular kinds in China, Japan, and neighbouring Asian countries, while Europeans and North Americans have historically favoured the acidic, yellow-fleshed kinds, though some prefer the other fruits.

History of peaches

Although its botanical name Prunus persica suggests the peach is native to Persia, it actually originated in China where it has been cultivated since the early days of Chinese culture. Peaches were mentioned in Chinese writings as far back as the tenth century BC and were a favored fruit of emperors.

Its English name derives from the Latin plural of persicum malum, meaning Persian apple. In Middle English, it melded into peche, much closer to what we call it today.

The Persians brought the peach from China and passed it on to the Romans. The peach was brought to America by Spanish explorers in the sixteenth century and eventually made it to England and France in the seventeenth century, where it was a prized albeit rare treat. The Peach is a ripe fruit most of the time and has fuzzy skin.

A horticultist by the name of George Minifie supposedly brought the first peaches from England to the USA in the early seventeenth century, planting them at his Estate of Buckland in Virginia.

Various American Indian tribes are credited with spreading the peach tree across the United States, taking seeds along with them and planting as they roved the country.

Although Thomas Jefferson had peach trees at Monticello, United States farmers did not begin commercial production until the nineteenth century in Maryland, Delaware, Georgia and finally Virginia. California grows 65% of peaches grown for commercial production in the United States, but the northern states, Colorado, Michigan, and Washington also grow a significant amount.

Today, peaches are the second largest commercial fruit crop in the States, second only to apples. Italy, China and Greece are major producers of peaches outside of the United States.

Cultivation

Harvested peaches

Peach trees grow very well in a fairly limited range, since they have a chilling requirement that subtropical areas cannot satisfy, and they are not very cold-hardy. The trees themselves can usually tolerate temperatures to around −26 °C to −30 °C, although the following season's flower buds are usually killed at these temperatures, leading to no crop that summer. Flower bud kill begins to occur at temperatures between −15 °C and −25 °C depending on the cultivar (some are more cold-tolerant than others) and the timing of the cold, with the buds becoming less cold tolerant in late winter. Certain cultivars are more tender and others can tolerate a few degrees colder. In addition, a lot of summer heat is required to mature the crop, with mean temperatures of the hottest month between 20 °C and 30 °C. Another problematic issue in many peach-growing areas is spring frost. The trees tend to flower fairly early in spring. The flowers can often be damaged or killed by freezes; typically, if temperatures drop below about −4 °C, most flowers will be killed. However, if the flowers are not fully open, they can tolerate a couple of degrees colder.

Peach and nectarine output in 2005

Important historical peach-producing areas are China, Iran, France, and the Mediterranean countries like Italy, Spain and Greece. More recently, the United States (where the three largest producing states are California, South Carolina, and Georgia), Canada (British Columbia), and Australia (the Riverland region) have also become important; peach growing in the Niagara Peninsula of Ontario, Canada, was formerly intensive but ended in 2008 when the last fruit cannery in Canada was closed by the proprietors. Oceanic climate areas like the Pacific Northwest and coastline of North Western Europe are generally not satisfactory for peach-growing due to inadequate summer heat, though they are sometimes grown trained against south-facing walls to catch extra heat from the sun. Trees grown in a sheltered and south-facing position in the southeast of England are capable of producing both flowers and a large crop of fruit.

White peach and cross section

Nectarines

Nectarine

The nectarine is a cultivar group of peach that has a smooth, fuzzless skin. Though fuzzy peaches and nectarines are commercially regarded as different fruits, with nectarines often erroneously believed to be a crossbreed between peaches and plums, or a "peach with a plum skin", they belong to the same species as peaches. Several genetic studies have concluded in fact that nectarines are created due to a recessive gene, whereas a fuzzy peach skin is dominant. Nectarines have arisen many times from peach trees, often as bud sports.

As with peaches, nectarines can be white or yellow, and clingstone or freestone. On average, nectarines are slightly smaller and sweeter than peaches, but with much overlap. The lack of skin fuzz can make nectarine skins appear more reddish than those of peaches, contributing to the fruit's plum-like appearance. The lack of down on nectarines' skin also means their skin is more easily bruised than peaches.

The history of the nectarine is unclear; the first recorded mention in English is from 1616, but they had probably been grown much earlier within the native range of the Peach in central and eastern Asia.

Diseases

Main article: List of peach and nectarine diseases

The trees are prone to a disease called leaf curl, which usually does not directly affect the fruit but does reduce the crop yield by partially defoliating the tree. The fruit is very susceptible to brown rot.

Planting

The development sequence of a nectarine over a 7½ month period, from bud formation in early winter to fruit ripening in midsummer (see image page for further information)

Most peach trees sold by nurseries are named cultivars grafted onto a suitable rootstock. It is also possible to grow a tree from either a peach or nectarine seed, but the fruit quality of the resulting tree will be very unpredictable.

Peaches should be located in full sun, and with good air flow. This allows cold air to flow away on frosty nights and keeps the area cool in summer. Peaches are best planted in early winter, as this allows time for the roots to establish and be able to sustain the new spring growth. When planting in rows, plant north-south.

For optimum growth, peach trees require a constant supply of water. This should be increased shortly before the harvest. The best tasting fruit is produced when the peach is watered throughout the season. Drip irrigation is ideal, at least one dripper per tree. Although it is better to use multiple drippers around the tree, this is not necessary. A quarter of the root being watered is sufficient.

Peaches have a high nutrient requirement, needing more nitrogen than most other fruit trees. An NPK fertiliser can be applied regularly, and an additional mulch of poultry manure in autumn soon after the harvest will benefit the tree. If the leaves of the peach are yellow or small, the tree needs more nitrogen. Blood meal and bone meal, 3–5 kg per mature tree, or calcium ammonium nitrate, 0.5–1 kg, are suitable fertilisers. This also applies if the tree is putting forth little growth.

If the full amount of peaches is left, they will be under-sized and lacking in sugar and flavour. In dry conditions, extra watering is important. The fruit should be thinned when they have reached 2 cm in diameter, usually about 2 months after flowering. Fresh fruit are best consumed on the day of picking, and do not keep well. They are best eaten when the fruit is slightly soft, having aroma, and heated by the sun.

Storage

Hard fruit can be softened at home at room temperature, though it may not get any sweeter. The process is facilitated by ethylene, similar to the ripening of bananas. Storage in a paper bag concentrates this gas and hastens the process. When the fruit is soft, it can be stored in the refrigerator for a few days to slow further changes.

In the August 13, 2004 edition of the Journal of Experimental Botany, researchers found that peaches stored around 40 °F (4 °C) became mealy and discolored.

After slicing, peaches exhibit enzymatic browning; ascorbic acid, usually in the form of lemon juice, is added to delay the process, and the flavors are complementary. Peaches also can be frozen, and can be blanched to inhibit enzymatic changes in texture. Peaches often are canned, both commercially and at home; added sugars and acids reduce the retort or pressure cooking time which reduces excessive softening.

Peaches in Asian tradition

Pan Tao, the Chinese flat peach. Also called Paraguaya (Paraguayan).

A Chinese Song Dynasty painting of a bird and peach blossom, by Song Emperor Huizong, 11th century.

Peaches are known in China, Japan, Korea, Laos, and Vietnam not only as a popular fruit but for the many folktales and traditions associated with it. Momotaro, one of Japan's most noble and semi-historical heroes, was born from within an enormous peach floating down a stream. Momotaro or "Peach Boy" went on to fight evil oni and face many adventures. Peach flowers are admired by the Japanese but not as much as the sakura (cherry).

In China, the peach was said to be consumed by the immortals due to its mystic virtue of conferring longevity on all who ate them. The divinity Yu Huang, also called the Jade Emperor, and his mother called Xi Wangmu also known as Queen Mother of the West, ensured the gods' everlasting existence by feeding them the peaches of immortality. The immortals residing in the palace of Xi Wangmu were said to celebrate an extravagant banquet called the Pantao Hui or "The Feast of Peaches". The immortals waited six thousand years before gathering for this magnificent feast; the peach tree put forth leaves once every thousand years and it required another three thousand years for the fruit to ripen. Ivory statues depicting Xi Wangmu's attendants often held three peaches.

The peach often plays an important part in Chinese tradition and is symbolic of long life. One example is in the peach-gathering story of Zhang Daoling, who many say is the true founder of Taoism. Elder Zhang Guo, one of the Chinese Eight Immortals, is often depicted carrying a Peach of Immortality. The peach blossoms are highly prized in Chinese culture.

It was in an orchard of flowering peach trees that Liu Bei, Guan Yu, and Zhang Fei took an oath of brotherhood in the opening chapter of the classic Chinese novel Romance of the Three Kingdoms.

Due to its delicious taste and soft texture, in ancient China "peach" was also a slang word for "young bride", and it has remained in many cultures as a way to define young women or a general state of goodness (as in English, with peach or peachy keen).

A Vietnamese mythic history states that, in the spring of the year 1789, after marching to Ngọc Hồi and then winning a great victory against invaders from the Qing Dynasty of China, the King Quang Trung ordered a messenger to gallop to Phú Xuân citadel (Huế nowadays) and deliver a flowering peach branch to the Princess Ngọc Hân. This took place on the 5th day of the first lunar month, 2 days before the predicted end of the battle. The branch of peach flowers that was sent from the North to the Center of Vietnam was not only a message of victory from the King to his wife, but also the start of a new spring of peace and happiness for all the Vietnamese people. In addition to that, since the land of Nhật Tân had freely given that very branch of peach flowers to the King, it became the loyal garden of his dynasty.

A peach tree is also the context in which Kim Trọng and Thuý Kiều fell in love in The Tale of Kieu. And in Vietnam, the blossoming peach flower is the signal of spring. Finally, peach bonsai trees are used as decoration during Vietnamese New Year — Tết in Northern Vietnam.

Nutrition

A medium peach (75g), has 30 Cal, 7g of carbohydrate (6g sugars and 1g fiber), 1g of protein, 140mg of potassium, and 8% of the daily value (DV) for vitamin C.

Gallery

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  Peach flower
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  Flavorcrest peaches
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  Autumn Red peaches
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  A peach dessert
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  Peach (cultivar 'Berry') — watercolour 1895
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  Peaches in syrup
• A sliced peach
  A sliced peach
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  _{Detail of a portrait, oil on canvas, of an English woman, Jane Aynscombe, c1707, holding a peach. Her father, Philip Stebbing, was a Norwich grocer}

External links

• Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5.
• National Center for Home Food Preservation — Freezing Peaches
• Prunus persica images at bioimages.vanderbilt.edu
• California commercial production terminology and standards