The peach (Prunus persica) is a deciduous tree native to the region of Northwest China between the Tarim Basin and the north slopes of the Kunlun Mountains, where it was first domesticated and cultivated. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fuzzy varieties), nectarines.The specific name persica refers to its widespread cultivation in Persia (modern-day Iran), from where it was transplanted to Europe.It belongs to the genus Prunus, which includes the cherry, apricot, almond, and plum, in the rose family.The peach is classified with the almond in the subgenus Amygdalus, distinguished from the other subgenera by the corrugated seed shell.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 has 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 varieties, especially when green.The single, large seed is red-brown, oval shaped, around 1.3–2 cm long, and surrounded by a wood-like husk.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 cultivars.Fossil endocarps with characteristics indistinguishable from those of modern peaches have been recovered from late Pliocene deposits in Kunming, dating to 2.6 million years ago.In the absence of evidence that the plants were in other ways identical to the modern peach, the name Prunus kunmingensis has been assigned to these fossils.Although its botanical name Prunus persica refers to Persia, genetic studies suggest peaches originated in China, where they have been cultivated since the neolithic period. More recent evidence indicates that domestication occurred as early as 6000 BC in Zhejiang Province of China. Peaches were mentioned in Chinese writings and literature beginning from the early first millennium BC. Alexander the Great is sometimes said to have introduced them into Greece after conquering Persia, but no historical evidence for this claim has been found.Horticulturist George Minifie supposedly brought the first peaches from England to its North American colonies in the early 17th century, planting them at his estate of Buckland in Virginia. Although Thomas Jefferson had peach trees at Monticello, American farmers did not begin commercial production until the 19th century in Maryland, Delaware, Georgia, South Carolina, and finally Virginia.As modernization and westernization swept through the city the Shanghai honey nectar peach nearly disappeared completely.In April 2010, an international consortium, the International Peach Genome Initiative, which include researchers from the United States, Italy, Chile, Spain, and France, announced they had sequenced the peach tree genome (doubled haploid Lovell).The sequence is composed of 227 million nucleotides arranged in eight pseudomolecules representing the eight peach chromosomes (2n = 16).Particular emphasis in this study is reserved for the analysis of the genetic diversity in peach germplasm and how it was shaped by human activities such as domestication and breeding.Major historical bottlenecks were found, one related to the putative original domestication that is supposed to have taken place in China about 4,000–5,000 years ago, the second is related to the western germplasm and is due to the early dissemination of the peach in Europe from China and the more recent breeding activities in the United States and Europe.These bottlenecks highlighted the substantial reduction of genetic diversity associated with domestication and breeding activities.Peaches grow in a fairly limited range in dry, continental or temperate climates, since the trees have a chilling requirement that tropical or subtropical areas generally do not satisfy except at high altitudes (for example in certain areas of Ecuador, Colombia, Ethiopia, India, and Nepal).During the chilling period, key chemical reactions occur, but the plant appears dormant.During quiescence, buds break and grow when sufficient warm weather favorable to growth is accumulated.The trees flower fairly early (in March in Western Europe), and the blossom is damaged or killed if temperatures drop below about −4 °C (25 °F).Finally, summer heat is required to mature the crop, with mean temperatures of the hottest month between 20 and 30 °C (68 and 86 °F).The fruit flesh may be creamy white to deep yellow, to dark red; the hue and shade of the color depend on the cultivar.Peach breeding has favored cultivars with more firmness, more red color, and shorter fuzz on the fruit surface.Peaches have a short shelf life, so commercial growers typically plant a mix of different cultivars to have fruit to ship all season long.In the United Kingdom, for example, these cultivars have gained the Royal Horticultural Society's Award of Garden Merit:.Several genetic studies have concluded nectarines are produced due to a recessive allele, whereas a fuzzy peach skin is dominant.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.The Koanga Institute lists varieties that ripen in the Southern Hemisphere in February and March.Most peach trees sold by nurseries are cultivars budded or grafted onto a suitable rootstock.During the growth season, they need a regular and reliable supply of water, with higher amounts just before harvest.Without regular fertilizer supply, peach tree leaves start turning yellow or exhibit stunted growth.The pattern of damage is distinct from that of caterpillars later in the year, as earwigs characteristically remove semicircles of petal and leaf tissue from the tips, rather than internally.The larvae of such moth species as the peachtree borer (Synanthedon exitiosa), the yellow peach moth (Conogethes punctiferalis), the well-marked cutworm (Abagrotis orbis), Lyonetia prunifoliella, Phyllonorycter hostis, the fruit tree borer (Maroga melanostigma), Parornix anguliferella, Parornix finitimella, Caloptilia zachrysa, Phyllonorycter crataegella, Trifurcula sinica, Suzuki's promolactis moth (Promalactis suzukiella), the white-spotted tussock moth (Orgyia thyellina), the apple leafroller (Archips termias), the catapult moth (Serrodes partita), the wood groundling (Parachronistis albiceps) or the omnivorous leafroller (Platynota stultana) are reported to feed on P.
Edward R. Forte