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Apple
'Cripps Pink' apples
Flowers
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Rosaceae
Genus: Malus
Species:
M. domestica
Binomial name
Malus domestica
Synonyms[1][2]
  • M. communis Desf., 1768
  • M. pumila Mil.
  • M. frutescens Medik.
  • M. paradisiaca (L.) Medikus
  • M. sylvestris Mil.
  • Pyrus malus L.
  • Pyrus malus var. paradisiaca L.
  • Pyrus dioica Moench

An apple is a round, edible fruit produced by an apple tree (Malus spp., among them the domestic or orchard apple; Malus domestica). Apple trees are cultivated worldwide and are the most widely grown species in the genus Malus. The tree originated in Central Asia, where its wild ancestor, Malus sieversii, is still found. Apples have been grown for thousands of years in Eurasia and were introduced to North America by European colonists. Apples have religious and mythological significance in many cultures, including Norse, Greek, and European Christian tradition.

Apples grown from seed tend to be very different from those of their parents, and the resultant fruit frequently lacks desired characteristics. For commercial purposes, including botanical evaluation, apple cultivars are propagated by clonal grafting onto rootstocks. Apple trees grown without rootstocks tend to be larger and much slower to fruit after planting. Rootstocks are used to control the speed of growth and the size of the resulting tree, allowing for easier harvesting.

There are more than 7,500 cultivars of apples. Different cultivars are bred for various tastes and uses, including cooking, eating raw, and cider or apple juice production. Trees and fruit are prone to fungal, bacterial, and pest problems, which can be controlled by a number of organic and non-organic means. In 2010, the fruit's genome was sequenced as part of research on disease control and selective breeding in apple production.

Etymology

The word apple, whose Old English ancestor is æppel, is descended from the Proto-Germanic noun *aplaz, descended in turn from Proto-Indo-European *h₂ébōl.[3] As late as the 17th century, the word also functioned as a generic term for all fruit, including nuts. This can be compared to the 14th-century Middle English expression appel of paradis, meaning a banana.[4]

Description

The apple is a deciduous tree, generally standing 2 to 4.5 metres (6 to 15 feet) tall in cultivation and up to 15 m (49 ft) in the wild, though more typically 2 to 10 m (6.5 to 33 ft).[5][1] When cultivated, the size, shape and branch density are determined by rootstock selection and trimming method.[5] Apple trees may naturally have a rounded to erect crown with a dense canopy of leaves.[6] The bark of the trunk is dark gray or gray-brown, but young branches are reddish or dark-brown with a smooth texture.[1][7] Young twigs are covered in fine downy hairs; they become hairless when older.[7]

The buds are egg-shaped and dark red or purple in color; they range in size from 3 to 5 millimeters, but are usually less than 4 mm. The bud scales have very hairy edges. When emerging from the buds, the leaves are convolute, meaning that their edges overlap each other.[1] Leaves can be simple ovals (elliptic), medium or wide in width, somewhat egg-shaped with the wider portion toward their base (ovate), or even with sides that are more parallel to each other instead of curved (oblong) with a narrow pointed end.[7][1] The edges have broadly-angled teeth, but do not have lobes. The top surface of the leaves are glabrescent, almost hairless, while the undersides are densely covered in fine hairs.[1] The leaves are attached alternately by short leaf stems 1-to-3.5 cm (12-to-1+12 in) long.[6][1]

Blossoms are produced in spring simultaneously with the budding of the leaves and are produced on spurs and some long shoots.[5] When the flower buds first begin to open the petals are rose-pink and fade to white or light pink when fully open with each flower 3-to-4-centimeter (1-to-1+12-inch) in diameter.[1] The five-petaled flowers are group in an inflorescence consisting of a cyme with 3–7 flowers.[8] The central flower of the inflorescence is called the "king bloom"; it opens first and can develop a larger fruit.[6] Open apple blossoms are damaged by even brief exposures to temperatures −2 °C (28 °F) or less, although the overwintering wood and buds are hardy down to −40 °C (−40 °F).[8]

Fruit

The fruit is a pome that matures in late summer or autumn.[1] The true fruits or carpels are the harder interior chambers inside the apple's core. There are usually five carpels inside an apple, but there may be as few as three. Each of the chambers contains one or two seeds.[9] The edible flesh is formed from the receptacle at the base of the flower.[10]

The seeds are egg- to pear-shaped and may be colored from light brown or tan to a very dark brown, often with red shades or even purplish-black. They may have a blunt or sharp point.[11] The five sepals remain attached and stand out from the surface of the apple.[1]

The size of the fruit varies widely between cultivars, but generally has a diameter between 2.5 and 12 cm (1 and 5 in).[7] The shape is quite variable and may be nearly round, elongated, conical, or short and wide.[12]

The groundcolor of ripe apples is yellow, green, yellow-green or whitish yellow. The overcolor of ripe apples can be orange-red, pink-red, red, purple-red or brown-red. The overcolor amount can be 0–100%.[13] The skin may be wholly or partly russeted, making it rough and brown. The skin is covered in a protective layer of epicuticular wax.[14] The skin may also be marked with scattered dots.[1] The flesh is generally pale yellowish-white, though it can be pink, yellow or green.[13]

Chemistry

Important volatile compounds in apples that contribute to their scent and flavour include acetaldehyde, ethyl acetate, 1-butanal, ethanol, 2-methylbutanal, 3-methylbutanal, ethyl propionate, ethyl 2-methylpropionate, ethyl butyrate, ethyl 2-methyl butyrate, hexanal, 1-butanol, 3-methylbutyl acetate, 2-methylbutyl acetate, 1-propyl butyrate, ethyl pentanoate, amyl acetate, 2-methyl-1-butanol, trans-2-hexenal, ethyl hexanoate, hexanol.[15][16]

Taxonomy

The apple as a species has more than 100 alternative scientific names, or synonyms.[17] In modern times, Malus pumila and Malus domestica are the two main names in use. M. pumila is the older name, but M. domestica has become much more commonly used starting in the 21st century, especially in the western world. Two proposals were made to make M. domestica a conserved name: the earlier proposal was voted down by the Committee for Vascular Plants of the IAPT in 2014, but in April 2017 the Committee decided, with a narrow majority, that the newly popular name should be conserved.[18] The General Committee of the IAPT decided in June 2017 to approve this change, officially conserving M. domestica.[19] Nevertheless, some works published after 2017 still use M. pumila as the correct name, under an alternate taxonomy.[2]

When first classified by Linnaeus in 1753, the pears, apples, and quinces were combined into one genus that he named Pyrus and he named the apple as Pyrus malus. This was widely accepted, however the botanist Philip Miller published an alternate classification in The Gardeners Dictionary with the apple species separated from Pyrus in 1754. He did not clearly indicate that by Malus pumila he meant the domesticated apple. Nonetheless, it was used as such by many botanists. When Moritz Balthasar Borkhausen published his scientific description of the apple in 1803 it may have been a new combination of P. malus var. domestica, but this was not directly referenced by Borkhausen.[17] The earliest use of var. domestica for the apple was by Georg Adolf Suckow in 1786.[2]

Genome

Apples are diploid, with two sets of chromosomes per cell (though triploid cultivars, with three sets, are not uncommon), have 17 chromosomes and an estimated genome size of approximately 650 Mb. Several whole genome sequences have been completed and made available. The first one in 2010 was based on the diploid cultivar 'Golden Delicious'.[20] However, this first whole genome sequence contained several errors,[21] in part owing to the high degree of heterozygosity in diploid apples which, in combination with an ancient genome duplication, complicated the assembly. Recently, double- and trihaploid individuals have been sequenced, yielding whole genome sequences of higher quality.[22][23]

The first whole genome assembly was estimated to contain around 57,000 genes,[20] though the more recent genome sequences support estimates between 42,000 and 44,700 protein-coding genes.[22][23] The availability of whole genome sequences has provided evidence that the wild ancestor of the cultivated apple most likely is Malus sieversii. Re-sequencing of multiple accessions has supported this, while also suggesting extensive introgression from Malus sylvestris following domestication.[24]

Cultivation

History

Map of the origins of the cultivated apple. The wild origin is in Kazakhstan; hybridisations and repeated domestications followed, modifying many attributes of the fruit.[24]
color photograph of a hand holding a red apple
Wild Malus sieversii apple in Kazakhstan

Central Asia is generally considered the center of origin for apples due to the genetic variability in specimens there.[25] The wild ancestor of Malus domestica was Malus sieversii, found growing wild in the mountains of Central Asia in southern Kazakhstan, Kyrgyzstan, Tajikistan, and northwestern China.[5][26] Cultivation of the species, most likely beginning on the forested flanks of the Tian Shan mountains, progressed over a long period of time and permitted secondary introgression of genes from other species into the open-pollinated seeds. Significant exchange with Malus sylvestris, the crabapple, resulted in populations of apples being more related to crabapples than to the more morphologically similar progenitor Malus sieversii. In strains without recent admixture the contribution of the latter predominates.[27][28][29]

The apple is thought to have been domesticated 4,000–10,000 years ago in the Tian Shan mountains, and then to have travelled along the Silk Road to Europe, with hybridization and introgression of wild crabapples from Siberia (M. baccata), the Caucasus (M. orientalis), and Europe (M. sylvestris). Only the M. sieversii trees growing on the western side of the Tian Shan mountains contributed genetically to the domesticated apple, not the isolated population on the eastern side.[24]

Chinese soft apples, such as M. asiatica and M. prunifolia, have been cultivated as dessert apples for more than 2,000 years in China. These are thought to be hybrids between M. baccata and M. sieversii in Kazakhstan.[24]

Among the traits selected for by human growers are size, fruit acidity, color, firmness, and soluble sugar. Unusually for domesticated fruits, the wild M. sieversii origin is only slightly smaller than the modern domesticated apple.[24]

At the Sammardenchia-Cueis site near Udine in Northeastern Italy, seeds from some form of apples have been found in material carbon dated to between 6570 and 5684 BCE.[30] Genetic analysis has not yet been successfully used to determine whether such ancient apples were wild Malus sylvestris or Malus domesticus containing Malus sieversii ancestry. It is hard to distinguish in the archeological record between foraged wild apples and apple plantations.[31]

There is indirect evidence of apple cultivation in the third millennium BCE in the Middle East.[31] There is direct evidence, apple cores, dated to the 10th century BCE from a Judean site between the Sinai and Negev. [32] There was substantial apple production in European classical antiquity, and grafting was certainly known then.[31] Grafting is an essential part of modern domesticated apple production, to be able to propagate the best cultivars; it is unclear when apple tree grafting was invented.[31]

The Roman writer Pliny the Elder describes a method of storage for apples from his time in the 1st century. He says they should be placed in a room with good air circulation from a north facing window on a bed of straw, chaff, or mats with windfalls kept separately.[33] Though methods like this will extend the availabity of reasonably fresh apples, without refrigeration their lifespan is limited. Even sturdy winter apple varieties will only keep well until December in cool climates.[34] For longer storage medieval Europeans strung up cored and peeled apples to dry, either whole or sliced into rings.[35]

Of the many Old World plants that the Spanish introduced to Chiloé Archipelago in the 16th century, apple trees became particularly well adapted.[36] Apples were introduced to North America by colonists in the 17th century,[5] and the first named apple cultivar was introduced in Boston by Reverend William Blaxton in 1640.[37] The only apples native to North America are crab apples.[38]

Apple cultivars brought as seed from Europe were spread along Native American trade routes, as well as being cultivated on colonial farms. An 1845 United States apples nursery catalogue sold 350 of the "best" cultivars, showing the proliferation of new North American cultivars by the early 19th century.[38] In the 20th century, irrigation projects in Eastern Washington began and allowed the development of the multibillion-dollar fruit industry, of which the apple is the leading product.[5]

Until the 20th century, farmers stored apples in frostproof cellars during the winter for their own use or for sale. Improved transportation of fresh apples by train and road replaced the necessity for storage.[39][40] Controlled atmosphere facilities are used to keep apples fresh year-round. Controlled atmosphere facilities use high humidity, low oxygen, and controlled carbon dioxide levels to maintain fruit freshness. They were first researched at Cambridge University in the 1920s and first used in the United States in the 1950s.[41]

Breeding

An apple tree in Germany

Many apples grow readily from seeds. However, apples must be propagated asexually to obtain cuttings with the characteristics of the parent. This is because seedling apples are "extreme heterozygotes". Rather than resembling their parents, seedlings are all different from each other and from their parents.[42] Triploid cultivars have an additional reproductive barrier in that three sets of chromosomes cannot be divided evenly during meiosis, yielding unequal segregation of the chromosomes (aneuploids). Even in the case when a triploid plant can produce a seed (apples are an example), it occurs infrequently, and seedlings rarely survive.[43]

Because apples are not true breeders when planted as seeds, propagation usually involves grafting of cuttings. The rootstock used for the bottom of the graft can be selected to produce trees of a large variety of sizes, as well as changing the winter hardiness, insect and disease resistance, and soil preference of the resulting tree. Dwarf rootstocks can be used to produce very small trees (less than 3.0 m or 10 ft high at maturity), which bear fruit many years earlier in their life cycle than full size trees, and are easier to harvest.[44]

Dwarf rootstocks for apple trees can be traced as far back as 300 BCE, to the area of Persia and Asia Minor. Alexander the Great sent samples of dwarf apple trees to Aristotle's Lyceum. Dwarf rootstocks became common by the 15th century and later went through several cycles of popularity and decline throughout the world.[45] The majority of the rootstocks used to control size in apples were developed in England in the early 1900s. The East Malling Research Station conducted extensive research into rootstocks, and their rootstocks are given an "M" prefix to designate their origin. Rootstocks marked with an "MM" prefix are Malling-series cultivars later crossed with trees of 'Northern Spy' in Merton, England.[46]

Most new apple cultivars originate as seedlings, which either arise by chance or are bred by deliberately crossing cultivars with promising characteristics.[47] The words "seedling", "pippin", and "kernel" in the name of an apple cultivar suggest that it originated as a seedling. Apples can also form bud sports (mutations on a single branch). Some bud sports turn out to be improved strains of the parent cultivar. Some differ sufficiently from the parent tree to be considered new cultivars.[48]

Apples have been acclimatized in Ecuador at very high altitudes, where they can often, with the needed factors, provide crops twice per year because of constant temperate conditions year-round.[49]

Pollination

Apple blossom from an old Ayrshire cultivar
An orchard mason bee on an apple bloom in British Columbia, Canada

Apples are self-incompatible; they must cross-pollinate to develop fruit. During the flowering each season, apple growers often utilize pollinators to carry pollen. Honey bees are most commonly used. Orchard mason bees are also used as supplemental pollinators in commercial orchards. Bumblebee queens are sometimes present in orchards, but not usually in sufficient number to be significant pollinators.[48][50]

Cultivars are sometimes classified by the day of peak bloom in the average 30-day blossom period, with pollinizers selected from cultivars within a 6-day overlap period. There are four to seven pollination groups in apples, depending on climate:

  • Group A – Early flowering, 1 to 3 May in England ('Gravenstein', 'Red Astrachan')
  • Group B – 4 to 7 May ('Idared', 'McIntosh')
  • Group C – Mid-season flowering, 8 to 11 May ('Granny Smith', 'Cox's Orange Pippin')
  • Group D – Mid/late season flowering, 12 to 15 May ('Golden Delicious', 'Calville blanc d'hiver')
  • Group E – Late flowering, 16 to 18 May ('Braeburn', 'Reinette d'Orléans')
  • Group F – 19 to 23 May ('Suntan')
  • Group H – 24 to 28 May ('Court-Pendu Gris' – also called Court-Pendu plat)

One cultivar can be pollinated by a compatible cultivar from the same group or close (A with A, or A with B, but not A with C or D).[51]

Maturation and harvest

L. K. Relander, the former President of Finland, with his family picking apples in the 1930s

Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock. Some cultivars, if left unpruned, grow very large—letting them bear more fruit, but making harvesting more difficult. Depending on tree density (number of trees planted per unit surface area), mature trees typically bear 40–200 kg (90–440 lb) of apples each year, though productivity can be close to zero in poor years. Apples are harvested using three-point ladders that are designed to fit amongst the branches. Trees grafted on dwarfing rootstocks bear about 10–80 kg (20–180 lb) of fruit per year.[48]

Some farms with apple orchards open them to the public so consumers can pick their own apples.[52]

Crops ripen at different times of the year according to the cultivar. Cultivar that yield their crop in the summer include 'Sweet Bough' and 'Duchess'; fall producers include 'Blenheim'; winter producers include 'King', 'Swayzie', and 'Tolman Sweet'.[38]

Storage

Different apple cultivars in a wholesale food market

Commercially, apples can be stored for months in controlled atmosphere chambers. Apples are commonly stored in chambers with lowered concentrations of oxygen to reduce respiration and slow softening and other changes if the fruit is already fully ripe. The gas ethylene is used by plants as a hormone which promotes ripening, decreasing the time an apple can be stored. For storage longer than about six months the apples are picked earlier, before full ripeness, when ethylene production by the fruit is low. However, in many varieties this increases their sensitivity to carbon dioxide, which also must be controlled.[53]

For home storage, most culitvars of apple can be stored for three weeks in a pantry and four to six weeks from the date of purchase in a refrigerator that maintains 4 to 0 °C (39 to 32 °F).[54][55] Some varieties of apples (e.g. 'Granny Smith' and 'Fuji') have more than three times the storage life of others.[56]

Non-organic apples may be sprayed with a substance 1-methylcyclopropene blocking the apples' ethylene receptors, temporarily preventing them from ripening.[57]

Pests and diseases

Codling moth larva tunnelling inside an apple

Apple trees are susceptible to fungal and bacterial diseases, and to damage by insect pests. Many commercial orchards pursue a program of chemical sprays to maintain high fruit quality, tree health, and high yields. These prohibit the use of synthetic pesticides, though some older pesticides are allowed. Organic methods include, for instance, introducing its natural predator to reduce the population of a particular pest.

A wide range of pests and diseases can affect the plant. Three of the more common diseases or pests are mildew, aphids, and apple scab.

  • Mildew is characterized by light grey powdery patches appearing on the leaves, shoots and flowers, normally in spring. The flowers turn a creamy yellow color and do not develop correctly. This can be treated similarly to Botrytis—eliminating the conditions that caused the disease and burning the infected plants are among recommended actions.[58]
  • Aphids are small insects with sucking mouthparts. Five species of aphids commonly attack apples: apple grain aphid, rosy apple aphid, apple aphid, spirea aphid, and the woolly apple aphid. The aphid species can be identified by color, time of year, and by differences in the cornicles (small paired projections from their rear).[59] Aphids feed on foliage using needle-like mouth parts to suck out plant juices. When present in high numbers, certain species reduce tree growth and vigor.[60]
  • Apple scab: Apple scab causes leaves to develop olive-brown spots with a velvety texture that later turn brown and become cork-like in texture. The disease also affects the fruit, which also develops similar brown spots with velvety or cork-like textures. Apple scab is spread through fungus growing in old apple leaves on the ground and spreads during warm spring weather to infect the new year's growth.[61]

Among the most serious disease problems is a bacterial disease called fireblight, and three fungal diseases: Gymnosporangium rust, black spot,[62] and bitter rot.[63] Codling moths, and the apple maggots of fruit flies, cause serious damage to apple fruits, making them unsaleable. Young apple trees are also prone to mammal pests like mice and deer, which feed on the soft bark of the trees, especially in winter.[61] The larvae of the apple clearwing moth (red-belted clearwing) burrow through the bark and into the phloem of apple trees, potentially causing significant damage.[64]

Cultivars

An assortment of apple cultivars

There are more than 7,500 known cultivars (cultivated varieties) of apples.[65] Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock.[66] Different cultivars are available for temperate and subtropical climates. The UK's National Fruit Collection, which is the responsibility of the Department of Environment, Food, and Rural Affairs, includes a collection of over 2,000 cultivars of apple tree in Kent.[67] The University of Reading, which is responsible for developing the UK national collection database, provides access to search the national collection. The University of Reading's work is part of the European Cooperative Programme for Plant Genetic Resources of which there are 38 countries participating in the Malus/Pyrus work group.[68]

The UK's national fruit collection database contains much information on the characteristics and origin of many apples, including alternative names for what is essentially the same "genetic" apple cultivar. Most of these cultivars are bred for eating fresh (dessert apples), though some are cultivated specifically for cooking (cooking apples) or producing cider. Cider apples are typically too tart and astringent to eat fresh, but they give the beverage a rich flavor that dessert apples cannot.[69]

In the United States there are many apple breeding programs associated with universities. Cornell University has had a program operating since 1880 in Geneva, New York. Among their recent well known apples is the 'SnapDragon' cultivar released in 2013. In the west Washington State University started a program to support their apple industry in 1994 and released the 'Cosmic Crisp' cultivar in 2017. The third most grown apple cultivar in the United States is the 'Honeycrisp', released by the University of Minnesota program in 1991.[70] Unusually for a popular cultivar, the 'Honeycrisp' is not directly related to another popular apple cultivar but instead to two unsuccessful cultivars.[71] In Europe there are also many breeding programs such as the Julius Kühn-Institut, the German federal research center for cultivated plants.[72]

Commercially popular apple cultivars are soft but crisp. Other desirable qualities in modern commercial apple breeding are a colorful skin, absence of russeting, ease of shipping, lengthy storage ability, high yields, disease resistance, common apple shape, and developed flavor.[66] Modern apples are generally sweeter than older cultivars, as popular tastes in apples have varied over time. Most North Americans and Europeans favor sweet, subacid apples, but tart apples have a strong minority following.[73] Extremely sweet apples with barely any acid flavor are popular in Asia,[73] especially the Indian subcontinent.[69]

Less common apple cultivars from an orchard in Italy

Old cultivars are often oddly shaped, russeted, and grow in a variety of textures and colors. Some find them to have better flavor than modern cultivars, but they may have other problems that make them commercially unviable—low yield, disease susceptibility, poor tolerance for storage or transport, or just being the "wrong" size.[74] A few old cultivars are still produced on a large scale, but many have been preserved by home gardeners and farmers that sell directly to local markets. Many unusual and locally important cultivars with their own unique taste and appearance exist; apple conservation campaigns have sprung up around the world to preserve such local cultivars from extinction. In the United Kingdom, old cultivars such as 'Cox's Orange Pippin' and 'Egremont Russet' are still commercially important even though by modern standards they are low yielding and susceptible to disease.[5]

Production

Apple production

2022, millions of tonnes

 China 47.6
 United States 4.8
 Turkey 4.4
 Poland 4.3
 India 2.6
World 95.8
Source: FAOSTAT of the United Nations[75]

World production of apples in 2022 was 96 million tonnes, with China producing 50% of the total (table).[75] Secondary producers were the United States, Turkey, and Poland.[75]

Toxicity

Amygdalin

Apple seeds contain small amounts of amygdalin, a sugar and cyanide compound known as a cyanogenic glycoside. Ingesting small amounts of apple seeds causes no ill effects, but consumption of extremely large doses can cause adverse reactions. It may take several hours before the poison takes effect, as cyanogenic glycosides must be hydrolyzed before the cyanide ion is released.[76] The U.S. National Library of Medicine's Hazardous Substances Data Bank records no cases of amygdalin poisoning from consuming apple seeds.[77]

Allergy

One form of apple allergy, often found in northern Europe, is called birch-apple syndrome and is found in people who are also allergic to birch pollen.[78] Allergic reactions are triggered by a protein in apples that is similar to birch pollen, and people affected by this protein can also develop allergies to other fruits, nuts, and vegetables. Reactions, which entail oral allergy syndrome (OAS), generally involve itching and inflammation of the mouth and throat,[78] but in rare cases can also include life-threatening anaphylaxis.[79] This reaction only occurs when raw fruit is consumed—the allergen is neutralized in the cooking process. The variety of apple, maturity and storage conditions can change the amount of allergen present in individual fruits. Long storage times can increase the amount of proteins that cause birch-apple syndrome.[78]

In other areas, such as the Mediterranean, some individuals have adverse reactions to apples because of their similarity to peaches.[78] This form of apple allergy also includes OAS, but often has more severe symptoms, such as vomiting, abdominal pain and urticaria, and can be life-threatening. Individuals with this form of allergy can also develop reactions to other fruits and nuts. Cooking does not break down the protein causing this particular reaction, so affected individuals cannot eat raw or cooked apples. Freshly harvested, over-ripe fruits tend to have the highest levels of the protein that causes this reaction.[78]

Breeding efforts have yet to produce a hypoallergenic fruit suitable for either of the two forms of apple allergy.[78]

Uses

Nutrition

Apples, with skin (edible parts)
Nutritional value per 100 g (3.5 oz)
Energy218 kJ (52 kcal)
13.81 g
Sugars10.39
Dietary fiber2.4 g
0.17 g
0.26 g
Vitamins and minerals
VitaminsQuantity
%DV
Vitamin A equiv.
0%
3 μg
0%
27 μg
29 μg
Thiamine (B1)
1%
0.017 mg
Riboflavin (B2)
2%
0.026 mg
Niacin (B3)
1%
0.091 mg
Pantothenic acid (B5)
1%
0.061 mg
Vitamin B6
2%
0.041 mg
Folate (B9)
1%
3 μg
Vitamin C
5%
4.6 mg
Vitamin E
1%
0.18 mg
Vitamin K
2%
2.2 μg
MineralsQuantity
%DV
Calcium
0%
6 mg
Iron
1%
0.12 mg
Magnesium
1%
5 mg
Manganese
2%
0.035 mg
Phosphorus
1%
11 mg
Potassium
4%
107 mg
Sodium
0%
1 mg
Zinc
0%
0.04 mg
Other constituentsQuantity
Water85.56 g

Percentages estimated using US recommendations for adults,[80] except for potassium, which is estimated based on expert recommendation from the National Academies.[81]

A raw apple is 86% water and 14% carbohydrates, with negligible content of fat and protein (table). A reference serving of a raw apple with skin weighing 100 g (3.5 oz) provides 52 calories and a moderate content of dietary fiber (table). Otherwise, there is low content of micronutrients, with the Daily Values of all falling below 10% (table).

Culinary

Machine for paring, coring, and slicing apples, from Henry B. Scammell's 1897 handbook Cyclopedia of Valuable Receipts

Apples varieties can be grouped as cooking apples, eating apples, and cider apples, the last so astringent as to be "almost inedible".[82] Apples are consumed as juice, raw in salads, baked in pies, cooked into sauces and apple butter, or baked.[83] They are sometimes used as an ingredient in savory foods, such as sausage and stuffing.[84]

Several techniques are used to preserve apples and apple products. Traditional methods include drying and making apple butter.[82] Juice and cider are produced commercially; cider is a significant industry in regions such as the West of England and Normandy.[82]

A toffee apple (UK) or caramel apple (US) is a confection made by coating an apple in hot toffee or caramel candy respectively and allowing it to cool.[85][8] Apples and honey are a ritual food pairing eaten during the Jewish New Year of Rosh Hashanah.[86]

Apples are an important ingredient in many desserts, such as pies, crumbles, and cakes. When cooked, some apple cultivars easily form a puree known as apple sauce, which can be cooked down to form a preserve, apple butter. They are often baked or stewed, and are cooked in some meat dishes.[82]

Apples are milled or pressed to produce apple juice, which may be drunk unfiltered (called apple cider in North America), or filtered. Filtered juice is often concentrated and frozen, then reconstituted later and consumed. Apple juice can be fermented to make cider (called hard cider in North America), ciderkin, and vinegar.[8] Through distillation, various alcoholic beverages can be produced, such as applejack, Calvados, and apple brandy.[8][87]

Organic production

Organic apples are commonly produced in the United States.[88] Due to infestations by key insects and diseases, organic production is difficult in Europe.[89] The use of pesticides containing chemicals, such as sulfur, copper, microorganisms, viruses, clay powders, or plant extracts (pyrethrum, neem) has been approved by the EU Organic Standing Committee to improve organic yield and quality.[89] A light coating of kaolin, which forms a physical barrier to some pests, also may help prevent apple sun scalding.[48]

Non-browning apples

Apple skins and seeds contain polyphenols.[90] These are oxidised by the enzyme polyphenol oxidase, which causes browning in sliced or bruised apples, by catalyzing the oxidation of phenolic compounds to o-quinones, a browning factor.[91] Browning reduces apple taste, color, and food value. Arctic apples, a non-browning group of apples introduced to the United States market in 2019, have been genetically modified to silence the expression of polyphenol oxidase, thereby delaying a browning effect and improving apple eating quality.[92][93] The US Food and Drug Administration in 2015, and Canadian Food Inspection Agency in 2017, determined that Arctic apples are as safe and nutritious as conventional apples.[94][95]

Other products

Apple seed oil is obtained by pressing apple seeds for manufacturing cosmetics.[96]

In culture

Germanic paganism

Illustration of girl in a red dress, holding 3 candles in one hand and a basket of apples in the other
"Brita as Iduna" (1901) by Carl Larsson

In Norse mythology, the goddess Iðunn is portrayed in the Prose Edda (written in the 13th century by Snorri Sturluson) as providing apples to the gods that give them eternal youthfulness. The English scholar H. R. Ellis Davidson links apples to religious practices in Germanic paganism, from which Norse paganism developed. She points out that buckets of apples were found in the Oseberg ship burial site in Norway, that fruit and nuts (Iðunn having been described as being transformed into a nut in Skáldskaparmál) have been found in the early graves of the Germanic peoples in England and elsewhere on the continent of Europe, which may have had a symbolic meaning, and that nuts are still a recognized symbol of fertility in southwest England.[97]

Davidson notes a connection between apples and the Vanir, a tribe of gods associated with fertility in Norse mythology, citing an instance of eleven "golden apples" being given to woo the beautiful Gerðr by Skírnir, who was acting as messenger for the major Vanir god Freyr in stanzas 19 and 20 of Skírnismál. Davidson also notes a further connection between fertility and apples in Norse mythology in chapter 2 of the Völsunga saga: when the major goddess Frigg sends King Rerir an apple after he prays to Odin for a child, Frigg's messenger (in the guise of a crow) drops the apple in his lap as he sits atop a mound.[97] Rerir's wife's consumption of the apple results in a six-year pregnancy and the birth (by Caesarean section) of their son—the hero Völsung.[98]

Further, Davidson points out the "strange" phrase "Apples of Hel" used in an 11th-century poem by the skald Thorbiorn Brúnarson. She states this may imply that the apple was thought of by Brúnarson as the food of the dead. Further, Davidson notes that the potentially Germanic goddess Nehalennia is sometimes depicted with apples and that parallels exist in early Irish stories. Davidson asserts that while cultivation of the apple in Northern Europe extends back to at least the time of the Roman Empire and came to Europe from the Near East, the native varieties of apple trees growing in Northern Europe are small and bitter. Davidson concludes that in the figure of Iðunn "we must have a dim reflection of an old symbol: that of the guardian goddess of the life-giving fruit of the other world."[97]

Greek mythology

Heracles with the apple of Hesperides

Apples appear in many religious traditions, including Greek and Roman mythology where it has an ambiguous symbolism of discord, fertility, or courtship.[99] In Greek mythology, the Greek hero Heracles, as a part of his Twelve Labours, was required to travel to the Garden of the Hesperides and pick the golden apples off the Tree of Life growing at its center.[100]

The Greek goddess of discord, Eris, became disgruntled after she was excluded from the wedding of Peleus and Thetis.[101] In retaliation, she tossed a golden apple inscribed Καλλίστη (Kallistē, "For the most beautiful one"), into the wedding party. Three goddesses claimed the apple: Hera, Athena, and Aphrodite. Paris of Troy was appointed to select the recipient. After being bribed by both Hera and Athena, Aphrodite tempted him with the most beautiful woman in the world, Helen of Sparta. He awarded the apple to Aphrodite, thus indirectly causing the Trojan War.[102][103]

The apple was thus considered, in ancient Greece, sacred to Aphrodite. To throw an apple at someone was to symbolically declare one's love; and similarly, to catch it was to symbolically show one's acceptance of that love. An epigram claiming authorship by Plato states:[104]

I throw the apple at you, and if you are willing to love me, take it and share your girlhood with me; but if your thoughts are what I pray they are not, even then take it, and consider how short-lived is beauty.

— Plato, Epigram VII

Atalanta, also of Greek mythology, raced all her suitors in an attempt to avoid marriage. She outran all but Hippomenes (also known as Melanion, a name possibly derived from melon, the Greek word for both "apple" and fruit in general),[100] who defeated her by cunning, not speed. Hippomenes knew that he could not win in a fair race, so he used three golden apples (gifts of Aphrodite, the goddess of love) to distract Atalanta. It took all three apples and all of his speed, but Hippomenes was finally successful, winning the race and Atalanta's hand.[105][106]

Celtic mythology

In Celtic mythology, the otherworld has many names, including Emain Ablach, "Emain of the Apple-trees". A version of this is Avalon in Arthurian legend, or in Welsh Ynys Afallon, "Island of Apples".[107]

China

Píngānguǒ ("Peace apples") on sale in Beijing for Christmas Eve (2017)

In China, apples symbolise peace, since the sounds of the first element ("píng") in the words "apple" (苹果, Píngguǒ) and "peace" (平安, Píng'ān) are homophonous in Mandarin and Cantonese.[3][108] When these two words are combined, the word Píngānguǒ (平安果, "Peace apples") is formed. This association developed further as the name for Christmas Eve in Mandarin is Píngānyè (平安夜, "Peaceful/Quiet Evening"), which made the gifting of apples at this season to friends and associates popular, as a way to wish them peace and safety.[108]

Christian art

Adam and Eve by Albrecht Dürer (1507), showcasing the apple as a symbol of sin

Though the forbidden fruit of Eden in the Book of Genesis is not identified, popular Christian tradition has held that it was an apple that Eve coaxed Adam to share with her.[109] The origin of the popular identification with a fruit unknown in the Middle East in biblical times is found in wordplay with the Latin words mālum (an apple) and mălum (an evil), each of which is normally written malum.[110] The tree of the forbidden fruit is called "the tree of the knowledge of good and evil" in Genesis 2:17,[111] and the Latin for "good and evil" is bonum et malum.[112]

Renaissance painters may also have been influenced by the story of the golden apples in the Garden of Hesperides. As a result, in the story of Adam and Eve, the apple became a symbol for knowledge, immortality, temptation, the fall of man into sin, and sin itself. The larynx in the human throat has been called the "Adam's apple" because of a notion that it was caused by the forbidden fruit remaining in the throat of Adam. The apple as symbol of sexual seduction has been used to imply human sexuality, possibly in an ironic vein.[109]

Proverb

The proverb, "An apple a day keeps the doctor away", addressing the supposed health benefits of the fruit, has been traced to 19th-century Wales, where the original phrase was "Eat an apple on going to bed, and you'll keep the doctor from earning his bread".[113] In the 19th century and early 20th, the phrase evolved to "an apple a day, no doctor to pay" and "an apple a day sends the doctor away"; the phrasing now commonly used was first recorded in 1922.[114]

See also

References

  1. ^ a b c d e f g h i j k Dickson, Elizabeth E. (28 May 2021). "Malus domestica". Flora of North America. Archived from the original on 28 July 2024. Retrieved 27 July 2024.
  2. ^ a b c "Malus domestica (Suckow) Borkh". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 31 July 2024.
  3. ^ a b Lim, Lisa (6 July 2021). "Where the word 'apple' came from and why the forbidden fruit was unlucky to be linked with the fall of man". Language Matters. South China Morning Post. Hong Kong, China: Alibaba Group. Archived from the original on 28 June 2023. Retrieved 28 June 2023.
  4. ^ "Origin and meaning of "apple" by Online Etymology Dictionary". Online Etymology Dictionary. Archived from the original on 21 December 2019. Retrieved 22 November 2019.
  5. ^ a b c d e f g Rieger, Mark. "Apple - Malus domestica". HORT 3020: Intro Fruit Crops. University of Georgia. Archived from the original on 21 January 2008. Retrieved 22 January 2008.
  6. ^ a b c "Apples - Malus domestica". North Carolina Extension Gardener Plant Toolbox. North Carolina State University. Archived from the original on 31 May 2024. Retrieved 31 July 2024.
  7. ^ a b c d Heil, Kenneth D.; O'Kane, Jr., Steve L.; Reeves, Linda Mary; Clifford, Arnold (2013). Flora of the Four Corners Region: Vascular Plants of the San Juan River Drainage, Arizona, Colorado, New Mexico, and Utah (First ed.). St. Louis, Missouri: Missouri Botanical Garden. p. 909. ISBN 978-1-930723-84-9. OCLC 859541992. Retrieved 27 July 2024.
  8. ^ a b c d e Lim, Tong Kwee (2012). "Malus x domestica". Edible Medicinal and Non-Medicinal Plants. Vol. 4, Fruit (First ed.). Dordrecht, the Netherlands: Springer. pp. 414–415. doi:10.1007/978-94-007-4053-2_49. ISBN 978-94-007-4053-2. OCLC 795503871.
  9. ^ Juniper, Barrie E.; Mabberley, David J. (2006). The Story of the Apple (First ed.). Portland, Oregon: Timber Press. p. 27. ISBN 978-0-88192-784-9. LCCN 2006011869. OCLC 67383484. Retrieved 1 August 2024.
  10. ^ "Fruit glossary". Royal Horticultural Society. Archived from the original on 7 August 2024. Retrieved 7 August 2024.
  11. ^ Burford, Tom (2013). Apples of North America : 192 Exceptional Varieties for Gardeners, Growers and Cooks (First ed.). Portland, Oregon: Timber Press. pp. 22, 50, 55, 122, 123, 137, 141, 147, 159, 245, 246. ISBN 978-1-60469-249-5. LCCN 2012045130. OCLC 819860825.
  12. ^ "Shape". Western Agricultural Research Center. Montana State University. Archived from the original on 23 April 2024. Retrieved 30 July 2024.
  13. ^ a b Janick, Jules; Cummins, James N.; Brown, Susan K.; Hemmat, Minou (1996). "Chapter 1: Apples" (PDF). Fruit Breeding. Vol. I: Tree and Tropical Fruits. New York: John Wiley & Sons. pp. 9, 48. ISBN 978-0-471-31014-3. LCCN 95016407. OCLC 1302621533. Archived (PDF) from the original on 19 July 2013. Retrieved 30 August 2024.
  14. ^ "Natural Waxes on Fruits". Postharvest.tfrec.wsu.edu. 29 October 2010. Archived from the original on 24 May 2013. Retrieved 14 June 2013.
  15. ^ Flath, R. A.; Black, D. R.; Forrey, R. R.; McDonald, G. M.; Mon, T. R.; Teranishi, R. (1 August 1969). "Volatiles in Gravenstein Apple Essence Identified by GC-Mass Spectrometry". Journal of Chromatographic Science. 7 (8): 508. doi:10.1093/CHROMSCI/7.8.508.
  16. ^ Flath, Robert A.; Black, Dale Robert.; Guadagni, Dante G.; McFadden, William H.; Schultz, Thomas H. (January 1967). "Identification and organoleptic evaluation of compounds in Delicious apple essence". Journal of Agricultural and Food Chemistry. 15 (1): 29. doi:10.1021/jf60149a032.
  17. ^ a b Qian, Guan-Ze; Liu, Lian-Fen; Tang, Geng-Guo (April 2010). "(1933) Proposal to conserve the name Malus domestica against M. pumila, M. communis, M. frutescens, and Pyrus dioica ( Rosaceae )". Taxon. 59 (2): 650–652. doi:10.1002/tax.592038.
  18. ^ Applequist, Wendy L. (2017). "Report of the Nomenclature Committee for Vascular Plants: 69" (PDF). Taxon. 66 (2): 500–513. doi:10.12705/662.17. Archived (PDF) from the original on 7 May 2024.
  19. ^ Wilson, Karen L. (June 2017). "Report of the General Committee: 18". Taxon. 66 (3): 742. doi:10.12705/663.15.
  20. ^ a b Velasco, Riccardo; Zharkikh, Andrey; Affourtit, Jason; Dhingra, Amit; Cestaro, Alessandro; et al. (2010). "The genome of the domesticated apple (Malus × domestica Borkh.)". Nature Genetics. 42 (10): 833–839. doi:10.1038/ng.654. PMID 20802477. S2CID 14854514.
  21. ^ Di Pierro, Erica A.; Gianfranceschi, Luca; Di Guardo, Mario; Koehorst-Van Putten, Herma J.J.; Kruisselbrink, Johannes W.; et al. (2016). "A high-density, multi-parental SNP genetic map on apple validates a new mapping approach for outcrossing species". Horticulture Research. 3 (1): 16057. Bibcode:2016HorR....316057D. doi:10.1038/hortres.2016.57. PMC 5120355. PMID 27917289.
  22. ^ a b Daccord, Nicolas; Celton, Jean-Marc; Linsmith, Gareth; et al. (2017). "High-quality de novo assembly of the apple genome and methylome dynamics of early fruit development". Nature Genetics. 49 (7). Nature Communications: 1099–1106. doi:10.1038/ng.3886. hdl:10449/42064. PMID 28581499. S2CID 24690391.
  23. ^ a b Zhang, Liyi; Hu, Jiang; Han, Xiaolei; Li, Jingjing; Gao, Yuan; et al. (2019). "A high-quality apple genome assembly reveals the association of a retrotransposon and red fruit colour". Nature Communications. 10 (1). Nature Genetics: 1494. Bibcode:2019NatCo..10.1494Z. doi:10.1038/s41467-019-09518-x. PMC 6445120. PMID 30940818.
  24. ^ a b c d e Duan, Naibin; Bai, Yang; Sun, Honghe; Wang, Nan; Ma, Yumin; et al. (2017). "Genome re-sequencing reveals the history of apple and supports a two-stage model for fruit enlargement". Nature Communications. 8 (1): 249. Bibcode:2017NatCo...8..249D. doi:10.1038/s41467-017-00336-7. PMC 5557836. PMID 28811498.
  25. ^ Richards, Christopher M.; Volk, Gayle M.; Reilley, Ann A.; Henk, Adam D.; Lockwood, Dale R.; et al. (2009). "Genetic diversity and population structure in Malus sieversii, a wild progenitor species of domesticated apple". Tree Genetics & Genomes. 5 (2): 339–347. doi:10.1007/s11295-008-0190-9. S2CID 19847067.
  26. ^ Lauri, Pierre-éric; Maguylo, Karen; Trottier, Catherine (March 2006). "Architecture and size relations: an essay on the apple (Malus × domestica, Rosaceae) tree". American Journal of Botany. 93 (3): 357–368. doi:10.3732/ajb.93.3.357. PMID 21646196. Archived from the original on 20 April 2019. Retrieved 27 July 2024.
  27. ^ Cornille, Amandine; Gladieux, Pierre; Smulders, Marinus J. M.; Roldán-Ruiz, Isabel; Laurens, François; et al. (2012). Mauricio, Rodney (ed.). "New Insight into the History of Domesticated Apple: Secondary Contribution of the European Wild Apple to the Genome of Cultivated Varieties". PLOS Genetics. 8 (5): e1002703. doi:10.1371/journal.pgen.1002703. PMC 3349737. PMID 22589740.
  28. ^ Kean, Sam (17 May 2012). "ScienceShot: The Secret History of the Domesticated Apple". Archived from the original on 11 June 2016.
  29. ^ Coart, E.; Van Glabeke, S.; De Loose, M.; Larsen, A.S.; Roldán-Ruiz, I. (2006). "Chloroplast diversity in the genus Malus: new insights into the relationship between the European wild apple (Malus sylvestris (L.) Mill.) and the domesticated apple (Malus domestica Borkh.)". Mol. Ecol. 15 (8): 2171–2182. Bibcode:2006MolEc..15.2171C. doi:10.1111/j.1365-294x.2006.02924.x. PMID 16780433. S2CID 31481730.
  30. ^ Rottoli, Mauro; Pessina, Andrea (2007). "Chapter 9: Neolithic agriculture in Italy: an update of archaeobotanical data with particular emphasis on northern settlements". In Colledge, Sue; Conolly, James (eds.). The Origins and Spread of Domestic Plants in Southwest Asia and Europe (First ed.). Walnut Creek, California: Left Coast Press; University College London Institute of Archaeology Publications. pp. 142–143. ISBN 978-1-59874-988-5. OCLC 84838157.
  31. ^ a b c d Schlumbaum, Angela; van Glabeke, Sabine; Roldan-Ruiz, Isabel (January 2012). "Towards the onset of fruit tree growing north of the Alps: Ancient DNA from waterlogged apple (Malus sp.) seed fragments". Annals of Anatomy - Anatomischer Anzeiger. 194 (1): 157–162. doi:10.1016/j.aanat.2011.03.004. PMID 21501956.
  32. ^ Sauer, Jonathan D. (1993). Historical Geography of Crop Plants: A Select Roster (First ed.). Boca Raton, Florida: CRC Press. pp. 109–113. ISBN 978-0-8493-8901-6. LCCN 92045590. OCLC 27224696.
  33. ^ Plinius, Gaius Secundus (1855). The Natural History of Pliny. Vol. III. Translated by Bostock, John; Riley, Henry T. London: Henry G. Bohn. p. 303. Retrieved 3 August 2024.
  34. ^ Martin, Alice A. (1976). All About Apples (First ed.). Boston, Massachusetts: Houghton Mifflin Company. pp. 64–65. ISBN 978-0-395-20724-6. OCLC 1733691. Retrieved 3 August 2024.
  35. ^ Adamson, Melitta Weiss (2004). Food in Medieval Times (First ed.). Westport, Connecticut: Greenwood Press. pp. 19–20. ISBN 978-0-313-32147-4. LCCN 2004014054. OCLC 55738647.
  36. ^ Torrejón, Fernando; Cisternas, Marco; Araneda, Alberto (2004). "Efectos ambientales de la colonización española desde el río Maullín al archipiélago de Chiloé, sur de Chile" [Environmental effects of the spanish colonization from de Maullín river to the Chiloé archipelago, southern Chile]. Revista Chilena de Historia Natural (in Spanish). 77 (4): 661–677. doi:10.4067/s0716-078x2004000400009.
  37. ^ Smith, Archibald William (1963). A Gardener's Book of Plant Names : A Handbook of the Meaning and Origins of Plant Names (First ed.). New York: Harper & Row. p. 40. LCCN 62009906. OCLC 710612. Retrieved 10 August 2024.
  38. ^ a b c Poole, Mike (1980). "Heirloom Apples". In Lawrence, James (ed.). The Harrowsmith Reader Volume II. Camden East, Ontario: Camden House Publishing. p. 122. ISBN 978-0-920656-11-2. OCLC 1336124440. Retrieved 10 August 2024.
  39. ^ Van Valen, James M. (1900). History of Bergen County, New Jersey. New York: New Jersey Publishing and Engraving Company. pp. 33–34. OCLC 25697876. Retrieved 9 August 2024.
  40. ^ Brox, Jane (1999). Five Thousand Days Like This One (First ed.). Boston, Massachusetts: Beacon Press. pp. 150–151. ISBN 978-0-8070-2106-4. LCCN 98035051. OCLC 39605684. Retrieved 9 August 2024.
  41. ^ Cohen, Rachel D. (26 November 2018). "Thanks To Science, You Can Eat An Apple Every Day". The Salt. NPR. Archived from the original on 18 June 2024. Retrieved 1 August 2024.
  42. ^ "The Heirloom Apple Orchard". The Jentsch Lab. Cornell University. Archived from the original on 30 July 2024. Retrieved 9 August 2024.
  43. ^ Ranney, Thomas G. "Polyploidy: From Evolution to Landscape Plant Improvement". Proceedings of the 11th Metropolitan Tree Improvement Alliance (METRIA) Conference. 11th Metropolitan Tree Improvement Alliance Conference held in Gresham, Oregon, August 23–24, 2000. METRIA (NCSU.edu). METRIA. Archived from the original on 23 July 2010. Retrieved 7 November 2010.
  44. ^ Lord, William G.; Ouellette, Amy (February 2010). "Dwarf Rootstocks for Apple Trees in the Home Garden" (PDF). University of New Hampshire. Archived from the original (PDF) on 30 September 2013. Retrieved 1 September 2013.
  45. ^ Fallahi, Esmaeil; Colt, W. Michael; Fallahi, Bahar; Chun, Ik-Jo (January 2002). "The Importance of Apple Rootstocks on Tree Growth, Yield, Fruit Quality, Leaf Nutrition, and Photosynthesis with an Emphasis on 'Fuji'". HortTechnology. 12 (1): 38–44. doi:10.21273/HORTTECH.12.1.38. Archived (PDF) from the original on 11 February 2014. Retrieved 9 August 2024.
  46. ^ Parker, M.L. (September 1993). "Apple Rootstocks and Tree Spacing". North Carolina Cooperative Extension Service. Archived from the original on 11 September 2013. Retrieved 1 September 2013.
  47. ^ Ferree, David Curtis; Warrington, Ian J. (2003). Apples: Botany, Production, and Uses. New York: Centre for Agriculture and Bioscience International. pp. 33–35. ISBN 978-0851995922. OCLC 133167834.
  48. ^ a b c d Polomski, Bob; Reighard, Greg. "Apple HGIC 1350". Home & Garden Information Center. Clemson University. Archived from the original on 28 February 2008. Retrieved 22 January 2008.
  49. ^ Barahona, M. (1992). "Adaptation of Apple Varieties in Ecuador". Acta Horticulturae (310): 135–142. doi:10.17660/ActaHortic.1992.310.17.
  50. ^ Adamson, Nancy Lee (2011). An Assessment of Non-Apis Bees as Fruit and Vegetable Crop Pollinators in Southwest Virginia (PDF) (Doctor of Philosophy in Entomology thesis). Virginia Polytechnic Institute and State University. Archived (PDF) from the original on 20 November 2015. Retrieved 15 October 2015.
  51. ^ Powell, L.E. (1986). "The Chilling Requirement in Apple and Its Role in Regulating Time of Flowering in Spring in Cold-Winter Climate". Acta Horticulturae (179). Wageningen, Netherlands: International Society for Horticultural Science: 129–140. doi:10.17660/ActaHortic.1986.179.10. ISBN 978-90-6605-182-9.
  52. ^ Romano, Andrea (10 September 2023). "20 Best Places to Go Apple Picking in the United States". Travel + Leisure. Archived from the original on 21 April 2024. Retrieved 2 August 2024.
  53. ^ Graziano, Jack; Farcuh, Macarena (10 September 2021). "Controlled Atmosphere Storage of Apples". University of Maryland Extension. Archived from the original on 24 March 2023. Retrieved 2 August 2024.
  54. ^ "FoodKeeper App". FoodSafety.gov. United States Department of Health and Human Services. 26 April 2019. Retrieved 17 September 2024.
  55. ^ "4 Steps to Food Safety". FoodSafety.gov. United States Department of Health and Human Services. 12 April 2019. Retrieved 17 September 2024.
  56. ^ "Refrigerated storage of perishable foods". CSIRO. 26 February 2015. Archived from the original on 15 March 2015. Retrieved 25 May 2007.
  57. ^ Karp, David (25 October 2006). "Puff the Magic Preservative: Lasting Crunch, but Less Scent". The New York Times. Archived from the original on 3 August 2011. Retrieved 26 July 2017.
  58. ^ Jackson, H.S. (1914). "Powdery Mildew". In Lowther, Granville; Worthington, William (eds.). The Encyclopedia of Practical Horticulture: A Reference System of Commercial Horticulture, Covering the Practical and Scientific Phases of Horticulture, with Special Reference to Fruits and Vegetables. Vol. I. North Yakima, Washington: The Encyclopedia of Horticulture Corporation. pp. 475–476. Retrieved 1 August 2024.
  59. ^ Lowther, Granville; Worthington, William, eds. (1914). The Encyclopedia of Practical Horticulture: A Reference System of Commercial Horticulture, Covering the Practical and Scientific Phases of Horticulture, with Special Reference to Fruits and Vegetables. Vol. I. North Yakima, Washington: The Encyclopedia of Horticulture Corporation. pp. 45–51. Retrieved 1 August 2024.
  60. ^ Coli, William M.; Los, Lorraine M., eds. (2003). "Insect Pests". 2003-2004 New England Apple Pest Management Guide. University of Massachusetts Amherst. pp. 28–29. Archived from the original on 12 February 2008. Retrieved 3 March 2008.{{cite book}}: CS1 maint: bot: original URL status unknown (link)
  61. ^ a b Atthowe, Helen; Gilkeson, Linda A.; Kite, L. Patricia; Michalak, Patricia S.; Pleasant, Barbara; Reich, Lee; Scheider, Alfred F. (2009). Bradley, Fern Marshall; Ellis, Bardara W.; Martin, Deborah L. (eds.). The Organic Gardener's Handbook of Natural Pest and Disease Control. New York: Rodale, Inc. pp. 32–34. ISBN 978-1-60529-677-7. LCCN 2009039996. OCLC 419860680.
  62. ^ Coli, William M.; Berkett, Lorraine P.; Spitko, Robin, eds. (2003). "Other Apple Diseases". 2003-2004 New England Apple Pest Management Guide. University of Massachusetts Amherst. pp. 19–27. Archived from the original on 12 February 2008. Retrieved 3 March 2008.{{cite book}}: CS1 maint: bot: original URL status unknown (link)
  63. ^ Martin, Phillip L.; Krawczyk, Teresa; Khodadadi, Fatemeh; Aćimović, Srđan G.; Peter, Kari A. (2021). "Bitter Rot of Apple in the Mid-Atlantic United States: Causal Species and Evaluation of the Impacts of Regional Weather Patterns and Cultivar Susceptibility". Phytopathology. 111 (6): 966–981. doi:10.1094/PHYTO-09-20-0432-R. ISSN 0031-949X. PMID 33487025. S2CID 231701083.
  64. ^ Erler, Fedai (1 January 2010). "Efficacy of tree trunk coating materials in the control of the apple clearwing, Synanthedon myopaeformis". Journal of Insect Science. 10 (1): 63. doi:10.1673/031.010.6301. PMC 3014806. PMID 20672979.
  65. ^ Elzebroek, A. T. G.; Wind, Koop (2008). Guide to Cultivated Plants. Wallingford, United Kingdom: CABI. p. 27. ISBN 978-1-84593-356-2. LCCN 2007028459. OCLC 156975183. Archived from the original on 20 October 2020. Retrieved 6 October 2020.
  66. ^ a b "Apple – Malus domestica". Natural England. Archived from the original on 12 May 2008. Retrieved 22 January 2008.
  67. ^ "Home". National Fruit Collection. Archived from the original on 15 June 2012. Retrieved 2 December 2012.
  68. ^ "ECPGR Malus/Pyrus Working Group Members". Ecpgr.cgiar.org. 22 July 2002. Archived from the original on 26 August 2014. Retrieved 25 August 2014.
  69. ^ a b Tarjan, Sue (Fall 2006). "Autumn Apple Musings" (PDF). News & Notes of the UCSC Farm & Garden, Center for Agroecology & Sustainable Food Systems. pp. 1–2. Archived from the original (PDF) on 11 August 2007. Retrieved 24 January 2008.
  70. ^ Beck, Kellen (17 October 2020). "How breeders bring out the best in new apples". Mashable. Archived from the original on 31 July 2024. Retrieved 31 July 2024.
  71. ^ Migicovsky, Zoë (22 August 2021). "How a few good apples spawned today's top varieties — and why breeders must branch out". The Conversation. Archived from the original on 31 July 2024. Retrieved 31 July 2024.
  72. ^ Peil, A.; Dunemann, F.; Richter, K.; Hoefer, M.; Király, I.; Flachowsky, H.; Hanke, M.-V. (2008). "Resistance Breeding in Apple at Dresden-Pillnitz". Ecofruit - 13th International Conference on Cultivation Technique and Phytopathological Problems in Organic Fruit-Growing: Proceedings to the Conference from 18thFebruary to 20th February 2008 at Weinsberg/Germany (in German): 220–225. Archived from the original on 28 January 2021. Retrieved 31 July 2024.
  73. ^ a b "World apple situation". Archived from the original on 11 February 2008. Retrieved 24 January 2008.
  74. ^ Weaver, Sue (June–July 2003). "Crops & Gardening – Apples of Antiquity". Hobby Farms Magazine. Archived from the original on 19 February 2017.
  75. ^ a b c "Apple production in 2022; from pick lists: Crops/World Regions/Production Quantity". FAOSTAT, UN Food and Agriculture Organization, Statistics Division. 2024. Archived from the original on 12 November 2016. Retrieved 18 June 2024.
  76. ^ Nelson, Lewis S.; Shih, Richard D.; Balick, Michael J. (2007). Handbook of Poisonous and Injurious Plants (Second ed.). New York: New York Botanical Garden : Springer. pp. 27, 211–212. ISBN 978-0387-31268-2. LCCN 2005938815. OCLC 77537459. Retrieved 11 September 2024.
  77. ^ "Amygdalin". Toxnet, US Library of Medicine. Archived from the original on 21 April 2017. Retrieved 20 April 2017.
  78. ^ a b c d e f "General Information – Apple". Informall. Archived from the original on 23 July 2012. Retrieved 17 October 2011.
  79. ^ Landau, Elizabeth, Oral allergy syndrome may explain mysterious reactions, 8 April 2009, CNN Health, accessed 17 October 2011
  80. ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". FDA. Archived from the original on 27 March 2024. Retrieved 28 March 2024.
  81. ^ National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.). Dietary Reference Intakes for Sodium and Potassium. The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US). ISBN 978-0-309-48834-1. PMID 30844154. Archived from the original on 9 May 2024. Retrieved 21 June 2024.
  82. ^ a b c d Davidson, Alan (2014). "Apple". In Jaine, Tom (ed.). The Oxford Companion to Food. Illustrated by Soun Vannithone (Third ed.). Oxford: Oxford University Press. pp. 27–31. ISBN 978-0-19-967733-7. LCCN 2013957569. OCLC 890807357. OL 27172691M. Retrieved 18 September 2024.
  83. ^ Traverso, Amy (2011). The Apple Lover's Cookbook. Photographs by Squire Fox (First ed.). New York: W.W. Norton & Company. pp. 16, 32, 35, 45, 92, 137, 262–263, 275. ISBN 978-0-393-06599-2. LCCN 2011016560. OCLC 711051767. OL 16450839W.
  84. ^ Kellogg, Kristi (15 January 2015). "81 Best Apple Recipes: Dinners, Desserts, Salads, and More". Epicurious. Archived from the original on 18 October 2020. Retrieved 17 October 2020.
  85. ^ Davidson, Alan (2014). "Toffee Apple". In Jaine, Tom (ed.). The Oxford Companion to Food. Illustrated by Soun Vannithone (Third ed.). Oxford: Oxford University Press. p. 824. ISBN 978-0-19-967733-7. LCCN 2013957569. OCLC 890807357. OL 27172691M. Retrieved 18 September 2024.
  86. ^ Shurpin, Yehuda. "Why All the Symbolic Rosh Hashanah Foods? "בולבול"". Chabad.org. Archived from the original on 21 March 2023. Retrieved 21 March 2023.
  87. ^ Yepsen, Roger B. (2017) [1994]. Apples (Revised and Updated ed.). New York: W.W. Norton & Company. p. 52. ISBN 978-1-68268-019-3. LCCN 2017010136. OCLC 973918728.
  88. ^ "Organic apples". USDA Agricultural Marketing Service. February 2016. Archived from the original on 24 February 2017. Retrieved 23 February 2017.
  89. ^ a b "European Organic Apple Production Demonstrates the Value of Pesticides" (PDF). CropLife Foundation, Washington, DC. December 2011. Archived (PDF) from the original on 24 February 2017. Retrieved 23 February 2017.
  90. ^ Ribeiro, Flávia A.P.; Gomes de Moura, Carolina F.; Aguiar, Odair; de Oliveira, Flavia; Spadari, Regina C.; Oliveira, Nara R.C.; Oshima, Celina T.F.; Ribeiro, Daniel A. (September 2014). "The chemopreventive activity of apple against carcinogenesis: antioxidant activity and cell cycle control". European Journal of Cancer Prevention (Review). 23 (5): 477–480. doi:10.1097/CEJ.0000000000000005. PMID 24366437. S2CID 23026644.
  91. ^ Nicolas, J. J.; Richard-Forget, F. C.; Goupy, P. M.; Amiot, M. J.; Aubert, S. Y. (1 January 1994). "Enzymatic browning reactions in apple and apple products". Critical Reviews in Food Science and Nutrition. 34 (2): 109–157. doi:10.1080/10408399409527653. PMID 8011143.
  92. ^ "PPO silencing". Okanagan Specialty Fruits. 2019. Archived from the original on 27 April 2021. Retrieved 14 November 2019.
  93. ^ "United States: GM non-browning Arctic apple expands into foodservice". Fresh Fruit Portal. 13 August 2019. Archived from the original on 27 June 2021. Retrieved 14 November 2019.
  94. ^ "Okanagan Specialty Fruits: Biotechnology Consultation Agency Response Letter BNF 000132". U.S. Food and Drug Administration. 20 March 2015. Archived from the original on 31 October 2017. Retrieved 14 November 2019.
  95. ^ "Questions and answers: Arctic Apple". Canadian Food Inspection Agency, Government of Canada. 8 September 2017. Archived from the original on 19 September 2018. Retrieved 14 November 2019.
  96. ^ Yu, Xiuzhu; Van De Voort, Frederick R.; Li, Zhixi; Yue, Tianli (2007). "Proximate Composition of the Apple Seed and Characterization of Its Oil". International Journal of Food Engineering. 3 (5). doi:10.2202/1556-3758.1283. S2CID 98590230.
  97. ^ a b c Davidson, Hilda Roderick Ellis (1990) [1st pub. 1964]. Gods and Myths of Northern Europe. London: Penguin Books. pp. 165–166. ISBN 0-14-013627-4. OCLC 29336401.
  98. ^ Davidson, Hilda Ellis (1998). Roles of the Northern Goddess. London; New York: Routledge. pp. 146–147. doi:10.4324/9780203025550. ISBN 0-415-13610-5. LCCN 97018309. OCLC 48138055.
  99. ^ Biedermann, Hans (1992). Dictionary of Symbolism. Translated by Hulbert, James. New York: Facts on File. pp. 16–17. ISBN 978-0-8160-2593-0. LCCN 91044933. OCLC 25092926. Retrieved 3 October 2024.
  100. ^ a b Ruck, Carl A. P.; Staples, Blaise D.; Heinrich, Clark (2001). The apples of Apollo : pagan and Christian mysteries of the Eucharist. Durham, North Carolina: Carolina Academic Press. pp. 64–70. ISBN 978-0-89089-924-3. LCCN 00040351. OCLC 46337324.
  101. ^ "Eris - Greek Goddess of Strife & Discord (Roman Discordia)". Theoi Project. Aaron J. Atsma. Archived from the original on 25 September 2024. Retrieved 26 September 2024.
  102. ^ Lucian (1905). The Works of Lucian of Samosata. Vol. I. Translated by Fowler, H.W.; Fowler, F.G. (First ed.). Oxford: Clarendon Press. pp. 78–85. LCCN 06001045. OCLC 506365. Retrieved 26 September 2024.
  103. ^ "Judgement of Paris - Greek Mythology". Theoi Project. Aaron J. Atsma. Archived from the original on 24 August 2024. Retrieved 26 September 2024.
  104. ^ Plato (1997). "Epigrams". In Cooper, John M.; Hutchinson, D.S. (eds.). Complete Works. Translated by Edmonds, J.M.; Cooper, John M. Indianapolis, Indiana: Hackett Publishing. p. 1744. ISBN 0-87220-349-2. LCCN 96053280. OCLC 36178550. Retrieved 27 September 2024.
  105. ^ Pinsent, John (1969). Greek Mythology (First ed.). London: Paul Hamlyn. p. 79. ISBN 978-0-600-02422-4. LCCN 78449216. OCLC 61702. Retrieved 3 October 2024.
  106. ^ "Atalanta (Atalante) - Arcadian Heroine of Greek Mythology". Theoi Project. Aaron J. Atsma. Archived from the original on 27 September 2024. Retrieved 3 October 2024.
  107. ^ Flieger, Verlyn (2005). Interrupted Music : The Making of Tolkien's Mythology. Kent, Ohio: Kent State University Press. pp. 122–123. ISBN 978-0-87338-824-5. LCCN 2004024490. OCLC 56805947.
  108. ^ a b "Why Do the Chinese Give Apples Around Christmas?". Teach English In China. 22 December 2019. Archived from the original on 1 October 2020. Retrieved 3 September 2024.
  109. ^ a b Macrone, Michael (1998). Brush up your Bible!. New York: Gramercy Books. pp. 15–16, 340–341. ISBN 978-0-517-20189-3. OCLC 38270894. Retrieved 31 July 2024.
  110. ^ Kissling, Paul J. (2004). Genesis. Vol. 1. Joplin, Missouri: College Press. p. 193. ISBN 978-0-89900-875-2. LCCN 2004022577. OCLC 56672257. Archived from the original on 26 January 2021. Retrieved 6 October 2020.
  111. ^ Genesis 2:17
  112. ^ Hendel, Ronald S. (2013). The Book of Genesis: A Biography. Princeton, New Jersey: Princeton University Press. p. 114. ISBN 978-0-69114012-4. LCCN 2012015634. OCLC 788265521. Archived from the original on 5 March 2023. Retrieved 4 October 2024.
  113. ^ Mieder, Wolfgang; Kingsbury, Stewart A.; Harder, Kelsie B., eds. (1996) [1992]. A Dictionary of American Proverbs (Paperback ed.). New York: Oxford University Press. p. 23. ISBN 978-0-19-511133-0. LCCN 91015508. OCLC 23693799. Retrieved 23 August 2024.
  114. ^ Pollan, Michael (2001). The Botany of Desire: A Plant's-Eye View of the World (First ed.). New York: Random House. pp. 9, 22, 50. ISBN 978-0-375-50129-6. LCCN 00066479. OCLC 49803415.

Further reading

  • Media related to Apples at Wikimedia Commons