94,129
edits
Changes
From Gardenology.org - Plant Encyclopedia and Gardening Wiki
Jump to navigationJump to searchno edit summary
The '''apple''' is a [[tree]] and its [[pome|pomaceous]] [[fruit]], of the [[species]] ''Malus domestica'' in the [[rose]] family [[Rosaceae]]. It is one of the most widely [[Cultivation|cultivated]] tree fruits. It is a small [[deciduous]] tree reaching 5-12 m tall, with a broad, often densely twiggy crown. The [[leaf|leaves]] are [[leaf arrangement|alternately]] arranged, simple oval with an acute tip and serrated margin, slightly downy below, 5-12 cm long and 3-6 cm broad on a 2-5 cm petiole. The [[flower]]s are produced in spring with the leaves, white, usually tinged pink at first, 2.5-3.5 cm diameter, with five [[petal]]s. The fruit matures in [[autumn]], and is typically 5-9 cm diameter (rarely up to 15 cm). The centre of the fruit contains five [[carpel]]s arranged star-like, each carpel containing one or two (rarely three) [[seed]]s.
The '''apple''' is a [[tree]] and its [[pome|pomaceous]] [[fruit]], of the [[species]] ''Malus domestica'' in the [[rose]] family [[Rosaceae]]. It is one of the most widely [[Cultivation|cultivated]] tree fruits. It is a small [[deciduous]] tree reaching 5-12 m tall, with a broad, often densely twiggy crown. The [[leaf|leaves]] are [[leaf arrangement|alternately]] arranged, simple oval with an acute tip and serrated margin, slightly downy below, 5-12 cm long and 3-6 cm broad on a 2-5 cm petiole. The [[flower]]s are produced in spring with the leaves, white, usually tinged pink at first, 2.5-3.5 cm diameter, with five [[petal]]s. The fruit matures in [[autumn]], and is typically 5-9 cm diameter (rarely up to 15 cm). The centre of the fruit contains five [[carpel]]s arranged star-like, each carpel containing one or two (rarely three) [[seed]]s.
== Origin of name ==
The word 'apple' comes from the Old English word '''æppel''', which in turn has recognisable cognates in a number of the northern branches of the Indo-European language family. The prevailing theory is that 'apple' may be one of the most ancient [[Indo-European languages|Indo-European]] words (*''abl-'') to come down to English in a recognisable form.{{Fact|date=February 2007}} The scientific name ''malus'', on the other hand, comes from the Latin word for apple, and ultimately from the archaic Greek ''mālon'' (''mēlon'' in later dialects). The legendary placename [[Avalon]] is thought to come from a Celtic evolution of the same root as the English 'apple'; the name of the town of [[Avellino]], near [[Naples]] in [[Italy]] is likewise thought to come from the same root via the [[Italic language]]s.
[[Carolus Linnaeus|Linnaeus]] assigned the apple to the genus ''Pyrus'', along with [[pear]]s and [[quince]]s. Philip Miller subsequently separated the apple into its own genus, a division repeatedly ratified over the years.
==Botanical information==
==Botanical information==
==Apple cultivars==
[[Image:Apples supermarket.jpg|thumb|Different kinds of apple cultivars in a supermarket]]
:''See [[List of apple cultivars]] for a listing.''
There are more than 7,500 known [[cultivar]]s of apples. Different cultivars are available for [[temperate]] and [[subtropical]] climates. Reputedly the world's biggest collection of apple [[cultivar]]s is housed at the [http://brogdale.org/ National Fruit Collection] in [[England]]. Apples do not flower in tropical climates because they have a chilling requirement.
Commercially popular apple cultivars are soft but crisp. Other desired qualities in modern commercial apple breeding are a colourful skin, absence of [[Russet apple|russet]]ing, ease of shipping, lengthy storage ability, high yields, disease resistance, typical 'Red Delicious' apple shape, long stem (to allow [[pesticide]]s to penetrate the top of the fruit), and popular flavour.
Old cultivars are often oddly shaped, russeted, and have a variety of textures and colours. Many of them have excellent flavour (often better than most modern cultivars), but may have other problems which make them commercially unviable, such as low yield, liability to disease, or poor tolerance for storage or transport. A few old cultivars are still produced on a large scale, but many have been kept alive by home gardeners and farmers that sell directly to local markets. Many unusual and locally important cultivars with their own unique taste and appearance are out there to discover; 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 Russett are still commercially important even though by modern standards they are low yielding and disease prone.
Although most cultivars are bred for eating fresh (dessert apples), some are cultivated specifically for cooking ([[cooking apple]]s) or producing [[cider]]. [[Cider apple]]s are typically too tart and astringent to eat fresh, but they give the beverage a rich flavour that dessert apples cannot.
Modern apples are, as a rule, sweeter than older cultivars. Most [[North America]]ns and [[Europe]]ans favour sweet, subacid apples, but tart apples have a strong minority following. Extremely sweet apples with barely any acid flavour are popular in [[Asia]] and especially India.
Tastes in apples vary from one person to another and change continually over time. As an example, the [[U.S. state]] of [[Washington#Agriculture|Washington]] made its reputation for apple growing on Red Delicious. In recent years, many apple connoisseurs have come to regard the Red Delicious as inferior to cultivars such as Fuji and Gala due to its merely mild flavour and insufficiently firm texture.
==Growing Apples==
===Apple breeding===
[[Image:Cyborglog-of-eating-old-apple-d360.jpg|thumb|right|In this hybrid of an orchard apple with a red-fruited crabapple cultivar, the pulp is of the same colour as the peel.]]
[[Image:Old-appleseed-d402.jpg|thumb|right|Seeds of the above apple, which are same colour as the rest of the fruit.]]
Like most perennial fruits, apples are ordinarily propagated asexually by [[grafting]]. Seedling apples are different from their parents, sometimes radically. Most new apple cultivars originate as seedlings, which either arise by chance or are bred by deliberately crossing cultivars with promising characteristics. 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 sport]]s (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.
Some breeders have crossed ordinary apples with [[Malus|crabapples]] or unusually hardy apples in order to produce [[hardiness|hardier]] cultivars. For example, the Excelsior Experiment Station of the [[University of Minnesota]] has, since the 1930s, introduced a steady progression of important hardy apples that are widely grown, both commercially and by backyard orchardists, throughout [[Minnesota]] and [[Wisconsin]]. Its most important introductions have included '[[Haralson (apple)|Haralson]]' (which is the most widely cultivated apple in Minnesota), 'Wealthy', 'Honeygold', and '[[Honeycrisp]]'.
===Starting an orchard===
Apple orchards are established by planting trees two to four year old. These small trees are usually purchased from a [[Nursery (horticulture)|nursery]] where they are produced by [[Fruit tree propagation|grafting or budding]]. First, a [[rootstock]] is produced either as a seedling or cloned using tissue culture or layering. This is allowed to grow for a year. Then, a small section of branch called a [[scion]] is obtained from a mature apple tree of the desired cultivar. The upper stem and branches of the rootstock are cut away and replaced with the scion. In time, the two sections grow together and produce a healthy [[tree]].
Rootstocks affect the ultimate size of the tree. While many rootstocks are available to commercial growers, those sold to homeowners who want just a few trees are usually one of two cultivars; a standard seedling rootstock that gives a full-size tree, or a semi-dwarf rootstock that produces a somewhat smaller tree. [[Dwarf]] rootstocks are generally more susceptible to damage from wind and cold. Full dwarf trees are often supported of posts or trellises and planted in high density orchards which are much simpler to culture and greatly increase productivity per unit of land.
There has been limited research into growing apples on their own roots (i.e. without a [[rootstock]])in [[England]] this was initiated by Hugh Ermen at Brogdale, Kent and has been carried on by [http://www.cooltemperate.co.uk/own_root.shtml Phil Corbett] in Nottinghamshire. Some of the supposed benefits are greater disease resistance and better flavour.
[[Image:Apple orchard.jpg|right|thumb|Apple orchard]]
[[Image:Orchard3.jpg|thumb|right|A community apple orchard originally planted for productive use during the 1920s, in [[Westcliff on Sea]] ([[Essex]], [[England]])]]
Some trees are produced with a dwarfing 'interstem' between a standard rootstock and the tree, resulting in two grafts.
After the small tree is planted in the orchard, it must grow for 3-5 years (semi-dwarf) or 4-10 years (standard trees) before it will bear sizeable amounts of [[fruit]]. Good training of limbs and careful nipping of buds growing in the wrong places, are extremely important during this time, to build a good scaffold that will later support a fruit load.
===Location===
Apples are relatively indifferent to [[soil]] conditions and will grow in a wide range of [[pH]] values and fertility levels. They do require some protection from the wind and should not be planted in low areas that are prone to late spring [[frost]]s. Apples do require good drainage, and heavy soils or flat land should be [[drainage|tilled]] to make certain that the root systems are never in saturated soil.
===Pollination===
Apples are self-incompatible and must be [[Pollination|cross-pollinated]] to develop fruit. [[Pollination management]] is an important component of apple culture. Before planting, it is important to arrange for [[pollenizer]]s, cultivars of apple or crab apple that provide plentiful, viable and compatible pollen. Orchard blocks may alternate rows of compatible cultivars, or may have periodic crab apple trees, or grafted-on limbs of crab apple. Some cultivars produce very little pollen, or the pollen is sterile, so these are not good pollenizers. Quality nurseries have pollenizer compatibility lists.
Growers with old orchard blocks of single cultivars sometimes provide bouquets of crab apple blossoms in drums or pails in the orchard for pollenizers. Home growers with a single tree, and no other cultivars in the neighbourhood can do the same on a smaller scale.
During the flowering each season, apple growers usually provide [[pollinator]]s to carry the pollen. [[Honeybee]] hives are most commonly used, and arrangements may be made with a commercial beekeeper who supplies hives for a fee. [[Megachilidae|Orchard mason bee]]s are also used as supplemental pollinators in commercial orchards. Home growers may find these more acceptable in suburban locations because they do not sting. Some wild bees such as [[carpenter bee]]s and other [[solitary bee]]s may help. [[Bumble bee]] [[queen bee|queen]]s are sometimes present in orchards, but not usually in enough quantity to be significant pollinators.
Symptoms of inadequate pollination are excessive fruit drop (when marble sized), small and misshapen apples, slowness to ripen, and low seed count. Well pollinated apples are the best quality, and will have 7 to 10 seeds. Apples having fewer than 3 seeds will usually not mature and will drop from the trees in the early summer. Inadequate pollination can result from either a lack of pollinators or pollenizers, or from poor pollinating weather at flowering time. It generally requires multiple bee visits to deliver sufficient grains of pollen to accomplish complete pollination.
[[Image:Apple blossoms04.jpg|thumb|Apple tree in flower]]
A common problem is a late frost that destroys the delicate outer structures of the flower. It is best to plant apples on a slope for air drainage, but not on a south facing slope (in the northern hemisphere) as this will encourage early flowering and increase susceptibility to frost. If the frost is not too severe, the tree can be wetted with water spray before the morning sun hits the flowers, and it may save them. Frost damage can be evaluated 24 hours after the frost. If the [[Carpel|pistil]] has turned black, the flower is ruined and will not produce fruit.
Growing apples near a body of water can give an advantage by slowing spring warm up, which retards flowering until frost is less likely. In some areas of the USA, such as the eastern shore of [[Lake Michigan]], the southern shore of [[Lake Ontario]], and around some smaller lakes, this cooling effect of water, combined with good, well-drained soils, has made apple growing concentrations possible. However, the cool, humid spring weather in such locations can also increase problems with fungal diseases, notably [[apple scab]]; many of the most important apple-growing regions (e.g. northern China, central Turkey, and eastern Washington in the USA) have climates more like the species' native region well away from the sea or any lakes, with cold winters leading to a short, but warm spring with low risk of frost.
Home growers may not have a body of water to help, but can utilise north slopes or other geographical features to retard spring flowering. Apples (or any fruit) planted on a south facing slope in the northern hemisphere (or north facing in the southern hemisphere), will flower early and be particularly vulnerable to spring f
rost.
===Pollination groups===
There are four to seven pollination groups in apples depending on climate :
* Group A – Early flowering, May 1 to 3 in England ([[Gravenstein]], [[Red Astrachan]])
* Group B – May 4 to 7 ([[Idared]], [[McIntosh]])
* Group C – Mid-season flowering, May 8 to 11 ([[Granny Smith]], [[Cox's Orange Pippin]])
* Group D – Mid/Late season flowering, May 12 to 15 ([[Golden Delicious]], [[Calville Blanc d'Hiver]]).
* Group E – Late flowering, May 16 to 18 ([[Braeburn]], [[Reinette d'Orléans]])
* Group F – May 19 to 23 ([[Suntan]])
* Group G – May 24 to 28 ([[Court Pendu Plat]])
One cultivar can be pollinized by a compatible cultivar from the same group or close (A with A or A with B but not A with C or D). Late groups are better to avoid frost in cold areas.
===Thinning===
Apples are prone to [[biennial bearing]]. If the fruit is not thinned when the tree carries a large crop, it may produce very little flower the following year. Good thinning helps even out the cycle, so that a reasonable crop can be grown every year.
Commercial orchardists practice chemical thinning, which is not practical for home fruit. Apples bear in groups of five (or more rarely six) blossoms. The first blossom to open is called the ''king bloom''. It will produce the best possible apple of the five. If it sets, it tends to suppress setting of the other blossoms, which, if they set anyway, should be removed. The next three blossoms tend to bloom and set simultaneously, therefore there is no dominance. All but one of these should be thinned for best quality. If the final blossom is the only one that sets, the crop will not be as good, but it will help reduce excessive woody growth (suckering) that usually happens when there is no crop.
===Maturation and harvest===
Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock. Some cultivars, if left unpruned, will grow very large, which allows them to bear a great deal more fruit, but makes harvest very difficult. Mature trees typically bear 40-200 kg 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. Dwarf trees will bear about 10-80 kg of fruit per year.
===Pests and diseases===
{{Main|List of apple diseases}}
[[Image:Apple tree leaves with insect damage.jpg|thumb|right|Leaves with significant insect damage.]]
The trees are susceptible to a number of [[fungus|fungal]] and [[bacterium|bacteria]]l diseases and [[insect]] pests. Nearly all commercial orchards pursue an aggressive program of chemical sprays to maintain high fruit quality, tree health, and high yields. A trend in orchard management is the use of [[Integrated Pest Management]] (IPM), which reduces needless spraying when pests are not present, or more likely, are being controlled by natural [[predator]]s.
Spraying for insect pests must never be done during flowering because it kills pollinators. Nor should bee-attractive plants be allowed to establish in the orchard floor if insecticides are used. [[White clover]] is a component of many grass seed mixes, and many bees are poisoned by insecticides while visiting the flowers on the orchard floor.
Among the most serious disease problems are [[fireblight]], a bacterial disease; and ''[[Gymnosporangium]]'' rust, [[apple scab]], and [[Black Spot (disease)|black spot]], three fungal diseases.
The [[plum curculio]] is the most serious insect pest. Others include [[Apple maggot]] and [[codling moth]]. For other [[Lepidoptera]] [[larva]]e which feed on apple trees, see [[List of Lepidoptera which feed on Malus]].
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. Growers usually sheath juvenile trees with wire mesh to protect them.
Apples are difficult to grow organically, though a few orchards have done so with commercial success, using disease-resistant cultivars and the very best cultural controls. The latest tool in the organic repertoire is to spray a light coating of [[kaolin]] clay, which forms a physical barrier to some pests, and also helps prevent apple sun scald.
==Commerce and uses==
==Commerce and uses==
