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138-410: Frank and Herbert Petty were orchardists, growing apples , pears , lemons , cherries and peaches . The entire orchard was cultivated. The Petty Plough was designed to plough between and around the fruit trees, working right up to the trees, eliminating the need for slow and tedious manual cultivation between the trees. The Petty Plough could be pulled by two horses or by a tractor. The Plough

276-429: A monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some reaching several thousand years old. Trees evolved around 370 million years ago, and it

414-409: A symbiotic relationship with Frankia species, a filamentous bacterium that can fix nitrogen from the air, converting it into ammonia . They have actinorhizal root nodules on their roots in which the bacteria live. This process enables the tree to live in low nitrogen habitats where they would otherwise be unable to thrive. The plant hormones called cytokinins initiate root nodule formation, in

552-405: A tree is a perennial plant with an elongated stem , or trunk , usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth , plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms , tree ferns , bananas , and bamboos are also trees. Trees are not

690-402: A bed of straw, chaff, or mats with windfalls kept separately. 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. For longer storage medieval Europeans strung up cored and peeled apples to dry, either whole or sliced into rings. Of

828-416: A classic example of parallel evolution . With an estimated 60,000-100,000 species, the number of trees worldwide might total twenty-five per cent of all living plant species. The greatest number of these grow in tropical regions; many of these areas have not yet been fully surveyed by botanists , making tree diversity and ranges poorly known. The majority of tree species are angiosperms or hardwoods. Of

966-503: A drier savanna climate and insufficient rainfall to support dense forests, the canopy is not closed, and plenty of sunshine reaches the ground which is covered with grass and scrub. Acacia and baobab are well adapted to living in such areas. The roots of a tree serve to anchor it to the ground and gather water and nutrients to transfer to all parts of the tree. They are also used for reproduction, defence, survival, energy storage and many other purposes. The radicle or embryonic root

1104-516: 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 . 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). When cultivated, the size, shape and branch density are determined by rootstock selection and trimming method. Apple trees may naturally have

1242-481: A handle which when turned was designed to mix the spray. On 10 October 1932, Frank made a 'Provisional Application' for a Plough and Cultivator. This lapsed in 1933. It is thought that he asked his brother Herbert, who had greater mechanical skills, to assist him with the development of the plough. Another application dated 24 July 1933 was lodged in joint names. This resulted in an Australian Patent being advertised on 4 October 1934 and subsequently granted. The plough

1380-418: A hundred litres are required to make one litre of birch syrup. Various parts of trees are used as spices. These include cinnamon , made from the bark of the cinnamon tree ( Cinnamomum zeylanicum ) and allspice , the dried small fruits of the pimento tree ( Pimenta dioica ). Nutmeg is a seed found in the fleshy fruit of the nutmeg tree ( Myristica fragrans ) and cloves are the unopened flower buds of

1518-420: 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. The apple

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1656-477: 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. 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 . As late as the 17th century, the word also functioned as

1794-536: 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). Some varieties of apples (e.g. ' Granny Smith ' and ' Fuji ') have more than three times the storage life of others. Non-organic apples may be sprayed with a substance 1-methylcyclopropene blocking the apples' ethylene receptors, temporarily preventing them from ripening. Apple trees are susceptible to fungal and bacterial diseases, and to damage by insect pests. Many commercial orchards pursue

1932-509: A process closely related to mycorrhizal association. It has been demonstrated that some trees are interconnected through their root system, forming a colony. The interconnections are made by the inosculation process, a kind of natural grafting or welding of vegetal tissues. The tests to demonstrate this networking are performed by injecting chemicals, sometimes radioactive , into a tree, and then checking for its presence in neighbouring trees. The roots are, generally, an underground part of

2070-404: A process known as cladoptosis . The crown is the spreading top of a tree including the branches and leaves, while the uppermost layer in a forest, formed by the crowns of the trees, is known as the canopy . A sapling is a young tree. Many tall palms are herbaceous monocots, which do not undergo secondary growth and never produce wood. In many tall palms, the terminal bud on the main stem

2208-447: 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. Among

2346-459: A rounded to erect crown with a dense canopy of leaves. The bark of the trunk is dark gray or gray-brown, but young branches are reddish or dark-brown with a smooth texture. Young twigs are covered in fine downy hairs; they become hairless when older. 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

2484-422: A second spurt of growth, a Lammas growth may occur which is believed to be a strategy to compensate for loss of early foliage to insect predators. Primary growth is the elongation of the stems and roots. Secondary growth consists of a progressive thickening and strengthening of the tissues as the outer layer of the epidermis is converted into bark and the cambium layer creates new phloem and xylem cells. The bark

2622-489: A significant role in reducing erosion and moderating the climate . They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are among the most biodiverse habitats in the world. Trees provide shade and shelter , timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In much of

2760-424: A similar growth form, by usually growing larger and having a single main stem; but there is no consistent distinction between a tree and a shrub, made more confusing by the fact that trees may be reduced in size under harsher environmental conditions such as on mountains and subarctic areas. The tree form has evolved separately in unrelated classes of plants in response to similar environmental challenges, making it

2898-402: A single furrow, double furrow or triple furrow plough. The single furrow plough had one 23-inch diameter disc, the double furrow had one 23-inch disc and one 20-inch disc, while the triple furrow had three 23-inch discs. "The Petty Orchard Disc Stripping Plough is the greatest labour saver of all time. It eliminates a lot of back-breaking work in cutting out the strips between trees. The operator

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3036-467: A single tree species, which will not flourish in the absence of its mycorrhizal associate. Others are generalists and associate with many species. The tree acquires minerals such as phosphorus from the fungus, while the fungus obtains the carbohydrate products of photosynthesis from the tree. The hyphae of the fungus can link different trees and a network is formed, transferring nutrients and signals from one place to another. The fungus promotes growth of

3174-636: A slightly looser definition; while the Joshua tree , bamboos and palms do not have secondary growth and never produce true wood with growth rings, they may produce "pseudo-wood" by lignifying cells formed by primary growth. Tree species in the genus Dracaena , despite also being monocots, do have secondary growth caused by meristem in their trunk, but it is different from the thickening meristem found in dicotyledonous trees. Aside from structural definitions, trees are commonly defined by use; for instance, as those plants which yield lumber. The tree growth habit

3312-409: A species has more than 100 alternative scientific names, or synonyms . 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

3450-552: A strong minority following. Extremely sweet apples with barely any acid flavor are popular in Asia, especially the Indian subcontinent . 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

3588-484: A tree is any plant with the general form of an elongated stem, or trunk, which supports the photosynthetic leaves or branches at some distance above the ground. Trees are also typically defined by height, with smaller plants from 0.5 to 10 m (1.6 to 32.8 ft) being called shrubs , so the minimum height of a tree is only loosely defined. Large herbaceous plants such as papaya and bananas are trees in this broad sense. A commonly applied narrower definition

3726-436: A wide range of edible fruits are found in the tropics. Other commercially important fruit include dates, figs and olives. Palm oil is obtained from the fruits of the oil palm ( Elaeis guineensis ). The fruits of the cocoa tree ( Theobroma cacao ) are used to make cocoa and chocolate and the berries of coffee trees, Coffea arabica and Coffea canephora , are processed to extract the coffee beans. In many rural areas of

3864-416: A wide range of shapes and sizes, in response to environmental pressures including climate and predation. They can be broad or needle-like, simple or compound, lobed or entire, smooth or hairy, delicate or tough, deciduous or evergreen. The needles of coniferous trees are compact but are structurally similar to those of broad-leaved trees. They are adapted for life in environments where resources are low or water

4002-542: A widespread diverse group of which the only survivor is the maidenhair tree Ginkgo biloba . This is considered to be a living fossil because it is virtually unchanged from the fossilised specimens found in Triassic deposits. During the Mesozoic (245 to 66 million years ago) the conifers flourished and became adapted to live in all the major terrestrial habitats. Subsequently, the tree forms of flowering plants evolved during

4140-549: Is a flavouring obtained from distilling bark from the roots of the sassafras tree ( Sassafras albidum ). The leaves of trees are widely gathered as fodder for livestock and some can be eaten by humans but they tend to be high in tannins which makes them bitter. Leaves of the curry tree ( Murraya koenigii ) are eaten, those of kaffir lime ( Citrus × hystrix ) (in Thai food ) and Ailanthus (in Korean dishes such as bugak ) and those of

4278-512: Is a rudimentary stalk and neatly folded miniature leaves, ready to expand when the next growing season arrives. Buds also form in the axils of the leaves ready to produce new side shoots. A few trees, such as the eucalyptus , have "naked buds" with no protective scales and some conifers, such as the Lawson's cypress , have no buds but instead have little pockets of meristem concealed among the scale-like leaves. When growing conditions improve, such as

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4416-416: Is a sudden movement of sap at the end of the winter as trees prepare to burst into growth. In North America, the sap of the sugar maple ( Acer saccharum ) is used in the production of maple syrup . About 90% of the sap is water, the remaining 10% being a mixture of various sugars and certain minerals. The sap is harvested by drilling holes in the trunks of the trees and collecting the liquid that flows out of

4554-407: Is able to ride on the plow seat, thus sitting down and doing the job in comfort." Frank Petty probably conceived the idea for a steerable plough, although the source of his inspiration is unknown. He invented many useful objects for use on his orchard. He developed and marketed the 'Whirlpool Spray Mix' a device not unlike a giant eggbeater which clamped to the inside of a drum of fruit spray, with

4692-545: Is also found in the southern hemisphere, as for example in the Eastern Australia temperate forest, characterised by Eucalyptus forest and open acacia woodland. In tropical regions with a monsoon or monsoon-like climate, where a drier part of the year alternates with a wet period as in the Amazon rainforest , different species of broad-leaved trees dominate the forest, some of them being deciduous. In tropical regions with

4830-528: Is an evolutionary adaptation found in different groups of plants: by growing taller, trees are able to compete better for sunlight. Trees tend to be tall and long-lived, some reaching several thousand years old. Several trees are among the oldest organisms now living. Trees have modified structures such as thicker stems composed of specialised cells that add structural strength and durability, allowing them to grow taller than many other plants and to spread out their foliage. They differ from shrubs , which have

4968-418: Is continually replaced by a living layer of cells called the cork cambium or phellogen. The London plane ( Platanus × hispanica ) periodically sheds its bark in large flakes. Similarly, the bark of the silver birch ( Betula pendula ) peels off in strips. As the tree's girth expands, newer layers of bark are larger in circumference, and the older layers develop fissures in many species. In some trees such as

5106-451: Is developed by the Indian banyan . Many large trees have buttress roots which flare out from the lower part of the trunk. These brace the tree rather like angle brackets and provide stability, reducing sway in high winds. They are particularly prevalent in tropical rainforests where the soil is poor and the roots are close to the surface. Some tree species have developed root extensions that pop out of soil, in order to get oxygen, when it

5244-414: Is estimated that there are around three trillion mature trees in the world currently. A tree typically has many secondary branches supported clear of the ground by the trunk, which typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees the trunk is surrounded by a layer of bark which serves as a protective barrier. Below

5382-477: Is generally considered the center of origin for apples due to the genetic variability in specimens there. 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 . Cultivation of the species, most likely beginning on the forested flanks of the Tian Shan mountains, progressed over

5520-562: Is generally pale yellowish-white, though it can be pink, yellow or green. 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 . The apple as

5658-557: Is hard to distinguish in the archeological record between foraged wild apples and apple plantations. There is indirect evidence of apple cultivation in the third millennium BCE in the Middle East . There is direct evidence, apple cores, dated to the 10th century BCE from a Judean site between the Sinai and Negev. There was substantial apple production in European classical antiquity, and grafting

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5796-486: Is inelastic. Eventually the growth of a tree slows down and stops and it gets no taller. If damage occurs the tree may in time become hollow. Leaves are structures specialised for photosynthesis and are arranged on the tree in such a way as to maximise their exposure to light without shading each other. They are an important investment by the tree and may be thorny or contain phytoliths , lignins , tannins or poisons to discourage herbivory. Trees have evolved leaves in

5934-424: Is not available in the soil because of excess water. These root extensions are called pneumatophores , and are present, among others, in black mangrove and pond cypress. The main purpose of the trunk is to raise the leaves above the ground, enabling the tree to overtop other plants and outcompete them for light. It also transports water and nutrients from the roots to the aerial parts of the tree, and distributes

6072-489: Is quite variable and may be nearly round, elongated, conical, or short and wide. 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%. The skin may be wholly or partly russeted , making it rough and brown. The skin is covered in a protective layer of epicuticular wax . The skin may also be marked with scattered dots. The flesh

6210-458: Is ready to eat when the process is complete, having been tenderised and flavoured by the smoke it has absorbed. In the cold process, the temperature is not allowed to rise above 100 °F (38 °C). The flavour of the food is enhanced but raw food requires further cooking. If it is to be preserved, meat should be cured before cold smoking. Wood has traditionally been used for fuel, especially in rural areas. In less developed nations it may be

6348-428: Is related to climatic conditions; growth normally ceases when conditions are either too cold or too dry. In readiness for the inactive period, trees form buds to protect the meristem , the zone of active growth. Before the period of dormancy, the last few leaves produced at the tip of a twig form scales. These are thick, small and closely wrapped and enclose the growing point in a waterproof sheath. Inside this bud there

6486-407: Is scarce. Frozen ground may limit water availability and conifers are often found in colder places at higher altitudes and higher latitudes than broad leaved trees. In conifers such as fir trees, the branches hang down at an angle to the trunk, enabling them to shed snow. In contrast, broad leaved trees in temperate regions deal with winter weather by shedding their leaves. When the days get shorter and

6624-402: Is that a tree has a woody trunk formed by secondary growth , meaning that the trunk thickens each year by growing outwards, in addition to the primary upwards growth from the growing tip . Under such a definition, herbaceous plants such as palms , bananas and papayas are not considered trees regardless of their height, growth form or stem girth. Certain monocots may be considered trees under

6762-471: Is the first part of a seedling to emerge from the seed during the process of germination . This develops into a taproot which goes straight downwards. Within a few weeks lateral roots branch out of the side of this and grow horizontally through the upper layers of the soil. In most trees, the taproot eventually withers away and the wide-spreading laterals remain. Near the tip of the finer roots are single cell root hairs . These are in immediate contact with

6900-452: Is the only one to develop, so they have unbranched trunks with large spirally arranged leaves. Some of the tree ferns, order Cyatheales , have tall straight trunks, growing up to 20 metres (66 ft), but these are composed not of wood but of rhizomes which grow vertically and are covered by numerous adventitious roots . The number of trees in the world, according to a 2015 estimate, is 3.04 trillion, of which 1.39 trillion (46%) are in

7038-677: 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. 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

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7176-582: 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

7314-504: The Cretaceous period. These began to displace the conifers during the Tertiary era (66 to 2 million years ago) when forests covered the globe. When the climate cooled 1.5 million years ago and the first of four glacial periods occurred, the forests retreated as the ice advanced. In the interglacials , trees recolonised the land that had been covered by ice, only to be driven back again in

7452-414: The annual growth rings There may also be rays running at right angles to growth rings. These are vascular rays which are thin sheets of living tissue permeating the wood. Many older trees may become hollow but may still stand upright for many years. Trees do not usually grow continuously throughout the year but mostly have spurts of active expansion followed by periods of rest. This pattern of growth

7590-460: The apple clearwing moth (red-belted clearwing) burrow through the bark and into the phloem of apple trees, potentially causing significant damage. There are more than 7,500 known cultivars (cultivated varieties) of apples. Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock . Different cultivars are available for temperate and subtropical climates. The UK's National Fruit Collection, which

7728-709: 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

7866-487: 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 + 1 ⁄ 2 -inch) in diameter. The five-petaled flowers are group in an inflorescence consisting of a cyme with 3–7 flowers. The central flower of the inflorescence is called the "king bloom"; it opens first and can develop a larger fruit. Open apple blossoms are damaged by even brief exposures to temperatures −2 °C (28 °F) or less, although

8004-546: The pine ( Pinus species) the bark exudes sticky resin which deters attackers whereas in rubber trees ( Hevea brasiliensis ) it is a milky latex that oozes out. The quinine bark tree ( Cinchona officinalis ) contains bitter substances to make the bark unpalatable. Large tree-like plants with lignified trunks in the Pteridophyta , Arecales , Cycadophyta and Poales such as the tree ferns, palms, cycads and bamboos have different structures and outer coverings. Although

8142-541: The "best" cultivars, showing the proliferation of new North American cultivars by the early 19th century. 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. 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

8280-710: The "wrong" size. 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. 2022, millions of tonnes Tree In botany ,

8418-585: 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. Unusually for a popular cultivar, the 'Honeycrisp' is not directly related to another popular apple cultivar but instead to two unsuccessful cultivars. In Europe there are also many breeding programs such as the Julius Kühn-Institut ,

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8556-525: The 12,000 years since the start of human agriculture, the number of trees worldwide has decreased by 46%. There are approximately 64,100 known tree species in the world. With 43% of all tree species, South America has the highest biodiversity, followed by Eurasia (22%), Africa (16%), North America (15%), and Oceania (11%). In suitable environments, such as the Daintree Rainforest in Queensland , or

8694-806: The 15th century and later went through several cycles of popularity and decline throughout the world. 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 . 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

8832-546: The English oak ( Quercus robur ) and 306 species of invertebrate on the Tasmanian oak ( Eucalyptus obliqua ). Non-native tree species provide a less biodiverse community, for example in the United Kingdom the sycamore ( Acer pseudoplatanus ), which originates from southern Europe, has few associated invertebrate species, though its bark supports a wide range of lichens, bryophytes and other epiphytes. Trees differ ecologically in

8970-484: The European bay tree ( Laurus nobilis ) and the California bay tree ( Umbellularia californica ) are used for flavouring food. Camellia sinensis , the source of tea, is a small tree but seldom reaches its full height, being heavily pruned to make picking the leaves easier. Wood smoke can be used to preserve food. In the hot smoking process the food is exposed to smoke and heat in a controlled environment. The food

9108-586: The German federal research center for cultivated plants. 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. 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

9246-533: The Malus/Pyrus work group. 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

9384-496: The arrival of warmer weather and the longer days associated with spring in temperate regions, growth starts again. The expanding shoot pushes its way out, shedding the scales in the process. These leave behind scars on the surface of the twig. The whole year's growth may take place in just a few weeks. The new stem is unlignified at first and may be green and downy. The Arecaceae (palms) have their leaves spirally arranged on an unbranched trunk. In some tree species in temperate climates,

9522-404: 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: 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). Cultivars vary in their yield and the ultimate size of the tree, even when grown on

9660-437: The bark functions as a protective barrier, it is itself attacked by boring insects such as beetles. These lay their eggs in crevices and the larvae chew their way through the cellulose tissues leaving a gallery of tunnels. This may allow fungal spores to gain admittance and attack the tree. Dutch elm disease is caused by a fungus ( Ophiostoma species) carried from one elm tree to another by various beetles. The tree reacts to

9798-431: The base of the flower. 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. The five sepals remain attached and stand out from the surface of the apple. The size of the fruit varies widely between cultivars, but generally has a diameter between 2.5 and 12 cm (1 and 5 in). The shape

9936-475: The beverage a rich flavor that dessert apples cannot. 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

10074-694: The branches. Trees grafted on dwarfing rootstocks bear about 10–80 kg (20–180 lb) of fruit per year. Some farms with apple orchards open them to the public so consumers can pick their own apples. 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'. 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

10212-421: The buds, the leaves are convolute , meaning that their edges overlap each other. 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. The edges have broadly-angled teeth, but do not have lobes. The top surface of

10350-453: The case when a triploid plant can produce a seed (apples are an example), it occurs infrequently, and seedlings rarely survive. 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

10488-410: 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. 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

10626-440: The clove tree ( Syzygium aromaticum ). Many trees have flowers rich in nectar which are attractive to bees. The production of forest honey is an important industry in rural areas of the developing world where it is undertaken by small-scale beekeepers using traditional methods. The flowers of the elder ( Sambucus ) are used to make elderflower cordial and petals of the plum ( Prunus spp. ) can be candied. Sassafras oil

10764-465: The cone for years waiting for a trigger event to liberate it. Fire stimulates release and germination of seeds of the jack pine , and also enriches the forest floor with wood ash and removes competing vegetation. Similarly, a number of angiosperms including Acacia cyclops and Acacia mangium have seeds that germinate better after exposure to high temperatures. The single extant species of Ginkgophyta ( Ginkgo biloba ) has fleshy seeds produced at

10902-572: The domesticated apple, not the isolated population on the eastern side. 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. Among the traits selected for by human growers are size, fruit acidity, color, firmness, and soluble sugar. Unusually for domesticated fruits,

11040-424: The ease with which they can be found by herbivores. Tree apparency varies with a tree's size and semiochemical content, and with the extent to which it is concealed by nonhost neighbours from its insect pests . In ecosystems such as mangrove swamps, trees play a role in developing the habitat, since the roots of the mangrove trees reduce the speed of flow of tidal currents and trap water-borne sediment, reducing

11178-645: The ends of short branches on female trees, and Gnetum , a tropical and subtropical group of gymnosperms produce seeds at the tip of a shoot axis. The earliest trees were tree ferns , horsetails and lycophytes , which grew in forests in the Carboniferous period. The first tree may have been Wattieza , fossils of which were found in New York state in 2007 dating back to the Middle Devonian (about 385 million years ago). Prior to this discovery, Archaeopteris

11316-461: The far north of the northern hemisphere is moist taiga or northern coniferous forest (also called boreal forest). Taiga is the world's largest land biome , forming 29% of the world's forest cover. The long cold winter of the far north is unsuitable for plant growth and trees must grow rapidly in the short summer season when the temperature rises and the days are long. Light is very limited under their dense cover and there may be little plant life on

11454-400: 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. Cultivars are sometimes classified by the day of peak bloom in

11592-480: The food produced by the leaves to all other parts, including the roots. In the case of angiosperms and gymnosperms, the outermost layer of the trunk is the bark , mostly composed of dead cells of phellem (cork). It provides a thick, waterproof covering to the living inner tissue. It protects the trunk against the elements, disease, animal attack and fire. It is perforated by a large number of fine breathing pores called lenticels , through which oxygen diffuses. Bark

11730-401: The forest floor, although fungi may abound. Similar woodland is found on mountains where the altitude causes the average temperature to be lower thus reducing the length of the growing season. Where rainfall is relatively evenly spread across the seasons in temperate regions, temperate broadleaf and mixed forest typified by species like oak, beech, birch and maple is found. Temperate forest

11868-483: 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. For home storage, most culitvars of apple can be stored for three weeks in

12006-425: The fruits and either discard the seeds, or swallow them so they pass through the gut to be deposited in the animal's droppings well away from the parent tree. The germination of some seeds is improved when they are processed in this way. Nuts may be gathered by animals such as squirrels that cache any not immediately consumed. Many of these caches are never revisited; the nut-casing softens with rain and frost, and

12144-480: The ground underneath trees there is shade, and often there is undergrowth, leaf litter , and decaying wood that provide other habitat. Trees stabilise the soil, prevent rapid run-off of rain water, help prevent desertification, have a role in climate control and help in the maintenance of biodiversity and ecosystem balance. Many species of tree support their own specialised invertebrates . In their natural habitats, 284 different species of insect have been found on

12282-557: The ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil . Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis , providing the food for the tree's growth and development. Trees usually reproduce using seeds . Flowering plants have their seeds inside fruits, while conifers carry their seeds in cones, and tree ferns produce spores instead. Trees play

12420-421: The ground. Trees use a variety of methods of seed dispersal . Some rely on wind, with winged or plumed seeds. Others rely on animals, for example with edible fruits. Others again eject their seeds (ballistic dispersal), or use gravity so that seeds fall and sometimes roll. Seeds are the primary way that trees reproduce and their seeds vary greatly in size and shape. Some of the largest seeds come from trees, but

12558-413: The growth of the fungus by blocking off the xylem tissue carrying sap upwards and the branch above, and eventually the whole tree, is deprived of nourishment and dies. In Britain in the 1990s, 25 million elm trees were killed by this disease. The innermost layer of bark is known as the phloem and this is involved in the transport of the sap containing the sugars made by photosynthesis to other parts of

12696-447: The heartwood are blocked in some species. Heartwood is usually darker in colour than the sapwood. It is the dense central core of the trunk giving it rigidity. Three quarters of the dry mass of the xylem is cellulose , a polysaccharide , and most of the remainder is lignin, a complex polymer . A transverse section through a tree trunk or a horizontal core will show concentric circles of lighter or darker wood – tree rings. These rings are

12834-411: The inserted spigots; the sap is then heated to concentrate the flavour. Similarly in northern Europe the spring rise in the sap of the silver birch ( Betula pendula ) is tapped and collected, either to be drunk fresh or fermented into an alcoholic drink. In Alaska, the sap of the sweet birch ( Betula lenta ) is made into a syrup with a sugar content of 67%. Sweet birch sap is more dilute than maple sap;

12972-400: The inside. The newly created xylem is the sapwood . It is composed of water-conducting cells and associated cells which are often living, and is usually pale in colour. It transports water and minerals from the roots to the upper parts of the tree. The oldest, inner part of the sapwood is progressively converted into heartwood as new sapwood is formed at the cambium. The conductive cells of

13110-528: The largest tree, Sequoiadendron giganteum , produces one of the smallest tree seeds. The great diversity in tree fruits and seeds reflects the many different ways that tree species have evolved to disperse their offspring. For a tree seedling to grow into an adult tree it needs light. If seeds only fell straight to the ground, competition among the concentrated saplings and the shade of the parent would likely prevent it from flourishing. Many seeds such as birch are small and have papery wings to aid dispersal by

13248-417: The leaves are glabrescent , almost hairless, while the undersides are densely covered in fine hairs. The leaves are attached alternately by short leaf stems 1-to-3.5 cm ( 1 ⁄ 2 -to- 1 + 1 ⁄ 2  in) long. Blossoms are produced in spring simultaneously with the budding of the leaves and are produced on spurs and some long shoots . When the flower buds first begin to open

13386-680: The many Old World plants that the Spanish introduced to Chiloé Archipelago in the 16th century, apple trees became particularly well adapted. Apples were introduced to North America by colonists in the 17th century, and the first named apple cultivar was introduced in Boston by Reverend William Blaxton in 1640. The only apples native to North America are crab apples . 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

13524-409: The mixed podocarp and broadleaf forest of Ulva Island, New Zealand , forest is the more-or-less stable climatic climax community at the end of a plant succession, where open areas such as grassland are colonised by taller plants, which in turn give way to trees that eventually form a forest canopy. In cool temperate regions, conifers often predominate; a widely distributed climax community in

13662-431: The most serious disease problems is a bacterial disease called fireblight , and three fungal diseases: Gymnosporangium rust, black spot , and bitter rot . 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. The larvae of

13800-620: 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. 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. Apples are self-incompatible; they must cross-pollinate to develop fruit. During

13938-458: The necessity for storage. 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. Many apples grow readily from seeds. However, apples must be propagated asexually to obtain cuttings with

14076-519: The next glacial period. Trees are an important part of the terrestrial ecosystem , providing essential habitats including many kinds of forest for communities of organisms. Epiphytic plants such as ferns , some mosses, liverworts, orchids and some species of parasitic plants (e.g., mistletoe ) hang from branches; these along with arboreal lichens, algae, and fungi provide micro-habitats for themselves and for other organisms, including animals. Leaves, flowers and fruits are seasonally available. On

14214-420: The old lineages of flowering plants called basal angiosperms or paleodicots ; these include Amborella , Magnolia , nutmeg and avocado , while trees such as bamboo, palms and bananas are monocots . Wood gives structural strength to the trunk of most types of tree; this supports the plant as it grows larger. The vascular system of trees allows water, nutrients and other chemicals to be distributed around

14352-415: The overwintering wood and buds are hardy down to −40 °C (−40 °F). The fruit is a pome that matures in late summer or autumn . 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. The edible flesh is formed from the receptacle at

14490-511: The patent holders. The plough was widely used in South Eastern Australia including Tasmania, Western Australia, New Zealand, New Guinea, and Germany. Changes in orchard management, specifically a change from cultivation (also referred to as tillage ) to mowing, limited the usefulness of the plough from the 1960s onwards. Apple An apple is a round, edible fruit produced by an apple tree ( Malus spp. , among them

14628-476: 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

14766-585: The plant and reduce water loss. Both the production of wood and the production of cork are forms of secondary growth. Trees are either evergreen , having foliage that persists and remains green throughout the year, or deciduous , shedding their leaves at the end of the growing season and then having a dormant period without foliage. Most conifers are evergreens, but larches ( Larix and Pseudolarix ) are deciduous, dropping their needles each autumn, and some species of cypress ( Glyptostrobus , Metasequoia and Taxodium ) shed small leafy shoots annually in

14904-409: The plant, and without it trees would not be able to grow as large as they do. Trees need to draw water high up the stem through the xylem from the roots by capillary action , as water continually evaporates from the leaves in the process of transpiration . If insufficient water is available the leaves will die. The three main parts of trees include the root, stem, and leaves; they are integral parts of

15042-439: The rear of the device. A subsequent prototype plough was constructed using the front axles from two T Model Fords. All four wheels were steerable. Front and rear wheels turned independently of each other. The tyres were removed, and the plough ran on the rims of the wheels, which had wooden spokes. The main structural members of the plough were made from 4-inch hardwood, joined at each end by specially made steel strips bolted to

15180-437: The rest, many are gymnosperms or softwood trees; these include conifers , cycads , ginkgophytes and gnetales , which produce seeds which are not enclosed in fruits, but in open structures such as pine cones , and many have tough waxy leaves, such as pine needles. Most angiosperm trees are eudicots , the "true dicotyledons", so named because the seeds contain two cotyledons or seed leaves. There are also some trees among

15318-685: 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

15456-517: 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. 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

15594-428: The roots and helps protect the trees against predators and pathogens. It can also limit damage done to a tree by pollution as the fungus accumulate heavy metals within its tissues. Fossil evidence shows that roots have been associated with mycorrhizal fungi since the early Paleozoic , four hundred million years ago, when the first vascular plants colonised dry land. Some trees such as Alder ( Alnus species) have

15732-429: 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

15870-464: The seeds on the surface of water. Mangroves often grow in water and some species have buoyant fruits with seeds that start germinating before they detach from the parent tree. These float on the water and may become lodged on emerging mudbanks and successfully take root. Other seeds, such as apple pips and plum stones, have fleshy receptacles and smaller fruits like hawthorns have seeds enclosed in edible tissue; animals including mammals and birds eat

16008-434: The soil particles and can absorb water and nutrients such as potassium in solution. The roots require oxygen to respire and only a few species such as mangroves and the pond cypress ( Taxodium ascendens ) can live in permanently waterlogged soil. In the soil, the roots encounter the hyphae of fungi. Many of these are known as mycorrhiza and form a mutualistic relationship with the tree roots. Some are specific to

16146-471: The start of the dry season. Many deciduous trees flower before the new leaves emerge. A few trees do not have true leaves but instead have structures with similar external appearance such as Phylloclades – modified stem structures – as seen in the genus Phyllocladus . Trees can be pollinated either by wind or by animals, mostly insects. Many angiosperm trees are insect pollinated. Wind pollination may take advantage of increased wind speeds high above

16284-413: The surviving seeds germinate in the spring. Pine cones may similarly be hoarded by red squirrels , and grizzly bears may help to disperse the seed by raiding squirrel caches. The seeds of conifers, the largest group of gymnosperms, are enclosed in a cone and most species have seeds that are light and papery that can be blown considerable distances once free from the cone. Sometimes the seed remains in

16422-661: The temperature begins to decrease, the leaves no longer make new chlorophyll and the red and yellow pigments already present in the blades become apparent. Synthesis in the leaf of a plant hormone called auxin also ceases. This causes the cells at the junction of the petiole and the twig to weaken until the joint breaks and the leaf floats to the ground. In tropical and subtropical regions, many trees keep their leaves all year round. Individual leaves may fall intermittently and be replaced by new growth but most leaves remain intact for some time. Other tropical species and those in arid regions may shed all their leaves annually, such as at

16560-471: The timber. The operator sat on the plough and steered using a series of levers and foot controls. The prototype sat for many years unused and forlorn under a row of pine trees on Frank's property. It was destroyed in a grass fire in the late 1960s. The ploughs were manufactured by Daniel Harvey, a machinery maker located in Box Hill, a locality adjoining Doncaster under licence from Frank and Herbert Petty as

16698-408: The tree, but some tree species have evolved roots that are aerial . The common purposes for aerial roots may be of two kinds, to contribute to the mechanical stability of the tree, and to obtain oxygen from air. An instance of mechanical stability enhancement is the red mangrove that develops prop roots that loop out of the trunk and branches and descend vertically into the mud. A similar structure

16836-432: The tree. It is a soft spongy layer of living cells, some of which are arranged end to end to form tubes. These are supported by parenchyma cells which provide padding and include fibres for strengthening the tissue. Inside the phloem is a layer of undifferentiated cells one cell thick called the vascular cambium layer. The cells are continually dividing, creating phloem cells on the outside and wood cells known as xylem on

16974-492: The tropics or sub-tropics , 0.61 trillion (20%) in the temperate zones , and 0.74 trillion (24%) in the coniferous boreal forests . The estimate is about eight times higher than previous estimates, and is based on tree densities measured on over 400,000 plots. It remains subject to a wide margin of error, not least because the samples are mainly from Europe and North America. The estimate suggests that about 15 billion trees are cut down annually and about 5 billion are planted. In

17112-403: The vascular system which interconnects all the living cells. In trees and other plants that develop wood, the vascular cambium allows the expansion of vascular tissue that produces woody growth. Because this growth ruptures the epidermis of the stem, woody plants also have a cork cambium that develops among the phloem. The cork cambium gives rise to thickened cork cells to protect the surface of

17250-429: The water depth and creating suitable conditions for further mangrove colonisation. Thus mangrove swamps tend to extend seawards in suitable locations. Mangrove swamps also provide an effective buffer against the more damaging effects of cyclones and tsunamis. Trees are the source of many of the world's best known fleshy fruits. Apples, pears, plums, cherries and citrus are all grown commercially in temperate climates and

17388-577: The wild M. sieversii origin is only slightly smaller than the modern domesticated apple. 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. 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

17526-437: The wind. Ash trees and maples have larger seeds with blade shaped wings which spiral down to the ground when released. The kapok tree has cottony threads to catch the breeze. The flame tree Delonix regia shoots its seeds through the air when the two sides of its long pods crack apart explosively on drying. The miniature cone-like catkins of alder trees produce seeds that contain small droplets of oil that help disperse

17664-465: The world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture. Because of their longevity and usefulness, trees have always been revered, with sacred groves in various cultures, and they play a role in many of the world's mythologies . Although "tree" is a common word, there is no universally recognised precise definition of what a tree is, either botanically or in common language. In its broadest sense,

17802-769: The world, fruit is gathered from forest trees for consumption. Many trees bear edible nuts which can loosely be described as being large, oily kernels found inside a hard shell. These include coconuts ( Cocos nucifera ), Brazil nuts ( Bertholletia excelsa ), pecans ( Carya illinoinensis ), hazel nuts ( Corylus ), almonds ( Prunus dulcis ), walnuts ( Juglans regia ), pistachios ( Pistacia vera ) and many others. They are high in nutritive value and contain high-quality protein, vitamins and minerals as well as dietary fibre. A variety of nut oils are extracted by pressing for culinary use; some such as walnut, pistachio and hazelnut oils are prized for their distinctive flavours, but they tend to spoil quickly. In temperate climates there

17940-402: Was also patented in the United States of America. Experimental versions of the plough went through several iterations. An early version involved the operator walking behind a device on which while all four wheels were steerable, the front and rear wheels turned together. The operator controlled the direction of the device by moving from side to side a long lever which projected tiller like from

18078-433: Was based on the diploid cultivar ' Golden Delicious '. However, this first whole genome sequence contained several errors, 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. The first whole genome assembly

18216-451: Was certainly known then. 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. 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

18354-469: Was estimated to contain around 57,000 genes, though the more recent genome sequences support estimates between 42,000 and 44,700 protein-coding genes. 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. Central Asia

18492-406: Was fitted with lever and foot controls which operated four straight disc wheels. These were turned in and out of the trees as the operator desired. The wheels would sink into the ground about 2.5 inches, giving good control and preventing side slipping often associated with ploughing uneven surfaces. The cutting discs were on an extended floating arm, which followed the land they were working. Depth

18630-417: Was regulated by two levers and the discs could be reversed to turn soil towards or away from trees. Soil was turned towards the trees in autumn and away from the trees in spring. This facilitated drainage in the wetter months and conserved water in the dryer months. The plough was manufactured in two types: light and heavy. The light weighed 7 cwt and the heavy 8 cwt 2 qrs. It could be used as

18768-450: Was the earliest known tree. Both of these reproduced by spores rather than seeds and are considered to be links between ferns and the gymnosperms which evolved in the Triassic period. The gymnosperms include conifers, cycads, gnetales and ginkgos and these may have appeared as a result of a whole genome duplication event which took place about 319 million years ago. Ginkgophyta was once

18906-639: 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. The earliest use of var. domestica for the apple was by Georg Adolf Suckow in 1786. 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

19044-725: 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. The General Committee of the IAPT decided in June 2017 to approve this change, officially conserving M. domestica . Nevertheless, some works published after 2017 still use M. pumila as the correct name , under an alternate taxonomy. When first classified by Linnaeus in 1753,

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