The tomato (Solanum lycopersicum, syn. Lycopersicon lycopersicum) is a herbaceous, usually sprawling plant in the Solanaceae or nightshade family, as are its close cousins tobacco, chili peppers, potato, and eggplant. It is a perennial, often grown outdoors in temperate climates as an annual, typically reaching to 1-3m (3 to 10 ft) in height, with a weak, woody stem that often vines over other plants.
The leaves are 10–25 cm long, odd pinnate, with 5–9 leaflets on petioles, each leaflet up to 8cm long, with a serrated margin; both the stem and leaves are densely glandular-hairy. The flowers are 1–2cm across, yellow, with five pointed lobes on the corolla; they are borne in a cyme of 3–12 together.
The tomato is native to Central, South, and southern North America from Mexico to Argentina. There is evidence that the first domesticated tomato was a little yellow fruit, ancestor of L. cerasiforme, grown by the Aztecs in Mexico, who called it xitomatl (pronounced shi-to-ma-tlh), meaning "plump thing with a navel". The word tomato comes from a word in the Nahuatl language, tomatl. The specific name, lycopersicum, means "wolf-peach" (compare the related species Solanum lycocarpum, whose scientific name means "wolf-fruit", common name "wolf-apple"), as they are a major food of wild canids in South America.
There is a competing hypothesis that the plant, like the word "tomato", originated in Mexico, where one of the two apparently oldest "wild" types grows. It is entirely possible that domestication arose in both regions independently. Diversity data suggests the center of diversity for wild tomatoes is located in Peru, while that of cultivated tomatoes, in Mexico. Thus, it can be hypothesized that wild tomatoes were introduced from Peru to Mexico, where they were domesticated.
In any case, by some means the tomato migrated to Central America. Mayans and other peoples in the region used the fruit in their cooking, and it was being cultivated in southern Mexico and probably other areas by the 16th Century. It is thought that the Pueblo people believed that those who witnessed the ingestion of tomato seeds were blessed with powers of divination. The large, lumpy tomato, a mutation from a smoother, smaller fruit, originated and was encouraged in Central America. Smith states this variant is the direct ancestor of some modern cultivated tomatoes.
Two modern tomato cultivar groups, one represented by the Matt's Wild Cherry tomato, the other by currant tomatoes, originate by recent domestication of the wild tomato plants apparently native to eastern Mexico.
Tomatoes were not grown in England until the 1590s, according to Smith. One of the earliest cultivators was John Gerard, a barber-surgeon. Gerard's Herbal, published in 1597 and largely plagiarized from continental sources, is also one of the earliest discussions of the tomato in England. Gerard knew that the tomato was eaten in Spain and Italy. Nonetheless, he believed that it was poisonous (tomato leaves and stems actually contain poisonous glycoalkaloids, but the fruit is safe). Gerard's views were influential, and the tomato was considered unfit for eating (though not necessarily poisonous) for many years in Britain and its North American colonies.
But by the mid-1700s, tomatoes were widely eaten in Britain; and before the end of that century, the Encyclopædia Britannica stated that the tomato was "in daily use" in soups, broths, and as a garnish. In Victorian times, cultivation reached an industrial scale in glasshouses, most famously in Worthing. Pressure for housing land in the 1930s to 1960s saw the industry move west to Littlehampton, and to the market gardens south of Chichester. Over the past 15 years, the British tomato industry has declined as more competitive imports from Spain and the Netherlands have reached the supermarkets.
According to FAOSTAT, the top producers of tomatoes (in tonnes) in 2005 were:
| Top Tomato Producers — 2005 (million tonnes) | |
|---|---|
| 31.6 | |
| 11.0 | |
| 9.7 | |
| 7.6 | |
| 7.6 | |
| World Total | 125 |
| Source: UN Food & Agriculture Organisation (FAO)
| |
Tomatoes are one of the most common garden fruits in the United States and, along with zucchini, have a reputation for outproducing the needs of the grower.
As in most sectors of agriculture, there is increasing demand in developed countries for organic tomatoes, as well as heirloom tomatoes, to make up for flavor and texture faults in commercial tomatoes . Quite a few seed merchants and banks provide a large selection of heirloom seeds. Tomato seeds are occasionally organically produced as well, but only a small percentage of organic crop area is grown with organic seed.
Tomato varieties are roughly divided into several categories, based mostly on shape and size. "Slicing" or "globe" tomatoes are the usual tomatoes of commerce; beefsteak are large tomatoes often used for sandwiches and similar applications - their kidney-bean shape makes commercial use impractical along with a thinner skin and being not bred for a long shelf life; globe tomatoes are of the category of canners used for a wide variety of processing and fresh eating; oxheart tomatoes can range in size up to beefsteaks, and are shaped like large strawberries; plum tomatoes, or paste tomatoes which does include pear tomatoes, are bred with a higher solid content for use in tomato sauce and paste and are usually oblong; pear tomatoes are obviously pear shaped and based upon the San Marzano types for a richer gourmet paste; cherry tomatoes are small and round, often sweet tomatoes generally eaten whole in salads; and grape tomatoes which are a more recent introduction are smaller and oblong used in salads.
Tomatoes are also commonly classified as determinate or indeterminate. Determinate, or bush, types bear a full crop all at once and top off at a specific height; they are often good choices for container growing. Determinate types are preferred by commercial growers who wish to harvest a whole field at one time, or home growers interested in canning. Indeterminate varieties develop into vines that never top off and continue producing until killed by frost. They are preferred by home growers and local-market farmers who want ripe fruit throughout the season. As an intermediate form, there are plants sometimes known as "vigorous determinate" or "semi-determinate"; these top off like determinates but produce a second crop after the initial crop. The majority of heirloom tomatoes are indeterminate, although some determinate heirlooms exist.
Most modern tomato cultivars are smooth surfaced but some older tomato cultivars and most modern beefsteaks often show pronounced ribbing, a feature that may have been common to virtually all pre-Columbian cultivars. In addition, some tomato cultivars produce fruit in colors other than red, including yellow, orange, pink, black, brown, and purple, though such fruit is not widely available in grocery stores, nor are their seedlings available in typical nurseries, but must be bought as seed, often via mail-order. Likewise, some less common varieties have fuzzy skin on the fruit, as is the case with the Fuzzy Peach tomato and Red Boar tomato plants.Also, a "stripy" or multi-colored tomatoes,most commonly red and yellow. Also known as hillbillies.
There is also a considerable gap between commercial and home-gardener cultivars; home cultivars are often bred for flavor to the exclusion of all other qualities, while commercial cultivars are bred for such factors as consistent size and shape, disease and pest resistance, and suitability for mechanized picking and shipping.
Another particularly dreaded disease is curly top, carried by the beet leafhopper, which interrupts the lifecycle, ruining a nightshade plant as a crop. As the name implies, it has the symptom of making the top leaves of the plant wrinkle up and grow abnormally.
Some common tomato pests are cutworms, tomato hornworms and tobacco hornworms, aphids, cabbage loopers, whiteflies, tomato fruitworms, flea beetles, red spider mite, slugs, and Colorado potato beetles.
As tomatoes were moved from their native areas, their traditional pollinators, (probably a species of halictid bee) did not move with them. The trait of self-fertility (or self-pollenizing) became an advantage and domestic cultivars of tomato have been selected to maximize this trait.
This is not the same as self-pollination, despite the common claim that tomatoes do so. That tomatoes pollinate themselves poorly without outside aid is clearly shown in greenhouse situations where pollination must be aided by artificial wind, vibration of the plants (one brand of vibrator is a wand called an "electric bee" that is used manually), or more often today, by cultured bumblebees.
The anther of a tomato flower is shaped like a hollow tube, with the pollen produced within the structure rather than on the surface, as with most species. The pollen moves through pores in the anther, but very little pollen is shed without some kind of outside motion.
The best source of outside motion is a sonicating bee such as a bumblebee or the original wild halictid pollinator. In an outside setting, wind or biological agents provide sufficient motion to produce commercially viable crops.
Hydroponic tomatoes are also available, and the technique is often used in hostile growing environments as well as high-density plantings.
Tomatoes are often picked unripe (and thus green) and ripened in storage with ethylene. Ethylene is a hydrocarbon gas produced by many fruits that acts as the molecular cue to begin the ripening process. Tomatoes ripened in this way tend to keep longer but have poorer flavor and a mealier, starchier texture than tomatoes ripened on the plant. They may be recognized by their color, which is more pink or orange than the other ripe tomatoes' deep red.
In 1994 Calgene introduced a genetically modified tomato called the 'FlavrSavr' which could be vine ripened without compromising shelf life. However, the product was not commercially successful (see main article for details) and was only sold until 1997.
Recently, stores have begun selling "tomatoes on the vine", which are determinate varieties that are ripened or harvested with the fruits still connected to a piece of vine. These tend to have more flavor than artificially ripened tomatoes (at a price premium), but still may not be the equal of local garden produce.
Slow-ripening cultivars of tomato have been developed by crossing a non-ripening cultivar with ordinary tomato cultivars. Cultivars were selected whose fruits have a long shelf life and at least reasonable flavor.
Today, tomatoes are mostly used for eating, and sometimes to make drinks.
Tomatoes which are under-ripened at the end of season are often used for making chutney.
Tomatoes are now eaten freely throughout the world, and their consumption is believed to benefit the heart among other things. They contain lycopene, one of the most powerful natural antioxidants, which, especially when tomatoes are cooked, has been found to help prevent prostate cancer. However, other research contradicts this claim. Tomato extract branded as Lycomato is now also being promoted for treatment of high blood pressure. Lycopene has also been show to improve the skin's ability to protect against harmful UV rays.
Though it is botanically a berry, a subset of fruit, the tomato is nutritionally categorized as a vegetable (see below). Since "vegetable" is not a botanical term, there is no contradiction in a plant part being a fruit botanically while still being considered a vegetable.
Tomatoes are used extensively in Mediterranean cuisine, especially Italian, and Middle Eastern cuisine. The tomato has an acidic property that is used to bring out other flavors, although excessive acidity often needs to be balanced with the proverbial "pinch of sugar". This acidity makes tomatoes especially easy to preserve in home canning as tomato sauce or paste. The first to commercially can tomatoes was Harrison Woodhull Crosby in Jamesburg, New Jersey. Tomato juice is often canned and sold as a beverage. Unripe green tomatoes can also be used to make salsa, be breaded and fried, or pickled.
The town of Buñol, Spain, annually celebrates La Tomatina, a festival centered on an enormous tomato fight. Tomatoes are also a popular "non-lethal" throwing weapon in mass protests; and there was a common tradition of throwing rotten tomatoes at bad performers on a stage during the 19th century; today it is usually referenced as a mere metaphor. Embracing it for this protest connotation, the Dutch Socialist party adopted the tomato as their logo.
Known for its tomato growth and production, the Mexican state of Sinaloa takes the tomato as its symbol.
Tomato plants are dicots, and grow as a series of branching stems, with a terminal bud at the tip that does the actual growing. When that tip eventually stops growing, whether because of pruning or flowering, lateral buds take over and grow into other, fully functional, vines.
Tomato plant vines are typically pubescent, meaning covered with fine short hairs. These hairs facilitate the vining process, turning into roots wherever the plant is in contact with the ground and moisture, especially if there is some issue with the vine's contact to its original root.
Most tomato plants have compound leaves, and are called regular leaf (RL) plants. But some cultivars have simple leaves known as potato leaf (PL) style because of their resemblance to that close cousin. Of regular leaves, there are variations, such as rugose leaves, which are deeply grooved, variegated, angora leaves, which have additional colors where a genetic mutation causes chlorophyll to be excluded from some portions of the leaves.
Their flowers, appearing on the apical meristem, have the anthers fused along the edges, forming a column surrounded by the pistil's style. Flowers tend to be self-fertilizing. This is because they are native to the Americas, where there were no honeybees (which are native to the old world). Similarly, many plants of the Americas are self-fertilizing, while others are pollinated by flies, butterflies, moths, other insects, or other external forces that present in the Americas, that made it possible for some new world plants to originally require biotic pollination.
Tomato fruit is classified as a berry. As a true fruit, it develops from the ovary of the plant after fertilization, its flesh comprising the pericarp walls. The fruit contains hollow spaces full of seeds and moisture, called locular cavities. These vary, among cultivated species, according to type. Some smaller varieties have two cavities, globe-shaped varieties typically have three to five, beefsteak tomatoes have a great number of smaller cavities, while paste tomatoes have very few, very small cavities.
The seeds need to come from a mature fruit, and be dried/fermented before germination.
However, genetic evidence (e.g., Peralta & Spooner 2001) has now shown that Linnaeus was correct in the placement of the tomato in the genus Solanum, making the Linnaean name correct; if Lycopersicon is excluded from Solanum, Solanum is left as a paraphyletic taxon. Despite this, it is likely that the exact taxonomic placement of the tomato will be controversial for some time to come, with both names found in the literature. Two of the major reasons that some still consider the genera separate are the leaf structure (tomato leaves are markedly different from any other Solanum), and the biochemistry (many of the alkaloids common to other Solanum species are conspicuously absent in the tomato).
The Boyce Thompson Institute for Plant Research began sequencing the tomato genome in 2004 and is creating a database of genomic sequences and information on the tomato and related plants. A draft version of the full genome expected to be published by 2008. The genomes of its organelles (mitochondria and chloroplast) are also expected to be published as part of the project.
Botanically, a tomato is the ovary, together with its seeds, of a flowering plant: therefore it is a fruit or, more precisely, a berry. However, the tomato is not as sweet as those foodstuffs usually called fruits and, from a culinary standpoint, it is typically served as part of a salad or main course of a meal, as are vegetables, rather than at dessert in the case of most fruits. As noted above, the term "vegetable" has no botanical meaning and is purely a culinary term.
This argument has had legal implications in the United States. In 1887, U.S. tariff laws that imposed a duty on vegetables but not on fruits caused the tomato's status to become a matter of legal importance. The U.S. Supreme Court settled the controversy in 1893 by declaring that the tomato is a vegetable, based on the popular definition that classifies vegetables by use, that they are generally served with dinner and not dessert (Nix v. Hedden (149 U.S. 304)). The holding of the case applies only to the interpretation of the Tariff Act of March 3, 1883, and the court did not purport to reclassify the tomato for botanical or other purposes other than paying a tax under a tariff act.
Tomatoes have been designated the state vegetable of New Jersey. Arkansas took both sides by declaring the "South Arkansas Vine Ripe Pink Tomato" to be both the state fruit and the state vegetable in the same law, citing both its culinary and botanical classifications. In 2006, the Ohio House of Representatives passed a law that would have declared the tomato to be the official state fruit, but the bill died when the Ohio Senate failed to act on it. Tomato juice has been the official beverage of Ohio since 1965. A.W. Livingston, of Reynoldsburg, Ohio played a large part in popularizing the tomato in the late 1800s.
Due to the scientific definition of a fruit, the tomato remains a fruit when not dealing with US tariffs. Nor is it the only culinary vegetable that is a botanical fruit: eggplants, cucumbers, and squashes of all kinds (such as zucchini and pumpkins) share the same ambiguity.
The pronunciation of tomato differs in different English-speaking countries; the two most common variants are /təˈmɑːtəʊ/ and /təˈmeɪɾoʊ/. Speakers from the British Isles, most of the Commonwealth, and older generations among speakers of Southern American English typically say /təˈmɑːtəʊ/, while most American and Canadian speakers usually say /təˈmeɪɾoʊ/. Many languages have a word that corresponds more to the former pronunciation, including the original Nahuatl word "tomatl" from which they are all taken. The latter pronunciation, however, fits in better with standard pronunciation tendencies in English, where it is usual to pronounce a tonic open-syllable A as a diphthong, i.e. by its name (as in the words "fatal" "debatable" and; perhaps more to the point in this case; "potato").
The word's dual pronunciations were immortalized in Ira and George Gershwin's 1937 song "Let's Call the Whole Thing Off" (You like /pəˈtʰeɪɾoʊ/ and I like /pəˈtʰɑːtəʊ/ / You like /təˈmeɪɾoʊ/ and I like /təˈmɑːtəʊ/) and have become a symbol for nitpicking pronunciation disputes. In this capacity it has even become an American and British slang term: saying when presented with two choices can mean "What's the difference?" or "It's all the same to me."
On October 30, 2006 the U.S. Centers for Disease Control and Prevention (CDC) announced that tomatoes might be the source of a salmonella outbreak causing 172 illnesses in 18 states . The affected states include Arkansas, Connecticut, Georgia, Indiana, Kentucky, Maine, Massachusetts, Michigan, Minnesota, North Carolina, New Hampshire, Ohio, Pennsylvania, Rhode Island, Tennessee, Virginia, Vermont and Wisconsin. Tomatoes have been linked to seven salmonella outbreaks since 1990 (from the Food Safety Network).
A 2008 salmonella outbreak caused the removal of tomatoes from stores and restaurants across the United States and parts of Canada. As of July 8, 2008, from April 10, 2008, the rare Saintpaul serotype of Salmonella enterica caused at least 1017 cases of salmonellosis food poisoning in 41 states throughout the United States, the District of Columbia, and Canada. As of July 2008, the U.S. Food and Drug Administration suspects that the contaminated food product is a common ingredient in fresh salsa, such as raw tomato, fresh jalapeño pepper, fresh serrano pepper, and fresh cilantro. It is the largest reported salmonellosis outbreak in the United States since 1985. New Mexico and Texas have been proportionally the hardest hit by far, with 49.7 and 16.1 reported cases per million, respectively. The greatest number of reported cases have occurred in Texas (384 reported cases), New Mexico (98), Illinois (100), and Arizona (49). There have been at least 203 reported hospitalizations linked to the outbreak, it has caused at least one death, and it may have been a contributing factor in at least one additional death. The CDC maintains that "it is likely many more illnesses have occurred than those reported." Applying a previous CDC estimated ratio of non-reported salmonellosis cases to reported cases (38.6:1), one would arrive at an estimated 40,273 illnesses from this outbreak.
The heaviest tomato ever was one of 3.51 kg (7 lb 12 oz), of the cultivar 'Delicious', grown by Gordon Graham of Edmond, Oklahoma in 1986. The largest tomato plant grown was of the cultivar 'Sungold' and reached 19.8 m (65 ft) length, grown by Nutriculture Ltd (UK) of Mawdesley, Lancashire, UK, in 2000.
The massive "tomato tree" growing inside the Walt Disney World Resort's experimental greenhouses in Lake Buena Vista, Florida may be the largest single tomato plant in the world. The plant has been recognized as a Guinness World Record Holder, with a harvest of more than 32,000 tomatoes and a total weight of 1,151.84 pounds (522 kg). It yields thousands of tomatoes at one time from a single vine. Yong Huang, Epcot's manager of agricultural science discovered the unique plant in Beijing, China. Huang brought its seeds to Epcot and created the specialized greenhouse for the fruit to grow. The vine grows golf ball-sized tomatoes which are served at Walt Disney World restaurants. The world record-setting tomato tree can be seen by guests along the Living With the Land boat ride at Epcot.Tomatina Festival
On August 30, 2007, 40,000 Spaniards gathered in Buñol to throw 115,000 kilograms of tomatoes at each other in the yearly Tomatina festival. Bare-chested tourists also included hundreds of British, French and Germans.
Heritage and heirloom varieties with exceptional taste include: