Lettuce is a cool-season crop that grows best with moderate daytime temperatures (73oF) and cool nights (45oF). Circa 50 AD, Roman agriculturalist Columella described several lettuce varieties – some of which may have been ancestors of today's lettuces. Lettuce can be grown from seed or from steams depending on the variety. This Primefact includes information on: This large price difference is justified; as hydroponic lettuce has a better taste, is grown without pesticides, and requires significantly less water to grow. These include fused anthers that form a tube which surrounds a style and bipartite stigma. [26], Due to its short lifespan after harvest, lettuce was originally sold relatively close to where it was grown. How to grow lettuce. [31] After harvest, lettuce lasts the longest when kept at 0 °C (32 °F) and 96 percent humidity. Your Fruits and Vegetables Come from: An Interactive Finder. The problem with the popular iceberg (head) lettuce is that when the first head appears, the remainder is not far behind. China alone produced about 13.5 million tons. Lettuce is most often grown as a leaf vegetable, but sometimes for its stem and seeds as well. Several other medicinal and religious lores are also associated with lettuce consumption. Diff… [1], The domestication of lettuce over the centuries has resulted in several changes through selective breeding: delayed bolting, larger seeds, larger leaves and heads, better taste and texture, a lower latex content, and different leaf shapes and colors. sativa,[1] L. scariola var. The cultivated lettuce Lactuca sativa is a popular salad vegetable and is grown on all continents throughout the world including Australia.. [10] This word has become the genus name, while sativa (meaning "sown" or "cultivated") was added to create the species name. Your Fruits and Vegetables Come from: An Interactive Finder. The 16th through 18th centuries saw the development of many varieties in Europe, and by the mid-18th century cultivars were described that can still be found in gardens. Lettuce is most often used for salads, although it is also seen in other kinds of food, such as soups, sandwiches and wraps; it can also be grilled. Lettuce is rich in Folate, Manganese, Vitamins A, C, K, and dietary fiber. Instead of growing the lettuce in soil, they are grown in nutrient solutions inside green houses. [43] Herbicides are often used to control weeds in commercial production. Lactuca virosa is biennial, similar to prickly lettuce Lactuca serriola but taller – it can grow to 200 cm (80 inches or almost 7 feet). [53] Salmonella bacteria, including the uncommon Salmonella braenderup type, have also caused outbreaks traced to contaminated lettuce. Butterhead – Also known as Boston or Bibb lettuce. This was done for several reasons, the most prominent being to boost sales by promoting a "new" variety or to prevent customers from knowing that the variety had been developed by a competing seed company. The International Space Station (ISS) has been experimenting with growing its own lettuce and good news for astronauts, a study found the space-grown variety to be just as nutritious as Earth-grown. Before World War I most lettuce grown in the U.S. was either leaf or butter lettuce [5]. This lettuce is so local, they grow it right in the supermarket QFC supermarkets around Seattle now feature standing indoor farms that grow the produce in the store. Lettuce has been traced back to a native weed that was cultivated in Egypt for the oil gained from the seeds. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is also eaten as part of the Jewish Passover Seder, where it is considered the optimal choice for use as the bitter herb, which is eaten together with the matzah. Miner’s lettuce is a perennial vegetable native to much of the western United States and Canada. Aster yellows are a disease-causing bacteria carried by leafhoppers, which causes deformed leaves. In these areas it was the most commonly grown lettuce in the twenty-first century. [40] Mammals, including rabbits and groundhogs, also eat the plants. [28], Lettuce is very easy to grow, and as such has been a significant source of sales for many seed companies. [2] L. sativa also has many identified taxonomic groups, subspecies and varieties, which delineate the various cultivar groups of domesticated lettuce. Work in these areas continues through the present day. The problem with the popular iceberg (head) lettuce is that when the first head appears, the remainder is not far behind. [55] This narcotic effect is a property of two sesquiterpene lactones which are found in the white liquid (latex) in the stems of lettuce,[30] called lactucarium or "lettuce opium". Space-Grown Lettuce Is Safe and Astronaut-Approved NASA’s vegetable production system, known as Veggie, may help pave the way for more sophisticated systems that could supplement astronauts’ diets during long trips to space. It has few leaves, bolts quickly and produces seeds around 50 percent larger than other types of lettuce. QUESTION: What lettuce grows well in summer? It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. According to estimates given by the Food and Agriculture Organization (FAO) in 2006, China produced around 11,005,000 metric tonnes of lettuce on 500,250 hectares of land. The religious ties of lettuce continue into the present day among the Yazidi people of northern Iraq, who have a religious prohibition against eating the plant. This plant was probably selectively bred by the Egyptians into a plant grown for its edible leaves,[22] with evidence of its cultivation appearing as early as 2680 BC. Incidence, Growth, and Survival of Pathogens in Fresh and Fresh-Cut Produce", "Bashiqa Journal: A Sect Shuns Lettuce and Gives the Devil His Due", https://en.wikipedia.org/w/index.php?title=Lettuce&oldid=997415699, Articles with dead external links from October 2017, Articles with permanently dead external links, Articles containing Chinese-language text, Creative Commons Attribution-ShareAlike License. [51] Lettuce has been linked to numerous outbreaks of the bacteria E. coli O157:H7 and Shigella; the plants were most likely contaminated through contact with animal feces. Before World War I most lettuce grown in the U.S. was Countries worldwide are steadily supplying more and more produce to Americans eager to “eat fresh” year-round Although lettuce is produced in many states, California and Arizona dominate U.S. production. Lettuce was originally farmed by the ancient Egyptians, who transformed it from a plant whose seeds were used to create oil into an important food crop raised for its succulent leaves and oil-rich seeds. Some American settlers claimed that smallpox could be prevented through the ingestion of lettuce,[55] and an Iranian belief suggested consumption of the seeds when afflicted with typhoid. Similar to Mycelis muralis but showing more than 5 florets.. Countries worldwide are steadily supplying more and more produce to Americans eager to “eat fresh” year-round Iceberg lettuce was mainly produced in the western U.S. They said the space-grown lettuce was similar in composition to the Earth-based controls. “Greenhouse manufacturers originally developed this type of greenhouse for fruit crops, but this approach is increasingly is being chosen for hydroponic production of lettuce too. [33] Hydroponic growing methods can reduce this water consumption by nearly two orders of magnitude. [24][25] Between the late 16th century and the early 18th century, many varieties were developed in Europe, particularly Holland. Types of Lettuce Produced The emergence of California as a dominant lettuce production area in the 1920s had a large impact on the types of lettuce consumed. The lettuce plant is a hardy annual that grows best in nitrogen-rich, loose soils that have a pH ranging between 6.0 and 6.8. Originally, the countries of North America and Western Europe ranked the highest in lettuce production in the world. Trying to grow lettuce again this year and want to mimic where it grows best - and wild. [31] There are seven main cultivar groups of lettuce, each including many varieties: The butterhead and crisphead types are sometimes known together as "cabbage" lettuce, because their heads are shorter, flatter, and more cabbage-like than romaine lettuces. However, genetically modified lettuce is not currently used in commercial agriculture. The fruits have 5–7 ribs on each side and are tipped by two rows of small white hairs. So, light but consistent watering is key. [32], Food-borne pathogens that can survive on lettuce include Listeria monocytogenes, the causative agent of listeriosis, which multiplies in storage. QUESTION: What lettuce grows well in summer? [54] Viruses, including hepatitis A, calicivirus and a Norwalk-like strain, have been found in lettuce. Lettuce is easily cultivated and is grown all year round. [11] The consumption of lettuce in China developed differently from in Western countries, due to health risks and cultural aversion to eating raw leaves. The plant was first cultivated by ancient Egyptians from where it spread to Greece and Rome and was soon cultivated in most parts of Europe. The study noted that in some trials, the space-grown plants tended to be richer in elements like potassium, sodium, phosphorus, sulphur, and zinc, as well as in some molecules with proven antiviral, anticancer, and anti-inflammatory activity. [41] Crowding lettuce tends to attract pests and diseases. "Lettuce" is synonymous with "salad" for people all over the world. By the late 20th century, the preferred types began to change, with crisphead, especially iceberg, lettuce becoming the dominant type in northern Europe and Great Britain and more popular in western Europe. Different locations tended to prefer different types of lettuce, with butterhead prevailing in northern Europe and Great Britain, romaine in the Mediterranean and stem lettuce in China and Egypt. The early 20th century saw the development of new packing, storage and shipping technologies that improved the lifespan and transportability of lettuce and resulted in a significant increase in availability. tatarica. [15] There are also a few varieties with yellow, gold or blue-teal leaves. Ancient Egyptians would relate lettuce to sexual prowess. Ancient records note that lettuce was served at the royal table of Persian kings as early as 550 B.C. Despite grown under low gravity and intense radiation, the space-grown lettuce is as nutritious as those grown on earth, said Christina … The FDA and the Centers for Disease Control and Prevention on Tuesday said romaine lettuce grown in Florida is safe to eat. Lettuce grown on the International Space Station has been served with tacos and cheeseburgers, and it turns out to be just as nutritious as the Earth-grown version Lettuces come in a wide variety of shapes, colours and textures. Lettuce spaced farther apart receives more sunlight, which improves color and nutrient quantities in the leaves. [16], Depending on the variety and time of year, lettuce generally lives 65–130 days from planting to harvesting. Temperatures above 24 °C are not optimum for the growth of this crop, as cooler temperatures give better yields. There are several types or cultivars of lettuce. Eight years later, almost four times as much iceberg as butter lettuce was shipped [5]. The study noted that in some trials, the space-grown plants tended to be richer in elements like potassium, sodium, phosphorus, sulphur, and zinc, as well as in some molecules with proven antiviral, anticancer, and anti-inflammatory activity. [7] L. scariola is itself a synonym for L. serriola, the common wild or prickly lettuce. Longer taproots and more extensive secondary systems are found in varieties from Asia. Sow seed on moist, well-prepared soil or compost in spring. integrifolia. The cultivated lettuce Lactuca sativa is a popular salad vegetable and is grown on all continents throughout the world including Australia.. [41] Lettuce contains several defensive compounds, including sesquiterpene lactones, and other natural phenolics such as flavonol and glycosides, which help to protect it against pests. They need moist soil to grow correctly. The cultivated variety appears to have been about 75 cm (30 in) tall and resembled a large version of the modern romaine lettuce. [52] A 2007 study determined that the vacuum cooling method, especially prevalent in the California lettuce industry, increased the uptake and survival rates of E. coli O157:H7. Oilseed – This type is grown for its seeds, which are pressed to extract an oil mainly used for cooking. The salad crops were free of disease and even more nutritious than ones grown on Earth. Researchers have found that the salad crop, red romaine lettuce, grown on board the International Space Station (ISS), is as nutritious as counterparts grown on the Earth, an advance that may help astronauts grow safe, fresh food during space missions. Trying to grow lettuce again this year and want to mimic where it grows best - and wild. protect from slugs and snails. In addition to its usual purpose as an edible leafy vegetable, lettuce has had a number of uses in ancient (and even some more modern) folk medicine and religious symbolism. However, this has led to the development of herbicide-resistant weeds and prompted environmental and health concerns.[20]. The vegetable has also been linked to outbreaks of parasitic infestations, including Giardia lamblia.[51]. Because lettuce is used in salads, we tend to eat more of it in summer. Plants generally have a height and spread of 15 to 30 cm (6 to 12 in). The pappus remains at the top of each fruit as a dispersal structure. Documentation from the late 19th century shows between 65 and 140 distinct varieties of lettuce, depending on the amount of variation allowed between types – a distinct difference from the 1,100 named lettuce varieties on the market at the time. California accounted for 71 percent of U.S. head lettuce production in 2013, followed by Arizona producing nearly 29 percent. List Notes: Production is in metric tonnes for the year 2007.List also includes chicory. It ships well, but is low in flavor and nutritional content, being composed of even more water than other lettuce types. [6] Synonyms for L. sativa include Lactuca scariola var. The original stem type traveled eastward, ... produce nearly all the commercially grown lettuce in the world. Lettuce parts have also been used in the preparation of traditional and herbal medicines in some places. [55] In contrast, the ancient Greeks connected the plant with male impotency,[10] and served it during funerals (probably due to its role in the myth of Adonis' death), and British women in the 19th century believed it would cause infertility and sterility. Pale to white lettuce, such as the centers in some iceberg lettuce, contain few nutrients.[18]. [18] Weeds can also be an issue, as cultivated lettuce is generally not competitive with them, especially when directly seeded into the ground. Lettuce growing systems Around the world, different styles of growing systems are used for greenhouse lettuce (Figure 1). It's by far the world's most popular salad plant and has been cultivated for more than 2,000 years. In addition to its main use as a leafy green, it has also gathered religious and medicinal signific… China is the world leader in lettuce production, producing half of the world's lettuce.Stem lettuce is grown in the country and the stems are prepared as a cooked vegetable. [10] Lettuce was considered a sacred plant of the reproduction god Min, and it was carried during his festivals and placed near his images. So, light but consistent watering is key. Lettuce (Lactuca sativa) is an annual plant of the daisy family, Asteraceae. The plant is usually cultivated as a leaf vegetable in different parts of the world. Lettuce (Lactuca sativa L.) is an annual of the Asteraceae family and native to the Mediterranean.It is thought to have originated in Europe and Asia and been cultivated for at least 2000 years. Lettuce can be grown in a garden almost anywhere in the US, but by far the majority of commercial lettuce is grown in the Salinas Valley on California's central coast. This is done through the aid of modern technology, namely aeroponics and hydroponics. The plant was thought to help the god "perform the sexual act untiringly. This photo was originally published in "This Tiny Country Feeds the World" in September 2017. For example, the larvae of the ghost moth is a common pest of lettuce plants. Lettuce is generally a rich source of vitamins K and A, though the nutritional quality varies, depending on the variety. Leaf – Also known as looseleaf, cutting or bunching lettuce. By 50 AD, many types were described, and lettuce appeared often in medieval writings, including several herbals. Cover with a very thin layer of compost or vermiculite. However, in China, a majority of the lettuce produced is utilized for domestic consumption. [22] Most lettuce is used in salads, either alone or with other greens, vegetables, meats and cheeses. Frankly, lettuce can now be grown almost anywhere in the World. By the late 1900s, Asia, South America, Australia and Africa became more substantial markets. Post-Roman Europe continued the tradition of poaching lettuce, mainly with large romaine types, as well as the method of pouring a hot oil and vinegar mixture over the leaves. Lettuce is grown in home gardens worldwide. Generally grown as a hardy annual, lettuce is easily cultivated, although it requires relatively low temperatures to prevent it from flowering quickly. How to Keep Growing Lettuce in Fall (and Winter) Even in cold winter areas, you can grow lettuce through the colder months if you give your plants some protection. [32] With the exception of the iceberg variety, lettuce is also a good source (10–19% DV) of folate and iron (table). [20] Scientific research into the genetic modification of lettuce is ongoing, with over 85 field trials taking place between 1992 and 2005 in the European Union and United States to test modifications allowing greater herbicide tolerance, greater resistance to insects and fungi and slower bolting patterns. Although this trait can be a problem to home gardeners who attempt to save seeds, biologists have used it to broaden the gene pool of cultivated lettuce varieties. In warm climates lettuce growing is usually restricted to the spring and fall, when temperatures are more moderate than in summer or winter. A video showing an actual step by step example. Lettuce flowers more quickly in hot temperatures, while freezing temperatures cause slower growth and sometimes damage to outer leaves. Amy Schleunes Mar 9, 2020. The serving of lettuce salads started in about 81–96 AD. [5] The species was first described in 1753 by Carl Linnaeus in the second volume of his Species Plantarum. In Alberta, some large commercial greenhouses use a raft system for producing lettuce. In the US, several varieties of lettuce are grown. LETTUCE has been successfully grown in space — bringing the colonisation of Mars a step closer say scientists. IKEA, the world's biggest furniture retailer, is preparing to serve lettuce grown in high-tech containers outside its stores as part of efforts to improve its environmental profile. Lettuce, annual leaf vegetable of the aster family. Books published in the mid-18th and early 19th centuries describe several varieties found in gardens today. Lactuca virosa is biennial, similar to prickly lettuce Lactuca serriola but taller – it can grow to 200 cm (80 inches or almost 7 feet). Description. This large price difference is justified; as hydroponic lettuce has a better taste, is grown without pesticides, and requires significantly less water to grow. And lettuce is a great plant to start with if you want to ease into year-round growing. Similar to Mycelis muralis but showing more than 5 florets.. Climate-controlled farms such as these grow crops around the clock and in every kind of weather. Some varieties, especially those found in the United States and Western Europe, have long, narrow taproots and a small set of secondary roots. It has become naturalized in Europe because of its use as a vegetable. [16][19] The ovaries form compressed, obovate (teardrop-shaped) dry fruits that do not open at maturity, measuring 3 to 4 mm long. Europe and North America originally dominated the market for lettuce, but by the late 20th century the consumption of lettuce had spread throughout the world. There are a number of features that make lettuce suitable for genetic studies. Weeds also act as homes for insects and disease and can make harvesting more difficult. It can be plagued by numerous nutrient deficiencies, as well as insect and mammal pests, and fungal and bacterial diseases. Currently, the crisphead variety is more dominant in northern and western Europe. The harvested lettuce is best stored at 0 °C and a humidity of 96%. Stem lettuce is more common in Egypt and China while butterhead was preferred in Northern Europe. Lettuce can be grown in a garden almost anywhere in the US, but by far the majority of commercial lettuce is grown in the Salinas Valley on California's central coast. Transplanted lettuce (started in flats and later moved to growing beds) is generally more competitive initially, but can still be crowded later in the season, causing misshapen lettuce and lower yields. The Romans likewise claimed that it increased sexual potency. It is also stouter, the stem and leaves are more purple flushed, [disputed – discuss] the leaves are less divided, but more spreading. In 2011, lettuce was grown on 206,000 acres in California, which represented 73% of the total U.S. acreage [11]. Lettuce (Lactuca sativa) is an annual plant of the daisy family, Asteraceae. Spacing of about 6 to 18 inches between romaine lettuce plants to ensure they get enough nutrients and space to grow. In 2013, 24.9 million tons of lettuce were produced in the world. So, with the hot months approaching, now is a good time to discuss growing this vegetable.. Lettuce can be grown in a garden almost anywhere in the US, but by far the majority of commercial lettuce is grown in the Salinas Valley on California's central coast. In the US, no one type predominated until the early 20th century, when crisphead lettuces began gaining popularity. Lettuce simply can't come into contact with the fecal matter that causes E. coli 0157 if it's grown in filtered water, inside a greenhouse and with limited human contact, according to Rindi Bristol. [13], Lettuce's native range spreads from the Mediterranean to Siberia, although it has been transported to almost all areas of the world. Earlier, Europe and North America were the leading producers of lettuce; however, since the late 20th century, lettuce’s production and consumption had spread throughout the world. As the anthers shed pollen, the style elongates to allow the stigmas, now coated with pollen, to emerge from the tube. Because lettuce is used in salads, we tend to eat more of it in summer. Up until now, only micro greens and herbs have proven financially viable for vertical production in the UK, but such developments will allow mainstream salad produce to be grown domestically for the retail sector – both in store and, more importantly, in big warehouses – starting with baby leaf and moving into gem and cos lettuce, lollo rossa, oakleaf and other salad leaves. integrata and L. scariola var. [34] Seeds keep best when stored in cool conditions, and, unless stored cryogenically, remain viable the longest when stored at −20 °C (−4 °F); they are relatively short lived in storage. Lettuce is easy to grow. [26] Lettuces meant for the cutting of individual leaves are generally planted straight into the garden in thick rows. Singapore, Malaysia, Japan, China, the Philippines and possibly certain parts of India would grow lettuce. Lettuce quickly degrades when stored with fruit such as apples, pears and bananas that release the ripening agent ethylene gas. Large areas of lettuce are also grown in southeastern Australia, Japan, China, Israel, northern Mexico, Chile, Argentina, Brazil, and Peru. Compost moist the two largest exporters of lettuce were produced in the world including Australia gained from the.... About 81–96 AD Viruses, including Giardia lamblia. [ 18 ] and seeds... It was the most common types are romaine, leaf, head and cos romaine... Accounted for 71 percent of production can be plagued by numerous nutrient,... 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