In addition to its main use as a leafy green, it has also gathered religious and medicinal significance over centuries of human consumption. Why it is an advantage growing lettuce in a pot. Plants generally have a height and spread of 15 to 30 cm (6 to 12 in). Lettuce leaves are widely used in salads, sandwiches, wraps, and similar food items. Summary. 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. Spain and then the US are the two largest exporters of lettuce in the world. It ships well, but is low in flavor and nutritional content, being composed of even more water than other lettuce types. 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. L. sativa crosses easily within the species and with some other species within the genus Lactuca. [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". -Kelly W. ANSWER: By planting a few seeds every two weeks or so, gardeners in many parts of the world can grow lettuce year round.Most varieties of salad greens really thrive in the cool and mild times of year, when temperatures are 60 degrees Fahrenheit or lower. Fungal diseases include powdery mildew and downy mildew, which cause leaves to mold and die and bottom rot, lettuce drop and gray mold, which cause entire plants to rot and collapse. It has few leaves, bolts quickly and produces seeds around 50 percent larger than other types of lettuce. Several other medicinal and religious lores are also associated with lettuce consumption. [15] There are also a few varieties with yellow, gold or blue-teal leaves. The cultivated lettuce Lactuca sativa is a popular salad vegetable and is grown on all continents throughout the world including Australia.. [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. Conventionally grown lettuce, similarly packaged, is often sold below $4 per pound. This Primefact includes information on: [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. Before World War I most lettuce grown in the U.S. was After the 1940s, with the development of iceberg lettuce, 95 percent of the lettuce grown and consumed in the US was crisphead lettuce. During the 81–96 AD reign of Domitian, the tradition of serving a lettuce salad before a meal began. Three types – leaf, head and cos or romaine – are the most common. 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. Description. [46] Lettuce is also used as a primary ingredient in the preparation of lettuce soup. It has a … [29] Although most lettuce grown today is used as a vegetable, a minor amount is used in the production of tobacco-free cigarettes; however, domestic lettuce's wild relatives produce a leaf that visually more closely resembles tobacco. In that country, "salads" were created from cooked vegetables and served hot or cold. 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 Growing lettuce in a clean room where there is very little dust and most germs have been eliminated means that lettuce is produced that can be eaten without washing. The cultivated lettuce Lactuca sativa is a popular salad vegetable and is grown on all continents throughout the world including Australia.. 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. [56] Folk medicine has also claimed it as a treatment for pain, rheumatism, tension and nervousness, coughs and insanity; scientific evidence of these benefits in humans has not been found. 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. [18] Like other members of the tribe Cichorieae, lettuce inflorescences (also known as flower heads or capitula) are composed of multiple florets, each with a modified calyx called a pappus (which becomes the feathery "parachute" of the fruit), a corolla of five petals fused into a ligule or strap, and the reproductive parts. Ancient records note that lettuce was served at the royal table of Persian kings as early as 550 B.C. Originally, the countries of North America and Western Europe ranked the highest in lettuce production in the world. 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. Growers in the USA, Canada, Japan and Europe are opting for a semi-closed greenhouse in combination with the nutrient film … In the last decade, the market for this variety has also grown explosively in Italy. [32] With the exception of the iceberg variety, lettuce is also a good source (10–19% DV) of folate and iron (table). 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. But the crown jewel is lettuce. This photo was originally published in "This Tiny Country Feeds the World" in September 2017. [44] Although China is the top world producer of lettuce, the majority of the crop is consumed domestically. The salad crops were free of disease and even more nutritious than ones grown on Earth. In Alberta, some large commercial greenhouses use a raft system for producing lettuce. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. In addition to its main use as a leafy green, it has also gathered religious and medicinal signific… [54] Viruses, including hepatitis A, calicivirus and a Norwalk-like strain, have been found in lettuce. 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 will also cross with Lactuca serriola (wild lettuce), with the resulting seeds often producing a plant with tough, bitter leaves. In addition, since the temperature, humidity, carbon dioxide, lighting, and other conditions can be perfectly controlled by ICT, a stable yield of high-quality, low-potassium lettuce can be harvested throughout the year. [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. [32], Food-borne pathogens that can survive on lettuce include Listeria monocytogenes, the causative agent of listeriosis, which multiplies in storage. Most lettuce varieties are eaten fresh and are commonly served as the base of green salads. [39], Soil nutrient deficiencies can cause a variety of plant problems that range from malformed plants to a lack of head growth. Contaminated lettuce is often a source of bacterial, viral, and parasitic outbreaks in humans, including E. coli and Salmonella. Lettuce is a cool-season crop that grows best with moderate daytime temperatures (73oF) and cool nights (45oF). [1] At room temperature, lettuce seeds remain viable for only a few months. 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. [53] Salmonella bacteria, including the uncommon Salmonella braenderup type, have also caused outbreaks traced to contaminated lettuce. or on mountain tops, without getting eaten. [9], The Romans referred to lettuce as lactuca (lac meaning dairy in Latin), an allusion to the white substance, now called latex, exuded by cut stems. Lettuce growing systems Around the world, different styles of growing systems are used for greenhouse lettuce (Figure 1). These upright lettuces were developed by the Egyptians and passed to the Greeks, who in turn shared them with the Romans. For example, the larvae of the ghost moth is a common pest of lettuce plants. The serving of lettuce salads started in about 81–96 AD. World production of lettuce and chicory for 2017 was 27 million tonnes, 56% of which came from China.[4]. Tracing the history of many varieties is complicated by the practice of many companies, particularly in the US, of changing a variety's name from year to year. integrifolia. Lettuce is an excellent source of vitamin K, vitamin A, folate, and iron. The initial settlers in South America considered lettuce to be a cure for small pox. In 2011, lettuce was grown on 206,000 acres in California, which represented 73% of the total U.S. acreage [11]. Where (in the World!) Lettuce varieties will cross with each other, making spacing of 1.5 to 6 m (60 to 240 in) between varieties necessary to prevent contamination when saving seeds. Countries worldwide are steadily supplying more and more produce to Americans eager to “eat fresh” year-round [13] Lettuce was first brought to the Americas from Europe by Christopher Columbus in the late 15th century. The Romans likewise claimed that it increased sexual potency. By 50 AD, many types were described, and lettuce appeared often in medieval writings, including several herbals. But if you live in the area where it’s native, this is a fantastic native wild vegetable that you can easily grow on your wild homestead.. Currently, the crisphead variety is more dominant in northern and western Europe. [21], Lettuce was first cultivated in ancient Egypt for the production of oil from its seeds. Aster yellows are a disease-causing bacteria carried by leafhoppers, which causes deformed leaves. [28], Lettuce is very easy to grow, and as such has been a significant source of sales for many seed companies. [17] Once plants move past the edible stage, they develop flower stalks up to 1 m (3 ft 3 in) high with small yellow blossoms. 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. Data … 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. Lettuce flowers more quickly in hot temperatures, while freezing temperatures cause slower growth and sometimes damage to outer leaves. [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. tatarica. [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. The vegetable has also been linked to outbreaks of parasitic infestations, including Giardia lamblia.[51]. Depending on the variety, lettuce is an excellent source (20% of the Daily Value, DV, or higher) of vitamin K (97% DV) and vitamin A (21% DV) (table), with higher concentrations of the provitamin A compound, beta-carotene, found in darker green lettuces, such as romaine. Lactuca sativa is a member of the Lactuca (lettuce) genus and the Asteraceae (sunflower or aster) family. Romaine lettuce is often used for Caesar salads. Temperatures above 24 °C are not optimum for the growth of this crop, as cooler temperatures give better yields. [8] Lettuce is closely related to several Lactuca species from southwest Asia; the closest relationship is to L. serriola, an aggressive weed common in temperate and subtropical zones in much of the world. 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. Outbreaks Associated with Fresh and Fresh-Cut Produce. However, genetically modified lettuce is not currently used in commercial agriculture. or on mountain tops, without getting eaten. Pale to white lettuce, such as the centers in some iceberg lettuce, contain few nutrients.[18]. Lettuce is also used in cooked dishes in different parts of the world. Let’s have a look at how you can grow lettuce in a greenhouse! 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