Sunflower 
(Helianthus annuus L.) is an annual plant of the popular kenikir-kenikiran (Asteraceae), both as an ornamental plant and oil-producing plant. This plant flower is very distinctive: large, usually bright yellow, with a large flower head (diameter can reach 30 cm). This flower is actually a compound interest, composed of hundreds to thousands of small flowers on one bump. Sunflower also has a typical behavior, the flowers are always facing / leaning toward the sun or heliotropisme. The French call it tournesol or "traveler of the Sun". However, this trait is removed in new cultivars for oil production because it consumes a lot of energy and reduces yield.
Sunflower is the national flower of Ukraine and the official flower of the state of Kansas, USA.
Characteristics
An annual seasonal plant originating from the North American Tropical (Mexico), is 3m to 5m high depending on its variety. Single leaf width. Stems are usually overgrown with rough hair, erect, rarely branching.
Flowers arranged compound. There are two types of flowers: a floral or flower of the tongue carrying a large yellow petal and sterile yellow, and a fertile tube flower and seed yield. The flower of this tube can reach 2000 buds in a bunch of flowers. Pollination is open (cross) and is assisted by insects. On a clear day, bunches of compound flowers follow the daily movement of the Sun (the origin of the name of this plant), whose symptoms are called heliotropism. Plants benefit 10% more photosynthesis due to this movement.
The fruit bertipe fruit brackets (achene). Dry fruits are rather hard and not too thick thick wall is often presumed 'seeds' sunflowers, because it can not easily be distinguished. The real seeds are located inside, sheltered by similar fruits of shell.
Group cultivation
Sunflower ornamental.
There are four groups of cultivation for sunflower which are distinguished by their usefulness. The assembled cultivars are usually directed to one particular purpose only.
Oil producing group, used seed oil. The seeds of this group have a thin seed shell. The oil content ranges from 48% to 52%. To produce one liter of oil is required seeds of approximately 60 bunches of compound interest.
Livestock feed group, harvested leaves as feed or green manure.
The group of ornamental plants, which have a varied petal color and has many branches of flowering,
Quartz group, to harvest the seeds as food.
Cultivation
History
This plant has been cultivated by North American Indians for thousands of years. Further spread to South America and become one food source for Inka citizens. After the conquest by Europeans, Sun flowers were introduced to Europe and other parts of the world in the 16th century. From the 17th century the seeds were used in a bread mixture or processed instead of coffee and chocolate. Its use as an oil source began to be pioneered in the 19th century.
Habitat
The sunflower likes the fertile and warm soil. This plant likes a bright atmosphere. Given the origin, these plants are suitable to grow in places with subtropical climates. In the tropics the results are high if planted in the highlands. In temperate climates such as Europe these plants can only be planted in spring until autumn and should be avoided by frost.
Density of planting is usually 60000 to 70000 plants per ha.
Sunflower oil
As already mentioned in the cultivation group, the utilization of Sun flower is primarily as a source of oil, both food and industry. As a food, sunflower oil is suitable for frying, thickening and mixing salad. Sunflower oil is rich in linoleic acid (C18: 2), an unsaturated fatty acid that is good for human health. Engineering interests want oils with higher levels of oleic acid and there are also sunflower cultivars that produce such quality of oil (containing 80% to 90% oleic acid, while cultivars for food have only 25% oleic acid).
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