The history of Sunflower
Sunflower is the most popular oilseed crop in Europe and North America, where the crop originated and was domesticated during the first millennium B.C. While the Native Americans used many different plant parts of wild sunflowers as medicines and culinary, the crop was first spread across the world as ornamental. Sunflower became a vital oilseed crop globally after the Russians bred the Mammoth Russian, increasing the side of the heads and the seed oil content from 28% to almost 50% in 1860. These new varieties were reintroduced back to the U.S. in 1893 (1). During the past 3,000 years, the sunflower seed size has increased by 1,000%.
Nowadays, sunflower is cultivated on almost every continent. Ukraine, Russia, European Union, Argentina, Turkey, and the U.S. are the top producers, with 86% of the world’s total production (2). However, France, Romania, and China are the champions regarding seeds production yield per hectare (3).
Uses of Sunflower and Nutritional value
From ancient times until today, sunflower has been grown and used for many different purposes. Among its various uses, sunflower had reputed medicinal value. Different plant parts were used to treat kidneys, chest pains, and pulmonary troubles, soothe coughs, as a dermatological aid, and to stimulate the appetite and alleviate fatigue and rheumatism (Heiser, 1976). The sunflower became famous and spread throughout the world as an ornamental plant. Today, it still has an important place in home and public gardens, in flower compositions or bouquets, and paintings. However, for the past half a century, the crop has been mainly cultivated as a hybrid to produce vegetable oil and biodiesel. At the same time, it is also used for human and bird consumption.
There are two main types of sunflower: The oil-type and the confections-type (non-oil, mainly for human consumption).
- Vegetable oil production
Almost 70—80% of the cultivated sunflowers belong to this type. Depending on the oleic content, this sunflower type is further sub-categorized into three different groups: the traditional, mid-oleic (NuSun), and high oleic (over 80%) (4). The main characteristic of these varieties is the high concentration of the seeds in oil, which usually ranges between 39-49%. Nowadays, sunflower oil is considered the most widely used vegetable oil with high quality for cooking purposes. The main reason for that is the high amount of fatty acid (oleic acid) that makes the oil very stable during frying and increases the shelf-life of the products. Finally, it is relatively healthy compared to other oils due to the very low saturated fatty acid content.
- Biofuel production
Sunflower is also a promising biofuel production plant. However, its increasing price makes it harder to be used for that purpose (1).
- For Livestock use
Many other mammals and birds are fed from sunflower seeds except for humans. Among them are grouses, blackbirds, sparrows and doves, longspurs, chipmunks, and mice.
Sunflower meal (the seeds after the oil extraction) can be used as the sole source of supplemental protein or as a protein supplement in lower-quality forage, in a cattle diet, thanks to its great degradability by ruminants. Sunflower silage can make a suitable feed for beef cows, ideally when the moisture level is less than 65%. It has the highest protein content compared to any other forage crop and has a relatively low acid detergent fiber making it easily digestible by the animals. It can also be used in a blend with corn silage, which is of lower quality. The seeds can also be used as feed in small quantities, but it is not an economically sustainable choice (2).
- Birdseed use
Feeding birds is a huge market, and the birdseed business is a multi-billion dollar industry, especially in the U.S. Generally, seeds from oil-type sunflowers are preferred due to their lower price, smaller size, and thinner hull than the confections-type seeds. However, in some cases, when confections seeds do not reach the commercially needed quality, they can also be used as bird feed.
The confections-type (non-oil type)
Sunflower seeds of this type are hulled, striped, larger, and are marketed as a snack for human consumption. The seeds can be eaten roasted or un-hulled and used in processed foods, like cereal bars, bread, etc.
100g of Sunflower seeds contain:
521 calories (25.5g of protein)
44.8 g fat (5.2 g saturated, 30 g polyunsaturated, and 9.4 monosaturated)
20.8 g Carbs
10 g fiber
The sunflower seeds are also rich in Vitamin E, Manganese, Pantothenic acid, Potassium, and Copper, while they also contain significant amounts of Vitamin B6, Folate, Niacin, Zinc, Iron, and Magnesium. Finally, sunflower plant parts can also be used in manufacturing paints, resins, plastics, soap, cosmetics, detergents, and many other industrial products (5). The hulls can be used in ethyl alcohol and furfural production, while the stems are used as a source of fiber for fabrics and paper. Finally, the roasted seeds of sunflower are used as a coffee substitute (6).
Sunflower Plant information
The cultivated sunflower (Helianthus annuus L.) is one of the 67 species in the genus Helianthus. Most species of the genus are perennial plants, while only a few are annuals. All the species belong to the Asteraceae (Compositae) family. The plant has a typical composite flower that follows the sun’s route. This means that the flowers face the east early in the morning, and during all day they follow the sun up until sunset, when they face West. This “habit” gave sunflower or Helianthus its name (“helios” that in Greek means sun and “anthos” that means flower). However, as the crop matures and the flower heads become heavier due to the seeds they contain, this phenomenon stops and the heads do not follow the sun’s route anymore.
The plant has a fast growth rhythm and a strong, erect, and rough-hairy stem reaching 0.6 to 3 m (2-10 ft) in height. The leaves are simple, large, egg-shaped to triangular. The high number of stomata on the leaves leads to two times higher transpiration levels than other spring crops. The head consists of the receptacle that carries the disc florets, the petals (ray florets), the bracts, and involucral bracts. The flower heads grow at the edge of branches, their number depends on the variety, and the size may vary between 7.5-15 cm (3-6 in). Larger heads are more common in cultivated types. Ray flowers are typically yellow, while the disk flowers in the center of the head are reddish-brown. When the “true” flowers (disk flowers) are pollinated and fertilized, they produce the seeds. Most modern varieties are self-fertile, but pollination by bees or other insects can improve the seed set. A single head can produce 350 to 2,000 seeds, with oil content from 35-55% (in the cultivated varieties) (5, 7, 2). The commercial cultivars have been bred to turn their heads towards the ground after blooming, making it harder for the birds to feed with the seeds.
A sunflower usually completes its life cycle approximately 90 to 125 days after planting. However, the duration of the total life cycle and each growth stage highly depends on the cultivated variety. Standardized growth stages have been established in order to facilitate communication between farmers, scientists, and industry. The vegetative stages are coded (VE-number) and concern the stages from the plant emergence to the start of bud formation. From that stage onwards, the plant enters the reproduction phase, which consists of 9 sub-stages. The most distinct is the R-4 (the opening of the inflorescences) and the R-9, which characterize the physiological maturity. In general, the average time needed from planting to emergence is 11 days, from emergence to the formation of the flower head is 33 days, while 27 more days are required for the first anther to appear. Around 38 days will pass from that moment until the plant’s maturity (8).
Generally, the sunflower is considered an “environmentally-friendly” crop due to its limited need for inputs (fertilizers, water, pesticides) and great adaptability, making its organic cultivation possible (Debaeke et al., 2017). The plant has a high drought tolerance since it is highly efficient in extracting and using water stored in the soil, especially in sandy loam soils. Moreover, it is a quite popular plant to use in a crop rotation scheme and can help reduce the population of important crop pests like corn borer or soybean cyst nematodes. Thanks to the flexibility in the planting date and the generally short life cycle, sunflowers can be double-crop planted, usually after wheat.
To sustainably maximize sunflower yield, the farmer must follow steps and best agricultural practices (10). The farmer needs to keep the field weed-free the first 40 days after planting, while top fertilization can be applied between the 20th and 40th day. The critical period for water needs (satisfied from irrigation or rainfalls) and disease detection-control is from the 45th to 85th and 65th to 90th day, respectively (9).
Debaeke, P., Bedoussac, L., Bonnet, C., Mestries, E., Seassau, C., Gavaland, A., … & Justes, E. (2017). Sunflower crop: environmental-friendly and agroecological. OCL Oilseeds and fats crops and lipids, 23(4), 12-p.
Heiser Jr, C. B. (1976). The sunflower. University of Oklahoma Press.
Yarnell, R.A. 1978. Domestication of sunflower and sumpweed in Eastern North America. In: The Nature and Status of Ethnobotany. Richard I. Ford (ed.) Anthropological Paper 67, Museum of Anthropology, University of Michigan, pp. 289-299.
Sunflower: History, Uses and Plant information