Sunflower

I. History:

Sunflower (Helianthus annuus L.) is one of the few crop species that originated in North America (most originated in the fertile crescent, Asia or South or Central America). It was probably a "camp follower" of several of the western native American tribes who domesticated the crop (possibly 1000 BC) and then carried it eastward and southward of North America. The first Europeans observed sunflower cultivated in many places from southern Canada to Mexico.

Sunflower was probably first introduced to Europe through Spain, and spread through Europe as a curiosity until it reached Russia where it was readily adapted. Selection for high oil in Russia began in 1860 and was largely responsible for increasing oil content from 28% to almost 50%. The high-oil lines from Russia were reintroduced into the U.S. after World War II, which rekindled interest in the crop. However, it was the discovery of the male-sterile and restorer gene system that made hybrids feasible and increased commercial interest in the crop.

II. Uses:

A. Edible oil:

Commercially available sunflower varieties contain from 39 to 49% oil in the seed. In 1985-86, sunflower seed was the third largest source of vegetable oil worldwide, following soybean and palm. The growth of sunflower as an oilseed crop has rivaled that of soybean, with both increasing production over 6-fold since the 1930s. Sunflower accounts for about 14% of the world production of seed oils (6.9 million metric tons in 1985-86) and about 7% of the oilcake and meal produced from oilseeds. Europe and the former USSR produce over 60% of the world's sunflowers.

The oil accounts for 80% of the value of the sunflower crop, as contrasted with soybean which derives most of its value from the meal. Sunflower oil is generally considered a premium oil because of its light colour, high level of unsaturated fatty acids and lack of linolenic acid, bland flavor and high smoke points. The primary fatty acids in the oil are oleic and linoleic (typically 90% unsaturated fatty acids), with the remainder consisting of palmitic and stearic saturated fatty acids. The primary use is as a salad and cooking oil or in margarine.

High oleic sunflower oil (over 80% oleic acid) was developed commercially in 1985 and has higher oxidated stability than conventional oil. It has expanded the application of sunflower oils for frying purposes, tends to enhance shelf life of snacks, and could be used as an ingredient of infant formulas requiring stability.

B. Meal:

Non-dehulled or partly dehulled sunflower meal has been substituted successfully for soybean meal in isonitrogenous (equal protein) diets for ruminant animals, as well as for swine and poultry feeding. Sunflower meal is higher in fiber, has a lower energy value and is lower in lysine but higher in methionine than soybean meal. Protein percentage of sunflower meal ranges from 28% for non-dehulled seeds to 42% for completely dehulled seeds. The color of the meal ranges from grey to black, depending upon extraction processes and degree of dehulling.

C. Industrial Applications:

The price of sunflower oil usually prohibits its widespread use in industry, but there are several applications that have been explored. It has been used in certain paints, varnishes and plastics because of good semidrying properties without color modification associated with oils high in linolenic acid. In Eastern Europe and the former USSR where sunflower oil is plentiful, sunflower oil is used commonly in the manufacture of soaps and detergents. The use of sunflower oil (and other vegetable oils) as a pesticide carrier, and in the production of agrichemicals, surfactants, adhesives, plastics, fabric softeners, lubricants and coatings has been explored. The utility of these applications is usually contingent upon petrochemical feedstock prices.

Sunflower oil contains 93% of the energy of US Number 2 diesel fuel and considerable work has been done to explore the potential of sunflower as an alternate fuel source in diesel engines. Blends of sunflower oil and diesel fuel are expected to have greater potential than the burning of pure vegetable oil.

D. Non-Oilseed:

The use of sunflower seed for birdfeed or in human diets as a snack, has grown consistently over the past 15 years. Varieties used for non-oilseed purposes are characterized by a larger seed size and require slightly different management practices. During processing, seed is divided into 1) larger seed for in-shell roasting, 2) medium for dehulling, and 3) small for birdseed. Standards for different uses vary.

E. Forage:

Sunflower can also be used as a silage crop. It can be used as a double crop after early harvested small grains or vegetables, an emergency crop, or in areas with a season too short to produce mature corn for silage.

Forage yields of sunflower are generally less than corn when a full growing season is available. In one study, sunflower dry matter yields ranged from 2.0 to 3.0 ton/acre compared with 3.1 to 3.8 ton/acre for corn. Moisture content of sunflower at maturity is usually high (80 to 90%) and would require wilting before ensiling.

Nutritional quality of sunflower silage is often higher than corn but lower than alfalfa hay (Table 1). Crude protein level of sunflower silage is similar to grass hay and higher than corn silage. Generally, crude protein of sunflower decreases and lignin percentage increases after the flowering stage. High plant populations increases fiber and lignin percentage. Seed size does not seem to affect yield or quality.

Table 8: Nutritional quality of sunflower, immature corn, and mature corn silage, alfalfa hay (harvested in early bloom) and timothy bay (harvested in late vegetative stage).

	Silage	Hay
	Sunflower	Immature corn	Mature corn	Alfalfa	Timothy
	% of dry matter
Total digestible nutrients	67.0	60.0	69.0	58.0	68.0
Crude protein	11-12	8.2	7.8	18.0	11.4
Ether extract	10-12	2.6	2.9	2.2	2.4
Crude fiber	31.0	31.0	23.0	31.0	31.0
Acid detergent fiber	32.0	---	31.0	38.0	33.0
Lignin	10-16	---	---	9.0	3.1
IVDDM^1	63-70	---	---	66.0	63.0

Дата добавления: 2015-05-23