Seed production oilseed crops

Sunflower. Two types of sunflowers are grown in the United States. Varieties grown for oilseed production, ca 85% of crop, are generally black-seeded, having thin seed coats that adhere to the kernels. These contain 40—50% oil and ca 20% protein. Nonoilseed varieties, ca 15% of crop, sometimes referred to as confectionery, striped, or large-seeded sunflowers, have striped, relatively thick hulls that do not adhere to the kernels. These contain 20—30% oil and are usually larger than seeds of oilseed varieties. 

The new oilseed crop is grown wherever flax and linseed varieties are currently cultivated (35, 36). The climate in northern Europe is highly suitable for production of Linola, where sunflower and com/maize cannot be produced. Linola seed can be processed by existing crushing plants using similar processing parameters. Linola meal is used for ruminant feed in the same way as linseed meal. 

Safflower is a minor oilseed crop limited in production by environmental constraints and by the plant s spiny nature. Unless the seed is well dehulled, the oilcake resulting from oil extraction will have a high fiber content. Undecorticated oil cake has a protein content of 20-22% and an end use as manure. In contrast, removal of the hull improves the protein content to 40%, making it acceptable as cattle feed despite low lysine levels. Leftover hulls and husks are added to cattle feed or are used to manufacture cellulose, insulation, and abrasives (5, 49). 

To date, the United States has not produced sizable quantities of rape-seed, probably because the agronomic conditions there are highly suitable for growing other oilseed crops, such as soybean, peanut, and cottonseed. Nevertheless, there are relatively large areas in the Midwestern United States and Alaska which are suitable for rapeseed production, and one may expect to find this oilseed crop to gain broader acceptance in the future. 

Rapeseed ranks fifth in world production of oilseed crops, surpassed only by soybean, sunflower seed, cottonseed, and peanut. It is a major source of dietary fat in many countries. Fifty countries are known to import rapeseed oil and 16 countries are major producers. Rapeseed oil has been used by humans for many centuries as a safe and acceptable dietary source of vegetable oil. 

The rapeseed breeding program at the University of Manitoba, Winnipeg, was initiated in 1953. Soybeans, sunflowers and safflowers were evaluated as potential edible oilseed crops for several years. Work on these crops was discontinued when it became evident that rapeseed was the best adapted edible oilseed for large-scale production in the Prairie Provinces. Since 1966, the plant breeder at Winnipeg has devoted most of his time to rape-seed. In 1958, a chemist joined the staff. The staff now includes one breeder, a chemist, and a pathologist. 

Through the efforts of the Research Branch of Agriculture Canada, rape-seed has been introduced into areas where other oilseed crops do not thrive, as for example, the regions north of the 52nd parallel in Canada s Western Provinces. The combined effort of these scientists has helped to propel rape-seed oil to fourth place in the world s production of edible vegetable oils and to firmly establish it in global commerce. 

Oilseed crops are already worldwide cultivated today Well-established industry and the handling of the different resources is developed Fatty acids can be directly converted to a valuable-energy product (biodiesel) Economic processes for the utilization of glycerol and seed cakes are underdeveloped Fertilizers required for high-yield production... 

But usually it is very difficult for a new oilseed species to compete favorably with established crops. A new crop needs a great investment in the selection of varieties. A crop must have good agronomic properties so that it can grow well in diverse environments, resist diseases, not scatter its seed before harvest, and have all its seeds ripen over a relatively short period. For an oilseed crop, additional selection for high oil production, desirable fatty acid composition and meal protein may be necessary. The presence of antinutritional and toxic factors may have to be minimized or eliminated. 

This oilseed is interesting because it is a halophyte capable of growing under irrigation with seawater (Glenn et al., 1991). Subtropical coastal desserts presently have little value in crop production. An oilseed crop that could grow under these conditions potentiaUy could make this almost worthless land agriculturally productive. The seed contain 28% oil and 31% protein. The fatty acid composition is 8% palmitate, 2% stearate, 12% oleate, 74% linoleate and 3% linolenate. Seed yields were superior to those of sunflower and soybean. 

The other major product of oilseed crops is a high protein meal, usually produced by expelling or extracting the oil from the seed. Total world production of high protein meals from oilseeds is approximately 180 million tons per year. The predominant oilseed meal is soybean meal containing approximately 44% protein. While there are some industrial uses for this meal, the bulk of it is fed to animals. 

Attempts to demonstrate the feasibility of profitable production on an agricultural scale are the next steps [282]. Poirier s group has proposed a number of oilseed crops that could be targeted for seed-specific PHA production, like rapeseed (closely related to A. thaliana), sunflower and soybean. Some of these are already under investigation by major companies. Depending on whether accumulation levels can be further increased PHAs stored in plants have any deleterious effects on crop value in other respects synthesis of PHAs other than PHB can be induced and extraction of the biopolyesters is feasible at reasonable costs, the cost of PHAs produced in plants might be lowered enough to make them competitive with conventional plastics. But the tendency of arable land to become one of the most precious commodities on Earth [286] will present a formidable obstacle to applications in this field. 

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