ABSTRACT
Edible oilseed plants are those whose seeds bear fixed nonvolatile oil, and oilseed crops are grown primarily for the oil contained in the seeds. The oil content of small grains (e.g., wheat) is only 1%–2%, and that of oilseeds ranges from about 20% for soybeans to over 40% for sunflowers and canola rapeseed. Crops like rapeseed-mustard, peanut, and sunflower have oil recovery ratio of 45%, 40%, and 30%, respectively, whereas cottonseed and soybean have oil recovery ratio of 11.5% and 17% only (Kumar 2014). Some of the oilseeds like peanut, sesame, sunflower could be consumed directly or may be eaten fried, roasted, or pounded and mixed with sugar; or the oil may be extracted from such seeds and directly used for cooking food or for confectionery purposes. Usually, refining of the oil is done before it is used as food. Edible vegetable oils may, however, be used occasionally for industrial purposes, for example, manufacturing of soaps, varnishes, hair oils, and lubricants. The residues left, that is, the oil cakes, serve as excellent animal or poultry feed. Oil cakes may also be used as manure to increase the fertility status of soils. The demand for edible oilseeds for human consumption in different parts of the world is principally derived from three categories of cultivated crop plants: (1) primarily cultivated annual oilseed crops, for example, peanut (Arachis hypogaea L.), rapeseed-mustard (Brassica campestris L., Brassica napus L., Brassica juncea [L], Czern and Coss. Eruca saliva Lam.), sunflower (Helianthus annuus L. var. macrocarpus [DC] Ckll.), sesame (Sesamum indicum L.), safflower (Carthamus tinctorius L.), niger seed (Guizotia abyssinica Cass.), and soybean (Glycine max [L.] Merrill); (2) an annual fiber crop cotton (Gossypium hirsutum L.) through its seed by-products; and (3) perennial oilseed plants such as coconut palm (Cocos nucifera L.) and oil palm (Elaeis guineensis Jacq). Corn (Zea mays L.) also contributes significantly to the world edible oil supply. Besides traditionally grown oilseed crops, technological innovations in refining, bleaching and deodorization, newer oils like cottonseed and rice bran oils have also become popular in the recent times. Thus, the range of plants that could be cultivated for edible oils is extensive, but only a few that are included in the first (1) category are suitable for large-scale commercial production or produce oil that is required in large quantities. In this chapter, only this category of primarily cultivated annual oilseed crops is considered with respect to diseases and their management.
