ABSTRACT
References ........................................................................................................................................17
In comparison with plant species distributed in the wild flora, the diversity of agricultural crops is strongly limited. Only a minor number of plant species are used for the production of foods, feedstuffs, and industrial products. That is particularly applying to the cereal species, which have the greatest cultivation area of all agricultural crops worldwide. In 2004 around 76% of the total world cereal area were cultivated only with three main cereal species: wheat (Triticum aestivum) with a relative part of 32%, rice (Oryza sativa) with a relative part of 23%, and maize (Zea mays L.) with a relative part of 21%. The rest of this area are particularly distributed the cereal species barley (Hordeum vulgare L.), rye (Secale cereale L.), sorghum (Sorghum bicolor L.), millet (Pennisetum americanum, Setaria italica, Panicum miliaceum and other), durum wheat (Triticum durum L.), oats (Avena sativa L.), and triticale (Triticosecale Wittm.). During the last years a slight reduction of the growing area of barley, rye, and oats was observed, which shows that in the future the crop diversity of cereals will continue to reduce and focus on the main cereal crops wheat, rice, and maize (table 1.1).
