COMMON WHEAT (Triticum aestivum L.)

Wheat is one of the oldest cultural crops. Beginning of its cultivation is means the beginning of agriculture as such. The oldest archaeological findings are from 8 000 – 7 500 B.C. and are related to cultivation of one-grain or two-grain wheat.

Common wheat is one of the most wide-spread crops worldwide and in this country. From the botanical viewpoint, there are four common wheat varieties of different colour (white and red) and awnyness of the ear (awny and awnyless). The most wide-spread are white, awny-less varieties. Most wheat varieties grown in this country belong to this group

Importance and grain composition:

Wheat grains are used for production of bread, pastry, pasta, groats and in the confectionery. Wheat meal, flour, pressed grains and bran are used as feed for farm animals.

Wheat is mainly an energy source because of a high content (50 – 70%) of easily digestible starch. Crude fibre content is low (1.6 – 2.0%). Fibre is found in envelopes that are directed to bran product during the production of human nutrition products.

Protein content in the grain ranges from 8 to 13%. Contents of reserve protein can be influenced by agro technological interventions. Reserve proteins gliadin (prolamin) and glutenin form gluten when mixed with water. High gluten content favourably influences bakery traits of wheat, but in animals (particularly monogasters) it can cause digestive disorders. During the digestion, gluten changes into a viscous substance that may impair intestinal peristalsis and decrease the utilization of dietary nutrients. For feeding, wheat with lower reserve protein content is desirable.

Fat content is low (1.5 – 3%). Fat contains a lot of unsaturated fatty acids, oleic acid and linoleic acid. These render fat susceptible to oxidation that is also facilitated by phosphoric acid released from phospholipid cleavage. In wheat grains, mainly B vitamins and vitamin E are present, as well as beta-carotene at a lower level. Phosphorus is mineral with the highest content.

Cultivation requirements:

In this country, spring and winter wheats are grown.

Winter wheat has higher requirements for soil quality. It requires structural soil, coarse loam and clay-loam soils with neutral or weakly acid soil reaction, rich in nutrients. Flinty, acid and permanently waterlogged soils are not suitable. Winter wheat is sown in the autumn. If moisture level is sufficient and  temperature is about 15°C, it comes up in 7-9 days. Then it grows relatively quickly until the temperature drops down to 4-5 ºC, then the growth stops. If winter comes slowly wheat acquires freeze resistance down to -18 to -25 ºC. Blooms and fruits are formed after the wintering in the spring and summer of the following year.

Of all the cereals, winter wheat is the most demanding for the previous crop. The best previous crops are legumes, clover, root crops, oil crops vegetables. It is not recommended to grow winter wheat after cereals because cereals deteriorate soil properties. Also the risk of weed, pest and disease infestation is increased.

Grain yields are considerably influenced by nitrogen fertilization. Recommended total amount of nitrogen used for fertilization ranges from 80 to 120 kg/ha. Organic fertilization is also recommended, particularly with straw and green manure.

Spring wheat is a supplementary form to winter wheat. It has similar requirements for soil, it does not suffer so much of stalk foot diseases and it can be used when there is a high occurrence of winter weeds. Suitable previous crops are the same as for winter wheat. Spring wheat is sown usually after late harvested root crops. It can be grown also after cereals. In that case, stubble intermediate crops used as green manure are recommended. Spring wheat is usually sown in March and it can sustain frost,

 Other wheat varieties:

Pšenice tvrdá (Triticum durum Desf.) was developed from the cultural dvouzrnka wheat. Grains contain firm and hard gluten that is not suitable for baking bread and pastry because it does not create large volume. It is mainly utilized for making pasta. Durum wheat has both winter and spring forms. The spring forms prevail, their quality is higher.

Pšenice špalda (Triticum spelta L.) is a historical cultural variety with glumy grains. The grain has higher contents of protein, fat, minerals, vitamins and essential aminoacids than common wheat. Gluten content is also higher, but its quality is lower. Spalda is suitable for pasta and muesli production. Green immature grains can be roasted (grünkern) or used as “green caviar” (seasoning). There are both winter and spring forms of spalda, the winter forms prevail in Europe. Spalda is one of the least demanding cereals as regards cultivation. It is resistant against unfavourable climatic conditions, diseases and pests. Because of low requirement for fertilization and protection against harmful effects, it is suitable for organic farming.