Common wheat

Common wheat(Triticum aestivum) is a species of monocotyledonous plant in the Poaceae family (grasses), subfamily Pooideae.

Domesticated in the Near East around 6,000 years ago, this cultivated plant, also known as "wheat", is currently the most widely grown wheat species in the world, particularly in France, in terms of both surface area and tonnage.

Description

Common wheat is a medium-sized, tufted annual herbaceous plant that forms a tillering plateau at ground level, with axillary buds that develop into leafy stems.

The stems, known as culms, are erect and 60 to 100 cm long. They generally have five to seven nodes and three or four true leaves. The uppermost leaf, or flag leaf, underlies the inflorescence. The internodes are hollow.

The leaves are composed of a glabrous or pubescent sheath with falciform auricles, a membranous ligule 1 mm long and a flat, pubescent blade 10 to 60 cm long and 10 to 15 mm wide.

The inflorescence consists of a single, linear or oblong, bilateral spike 5 to 18 cm long.

The fertile, oval, laterally compressed spikelets, 10 to 15 mm long and 9 to 18 mm wide, contain 2 to 4 fertile florets, with the florets reduced at the apex. They are persistent on the plant. The spikelets are subtended by a pair of similar glumes, which are oval, leathery, 6 to 11 mm long and shorter than the spikelet. The upper glume is as long as the adjacent fertile lemma. Both glumes have two carinae and 5 to 9 veins, diverging towards the apex in the upper glume. They are glabrous, puberulent or urbanised on the surface. Their tips are mute or aristate, in which case the ridge can be up to 40 mm long.

The fertile florets are subtended by two glumes (lemma and paleola). The lemma is oval, cartaceous and 12 to 15 mm long, with 5 to 9 veins. The apex of the lemma is acute, mute or aristate, and the apex can be up to 150 mm long. The paleolae has two veins and winged carinae. The sterile apical florets resemble the fertile florets but are less developed. The fertile florets have three anthers and an ovary, pubescent at the apex, with a fleshy appendage below the insertion point of the style.

The fruit is an oblong caryopsis, 5 to 7 mm long, with an adherent pericarp, furrowed on the side of the hilum and hairy at the apex. The hilum is linear.

Spikelet spikes
Mature spikelets
Soft wheat grains

Use

Common wheat is widely used to feed livestock, and sometimes by hunters to feed game. As balanced in amino acids as maize, it is highly palatable and nutritious for many species. In some countries, during periods of drought, subsidised wheat intended for human consumption is sometimes diverted to feed livestock, when the latter are short of food.

It is also used, and this was once its primary use, to produce bread flour used to make bread, pastries and other foods.

It is also used to make white beers.

Origin

Soft wheat Triticum aestivum is a hexaploid species resulting from a double hybridisation :

crossing, around 500,000 years ago, of two wild Poaceae, Triticum urartu (2n=14) and an as yet unidentified egilope (2n=14), closely related to Aegilops speltoides, resulted in the wild starch plant Triticum dicoccoides (2n=28), which through domestication and selection by the first farmers gave rise to the domestic starch plant Triticum turgidum, the first tetraploid domestic wheat (2n=28); the genomes of the two cereals became functional in the hybrid nucleus, which proved fertile;
the crossing, less than 10,000 years ago, of this tetraploid hybrid with another egilope, Aegilops tauschii (en), diploid (2n=14) gave rise to a hexaploid wheat, soft wheat Triticum aestivum (2n=42).

Soft wheat thus has three different genomes in its nucleus. The two founding species (Triticum and Aegilops) separated from their common ancestor around 6.5 Ma ago.

Name

The term " soft wheat " is used in contrast to "durum wheat". durum wheat "which refers to the Mediterranean cereal par excellence, prized for making semolina and pasta. Long before medieval times, soft wheat was the cereal of the northern part of France, once the wheat par excellence whose grains were ground to produce white flour and bran. In the early 1990s, Lorraine's cereal fields produced 900,000 tonnes.

There are now over 100 known varieties.

Common names

Wheat, soft wheat, ordinary wheat, summer wheat, bearded spring wheat, wheat for bread flour, wheat, touselle or touzelle.

Geographical distribution

It is grown mainly in high latitudes (e.g. France, Canada and Ukraine), but is also found in some southern countries with varieties that are more resistant to drought. In Morocco, for example, it was first grown in the 1930s and 1940s for export to war-torn Europe, and then became a staple food and animal feed; in the 2000s, it accounted for almost 70% of Moroccan wheat consumption (compared with 25% for durum wheat).

Economic importance

Common wheat is the most widely grown arable crop in France, with a surface area of almost 5 million hectares, representing over 60% of straw cereal acreage.

French soft wheat production totalled almost 37 million tonnes in 2017, 34% more than in 2016. At the start of the 2017/2018 campaign, French soft wheat carryover stocks were estimated at 2.944 million tonnes (Mt). These figures are updated monthly on the FranceAgriMer website.

France is the world's second largest soft wheat producer, just behind Russia. It is ahead of Australia, Germany, the United States, Canada and Ukraine. Every year, around half of French production is available for export. France's main customers are divided equally between the countries of the European Union and third countries (mainly the southern shores of the Mediterranean and West and Central Africa).

Cultivation

Long grown on ploughed soils to control weeds and certain undesirable species(snails, slugs), then cultivated with an increasing amount of fertiliser and pesticides, it is now locally the subject of simplified cultivation techniques (direct seeding, etc.) to better protect or restore soils that have been degraded by repeated ploughing(erosion, destructuring, loss of carbon and organic matter, leaching of nutrients, appearance of a plough sole, etc.).

Appendices

Sources

Wikipedia page on soft wheat