Wheat#Marquis

File:Triticum aestivum - Köhler–s Medizinal-Pflanzen-274.jpg before flowering; 2 the same, flowering and spread, enlarged; 3 flowers with glumes; 4 stamens 5 pollen; 6 and 7 ovaries with juice scales; 8 and 9 parts of the scar; 10 fruit husks; 11, 12, 13 seeds, natural size and enlarged; 14 the same cut up, enlarged.]]

Wheat is a stout grass of medium to tall height. Its stem is jointed and usually hollow, forming a straw. There can be many stems on one plant. It has long narrow leaves, their bases sheathing the stem, one above each joint. At the top of the stem is the flower head, containing some 20 to 100 flowers. Each flower contains both male and female parts. The flowers are wind-pollinated, with over 99% of pollination events being self-pollinations and the rest cross-pollinations.{{Cite journal |last1=Yang |first1=Hong |last2=Li |first2=Yongpeng |last3=Li |first3=Dongxiao |last4=Liu |first4=Liantao |last5=Qiao |first5=Yunzhou |last6=Sun |first6=Hongyong |last7=Liu |first7=Wenwen |last8=Qiao |first8=Wenjun |last9=Ma |first9=Yuzhao |last10=Liu |first10=Mengyu |last11=Li |first11=Cundong |last12=Dong |first12=Baodi |display-authors=6 |date=9 June 2022 |title=Wheat Escapes Low Light Stress by Altering Pollination Types |journal=Frontiers in Plant Science |volume=13 |page=924565 |doi=10.3389/fpls.2022.924565 |doi-access=free |pmid=35755640|pmc=9218482 }} The flower is housed in a pair of small leaflike glumes. The two (male) stamens and (female) stigmas protrude outside the glumes. The flowers are grouped into spikelets, each with between two and six flowers. Each fertilised carpel develops into a wheat grain or berry; botanically a caryopsis fruit, it is often called a seed. The grains ripen to a golden yellow; a head of grain is called an ear.{{cite encyclopedia |title=wheat (plant) |url=http://www.britannica.com/EBchecked/topic/641558/wheat |encyclopedia=britannica.com |accessdate=23 December 2023}}

Leaves emerge from the shoot apical meristem in a telescoping fashion until the transition to reproduction i.e. flowering.{{cite web |url=https://www.ipipotash.org/udocs/ipi-bulletin-17-cereals.pdf |title=Fertilising for High Yield and Quality – Cereals}} The last leaf produced by a wheat plant is known as the flag leaf. It is denser and has a higher photosynthetic rate than other leaves, to supply carbohydrate to the developing ear. In temperate countries the flag leaf, along with the second and third highest leaf on the plant, supply the majority of carbohydrate in the grain and their condition is paramount to yield formation.{{cite journal |jstor=23786279 |title=Photosynthesis of Flag and Second Wheat Leaves During Senescence |journal=Cereal Research Communications |volume=27 |issue=1/2 |pages=155–162 |last1= Pajević |first1=Slobodanka |last2=Krstić |first2= Borivoj |last3=Stanković|first3=Živko |last4=Plesničar |first4=Marijana |last5=Denčić |first5=Srbislav |year=1999 |doi=10.1007/BF03543932}}{{Cite book |doi=10.1007/978-94-009-4384-1_18 |chapter=Photosynthesis, Nitrogen Levels, and Dry Matter Accumulation in Flag Wheat Leaves During Grain Filling |title=Biological Control of Photosynthesis |pages=199–207 |year=1986 |last1=Araus |first1=J. L. |last2=Tapia |first2=L. |last3=Azcon-Bieto |first3=J. |last4=Caballero |first4=A. |isbn=978-94-010-8449-9}} Wheat is unusual among plants in having more stomata on the upper (adaxial) side of the leaf, than on the under (abaxial) side.{{Cite journal |jstor=23783891|title=Stomatal Size, Frequency and Distribution in Triticum Aestivum, Secale Cereale and Their Amphiploids|journal=Cereal Research Communications |volume=23|issue=1/2|pages=103–108 |last1=Singh |first1=Sarvjeet |last2=Sethi |first2=G.S. |year=1995}} It has been theorised that this might be an effect of it having been domesticated and cultivated longer than any other plant.{{Cite journal |doi=10.1093/jxb/ert147 |pmid=23918960 |title=Shifts in stomatal traits following the domestication of plant species |journal=Journal of Experimental Botany |volume=64 |issue=11 |pages=3137–3146 |year=2013 |last1=Milla |first1=Rubén |last2=De Diego-Vico |first2=Natalia |last3=Martín-Robles |first3=Nieves |doi-access=free}} Winter wheat generally produces up to 15 leaves per shoot and spring wheat up to 9{{cite web |url=https://cereals.ahdb.org.uk/media/185687/g66-wheat-growth-guide.pdf |title=Wheat Growth Guide |publisher=Agriculture and Horticulture Development Board}} and winter crops may have up to 35 tillers (shoots) per plant (depending on cultivar).

Wheat roots are among the deepest of arable crops, extending as far down as {{convert|2|m}}.{{cite book |url=https://books.google.com/books?id=XedeDwAAQBAJ&q=wheat+roots+2+metres&pg=PA39 |title=Wheat Crop Management |isbn=9789387741287 |last1=Das |first1=N. R. |date=1 October 2008 |publisher=Scientific Publishers }} While the roots of a wheat plant are growing, the plant also accumulates an energy store in its stem, in the form of fructans,{{Cite journal |pmc=1075255 |year=1986 |last1=Hogan |first1=M. E. |title=Labeling of Fructans in Winter Wheat Stems |journal=Plant Physiology |volume=80 |issue=4 |pages=1048–1050 |last2=Hendrix |first2=J. E. |pmid=16664718 |doi=10.1104/pp.80.4.1048}} which helps the plant to yield under drought and disease pressure,{{cite journal |pmc=4531436 |year=2015 |last1=Zhang |first1=J. |title=Wheat genotypic variation in dynamic fluxes of WSC components in different stem segments under drought during grain filling |journal=Frontiers in Plant Science |volume=6 |pages=624 |last2=Chen |first2=W. |last3=Dell |first3=B. |last4=Vergauwen |first4=R. |last5=Zhang |first5=X. |last6=Mayer |first6=J. E. |last7=Van Den Ende |first7=W. |pmid=26322065 |doi=10.3389/fpls.2015.00624 |doi-access=free}} but it has been observed that there is a trade-off between root growth and stem non-structural carbohydrate reserves. Root growth is likely to be prioritised in drought-adapted crops, while stem non-structural carbohydrate is prioritised in varieties developed for countries where disease is a bigger issue.{{cite journal |title=Partitioning of assimilates to deeper roots is associated with cooler canopies and increased yield under drought in wheat |journal=Functional Plant Biology |volume=37 |issue=2 |pages=147 |citeseerx=10.1.1.535.6514 |doi=10.1071/FP09121|year=2010 |last1=Lopes |first1=Marta S. |last2=Reynolds |first2=Matthew P. }}

Depending on variety, wheat may be awned or not awned. Producing awns incurs a cost in grain number,{{cite journal |last1=Rebetzke |first1=G. J. |last2=Bonnett |first2=D. G. |last3=Reynolds |first3=M. P. |title=Awns reduce grain number to increase grain size and harvestable yield in irrigated and rainfed spring wheat |journal=Journal of Experimental Botany |volume=67 |issue=9 |pages=2573–2586 |year=2016 |doi=10.1093/jxb/erw081 |pmid=26976817 |pmc=4861010}} but wheat awns photosynthesise more efficiently than their leaves with regards to water usage,{{cite journal |last1=Duwayri |first1=Mahmud |title=Effect of flag leaf and awn removal on grain yield and yield components of wheat grown under dryland conditions |journal=Field Crops Research |year=1984 |volume=8 |pages=307–313 |doi=10.1016/0378-4290(84)90077-7 |bibcode=1984FCrRe...8..307D }} so awns are much more frequent in varieties of wheat grown in hot drought-prone countries than those generally seen in temperate countries. For this reason, awned varieties could become more widely grown due to climate change. In Europe, however, a decline in climate resilience of wheat has been observed.{{cite journal |doi=10.1073/pnas.1804387115 |pmid=30584094 |pmc=6320549 |title=Decline in climate resilience of European wheat |journal=Proceedings of the National Academy of Sciences |volume=116 |issue=1 |pages=123–128 |year=2019 |last1=Kahiluoto |first1=Helena |last2=Kaseva |first2=Janne |last3=Balek |first3=Jan |last4=Olesen |first4=Jørgen E. |last5=Ruiz-Ramos |first5=Margarita |last6=Gobin |first6=Anne |last7=Kersebaum |first7=Kurt Christian |last8=Takáč |first8=Jozef|last9=Ruget |first9=Francoise |last10=Ferrise |first10=Roberto |last11=Bezak |first11=Pavol |last12=Capellades |first12=Gemma |last13=Dibari |first13=Camilla|last14=Mäkinen |first14=Hanna |last15=Nendel |first15=Claas |last16=Ventrella |first16=Domenico |last17=Rodríguez |first17=Alfredo |last18=Bindi |first18=Marco |last19=Trnka |first19=Mirek |display-authors=5 |bibcode=2019PNAS..116..123K |doi-access=free}}

File:wheatareal.PNG

{{further|Domestication}}

Hunter-gatherers in West Asia harvested wild wheats for thousands of years before they were domesticated,{{cite journal |last1=Richter |first1=Tobias |last2=Maher |first2=Lisa A. |date=2013 |title=Terminology, process and change: reflections on the Epipalaeolithic of South-west Asia |url=https://doi.org/10.1179/0075891413Z.00000000020 |journal=Levant |volume=45 |issue=2 |pages=121–132 |doi=10.1179/0075891413Z.00000000020 |s2cid=161961145}} perhaps as early as 21,000 BC,{{Cite journal |last1=Piperno |first1=Dolores R. |last2=Weiss |first2=Ehud |last3=Holst |first3=Irene |last4=Nadel |first4=Dani |date=August 2004 |title=Processing of wild cereal grains in the Upper Palaeolithic revealed by starch grain analysis |url=https://www.nature.com/articles/nature02734 |journal=Nature |volume=430 |issue=7000 |pages=670–673 |doi=10.1038/nature02734 |pmid=15295598 |bibcode=2004Natur.430..670P |s2cid=4431395}} but they formed a minor component of their diets.{{cite journal |last1=Arranz-Otaegui |first1=Amaia |last2=González Carretero |first2=Lara |last3=Roe |first3=Joe |last4=Richter |first4=Tobias |date=2018 |title="Founder crops" v. wild plants: Assessing the plant-based diet of the last hunter-gatherers in southwest Asia |url=https://www.sciencedirect.com/science/article/pii/S0277379117306145 |journal=Quaternary Science Reviews |volume=186 |pages=263–283 |doi=10.1016/j.quascirev.2018.02.011 |bibcode=2018QSRv..186..263A}} In this phase of pre-domestication cultivation, early cultivars were spread around the region and slowly developed the traits that came to characterise their domesticated forms.{{cite journal |last1=Fuller |first1=Dorian Q. |last2=Willcox |first2=George |last3=Allaby |first3=Robin G. |date=2011 |title=Cultivation and domestication had multiple origins: arguments against the core area hypothesis for the origins of agriculture in the Near East |url=https://doi.org/10.1080/00438243.2011.624747 |journal=World Archaeology |volume=43 |issue=4 |pages=628–652 |doi=10.1080/00438243.2011.624747 |s2cid=56437102}}

Repeated harvesting and sowing of the grains of wild grasses led to the creation of domestic strains, as mutant forms ('sports') of wheat were more amenable to cultivation. In domesticated wheat, grains are larger, and the seeds (inside the spikelets) remain attached to the ear by a toughened rachis during harvesting.{{cite journal |last1=Hughes |first1=N. |last2=Oliveira |first2=H.R. |last3=Fradgley |first3=N. |last4=Corke |first4=F. |last5=Cockram |first5=J. |last6=Doonan |first6=J.H. |last7=Nibau |first7=C. |title=μCT trait analysis reveals morphometric differences between domesticated temperate small grain cereals and their wild relatives |journal=The Plant Journal |volume=99 |issue=1 |pages=98–111 |date=14 March 2019 |doi=10.1111/tpj.14312 |pmid=30868647 |pmc=6618119 }} In wild strains, a more fragile rachis allows the ear to shatter easily, dispersing the spikelets.{{cite journal |last1=Tanno |first1=K. |last2=Willcox |first2=G. |year=2006 |title=How fast was wild wheat domesticated? |journal= Science |volume=311 |issue=5769 |page=1886 |doi=10.1126/science.1124635 |pmid=16574859 |s2cid=5738581 }} Selection for larger grains and non-shattering heads by farmers might not have been deliberately intended, but simply have occurred because these traits made gathering the seeds easier; nevertheless such 'incidental' selection was an important part of crop domestication. As the traits that improve wheat as a food source involve the loss of the plant's natural seed dispersal mechanisms, highly domesticated strains of wheat cannot survive in the wild.{{cite journal |last1=Purugganan |first1=Michael D. |last2=Fuller |first2=Dorian Q. |title=The nature of selection during plant domestication |journal=Nature |publisher=Springer |volume=457 |issue=7231 |date=1 February 2009 |doi=10.1038/nature07895 |pages=843–848|pmid=19212403 |bibcode=2009Natur.457..843P |s2cid=205216444 }}

Wild einkorn wheat (T. monococcum subsp. boeoticum) grows across Southwest Asia in open parkland and steppe environments.{{cite book |last1=Zohary |first1=Daniel |author1-link=Daniel Zohary |last2=Hopf |first2=Maria |last3=Weiss |first3=Ehud |date=2012 |chapter=Cereals |title=Domestication of Plants in the Old World |edition=4 |place=Oxford |publisher=Oxford University Press |doi=10.1093/acprof:osobl/9780199549061.001.0001 |isbn=978-0-19-954906-1 }} It comprises three distinct races, only one of which, native to Southeast Anatolia, was domesticated.{{cite journal |last1=Ozkan |first1=H. |last2=Brandolini |first2=A. |last3=Schäfer-Pregl |first3=R. |last4=Salamini |first4=F. |date=2002 |title=AFLP analysis of a collection of tetraploid wheats indicates the origin of emmer and hard wheat domestication in southeast Turkey |journal=Molecular Biology and Evolution |volume=19 |issue=10 |pages=1797–1801 |doi=10.1093/oxfordjournals.molbev.a004002 |pmid=12270906 |doi-access=free }} The main feature that distinguishes domestic einkorn from wild is that its ears do not shatter without pressure, making it dependent on humans for dispersal and reproduction. It also tends to have wider grains. Wild einkorn was collected at sites such as Tell Abu Hureyra ({{circa|10,700–9000 BC}}) and Mureybet ({{circa|9800–9300 BC}}), but the earliest archaeological evidence for the domestic form comes after {{circa| 8800 BC}} in southern Turkey, at Çayönü, Cafer Höyük, and possibly Nevalı Çori. Genetic evidence indicates that it was domesticated in multiple places independently.

Wild emmer wheat (T. turgidum subsp. dicoccoides) is less widespread than einkorn, favouring the rocky basaltic and limestone soils found in the hilly flanks of the Fertile Crescent. It is more diverse, with domesticated varieties falling into two major groups: hulled or non-shattering, in which threshing separates the whole spikelet; and free-threshing, where the individual grains are separated. Both varieties probably existed in prehistory, but over time free-threshing cultivars became more common. Wild emmer was first cultivated in the southern Levant, as early as 9600 BC.{{cite journal |last1=Feldman |first1=Moshe |last2=Kislev |first2=Mordechai E. |date=2007 |title=Domestication of emmer wheat and evolution of free-threshing tetraploid wheat in "A Century of Wheat Research-From Wild Emmer Discovery to Genome Analysis", Published Online: 3 November 2008 |url=http://www.sciencefromisrael.com/app/home/contribution.asp?referrer=parent&backto=issue,2,14;journal,9,41;linkingpublicationresults,1:300170,1 |url-status=dead |journal=Israel Journal of Plant Sciences |volume=55 |pages=207–221 |archive-url=https://web.archive.org/web/20131206013930/http://www.sciencefromisrael.com/app/home/contribution.asp?referrer=parent&backto=issue,2,14;journal,9,41;linkingpublicationresults,1:300170,1 |archive-date=6 December 2013 |access-date=6 July 2011 |number=3–4|doi=10.1560/IJPS.55.3-4.207 |doi-broken-date=2 November 2024 }}{{cite book |last=Colledge |first=Sue |url=https://books.google.com/books?id=D2nym35k_EcC&pg=PA40 |title=The origins and spread of domestic plants in southwest Asia and Europe |publisher=Left Coast Press |year=2007 |isbn=978-1-59874-988-5 |pages=40–}} Genetic studies have found that, like einkorn, it was domesticated in southeastern Anatolia, but only once.{{cite journal |last1=Luo |first1=M.-C. |last2=Yang |first2=Z.-L. |last3=You |first3=F. M. |last4=Kawahara |first4=T. |last5=Waines |first5=J. G. |last6=Dvorak |first6=J. |date=2007 |title=The structure of wild and domesticated emmer wheat populations, gene flow between them, and the site of emmer domestication |url=https://doi.org/10.1007/s00122-006-0474-0 |journal=Theoretical and Applied Genetics |volume=114 |issue=6 |pages=947–959 |doi=10.1007/s00122-006-0474-0 |pmid=17318496 |s2cid=36096777}} The earliest secure archaeological evidence for domestic emmer comes from Çayönü, {{circa|8300–7600 BC}}, where distinctive scars on the spikelets indicated that they came from a hulled domestic variety. Slightly earlier finds have been reported from Tell Aswad in Syria, {{circa|8500–8200 BC}}, but these were identified using a less reliable method based on grain size.

File:NHM - Jungsteinzeit Sichel 2.jpgs were used to harvest wheat in the Neolithic period, {{circa|8500–4000 BC}}]]

Einkorn and emmer are considered two of the founder crops cultivated by the first farming societies in Neolithic West Asia. These communities also cultivated naked wheats (T. aestivum and T. durum) and a now-extinct domesticated form of Zanduri wheat (T. timopheevii),{{Cite journal |last1=Czajkowska |first1=Beata I. |last2=Bogaard |first2=Amy |last3=Charles |first3=Michael |last4=Jones |first4=Glynis |last5=Kohler-Schneider |first5=Marianne |last6=Mueller-Bieniek |first6=Aldona |last7=Brown |first7=Terence A. |date=2020-11-01 |title=Ancient DNA typing indicates that the "new" glume wheat of early Eurasian agriculture is a cultivated member of the Triticum timopheevii group |url=https://www.sciencedirect.com/science/article/pii/S0305440320301795 |journal=Journal of Archaeological Science |volume=123 |pages=105258 |doi=10.1016/j.jas.2020.105258 |bibcode=2020JArSc.123j5258C |s2cid=225168770}} as well as a wide variety of other cereal and non-cereal crops.{{Cite journal |last1=Arranz-Otaegui |first1=Amaia |last2=Roe |first2=Joe |date=2023-09-01 |title=Revisiting the concept of the 'Neolithic Founder Crops' in southwest Asia |journal=Vegetation History and Archaeobotany |volume=32 |issue=5 |pages=475–499 |doi=10.1007/s00334-023-00917-1 |bibcode=2023VegHA..32..475A |s2cid=258044557 |doi-access=free }} Wheat was relatively uncommon for the first thousand years of the Neolithic (when barley predominated), but became a staple after around 8500 BC. Early wheat cultivation did not demand much labour. Initially, farmers took advantage of wheat's ability to establish itself in annual grasslands by enclosing fields against grazing animals and re-sowing stands after they had been harvested, without the need to systematically remove vegetation or till the soil.{{Cite journal |last1=Weide |first1=Alexander |last2=Green |first2=Laura |last3=Hodgson |first3=John G. |last4=Douché |first4=Carolyne |last5=Tengberg |first5=Margareta |last6=Whitlam |first6=Jade |last7=Dovrat |first7=Guy |last8=Osem |first8=Yagil |last9=Bogaard |first9=Amy |date=June 2022 |title=A new functional ecological model reveals the nature of early plant management in southwest Asia |url=https://www.nature.com/articles/s41477-022-01161-7 |journal=Nature Plants |volume=8 |issue=6 |pages=623–634 |doi=10.1038/s41477-022-01161-7 |pmid=35654954 |bibcode=2022NatPl...8..623W |s2cid=249313666}} They may also have exploited natural wetlands and floodplains to practice décrue farming, sowing seeds in the soil left behind by receding floodwater.{{Cite journal |last=Sherratt |first=Andrew |date=February 1980 |title=Water, soil and seasonality in early cereal cultivation |url=http://www.tandfonline.com/doi/abs/10.1080/00438243.1980.9979770 |journal=World Archaeology |volume=11 |issue=3 |pages=313–330 |doi=10.1080/00438243.1980.9979770}}{{cite book |last=Scott |first=James C. |url=https://books.google.com/books?id=UjYuDwAAQBAJ |title=Against the Grain: A Deep History of the Earliest States |date=2017 |publisher=Yale University Press |isbn=978-0-3002-3168-7 |publication-place=New Haven |page=66 |chapter=The Domestication of Fire, Plants, Animals, and ... Us |quote=The general problem with farming — especially plough agriculture — is that it involves so much intensive labor. One form of agriculture, however, eliminates most of this labor: 'flood-retreat' (also known as décrue or recession) agriculture. In flood-retreat agriculture, seeds are generally broadcast on the fertile silt deposited by an annual riverine flood. |author-link1=James C. Scott |access-date=19 March 2023}}{{cite book |last1=Graeber |first1=David |title=The dawn of everything: a new history of humanity |last2=Wengrow |first2=David |date=2021 |publisher=Allen Lane |isbn=978-0-241-40242-9 |location=London |page=235}} It was harvested with stone-bladed sickles.{{Cite journal |last1=Maeda |first1=Osamu |last2=Lucas |first2=Leilani |last3=Silva |first3=Fabio |last4=Tanno |first4=Ken-Ichi |last5=Fuller |first5=Dorian Q. |date=2016-08-01 |title=Narrowing the Harvest: Increasing sickle investment and the rise of domesticated cereal agriculture in the Fertile Crescent |journal=Quaternary Science Reviews |volume=145 |pages=226–237 |doi=10.1016/j.quascirev.2016.05.032 |bibcode=2016QSRv..145..226M |doi-access=free }} The ease of storing wheat and other cereals led farming households to become gradually more reliant on it over time, especially after they developed individual storage facilities that were large enough to hold more than a year's supply.{{Cite journal |last=Weide |first=Alexander |date=29 November 2021 |title=Towards a Socio-Economic Model for Southwest Asian Cereal Domestication |journal=Agronomy |volume=11 |issue=12 |pages=2432 |doi=10.3390/agronomy11122432 |doi-access=free |bibcode=2021Agron..11.2432W }}

Wheat grain was stored after threshing, with the chaff removed. It was then processed into flour using ground stone mortars.{{Cite journal |last=Dubreuil |first=Laure |date=2004-11-01 |title=Long-term trends in Natufian subsistence: a use-wear analysis of ground stone tools |url=https://www.sciencedirect.com/science/article/pii/S0305440304000731 |journal=Journal of Archaeological Science |volume=31 |issue=11 |pages=1613–1629 |doi=10.1016/j.jas.2004.04.003 |bibcode=2004JArSc..31.1613D}} Bread made from ground einkorn and the tubers of a form of club rush (Bolboschoenus glaucus) was made as early as 12,400 BC.{{Cite journal |last1=Arranz-Otaegui |first1=Amaia |last2=Gonzalez Carretero |first2=Lara |last3=Ramsey |first3=Monica N. |last4=Fuller |first4=Dorian Q. |last5=Richter |first5=Tobias |date=2018-07-31 |title=Archaeobotanical evidence reveals the origins of bread 14,400 years ago in northeastern Jordan |journal=Proceedings of the National Academy of Sciences |volume=115 |issue=31 |pages=7925–7930 |doi=10.1073/pnas.1801071115 |pmc=6077754 |pmid=30012614 |bibcode=2018PNAS..115.7925A |doi-access=free }} At Çatalhöyük ({{Circa|7100–6000 BC}}), both wholegrain wheat and flour was used to prepare bread, porridge and gruel.{{Cite journal |last1=González Carretero |first1=Lara |last2=Wollstonecroft |first2=Michèle |last3=Fuller |first3=Dorian Q. |date=2017-07-01 |title=A methodological approach to the study of archaeological cereal meals: a case study at Çatalhöyük East (Turkey) |url=https://doi.org/10.1007/s00334-017-0602-6 |journal=Vegetation History and Archaeobotany |volume=26 |issue=4 |pages=415–432 |doi=10.1007/s00334-017-0602-6 |pmid=28706348 |pmc=5486841 |bibcode=2017VegHA..26..415G |s2cid=41734442}}{{Cite journal |last1=Fuller |first1=Dorian Q. |last2=Carretero |first2=Lara Gonzalez |date=2018-12-05 |title=The Archaeology of Neolithic Cooking Traditions: Archaeobotanical Approaches to Baking, Boiling and Fermenting |journal=Archaeology International |volume=21 |pages=109–121 |doi=10.5334/ai-391 |doi-access=free }} Apart from food, wheat may also have been important to Neolithic societies as a source of straw, which could be used for fuel, wicker-making, or wattle and daub construction.{{cite book |last1=Graeber |first1=David |title=The dawn of everything: a new history of humanity |last2=Wengrow |first2=David |date=2021 |publisher=Allen Lane |isbn=978-0-241-40242-9 |location=London |pages=232}}

Domestic wheat was quickly spread to regions where its wild ancestors did not grow naturally. Emmer was introduced to Cyprus as early as 8600 BC and einkorn {{Circa|7500 BC}};{{Cite journal |last1=Vigne |first1=Jean-Denis |last2=Briois |first2=François |last3=Zazzo |first3=Antoine |last4=Willcox |first4=George |last5=Cucchi |first5=Thomas |last6=Thiébault |first6=Stéphanie |last7=Carrère |first7=Isabelle |last8=Franel |first8=Yodrik |last9=Touquet |first9=Régis |last10=Martin |first10=Chloé |last11=Moreau |first11=Christophe |last12=Comby |first12=Clothilde |last13=Guilaine |first13=Jean |date=2012-05-29 |title=First wave of cultivators spread to Cyprus at least 10,600 y ago |journal=Proceedings of the National Academy of Sciences |volume=109 |issue=22 |pages=8445–8449 |doi=10.1073/pnas.1201693109 |pmc=3365171 |pmid=22566638 |bibcode=2012PNAS..109.8445V |doi-access=free }}{{Cite journal |last1=Lucas |first1=Leilani |last2=Colledge |first2=Sue |last3=Simmons |first3=Alan |last4=Fuller |first4=Dorian Q. |date=2012-03-01 |title=Crop introduction and accelerated island evolution: archaeobotanical evidence from 'Ais Yiorkis and Pre-Pottery Neolithic Cyprus |url=https://doi.org/10.1007/s00334-011-0323-1 |journal=Vegetation History and Archaeobotany |volume=21 |issue=2 |pages=117–129 |doi=10.1007/s00334-011-0323-1 |bibcode=2012VegHA..21..117L |s2cid=129727157}} emmer reached Greece by 6500 BC, Egypt shortly after 6000 BC, and Germany and Spain by 5000 BC.{{cite book |last=Diamond |first=Jared |author-link=Jared Diamond |year=2005 |orig-year=1997 |title=Guns, Germs and Steel |publisher=Vintage |isbn=978-0-099-30278-0 |page=97}} "The early Egyptians were developers of bread and the use of the oven and developed baking into one of the first large-scale food production industries."{{cite encyclopedia |last=Grundas |first=S.T. |chapter=Wheat: The Crop |title=Encyclopedia of Food Sciences and Nutrition |page=6130 |year=2003 |publisher=Elsevier Science |isbn=978-012227055-0}} By 4000 BC, wheat had reached the British Isles and Scandinavia.{{cite web |last=Piotrowski |first=Jan |title=Britons may have imported wheat long before farming it |website=New Scientist |date=26 February 2019 |url=https://www.newscientist.com/article/dn27044-britons-may-have-imported-wheat-long-before-farming-it/ |access-date=4 June 2020}}{{cite journal |last1=Smith |first1=Oliver |last2=Momber |first2=Garry |last3=Bates |first3=Richard |last4=Garwood |first4=Paul |last5=Fitch |first5=Simon |last6=Pallen |first6=Mark |last7=Gaffney |first7=Vincent |last8=Allaby |first8=Robin G. |s2cid=1167101 |display-authors=3 |title=Sedimentary DNA from a submerged site reveals wheat in the British Isles 8000 years ago |journal=Science |volume=347 |issue=6225 |year=2015 |pages=998–1001 |doi=10.1126/science.1261278 |pmid=25722413 |bibcode=2015Sci...347..998S |hdl=10454/9405 |hdl-access=free}}{{cite journal |last1=Brace |first1=Selina |last2=Diekmann |first2=Yoan |last3=Booth |first3=Thomas J. |last4=van Dorp |first4=Lucy |last5=Faltyskova |first5=Zuzana |last6=Rohland |first6=Nadin |last7=Mallick |first7=Swapan |last8=Olalde |first8=Iñigo |last9=Ferry |first9=Matthew |last10=Michel |first10=Megan |last11=Oppenheimer |first11=Jonas |last12=Broomandkhoshbacht |first12=Nasreen |last13=Stewardson |first13=Kristin |last14=Martiniano |first14=Rui |last15=Walsh |first15=Susan |last16=Kayser |first16=Manfred |last17=Charlton |first17=Sophy |last18=Hellenthal |first18=Garrett|last19=Armit |first19=Ian |last20=Schulting |first20=Rick |last21=Craig |first21=Oliver E. |last22=Sheridan |first22=Alison |last23=Parker Pearson |first23=Mike |last24=Stringer |first24=Chris |last25=Reich |first25=David |last26=Thomas |first26=Mark G. |last27=Barnes |first27=Ian |display-authors=5 |title=Ancient genomes indicate population replacement in Early Neolithic Britain |journal=Nature Ecology & Evolution |volume=3 |issue=5 |year=2019 |pages=765–771 |doi=10.1038/s41559-019-0871-9 |pmid=30988490 |pmc=6520225 |bibcode=2019NatEE...3..765B |doi-access=free |quote=Neolithic cultures first appear in Britain circa 4000 bc, a millennium after they appeared in adjacent areas of continental Europe.}} Wheat was also cultivated in India around 3500 BC.{{Cite journal|last1=Jarrige| first1= Jean-François| last2=Meadow| first2= Richard H |date=1980|title= The antecedents of civilization in the Indus Valley|journal= Scientific American| volume=243|issue=2|pages= 122-137}} Wheat likely appeared in China's lower Yellow River around 2600 BC.{{Cite journal |last1=Long |first1=Tengwen |last2=Leipe |first2=Christian |last3=Jin |first3=Guiyun |last4=Wagner |first4=Mayke |last5=Guo |first5=Rongzhen |last6=Schröder |first6=Oskar |last7=Tarasov |first7=Pavel E. |display-authors=5 |date=2018 |title=The early history of wheat in China from 14C dating and Bayesian chronological modelling |journal=Nature Plants |volume=4 |issue=5 |pages=272–279 |doi=10.1038/s41477-018-0141-x |pmid=29725102 |s2cid=19156382}}

The oldest evidence for hexaploid wheat has been confirmed through DNA analysis of wheat seeds, dating to around 6400–6200 BC, recovered from Çatalhöyük.{{cite journal |last1=Bilgic |first1=Hatice |display-authors=etal |title=Ancient DNA from 8400 Year-Old Çatalhöyük Wheat: Implications for the Origin of Neolithic Agriculture |journal=PLOS One |volume=11 |issue=3 |pages=e0151974 |date=2016 |doi=10.1371/journal.pone.0151974 |pmid=26998604 |pmc=4801371 |bibcode=2016PLoSO..1151974B |doi-access=free}} {{As of|2023|post=,}} the earliest known wheat with sufficient gluten for yeasted breads was found in a granary at Assiros in Macedonia dated to 1350 BC.{{cite web |url=http://www.sheffield.ac.uk/archaeology/research/wheat/wheat2 |title=The science in detail – Wheats DNA – Research – Archaeology |publisher=The University of Sheffield |date=19 July 2011|access-date=27 May 2012}} From the Middle East, wheat continued to spread across Europe and to the Americas in the Columbian exchange. In the British Isles, wheat straw (thatch) was used for roofing in the Bronze Age, and remained in common use until the late 19th century.{{cite book |last1=Belderok |first1=B. |display-authors=etal |year=2000 |title=Bread-Making Quality of Wheat |publisher=Springer |page=3 |isbn=0-7923-6383-3}}{{cite book |last1=Cauvain |first1=S.P. |last2=Cauvain |first2=P. |year=2003 |title=Bread Making |publisher=CRC Press |page=540 |isbn=1-85573-553-9}} White wheat bread was historically a high status food, but during the nineteenth century it became in Britain an item of mass consumption, displacing oats, barley and rye from diets in the North of the country. It became "a sign of a high degree of culture".{{cite book |last1=Otter|first1=Chris |title=Diet for a large planet |date=2020 |publisher=University of Chicago Press |isbn=978-0-226-69710-9 |page=50 }} After 1860, the enormous expansion of wheat production in the United States flooded the world market, lowering prices by 40%, and (along with the expansion of potato growing) made a major contribution to the nutritional welfare of the poor.{{cite book |last=Nelson |first=Scott Reynolds |title=Oceans of Grain: How American Wheat Remade the World |publisher=Basic Books |year=2022 |pages=3–4 |isbn=978-1-5416-4646-9}}

File:UrukPlate3000BCE.jpg|Sumerian cylinder seal impression dating to {{circa}} 3200 BC showing an ensi and his acolyte feeding a sacred herd wheat stalks; Ninurta was an agricultural deity and, in a poem known as the "Sumerian Georgica", he offers detailed advice on farming

File:Trilla del trigo en el Antiguo Egipto.jpg|Threshing of wheat in ancient Egypt

File:Woman harvesting wheat, Raisen district, Madhya Pradesh, India ggia version.jpg|Traditional wheat harvesting
India, 2012

File:Polyploid wheat origins.svg and polyploidy. Not all species are shown.]]

Some wheat species are diploid, with two sets of chromosomes, but many are stable polyploids, with four sets of chromosomes (tetraploid) or six (hexaploid). Einkorn wheat (Triticum monococcum) is diploid (AA, two complements of seven chromosomes, 2n=14). Most tetraploid wheats (e.g. emmer and durum wheat) are derived from wild emmer, T. dicoccoides. Wild emmer is itself the result of a hybridization between two diploid wild grasses, T. urartu and a wild goatgrass such as Ae. speltoides.{{cite journal |last1=Friebe |first1=B. |last2=Qi |first2=L.L. |last3=Nasuda |first3=S. |last4=Zhang |first4=P. |last5=Tuleen |first5=N.A. |last6=Gill |first6=B.S. |s2cid=13010134 |title=Development of a complete set of Triticum aestivum-Aegilops speltoides chromosome addition lines |journal=Theoretical and Applied Genetics |date=July 2000 |volume=101 |issue=1 |pages=51–58 |doi=10.1007/s001220051448}} The hybridization that formed wild emmer (AABB, four complements of seven chromosomes in two groups, 4n=28) occurred in the wild, long before domestication, and was driven by natural selection. Hexaploid wheats evolved in farmers' fields as wild emmer hybridized with another goatgrass, Ae. squarrosa or Ae. tauschii, to make the hexaploid wheats including bread wheat.{{Cite journal |last1=Dvorak |first1=Jan |last2=Deal |first2=Karin R. |last3=Luo |first3=Ming-Cheng |last4=You |first4=Frank M. |last5=von Borstel |first5=Keith |last6=Dehghani |first6=Hamid |date=2012-05-01 |title=The Origin of Spelt and Free-Threshing Hexaploid Wheat |journal=Journal of Heredity |volume=103 |issue=3 |pages=426–441 |doi=10.1093/jhered/esr152 |pmid=22378960 |doi-access=free}}

A 2007 molecular phylogeny of the wheats gives the following not fully-resolved cladogram of major cultivated species; the large amount of hybridisation makes resolution difficult. Markings like "6N" indicate the degree of polyploidy of each species:{{cite journal |last1=Golovnina |first1=K. A. |last2=Glushkov |first2=S. A. |last3=Blinov |first3=A. G. |last4=Mayorov |first4=V. I. |last5=Adkison |first5=L. R. |last6=Goncharov |first6=N. P. |title=Molecular phylogeny of the genus Triticum L |journal=Plant Systematics and Evolution |publisher=Springer |volume=264 |issue=3–4 |date=2007-02-12 |doi=10.1007/s00606-006-0478-x |pages=195–216|bibcode=2007PSyEv.264..195G |s2cid=39102602 }}

{{clade

|label1=Triticeae

|1={{clade

|1=Barley 2N, rye 2N/4N, and other cereals

|label2=Wheats

|2={{clade

|1={{clade

|1=Triticum monococcum (einkorn) 2N

|2=× Aegilotriticum hybrids (Aegilops x Triticum) 6N

}}

|2={{clade

|1= Triticum timopheevii (zanduri wheat) and others 4N

|2={{clade

|1=Triticum aestivum (common or bread wheat) 6N

|2=Triticum durum/turgidum (durum wheat) 4N

|3=Triticum spelta (spelt) 6N

|4=Triticum turanicum (khorasan wheat) 4N

|5=Triticum dicoccum (emmer) 4N

|6= many other species

}}

}}

}}

}}

}}

{{main|Taxonomy of wheat}}

During 10,000 years of cultivation, numerous forms of wheat, many of them hybrids, have developed under a combination of artificial and natural selection. This complexity and diversity of status has led to much confusion in the naming of wheats.{{Cite journal |last=Shewry |first=P. R. |date=2009-04-01 |title=Wheat |journal=Journal of Experimental Botany |volume=60 |issue=6 |pages=1537–1553 |doi=10.1093/jxb/erp058 |pmid=19386614 |issn=0022-0957 |doi-access=free}}{{Citation |last1=Fuller |first1=Dorian Q. |last2=Lucas |first2=Leilani |title=Wheats: Origins and Development |date=2014 |encyclopedia=Encyclopedia of Global Archaeology |pages=7812–7817 |publisher=Springer New York |doi=10.1007/978-1-4419-0465-2_2192 |isbn=9781441904263 |s2cid=129138746 }}

Hexaploid species (6N)

• Common wheat or bread wheat (T. aestivum) – The most widely cultivated species in the world.{{Cite journal |last1=Yang |first1=Fan |last2=Zhang |first2=Jingjuan |last3=Liu |first3=Qier |last4=Liu |first4=Hang |last5=Zhou |first5=Yonghong |last6=Yang |first6=Wuyun |last7=Ma |first7=Wujun |display-authors=3 |date=2022-02-17 |title=Improvement and Re-Evolution of Tetraploid Wheat for Global Environmental Challenge and Diversity Consumption Demand |journal=International Journal of Molecular Sciences|volume=23 |issue=4 |pages=2206 |doi=10.3390/ijms23042206 |pmc=8878472 |pmid=35216323|doi-access=free }}
• Spelt (T. spelta) – Another species largely replaced by bread wheat, but in the 21st century grown, often organically, for artisanal bread and pasta.{{cite news |last=Smithers |first=Rebecca |title=Spelt flour 'wonder grain' set for a price hike as supplies run low |newspaper=The Guardian |date=15 May 2014 |url=https://www.theguardian.com/money/2014/may/15/spelt-grain-supplies-under-pressure-high-demand }}

Tetraploid species (4N)

• Durum (T. durum) – A wheat widely used today, and the second most widely cultivated wheat.
• Emmer (T. turgidum subsp. dicoccum and T. t. conv. durum) – A species cultivated in ancient times, derived from wild emmer, T. dicoccoides, but no longer in widespread use.{{GRIN |Triticum turgidum subsp. dicoccon |314587 |access-date=11 December 2017}}
• Khorasan or Kamut (T. turgidum ssp. turanicum, also called T. turanicum) is an ancient grain type; Khorasan is a historical region in modern-day Afghanistan and the northeast of Iran. The grain is twice the size of modern wheat and has a rich nutty flavor.{{cite journal |last1=Khlestkina |first1=Elena K. |last2=Röder |first2=Marion S. |last3=Grausgruber |first3=Heinrich |last4=Börner |first4=Andreas |year=2006 |title=A DNA fingerprinting-based taxonomic allocation of Kamut wheat |journal=Plant Genetic Resources |volume=4 |issue=3 |pages=172–180 |doi=10.1079/PGR2006120 |s2cid=86510231 }}

Diploid species (2N)

• Einkorn (T. monococcum). Domesticated from wild einkorn, T. boeoticum, at the same time as emmer wheat.{{ Cite book |last=Anderson |first=Patricia C. |year=1991 |chapter=Harvesting of Wild Cereals During the Natufian as seen from Experimental Cultivation and Harvest of Wild Einkorn Wheat and Microwear Analysis of Stone Tools|title=Natufian Culture in the Levant |editor-first=Ofer |editor-last=Bar-Yosef |location=Ann Arbor, Michigan |series=International Monographs in Prehistory |page=523 |publisher=Berghahn Books}}

File:Naked and hulled wheat.jpg. Note how the einkorn ear breaks down into intact spikelets.]]

The wild species of wheat, along with the domesticated varieties einkorn,{{cite book |last=Potts |first=D.T. |year=1996 |title=Mesopotamia Civilization: The Material Foundations |publisher=Cornell University Press |page=62 |isbn=0-8014-3339-8}} emmer{{cite book |last=Nevo |first=E. |title=Evolution of Wild Emmer and Wheat Improvement |publisher=Springer Science & Business Media |publication-place=Berlin ; New York |date=2002-01-29 |isbn=3-540-41750-8 |page=8}} and spelt,{{cite book |last1=Vaughan |first1=J.G. |last2=Judd |first2=P.A. |year=2003 |title=The Oxford Book of Health Foods |publisher=Oxford University Press |page=35 |isbn=0-19-850459-4}} have hulls. This more primitive morphology (in evolutionary terms) consists of toughened glumes that tightly enclose the grains, and (in domesticated wheats) a semi-brittle rachis that breaks easily on threshing. The result is that when threshed, the wheat ear breaks up into spikelets. To obtain the grain, further processing, such as milling or pounding, is needed to remove the hulls or husks. Hulled wheats are often stored as spikelets because the toughened glumes give good protection against pests of stored grain. In free-threshing (or naked) forms, such as durum wheat and common wheat, the glumes are fragile and the rachis tough. On threshing, the chaff breaks up, releasing the grains.{{cite web |title=Field Crop Information |publisher=College of Agriculture and Bioresources, University of Saskatchewan |url=https://agbio.usask.ca/cdc/field-crop-information.php |access-date=10 July 2023 |archive-date=18 October 2023 |archive-url=https://web.archive.org/web/20231018003729/https://agbio.usask.ca/cdc/field-crop-information.php |url-status=dead }}

{{main|Wheat grain classes}}

Classification of wheat greatly varies by the producing country.{{sfn|Khan|2016|pp=109-116}}

Argentina's grain classes were formerly related to the production region or port of shipment: Rosafe (grown in Santa Fe province, shipped through Rosario), Bahia Blanca (grown in Buenos Aires and La Pampa provinces and shipped through Bahia Blanca), Buenos Aires (shipped through the port of Buenos Aires). While mostly similar to the US Hard Red Spring wheat, the classification caused inconsistencies, so Argentina introduced three new classes of wheat, with all names using a prefix Trigo Dura Argentina (TDA) and a number.{{sfn|Khan|2016|pp=109-110}}

The grain classification in Australia is within the purview of its National Pool Classification Panel. Australia chose to measure the protein content at 11% moisture basis.{{sfn|Khan|2016|p=110}}

The decisions on the wheat classification in Canada are coordinated by the Variety Registration Office of the Canadian Food Inspection Agency. Like in the US system, the eight classes in the Western Canada and six classes in the Eastern Canada are based on colour, season, and hardness. Canada has a unique requirement that the varieties of wheat grains should allow for purely visual identification.{{sfn|Khan|2016|pp=110-111}}

The wheat grain classes used in the United States are named by colour, season, and hardness:{{cite encyclopedia |last1=Bridgwater |first1=W. |last2=Aldrich |first2=Beatrice |year=1966 |chapter=Wheat |title=The Columbia-Viking Desk Encyclopedia |publisher=Columbia University Press |page=1959}}{{cite news |title=Flour types: Wheat, Rye, and Barley |url=https://www.nytimes.com/1981/02/18/garden/flour-types-wheat-rye-and-barley.html |work=The New York Times |date=18 February 1981}}{{cite web |title=Wheat: Background |url=http://www.ers.usda.gov/topics/crops/wheat/background.aspx |publisher=USDA |access-date=2 October 2016}}

File:USDA wheat.jpg

{{nutritionalvalue

|name=Wheat, hard red winter

|kJ=1368

|protein=12.61 g

|water=13.1 g

|fat=1.54 g

|carbs=71.18 g

|fiber=12.2 g

|sugars=0.41

|calcium_mg=29

|iron_mg=3.19

|magnesium_mg=126

|phosphorus_mg=288

|potassium_mg=363

|sodium_mg=2

|zinc_mg=2.65

|manganese_mg=3.985

|thiamin_mg=0.383

|riboflavin_mg=0.115

|niacin_mg=5.464

|pantothenic_mg=0.954

|vitB6_mg=0.3

|folate_ug=38

|choline_mg=31.2

|vitE_mg=1.01

|vitK_ug=1.9

|opt1n=Selenium

|opt1v=70.7 µg

|source_usda=1

|note=[https://fdc.nal.usda.gov/fdc-app.html#/food-details/168890/nutrients Link to USDA Database Entry]

}}

Wheat is a staple cereal worldwide.{{cite book |last=Mauseth |first=James D. |title=Botany |url=https://books.google.com/books?id=0BGEs95p5EsC&pg=PA223 |year=2014 |publisher=Jones & Bartlett Publishers |isbn=978-1-4496-4884-8 |page=223 |quote=Perhaps the simplest of fruits are those of grasses (all cereals such as corn and wheat)...These fruits are caryopses.}}{{cite book |last1=Belderok |first1=Robert 'Bob' |first2=Hans |last2=Mesdag |first3=Dingena A. |last3=Donner |year=2000 |title=Bread-Making Quality of Wheat |publisher=Springer |page=3 |isbn=978-0-7923-6383-5}} Raw wheat berries can be ground into flour or, using hard durum wheat only, can be ground into semolina; germinated and dried creating malt; crushed or cut into cracked wheat; parboiled (or steamed), dried, and de-branned into groats, then crushed into bulgur.{{Cite book |last1=Ensminger |first1=Marion |last2=Ensminger |first2=Audrey H. Eugene |url=https://books.google.com/books?id=XMA9gYIj-C4C&pg=PA164 |title=Foods & Nutrition Encyclopedia, Two Volume Set |date=1993 |publisher=CRC Press |isbn=978-0-8493-8980-1 |page=164}} If the raw wheat is broken into parts at the mill, as is usually done, the outer husk or bran can be used in several ways. Wheat is a major ingredient in baked foods, such as bread, rolls, crackers, biscuits, pancakes, pasta, pies, pastries, pizza, cakes, cookies, and muffins; in fried foods, such as doughnuts; in breakfast cereals, gravy, porridge, and muesli; in semolina; and in drinks such as beer, vodka, and boza (a fermented beverage).{{Cite web|url=https://foodallergycanada.ca/about-allergies/food-allergens/wheat/|title=Wheat |website=Food Allergy Canada |access-date=25 February 2019}} In manufacturing wheat products, gluten is valuable to impart viscoelastic functional qualities in dough,{{cite journal |year=2002 |last1=Shewry |first1=P. R. |title=The structure and properties of gluten: An elastic protein from wheat grain |journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=357 |issue=1418 |pages=133–42 |last2=Halford |first2=N. G. |last3=Belton |first3=P. S. |last4=Tatham |first4=A. S. |doi=10.1098/rstb.2001.1024 |pmc=1692935 |pmid=11911770}} enabling the preparation of diverse processed foods such as breads, noodles, and pasta that facilitate wheat consumption.

Raw red winter wheat is 13% water, 71% carbohydrates including 12% dietary fiber, 13% protein, and 2% fat (table). Some 75–80% of the protein content is as gluten. In a reference amount of {{convert|100|g}}, wheat provides {{convert|1368|kJ|kcal|abbr=off}} of food energy and is a rich source (20% or more of the Daily Value, DV) of multiple dietary minerals, such as manganese, phosphorus, magnesium, zinc, and iron (table). The B vitamins, niacin (36% DV), thiamine (33% DV), and vitamin B6 (23% DV), are present in significant amounts (table).

Wheat is a significant source of vegetable proteins in human food, having a relatively high protein content compared to other major cereals.{{cite web |url=http://cordis.europa.eu/news/rcn/124823_en.html |title=Genetic markers signal increased crop productivity potential |author=European Community, Community Research and Development Information Service |date=24 February 2016 |access-date=1 June 2017}} However, wheat proteins have a low quality for human nutrition, according to the DIAAS protein quality evaluation method.{{cite book |url=http://www.fao.org/ag/humannutrition/35978-02317b979a686a57aa4593304ffc17f06.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.fao.org/ag/humannutrition/35978-02317b979a686a57aa4593304ffc17f06.pdf |archive-date=2022-10-09 |url-status=live |title=Dietary protein quality evaluation in human nutrition |publisher=Food and Agriculture Organization of the United Nations |date=2013 |access-date=1 June 2017 |isbn=978-92-5-107417-6}}{{cite journal |last=Wolfe |first=R. R. |title=Update on protein intake: importance of milk proteins for health status of the elderly |journal=Nutrition Reviews |volume=73 |pages=41–47 |date=August 2015 |issue=Suppl 1 |pmid=26175489 |pmc=4597363 |doi=10.1093/nutrit/nuv021 |type=Review}} Though they contain adequate amounts of the other essential amino acids, at least for adults, wheat proteins are deficient in the essential amino acid lysine.{{cite web |url=http://www.eolss.net/sample-chapters/c10/E5-21-04-04.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.eolss.net/sample-chapters/c10/E5-21-04-04.pdf |archive-date=2022-10-09 |url-status=live |title=Impacts of agriculture on human health and nutrition – Vol. II – Improving the Protein Content and Quality of Temperate Cereals: Wheat, Barley and Rye |last=Shewry |first=Peter R. |publisher=UNESCO – Encyclopedia Life Support Systems (UNESCO-EOLSS) |access-date=2 June 2017 |quote=When compared with the WHO requirements of essential amino acids for humans, wheat, barley and rye are seen to be deficient in lysine, with threonine being the second limiting amino acid (Table 1).}} Because the proteins present in the wheat endosperm (gluten proteins) are particularly poor in lysine, white flours are more deficient in lysine compared with whole grains. Significant efforts in plant breeding are made to develop lysine-rich wheat varieties, without success, {{as of|2017|lc=yes}}.{{cite web |url=http://www.fao.org/docrep/007/y5019e/y5019e0b.htm |title=The role of high lysine cereals in animal and human nutrition in Asia |last=Vasal |first=S. K. |publisher=Food and Agriculture Organization of the United Nations |access-date=1 June 2017}} Supplementation with proteins from other food sources (mainly legumes) is commonly used to compensate for this deficiency,{{cite web |url=http://www.fao.org/docrep/x2184e/x2184e05.htm |title=Nutritional quality of cereals |publisher=Food and Agriculture Organization of the United Nations |access-date=1 June 2017}} since the limitation of a single essential amino acid causes the others to break down and become excreted, which is especially important during growth.

Consumed worldwide by billions of people, wheat is a significant food for human nutrition, particularly in the least developed countries where wheat products are primary foods.{{cite journal |title=Review: The contribution of wheat to human diet and health |journal=Food and Energy Security |year=2015 |volume=4 |issue=3 |pages=178–202 |last1=Shewry |first1=Peter R. |author2=Hey, S. J. |doi=10.1002/fes3.64 |pmid=27610232 |pmc=4998136}}{{cite journal |last1=Shewry |first1=Peter R. |title=Wheat |journal=Journal of Experimental Botany |year=2009 |volume=60 |issue=6 |pages=1537–53 |doi=10.1093/jxb/erp058 |pmid=19386614 |doi-access=free }} When eaten as the whole grain, wheat supplies multiple nutrients and dietary fiber recommended for children and adults.{{cite web|url=http://www.eufic.org/article/en/expid/whole-grain-fact-sheet/ |publisher=European Food Information Council |title=Whole Grain Fact Sheet |date=1 January 2009 |access-date=6 December 2016 |archive-url=https://web.archive.org/web/20161220064848/http://www.eufic.org/article/en/expid/whole-grain-fact-sheet/ |archive-date=20 December 2016 |url-status=dead}}{{cite web|url=http://www.fns.usda.gov/sites/default/files/WholeGrainResource.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.fns.usda.gov/sites/default/files/WholeGrainResource.pdf |archive-date=2022-10-09 |url-status=live |publisher=US Department of Agriculture, Food and Nutrition Service |date=January 2014|title=Whole Grain Resource for the National School Lunch and School Breakfast Programs: A Guide to Meeting the Whole Grain-Rich criteria |quote=Additionally, menu planners are encouraged to serve a variety of foods that meet whole grain-rich criteria and may not serve the same product every day to count for the HUSSC whole grain-rich criteria.}}{{cite web |url=https://www.choosemyplate.gov/grains|publisher=US Department of Agriculture, MyPlate |title=All About the Grains Group|date=2016|access-date=6 December 2016}}

In genetically susceptible people, wheat gluten can trigger coeliac disease. Coeliac disease affects about 1% of the general population in developed countries.{{cite web|url=http://www.worldgastroenterology.org/guidelines/global-guidelines/celiac-disease/celiac-disease-english|title=Celiac disease|date=July 2016 |publisher=World Gastroenterology Organisation Global Guidelines|access-date=7 December 2016}}{{cite web|url=https://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/celiac-disease/Pages/definition-facts.aspx |title=Definition and Facts for Celiac Disease |publisher=The National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD|date=2016|access-date=5 December 2016}} The only known effective treatment is a strict lifelong gluten-free diet. While coeliac disease is caused by a reaction to wheat proteins, it is not the same as a wheat allergy. Other diseases triggered by eating wheat are non-coeliac gluten sensitivity{{cite journal |last1=Ludvigsson |first1=Jonas F. |last2=Leffler |first2=Daniel A. |last3=Bai |first3=Julio C. |last4=Biagi |first4=Federico |last5=Fasano |first5=Alessio |last6=Green |first6=Peter H. R. |last7=Hadjivassiliou |first7=Marios |last8=Kaukinen |first8=Katri |last9=Kelly |first9=Ciaran P. |last10=Leonard |first10=Jonathan N. |last11=Lundin |first11=Knut Erik Aslaksen |last12=Murray |first12=Joseph A. |last13=Sanders |first13=David S. |last14=Walker |first14=Marjorie M. |last15=Zingone |first15=Fabiana |last16=Ciacci |first16=Carolina |display-authors=5 |title=The Oslo definitions for coeliac disease and related terms |journal=Gut |publisher=BMJ |volume=62 |issue=1 |date=2012-02-16 |doi=10.1136/gutjnl-2011-301346 |pages=43–52|pmid=22345659 |pmc=3440559 }} (estimated to affect 0.5% to 13% of the general population{{cite journal |last1=Molina-Infante |first1=J. |last2=Santolaria |first2=S. |last3=Sanders |first3=D. S. |last4=Fernández-Bañares |first4=F. |title=Systematic review: noncoeliac gluten sensitivity |journal=Alimentary Pharmacology & Therapeutics |volume=41 |issue=9 |pages=807–820 |date=May 2015 |pmid=25753138 |doi=10.1111/apt.13155 |s2cid=207050854 |doi-access=free}}), gluten ataxia, and dermatitis herpetiformis.

Certain short-chain carbohydrates present in wheat, known as FODMAPs (mainly fructose polymers), may be the cause of non-coeliac gluten sensitivity. {{As of|2019}}, reviews have concluded that FODMAPs only explain certain gastrointestinal symptoms, such as bloating, but not the extra-digestive symptoms that people with non-coeliac gluten sensitivity may develop.{{cite journal |last1=Volta |first1=Umberto |last2=De Giorgio |first2=Roberto |last3=Caio |first3=Giacomo |last4=Uhde |first4=Melanie |last5=Manfredini |first5=Roberto |last6=Alaedini |first6=Armin |title=Nonceliac Wheat Sensitivity |journal=Gastroenterology Clinics of North America |volume=48 |issue=1 |year=2019 |doi=10.1016/j.gtc.2018.09.012 |pages=165–182 |pmid=30711208 |pmc=6364564 }}{{cite journal |last1=Verbeke |first1=K. |title=Nonceliac Gluten Sensitivity: What Is the Culprit? |journal=Gastroenterology |date=February 2018 |volume=154 |issue=3 |pages=471–473 |doi=10.1053/j.gastro.2018.01.013 |pmid=29337156 |doi-access=free }}{{cite journal |last1=Fasano |first1=Alessio |last2=Sapone |first2=Anna |last3=Zevallos |first3=Victor |last4=Schuppan |first4=Detlef |title=Nonceliac Gluten Sensitivity |journal=Gastroenterology |volume=148 |issue=6 |year=2015 |doi=10.1053/j.gastro.2014.12.049 |pages=1195–1204 |pmid=25583468 |doi-access=free }}

Other wheat proteins, amylase-trypsin inhibitors, have been identified as the possible activator of the innate immune system in coeliac disease and non-coeliac gluten sensitivity. These proteins are part of the plant's natural defense against insects and may cause intestinal inflammation in humans.{{cite journal |last1=Barone |first1=Maria |last2=Troncone |first2=Riccardo |last3=Auricchio |first3=Salvatore |title=Gliadin Peptides as Triggers of the Proliferative and Stress/Innate Immune Response of the Celiac Small Intestinal Mucosa |journal=International Journal of Molecular Sciences |volume=15 |issue=11 |year=2014 |pages=20518–20537 |doi=10.3390/ijms151120518 |pmid=25387079 |type=Review |pmc=4264181 |doi-access=free}}

{{Main|International wheat production statistics}}

File:WheatYield.png|Wheat-growing areas of the world

File:Production of wheat (2019).svg|Production of wheat (2019){{Cite book|url=https://doi.org/10.4060/cb4477en |title=World Food and Agriculture – Statistical Yearbook 2021 |publisher=FAO |year=2021 |isbn=978-92-5-134332-6 |location=Rome |doi=10.4060/cb4477en |s2cid=240163091 }}

File:World Production Of Primary Crops, Main Commodities.svg|Wheat's share (brown) of world crop production fell in the 21st century.

In 2022, world wheat production was 808.4 million tonnes, led by China, India, and Russia which collectively provided 43.22% of the world total.{{Cite web |title=Wheat production in 2022 from pick lists: Crops/World regions/Production quantity/Year |url=https://www.fao.org/faostat/en/#data/QCL |access-date=2024-04-11 |website=www.fao.org}} {{As of|2019}}, the largest exporters were Russia (32 million tonnes), United States (27), Canada (23) and France (20), while the largest importers were Indonesia (11 million tonnes), Egypt (10.4) and Turkey (10.0).{{cite web |publisher=UN Food and Agriculture Organization, Statistics Division, FAOSTAT |title=Crops and livestock products |url=http://www.fao.org/faostat/en/#data/TP |date=2021 |access-date=18 April 2021}}

In 2021, wheat was grown on {{convert|220.7|e6ha|abbr=off|disp=or}} worldwide, more than any other food crop.{{cite web |title=Wheat area harvested, world total from pick lists: Crops/World regions/Area harvested/Year |url=http://www.fao.org/faostat/en/#data/QC |date=2023 |access-date=5 October 2023}}

World trade in wheat is greater than for all other crops combined.{{cite web |last1=Curtis |last2=Rajaraman |last3=MacPherson |title=Bread Wheat |publisher=Food and Agriculture Organization of the United Nations |year=2002 |url=http://www.fao.org/docrep/006/y4011e/y4011e00.htm}}

Global demand for wheat is increasing due to the unique viscoelastic and adhesive properties of gluten proteins, which facilitate the production of processed foods, whose consumption is increasing as a result of the worldwide industrialization process and westernization of diets.{{cite journal |last1=Day |first1=L. |last2=Augustin |first2=M.A. |last3=Batey |first3=I.L. |last4=Wrigley |first4=C.W. |title=Wheat-gluten uses and industry needs |journal=Trends in Food Science & Technology |publisher=Elsevier |volume=17 |issue=2 |pages=82–90 |date=2006 |type=Review |doi=10.1016/j.tifs.2005.10.003}}

File:Wheat prices in England, OWID.svg

Wheat became a central agriculture endeavor in the worldwide British Empire in the 19th century, and remains of great importance in Australia, Canada and India.{{cite book |last=Palmer |first=Alan |title=Dictionary of the British Empire and Commonwealth |year=1996 |pages=193, 320, 338}} In Australia, with vast lands and a limited work force, expanded production depended on technological advances, especially regarding irrigation and machinery. By the 1840s there were 900 growers in South Australia. They used "Ridley's Stripper", a reaper-harvester perfected by John Ridley in 1843,{{cite book |last=Ridley |first=Annie E. |title=A Backward Glance: The Story of John Ridley, a Pioneer |publisher=J. Clarke |year=1904 |url=https://books.google.com/books?id=B44WAAAAYAAJ&dq=john+Ridley+australia+wheat&pg=PP21 |page=21}} to remove the heads of grain. In Canada, modern farm implements made large scale wheat farming possible from the late 1840s. By 1879, Saskatchewan was the center, followed by Alberta, Manitoba and Ontario, as the spread of railway lines allowed easy exports to Britain. By 1910, wheat made up 22% of Canada's exports, rising to 25% in 1930 despite the sharp decline in prices during the worldwide Great Depression.{{Cite journal |last1=Furtan |first1=W. Hartley |last2=Lee |first2=George E. |title=Economic Development of the Saskatchewan Wheat Economy |date=1977 |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1744-7976.1977.tb02882.x |journal=Canadian Journal of Agricultural Economics |volume=25 |issue=3 |pages=15–28 |doi=10.1111/j.1744-7976.1977.tb02882.x|bibcode=1977CaJAE..25...15F }} Efforts to expand wheat production in South Africa, Kenya and India were stymied by low yields and disease. However, by 2000 India had become the second largest producer of wheat in the world.{{Cite journal |last1=Joshi |first1=A. K. |last2=Mishra |first2=B. |last3=Chatrath |first3=R. |last4=Ortiz Ferrara |first4=G. |last5=Singh |first5=Ravi P. |date=2007 |title=Wheat improvement in India: present status, emerging challenges and future prospects |url=https://link.springer.com/10.1007/s10681-007-9385-7 |journal=Euphytica |volume=157 |issue=3 |pages=431–446 |doi=10.1007/s10681-007-9385-7 |s2cid=38596433}} In the 19th century the American wheat frontier moved rapidly westward. By the 1880s 70% of American exports went to British ports. The first successful grain elevator was built in Buffalo in 1842.{{cite book |last1=Otter |first1=Chris |title=Diet for a large planet |date=2020 |publisher=University of Chicago Press |location=USA |isbn=978-0-226-69710-9 |page=51 }} The cost of transport fell rapidly. In 1869 it cost 37 cents to transport a bushel of wheat from Chicago to Liverpool. In 1905 it was 10 cents.{{cite book |last1=Otter |first1=Chris |title=Diet for a large planet |date=2020 |publisher=University of Chicago Press |location=USA |isbn=978-0-226-69710-9 |page=69}}

In the 20th century, global wheat output expanded by about 5-fold, but until about 1955 most of this reflected increases in wheat crop area, with lesser (about 20%) increases in crop yields per unit area. After 1955 however, there was a ten-fold increase in the rate of wheat yield improvement per year, and this became the major factor allowing global wheat production to increase. Thus technological innovation and scientific crop management with synthetic nitrogen fertilizer, irrigation and wheat breeding were the main drivers of wheat output growth in the second half of the century. There were some significant decreases in wheat crop area, for instance in North America.{{cite book |last1=Slafer |first1=G.A. |last2=Satorre |first2=E.H. |chapter=Chapter 1 |year=1999 |title=Wheat: Ecology and Physiology of Yield Determination |publisher=Haworth Press |isbn=1-56022-874-1}} Better seed storage and germination ability (and hence a smaller requirement to retain harvested crop for next year's seed) is another 20th-century technological innovation. In medieval England, farmers saved one-quarter of their wheat harvest as seed for the next crop, leaving only three-quarters for food and feed consumption. By 1999, the global average seed use of wheat was about 6% of output.{{cite book |last1=Wright |first1=B. D. |last2=Pardey |first2=P. G. |chapter=Agricultural R&D, productivity, and global food prospects |title=Plants, Genes and Crop Biotechnology |year=2002 |pages=22-51 |publisher=Jones & Bartlett Learning |isbn=9780763715861 |chapter-url=https://books.google.com/books?id=UF94McWtLP0C&pg=PA22}}

In the 21st century, rising temperatures associated with global warming are reducing wheat yield in several locations.{{Cite journal |last1=Asseng |first1=S. |last2=Ewert |first2=F. |last3=Martre |first3=P. |last4=Rötter |first4=R. P.|last5=Lobell |first5=D. B. |last6=Cammarano |first6=D. |last7=Kimball |first7=B. A. |last8=Ottman |first8=M. J. |last9=Wall |first9=G. W. |last10=White |first10=J. W. |last11=Reynolds |first11=M. P. |display-authors=5 |date=2015 |title=Rising temperatures reduce global wheat production |journal=Nature Climate Change |volume=5 |issue=2 |pages=143–147 |doi=10.1038/nclimate2470 |bibcode=2015NatCC...5..143A |url=http://eprints.whiterose.ac.uk/85540/1/Main_Asseng_2014-9-22.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://eprints.whiterose.ac.uk/85540/1/Main_Asseng_2014-9-22.pdf |archive-date=2022-10-09 |url-status=live}}

Wheat is an annual crop. It can be planted in autumn and harvested in early summer as winter wheat in climates that are not too severe, or planted in spring and harvested in autumn as spring wheat. It is normally planted after tilling the soil by ploughing and then harrowing to kill weeds and create an even surface. The seeds are then scattered on the surface, or drilled into the soil in rows. Winter wheat lies dormant during a winter freeze. It needs to develop to a height of 10 to 15 cm before the cold intervenes, so as to be able to survive the winter; it requires a period with the temperature at or near freezing, its dormancy then being broken by the thaw or rise in temperature. Spring wheat does not undergo dormancy. Wheat requires a deep soil, preferably a loam with organic matter, and available minerals including soil nitrogen, phosphorus, and potassium. An acid and peaty soil is not suitable. Wheat needs some 30 to 38 cm of rain in the growing season to form a good crop of grain.

The farmer may intervene while the crop is growing to add fertilizer, water by irrigation, or pesticides such as herbicides to kill broad-leaved weeds or insecticides to kill insect pests. The farmer may assess soil minerals, soil water, weed growth, or the arrival of pests to decide timely and cost-effective corrective actions, and crop ripeness and water content to select the right moment to harvest. Harvesting involves reaping, cutting the stems to gather the crop; and threshing, breaking the ears to release the grain; both steps are carried out by a combine harvester. The grain is then dried so that it can be stored safe from mould fungi.{{cite web |title=How To Grow Wheat Efficiently On A Large Farm |website=EOS Data Analytics |date=10 May 2023 |url=https://eos.com/blog/growing-wheat/ |access-date=23 December 2023}}

File:Wheat developmental stages.tif and Zadok's scales]]

Wheat normally needs between 110 and 130 days between sowing and harvest, depending upon climate, seed type, and soil conditions. Optimal crop management requires that the farmer have a detailed understanding of each stage of development in the growing plants. In particular, spring fertilizers, herbicides, fungicides, and growth regulators are typically applied only at specific stages of plant development. For example, it is currently recommended that the second application of nitrogen is best done when the ear (not visible at this stage) is about 1 cm in size (Z31 on Zadoks scale). Knowledge of stages is also important to identify periods of higher risk from the climate. Farmers benefit from knowing when the 'flag leaf' (last leaf) appears, as this leaf represents about 75% of photosynthesis reactions during the grain filling period, and so should be preserved from disease or insect attacks to ensure a good yield. Several systems exist to identify crop stages, with the Feekes and Zadoks scales being the most widely used. Each scale is a standard system which describes successive stages reached by the crop during the agricultural season.{{cite book |last1=Slafer |first1=G.A. |last2=Satorre |first2=E.H. |year=1999 |title=Wheat: Ecology and Physiology of Yield Determination |publisher=Haworth Press |isbn=1-56022-874-1 |pages=322–323}} For example, the stage of pollen formation from the mother cell, and the stages between anthesis and maturity, are susceptible to high temperatures, and this adverse effect is made worse by water stress.{{cite journal |last1=Saini |first1=H.S. |last2=Sedgley |first2=M. |last3=Aspinall |first3=D. |year=1984 |title=Effect of heat stress during floral development on pollen tube growth and ovary anatomy in wheat (Triticum aestivum L.) |journal=Australian Journal of Plant Physiology |volume=10 |issue=2 |pages=137–144 |doi=10.1071/PP9830137 }}

File:WheatFlower1-rotated.jpg|Anthesis stage

File:Wheat Ear milk full.jpg|Late milk stage

Melissa Askew 2015-08-08 (Unsplash).jpg|Right before harvest

{{further|British agricultural revolution}}

Technological advances in soil preparation and seed placement at planting time, use of crop rotation and fertilizers to improve plant growth, and advances in harvesting methods have all combined to promote wheat as a viable crop. When the use of seed drills replaced broadcasting sowing of seed in the 18th century, another great increase in productivity occurred. Yields of pure wheat per unit area increased as methods of crop rotation were applied to land that had long been in cultivation, and the use of fertilizers became widespread.{{cite book |last=Overton |first=Mark |author-link=Mark Overton |title=Agricultural Revolution in England: The transformation of the agrarian economy 1500-1850 |url=https://archive.org/details/isbn_9780521568593 |url-access=registration |year=1996 |publisher=Cambridge University Press |isbn=978-0-521-56859-3 |page=1, and throughout}}

Improved agricultural husbandry has more recently included pervasive automation, starting with the use of threshing machines,{{Cite journal |last1=Caprettini |first1=Bruno |last2=Voth |first2=Hans-Joachim |title=Rage against the Machines: Labor-Saving Technology and Unrest in Industrializing England |journal=American Economic Review: Insights |year=2020 |volume=2 |issue=3 |pages=305–320 |doi=10.1257/aeri.20190385 |s2cid=234622559 |doi-access=free}} and progressing to large and costly machines like the combine harvester which greatly increased productivity.{{cite book |title=A Century of Innovation: Twenty Engineering Achievements That Transformed Our Lives, Chapter 7, Agricultural Mechanization |last=Constable |first=George |author2=Somerville, Bob |year=2003 |publisher=Joseph Henry Press |location=Washington, DC |isbn=0-309-08908-5 |url= http://www.greatachievements.org/?id=2955}} At the same time, better varieties such as Norin 10 wheat, developed in Japan in the 1930s,{{cite journal |last1=Borojevic |first1=Katarina |last2=Borojevic |first2=Ksenija |date=July–August 2005 |title=The Transfer and History of "Reduced Height Genes" (Rht) in Wheat from Japan to Europe |journal=Journal of Heredity |publisher=Oxford University Press |volume=96 |issue=4 |pages=455–459 |doi=10.1093/jhered/esi060 |pmid=15829727 |doi-access=free }} or the dwarf wheat developed by Norman Borlaug in the Green Revolution, greatly increased yields.{{cite web |last1=Shindler |first1=Miriam |title=From east Asia to south Asia, via Mexico: how one gene changed the course of history |url=https://www.cimmyt.org/news/from-east-asia-to-south-asia-via-mexico-how-one-gene-changed-the-course-of-history/ |website=CIMMYT |date=3 January 2016 |access-date=19 November 2021}}{{cite journal |last=Brown |first=L. R. |title=Nobel Peace Prize: developer of high-yield wheat receives award (Norman Ernest Borlaug) |journal=Science |date=30 October 1970 |volume=170 |issue=957 |pages=518–519|doi=10.1126/science.170.3957.518 |pmid=4918766 }}

In addition to gaps in farming system technology and knowledge, some large wheat grain-producing countries have significant losses after harvest at the farm and because of poor roads, inadequate storage technologies, inefficient supply chains and farmers' inability to bring the produce into retail markets dominated by small shopkeepers. Some 10% of total wheat production is lost at farm level, another 10% is lost because of poor storage and road networks, and additional amounts are lost at the retail level.{{cite journal |title=Economic Analysis of Post-harvest Losses in Food Grains in India: A Case Study of Karnataka |author1= Basavaraja, H. |author2=Mahajanashetti, S.B. |author3=Udagatti, N.C. |journal=Agricultural Economics Research Review |volume=20 |pages=117–126 |url=http://ageconsearch.umn.edu/bitstream/47429/2/8.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://ageconsearch.umn.edu/bitstream/47429/2/8.pdf |archive-date=2022-10-09 |url-status=live|year=2007}}

In the Punjab region of the Indian subcontinent, as well as North China, irrigation has been a major contributor to increased grain output. More widely over the last 40 years, a massive increase in fertilizer use together with the increased availability of semi-dwarf varieties in developing countries, has greatly increased yields per hectare.{{cite journal |last1=Godfray |first1=H.C. |last2=Beddington |first2=J. R. |last3=Crute |first3=I. R. |last4=Haddad |first4=L. |last5=Lawrence |first5=D. |last6=Muir |first6=J. F. |last7=Pretty |first7=J. |last8=Robinson |first8=S. |last9=Thomas |first9=S. M. |last10=Toulmin |first10=C. |display-authors=5 |year=2010 |title=Food security: The challenge of feeding 9 billion people |journal=Science |volume=327 |issue=5967 |pages=812–818 |bibcode=2010Sci...327..812G |doi=10.1126/science.1185383 |pmid=20110467 |doi-access=free}} In developing countries, use of (mainly nitrogenous) fertilizer increased 25-fold in this period. However, farming systems rely on much more than fertilizer and breeding to improve productivity. A good illustration of this is Australian wheat growing in the southern winter cropping zone, where, despite low rainfall (300 mm), wheat cropping is successful even with relatively little use of nitrogenous fertilizer. This is achieved by crop rotation with leguminous pastures. The inclusion of a canola crop in the rotations has boosted wheat yields by a further 25%.{{cite web |last=Swaminathan |first=M. S. |date=2004 |url=http://www.cropscience.org.au/icsc2004/plenary/0/2159_swaminathan.htm |archive-url=https://web.archive.org/web/20050618044418/http://cropscience.org.au/icsc2004/plenary/0/2159_swaminathan.htm |url-status=usurped |archive-date=18 June 2005 |title=Stocktake on cropping and crop science for a diverse planet |publisher=Proceedings of the 4th International Crop Science Congress, Brisbane, Australia}} In these low rainfall areas, better use of available soil-water (and better control of soil erosion) is achieved by retaining the stubble after harvesting and by minimizing tillage.{{cite web |url=http://www.grainscouncil.com/EMS/06_Nov_02_Production_Farming_Practices.pdf|title=Umbers, Alan (2006, Grains Council of Australia Limited) Grains Industry trends in Production – Results from Today's Farming Practices |url-status=dead |archive-url=https://web.archive.org/web/20170126000226/http://www.grainscouncil.com/EMS/06_Nov_02_Production_Farming_Practices.pdf |archive-date=26 January 2017}}

File:John Constable, The Wheat Field.jpg|The Wheat Field by John Constable, 1816

Wheat Farm in Behbahan, Iran.jpg|Field ready for harvesting

Unload wheat by the combine Claas Lexion 584.jpg|Combine harvester cuts the wheat stems, threshes the wheat, crushes the chaff and blows it across the field, and loads the grain onto a tractor trailer.

Pests and diseases consume 21.47% of the world's wheat crop annually.{{cite journal |last1=Savary |first1=Serge |last2=Willocquet |first2=Laetitia |last3=Pethybridge |first3=Sarah Jane |last4=Esker |first4=Paul |last5=McRoberts |first5=Neil |last6=Nelson |first6=Andy |title=The global burden of pathogens and pests on major food crops |journal=Nature Ecology & Evolution |publisher=Springer Science and Business Media LLC |volume=3 |issue=3 |date=4 February 2019 |doi=10.1038/s41559-018-0793-y |pages=430–439 |pmid=30718852 |bibcode=2019NatEE...3..430S |s2cid=59603871 |url=https://research.utwente.nl/en/publications/cd23339a-cd2a-4075-b093-e74a05f71d98 }}

{{main|Wheat diseases|List of wheat diseases}}

File:CSIRO ScienceImage 10772 Rustaffected wheat seedlings.jpg

There are many wheat diseases, mainly caused by fungi, bacteria, and viruses.{{Cite web |last=Abhishek |first=Aditya |date=11 January 2021 |title=Disease of Wheat: Get To Know Everything About Wheat Diseases |url=https://agriculturereview.com/2021/01/disease-of-wheat-symptoms-and-management.html |access-date=29 January 2021 |website=Agriculture Review |archive-date=24 January 2021 |archive-url=https://web.archive.org/web/20210124121141/https://agriculturereview.com/2021/01/disease-of-wheat-symptoms-and-management.html |url-status=dead }} Plant breeding to develop new disease-resistant varieties, and sound crop management practices are important for preventing disease. Fungicides, used to prevent the significant crop losses from fungal disease, can be a significant variable cost in wheat production. Estimates of the amount of wheat production lost owing to plant diseases vary between 10 and 25% in Missouri.{{cite web|url=http://muextension.missouri.edu/explore/agguides/crops/g04319.htm |title=G4319 Wheat Diseases in Missouri, MU Extension |publisher= University of Missouri Extension |access-date=18 May 2009 |url-status=dead |archive-url=https://web.archive.org/web/20070227045640/http://muextension.missouri.edu/explore/agguides/crops/g04319.htm |archive-date=27 February 2007 }} A wide range of organisms infect wheat, of which the most important are viruses and fungi.{{cite encyclopedia |last=Hogan |first=C. Michael |chapter=Wheat |year=2013 |url=http://www.eoearth.org/view/article/51cbf3547896bb431f6ac8f3/?topic=51cbfc77f702fc2ba8129ab9 |editor-last=Saundry |editor-first=P. |title=Encyclopedia of Earth |publisher=National Council for Science and the Environment |location=Washington DC}}

The main wheat-disease categories are:

• Seed-borne diseases: these include seed-borne scab, seed-borne Stagonospora (previously known as Septoria), common bunt (stinking smut), and loose smut. These are managed with fungicides.
• Leaf- and head- blight diseases: Powdery mildew, leaf rust, Septoria tritici leaf blotch, Stagonospora (Septoria) nodorum leaf and glume blotch, and Fusarium head scab.{{cite journal |last1=Gautam |first1=P. |last2=Dill-Macky |first2=R. |s2cid=16596348 |year=2012 |title=Impact of moisture, host genetics and Fusarium graminearum isolates on Fusarium head blight development and trichothecene accumulation in spring wheat |journal=Mycotoxin Research |volume=28 |issue=1 |pages=45–58 |doi=10.1007/s12550-011-0115-6 |pmid=23605982 }}
• Crown and root rot diseases: Two of the more important of these are 'take-all' and Cephalosporium stripe. Both of these diseases are soil borne.
• Stem rust diseases: Caused by Puccinia graminis f. sp. tritici (basidiomycete) fungi e.g. Ug99{{Cite book |last=Singh |first=Ravi P. |author2=Hodson, David |author3=Huerta-Espino, Julio |author4=Jin, Yue |author5=Njau, Peter |author6=Wanyera, Ruth |author7=Herrera-Foessel, Sybil |author8=Ward, Richard W. |title=Will Stem Rust Destroy the World's Wheat Crop? |series=Advances in Agronomy |display-authors=5 |year=2008 |volume=98 |pages=272–309 |doi=10.1016/S0065-2113(08)00205-8 |url=https://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=36520&content=PDF |isbn=9780123743558 |access-date=4 October 2023 |archive-date=8 November 2020 |archive-url=https://web.archive.org/web/20201108063602/https://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=36520&content=PDF |url-status=dead }}
• Wheat blast: Caused by Magnaporthe oryzae Triticum.{{ Cite book |date=2020 |edition=1 |publication-place=Boca Raton, Florida |publisher=CRC Press |first3=Gyanendra |first2=Prem |first1=Sudheer |last3=Singh |last2=Kashyap |last1=Kumar |editor-first1=Sudheer |editor-first2=Prem Lal |editor-first3=Gyanendra Pratap |editor-last1=Kumar |editor-last2=Kashyap |editor-last3=Singh |oclc=1150902336 |doi=10.1201/9780429470554 |isbn=978-0-429-47055-4 |title=Wheat Blast |s2cid=235049332 |page=70}}
• Viral diseases: Wheat spindle streak mosaic (yellow mosaic) and barley yellow dwarf are the two most common viral diseases. Control can be achieved by using resistant varieties.{{cite journal |doi=10.3389/fpls.2022.1010191 |doi-access=free |title=Important wheat diseases in the US and their management in the 21st century |date=2023 |last1=Singh |first1=Jagdeep |last2=Chhabra |first2=Bhavit |last3=Raza |first3=Ali |last4=Yang |first4=Seung Hwan |last5=Sandhu |first5=Karansher S. |journal=Frontiers in Plant Science |volume=13 |pmid=36714765 |pmc=9877539 }}

A historically significant disease of cereals including wheat, though commoner in rye is ergot; it is unusual among plant diseases in also causing sickness in humans who ate grain contaminated with the fungus involved, Claviceps purpurea.{{Cite web |last=Harveson |first=Bob |date=2017-08-17 |title=Has Ergot Altered Events in World History? |url=https://cropwatch.unl.edu/2017/has-ergot-altered-events-world-history |website=Cropwatch |publisher=University of Nebraska–Lincoln }}

File:Pupa of Sitophilus granarius (L.) inside a wheat kernel (cropped).jpg of the wheat weevil, Sitophilus granarius, inside a wheat kernel]]

Among insect pests of wheat is the wheat stem sawfly,

a chronic pest in the Northern Great Plains of the United States and in the Canadian Prairies.{{cite journal |last1= Cárcamo |first1= Héctor |last2= Entz |first2= Toby |last3= Beres |first3= Brian |title= Estimating Cephus cinctus wheat stem cutting damage – can we cut stem counts? |journal= Journal of Agricultural and Urban Entomology |year=2007|volume= 24|issue=3 |pages=117–124 |url= http://www.bioone.org/doi/abs/10.3954/1523-5475-24.3.117?journalCode=jaue |doi=10.3954/1523-5475-24.3.117 |s2cid=86001776}}

Wheat is the food plant of the larvae of some Lepidoptera (butterfly and moth) species including the flame, rustic shoulder-knot, setaceous Hebrew character and turnip moth. Early in the season, many species of birds and rodents feed upon wheat crops. These animals can cause significant damage to a crop by digging up and eating newly planted seeds or young plants. They can also damage the crop late in the season by eating the grain from the mature spike. Recent post-harvest losses in cereals amount to billions of dollars per year in the United States alone, and damage to wheat by various borers, beetles and weevils is no exception.[http://www.entomology.wisc.edu/mbcn/fea210.html Biological Control of Stored-Product Pests. Biological Control News Volume II, Number 10 October 1995] {{Webarchive|url=https://web.archive.org/web/20100615060931/http://www.entomology.wisc.edu/mbcn/fea210.html |date=15 June 2010 }}

• [http://www.fao.org/inpho/content/compend/allintro.htm Post-harvest Operations Compendium, FAO.] Rodents can also cause major losses during storage, and in major grain growing regions, field mice numbers can sometimes build up explosively to plague proportions because of the ready availability of food.[http://www.cse.csiro.au/research/rodents/focus.htm CSIRO Rodent Management Research Focus: Mice plagues] {{webarchive|url=https://web.archive.org/web/20100721001101/http://www.cse.csiro.au/research/rodents/focus.htm |date=21 July 2010 }} To reduce the amount of wheat lost to post-harvest pests, Agricultural Research Service scientists have developed an "insect-o-graph", which can detect insects in wheat that are not visible to the naked eye. The device uses electrical signals to detect the insects as the wheat is being milled. The new technology is so precise that it can detect 5–10 infested seeds out of 30,000 good ones.{{cite web |url=http://www.ars.usda.gov/is/pr/2010/100624.htm |title=ARS, Industry Cooperation Yields Device to Detect Insects in Stored Wheat |publisher=USDA Agricultural Research Service |date=24 June 2010}}

{{anchor|Genetics|Breeding}}

In traditional agricultural systems, wheat populations consist of landraces, informal farmer-maintained populations that often maintain high levels of morphological diversity. Although landraces of wheat are no longer extensively grown in Europe and North America, they continue to be important elsewhere. The origins of formal wheat breeding lie in the nineteenth century, when single line varieties were created through selection of seed from a single plant noted to have desired properties. Modern wheat breeding developed in the first years of the twentieth century and was closely linked to the development of Mendelian genetics. The standard method of breeding inbred wheat cultivars is by crossing two lines using hand emasculation, then selfing or inbreeding the progeny. Selections are identified (shown to have the genes responsible for the varietal differences) ten or more generations before release as a variety or cultivar.

Major breeding objectives include high grain yield, good quality, disease- and insect resistance and tolerance to abiotic stresses, including mineral, moisture and heat tolerance.{{cite journal |last1=Sarkar |first1=S. |last2=Islam |first2=A.K.M.Aminul |last3=Barma |first3=N.C.D. |last4=Ahmed |first4=J.U. |title=Tolerance mechanisms for breeding wheat against heat stress: A review |journal=South African Journal of Botany |date=May 2021 |volume=138 |pages=262–277 |doi=10.1016/j.sajb.2021.01.003|doi-access=free }} Wheat has been the subject of mutation breeding, with the use of gamma-, x-rays, ultraviolet light (collectively, radiation breeding), and sometimes harsh chemicals. The varieties of wheat created through these methods are in the hundreds (going as far back as 1960), more of them being created in higher populated countries such as China.{{cite web |url=http://mvgs.iaea.org/ |title=Mutant variety database |website=MVGS International Atomic Energy Agency}} Bread wheat with high grain iron and zinc content has been developed through gamma radiation breeding,{{Cite journal |last1=Verma |first1=Shailender Kumar |last2=Kumar |first2=Satish |last3=Sheikh |first3=Imran |last4=Malik |first4=Sachin |last5=Mathpal |first5=Priyanka |last6=Chugh |first6=Vishal |last7=Kumar |first7=Sundeep |last8=Prasad |first8=Ramasare |last9=Dhaliwal |first9=Harcharan Singh |display-authors=3 |s2cid=10873152 |date=3 March 2016 |title=Transfer of useful variability of high grain iron and zinc from Aegilops kotschyi into wheat through seed irradiation approach |journal=International Journal of Radiation Biology |volume=92 |issue=3 |pages=132–139 |doi=10.3109/09553002.2016.1135263 |pmid=26883304 }} and through conventional selection breeding.{{cite web |last=MacNeil |first=Marcia |title=CIMMYT scientist Ravi Singh receives prestigious award from the Government of India |website=International Maize and Wheat Improvement Center |date=20 January 2021 |url=http://www.cimmyt.org/news/cimmyt-scientist-ravi-singh-receives-prestigious-award-from-the-government-of-india/ |access-date=27 January 2021}} International wheat breeding is led by the International Maize and Wheat Improvement Center in Mexico. ICARDA is another major public sector international wheat breeder, but it was forced to relocate from Syria to Lebanon in the Syrian Civil War.{{cite web |title=Press Release: ICARDA safeguards world heritage of genetic resources during the conflict in Syria |website=International Center for Agricultural Research in the Dry Areas |url=http://www.icarda.org/media/news/press-release-icarda-safeguards-world-heritage-genetic-resources-during-conflict-syria |access-date=27 January 2021}}

Pathogens and wheat are in a constant process of coevolution. Spore-producing wheat rusts are substantially adapted towards successful spore propagation, which is essentially to say its basic reproduction number. These pathogens tend towards high-R{{ Sub |0}} evolutionary attractors.{{ cite journal |year=2022 |publisher=John Wiley & Sons |issue=1 |volume=15 |pages=95–110 |first6=Ramses |first5=Quentin |first4=Sebastien |first3=Arnaud |first2=Jean-Baptiste |first1=Frederic |last6=Demasse |last5=Richard |last4=Lion |last3=Ducrot |last2=Burie |last1=Fabre |journal=Evolutionary Applications |title=An epi-evolutionary model for predicting the adaptation of spore-producing pathogens to quantitative resistance in heterogeneous environments |doi=10.1111/eva.13328 |pmid=35126650 |pmc=8792485|bibcode=2022EvApp..15...95F }}

File:Long-term wheat yields in Europe, OWID.svg

The presence of certain versions of wheat genes has been important for crop yields. Genes for the 'dwarfing' trait, first used by Japanese wheat breeders to produce Norin 10 short-stalked wheat, have had a huge effect on wheat yields worldwide, and were major factors in the success of the Green Revolution in Mexico and Asia, an initiative led by Norman Borlaug.{{Cite journal |last1=Würschum |first1=Tobias |last2=Langer |first2=Simon M. |last3=Longin |first3=C. Friedrich H. |last4=Tucker |first4=Matthew R. |last5=Leiser |first5=Willmar L. |date=2017-09-26 |title=A modern Green Revolution gene for reduced height in wheat |journal=The Plant Journal |volume=92 |issue=5 |pages=892–903 |doi=10.1111/tpj.13726 |pmid=28949040|s2cid=30146700 |doi-access=free }} Dwarfing genes enable the carbon that is fixed in the plant during photosynthesis to be diverted towards seed production, and they also help prevent the problem of lodging.{{Cite journal |last1=Kulshrestha |first1=V. P. |last2=Tsunoda |first2=S. |date=1981-03-01 |title=The role of 'Norin 10' dwarfing genes in photosynthetic and respiratory activity of wheat leaves |url=https://doi.org/10.1007/BF00282421 |journal=Theoretical and Applied Genetics |volume=60 |issue=2 |pages=81–84 |doi=10.1007/BF00282421 |pmid=24276628 |s2cid=22243940}} "Lodging" occurs when an ear stalk falls over in the wind and rots on the ground, and heavy nitrogenous fertilization of wheat makes the grass grow taller and become more susceptible to this problem.{{ Cite book |last1=Milach |first1=S. C. K. |title=Dwarfing genes in plant improvement |date=2001-01-01 |volume=73 |pages=35–63 |publisher=Academic Press |last2=Federizzi |first2=L. C.|series= Advances in Agronomy |doi=10.1016/S0065-2113(01)73004-0 |isbn=9780120007738}} By 1997, 81% of the developing world's wheat area was planted to semi-dwarf wheats, giving both increased yields and better response to nitrogenous fertilizer.{{Cite journal |last1=Lupton |first1=F. G. H.|last2=Oliver |first2=R. H. |last3=Ruckenbauer |first3=P. |date=2009-03-27 |title=An analysis of the factors determining yields in crosses between semi-dwarf and taller wheat varieties|journal=The Journal of Agricultural Science |volume=82 |issue=3 |pages=483–496 |doi=10.1017/S0021859600051388 |s2cid=85738377}}

T. turgidum subsp. polonicum, known for its longer glumes and grains, has been bred into main wheat lines for its grain size effect, and likely has contributed these traits to Triticum petropavlovskyi and the Portuguese landrace group Arrancada.{{cite journal |publisher=Oxford University Press |last1=Adamski |first1=Nikolai M. |last2=Simmonds |first2=James |last3=Brinton |first3=Jemima F. |last4=Backhaus |first4=Anna E. |last5=Chen |first5=Yi |last6=Smedley |first6=Mark |last7=Hayta |first7=Sadiye |last8=Florio |first8=Tobin |last9=Crane |first9=Pamela |last10=Scott |first10=Peter |last11=Pieri |first11=Alice |last12=Hall |first12=Olyvia |last13=Barclay |first13=J Elaine |last14=Clayton |first14=Myles |last15=Doonan |first15=John H. |last16=Nibau |first16=Candida |last17=Uauy |first17=Cristobal |display-authors=3 |title=Ectopic expression of Triticum polonicum VRT-A2 underlies elongated glumes and grains in hexaploid wheat in a dosage-dependent manner |journal=The Plant Cell |date=2021-05-01 |volume=33 |issue=7 |doi=10.1093/plcell/koab119 |pages=2296–2319 |pmid=34009390 |pmc=8364232 |doi-access=free }} As with many plants, MADS-box influences flower development, and more specifically, as with other agricultural Poaceae, influences yield. Despite that importance, {{as of|2021|lc=yes}} little research has been done into MADS-box and other such spikelet and flower genetics in wheat specifically.

The world record wheat yield is about {{convert|17|t/ha|lb/acre|abbr=off|lk=in}}, reached in New Zealand in 2017.{{cite web |url=http://www.guinnessworldrecords.com/world-records/highest-wheat-yield |title=Guinness World Records – Highest Wheat Yield |date=10 August 2022}} A project in the UK, led by Rothamsted Research has aimed to raise wheat yields in the country to {{convert|20|t/ha|lb/acre|abbr=unit}} by 2020, but in 2018 the UK record stood at {{convert|16|t/ha|lb/acre|abbr=unit}}, and the average yield was just {{convert|8|t/ha|lb/acre|abbr=unit}}.{{cite web |url=https://www.fwi.co.uk/arable/crop-management/lincs-grower-scoops-top-wheat-and-rapeseed-yield-awards|author=Farmers Weekly |title=Lincs grower scoops top wheat and rapeseed yield awards |date=23 November 2018}}{{cite web |url=https://cereals.ahdb.org.uk/markets/market-news/2018/september/28/gb-harvest-progress-2018-report-6.aspx |title=Agricultural and Horticultural Development Board – 2018 GB Harvest Progress Results}}

File:Stem rust on differential lines wheat.jpg. The strains bred to be resistant have their leaves unaffected or relatively unaffected by the fungus.]]

Wild grasses in the genus Triticum and related genera, and grasses such as rye have been a source of many disease-resistance traits for cultivated wheat breeding since the 1930s.{{cite journal |last1=Hoisington |first1=D. |last2=Khairallah |first2=M. |last3=Reeves |first3=T. |last4=Ribaut |first4=J.M. |last5=Skovmand |first5=B. |last6=Taba |first6=S. |last7=Warburton |first7=M. |display-authors=3 |year=1999 |title=Plant genetic resources: What can they contribute toward increased crop productivity? |journal=Proceedings of the National Academy of Sciences|volume=96 |issue=11 |pages=5937–43 |pmid=10339521 |doi=10.1073/pnas.96.11.5937 |pmc=34209|bibcode=1999PNAS...96.5937H |doi-access=free }} Some resistance genes have been identified against Pyrenophora tritici-repentis, especially races 1 and 5, those most problematic in Kazakhstan.{{cite web |first1=Madeline |last1=Dahm |title=Genome-wide association study puts tan spot-resistant genes in the spotlight |website=WHEAT |date=27 July 2021 |url=http://wheat.org/genome-wide-association-study-puts-tan-spot-resistant-genes-in-the-spotlight/ |access-date=28 July 2021 |archive-date=22 September 2021 |archive-url=https://web.archive.org/web/20210922142934/https://wheat.org/genome-wide-association-study-puts-tan-spot-resistant-genes-in-the-spotlight/ |url-status=dead }} Wild relative, Aegilops tauschii is the source of several genes effective against TTKSK/Ug99 - Sr33, Sr45, Sr46, and SrTA1662 - of which Sr33 and SrTA1662 are the work of Olson et al., 2013, and Sr45 and Sr46 are also briefly reviewed therein.{{cite journal |last1=Bohra |first1=Abhishek |last2=Kilian |first2=Benjamin |last3=Sivasankar |first3=Shoba |last4=Caccamo |first4=Mario |last5=Mba |first5=Chikelu |last6=McCouch |first6=Susan R. |last7=Varshney |first7=Rajeev K. |title=Reap the crop wild relatives for breeding future crops |journal=Trends in Biotechnology |publisher=Cell Press |year=2021 |volume=40 |issue=4 |doi=10.1016/j.tibtech.2021.08.009 |pages=412–431|pmid=34629170 |s2cid=238580339 |doi-access=free }}

• {{visible anchor|Lr67}} is an R gene, a dominant negative for partial adult resistance discovered and molecularly characterized by Moore et al., 2015. {{As of|2018}} Lr67 is effective against all races of leaf, stripe, and stem rusts, and powdery mildew (Blumeria graminis). This is produced by a mutation of two amino acids in what is predicted to be a hexose transporter. The product then heterodimerizes with the susceptible's product, with the downstream result of reducing glucose uptake.{{cite journal |last1=Kourelis |first1=Jiorgos |last2=van der Hoorn |first2=Renier A.L. |title=Defended to the Nines: 25 Years of Resistance Gene Cloning Identifies Nine Mechanisms for R Protein Function |journal=The Plant Cell |publisher=American Society of Plant Biologists (OUP) |volume=30 |issue=2 |date=2018-01-30 |doi=10.1105/tpc.17.00579 |pages=285–299|pmid=29382771 |pmc=5868693 |bibcode=2018PlanC..30..285K }}
• {{visible anchor|Lr34}} is widely deployed in cultivars due to its abnormally broad effectiveness, conferring resistance against leaf- and stripe-rusts, and powdery mildew.{{cite journal |last1=Dodds |first1=Peter N. |last2=Rathjen |first2=John P. |title=Plant immunity: towards an integrated view of plant–pathogen interactions |journal=Nature Reviews Genetics |publisher=Nature Portfolio |volume=11 |issue=8 |date=2010-06-29 |doi=10.1038/nrg2812 |pages=539–548|pmid=20585331 |hdl=1885/29324 |s2cid=8989912 |hdl-access=free }} An important quantitative resistance gene, Lr34, has been isolated and used intensively in wheat cultivation worldwide; it provides a novel resistance mechanism.{{cite journal |last1=Krattinger |first1=Simon G. |last2=Lagudah |first2=Evans S. |last3=Spielmeyer |first3=Wolfgang |last4=Singh |first4=Ravi P. |last5=Huerta-Espino |first5=Julio |last6=McFadden |first6=Helen |last7=Bossolini |first7=Eligio |last8=Selter |first8=Liselotte L. |last9=Keller |first9=Beat |display-authors=6 |title=A Putative ABC Transporter Confers Durable Resistance to Multiple Fungal Pathogens in Wheat |journal=Science |volume=323 |issue=5919 |date=2009-03-06 |issn=0036-8075 |doi=10.1126/science.1166453 |pages=1360–1363|pmid=19229000 |bibcode=2009Sci...323.1360K }}{{cite journal |last1=Krattinger |first1=Simon G. |last2=Kang |first2=Joohyun |last3=Bräunlich |first3=Stephanie |last4=Boni |first4=Rainer |last5=Chauhan |first5=Harsh |last6=Selter |first6=Liselotte L. |last7=Robinson |first7=Mark D. |last8=Schmid |first8=Marc W. |last9=Wiederhold |first9=Elena |last10=Hensel |first10=Goetz |last11=Kumlehn |first11=Jochen |last12=Sucher |first12=Justine |last13=Martinoia |first13=Enrico |last14=Keller |first14=Beat |display-authors=6 |title=Abscisic acid is a substrate of the ABC transporter encoded by the durable wheat disease resistance gene Lr34 |journal=New Phytologist |volume=223 |issue=2 |date=2019 |issn=0028-646X |pmid=30913300 |pmc=6618152 |doi=10.1111/nph.15815 |pages=853–866|bibcode=2019NewPh.223..853K }} Krattinger et al. 2009 find Lr34 to be an ABC transporter, and conclude that this is the probable reason for its effectiveness{{cite journal |last1=Furbank |first1=Robert T. |last2=Tester |first2=Mark |title=Phenomics – technologies to relieve the phenotyping bottleneck |journal=Trends in Plant Science |publisher=Cell Press |volume=16 |issue=12 |year=2011 |doi=10.1016/j.tplants.2011.09.005 |pages=635–644|pmid=22074787 |bibcode=2011TPS....16..635F }} and the reason that it produces a 'slow rusting'/adult resistance phenotype.
• {{ Visible anchor |Pm8 }} is a widely used powdery mildew resistance introgressed from rye (Secale cereale). It comes from the rye 1R chromosome, a source of many resistances since the 1960s.{{cite journal |pages=1–9 |year=2017 |issue=1 |volume=154 |publisher=BioMed Central |journal=Hereditas |first3=Inger |first2=Larisa |first1=Leonardo |last3=Åhman |last2=Gustavsson |last1=Herrera |doi=10.1186/s41065-017-0033-5 |title=A systematic review of rye (Secale cereale L.) as a source of resistance to pathogens and pests in wheat (Triticum aestivum L.)|pmid=28559761 |pmc=5445327 |doi-access=free }}

{{visible anchor|Fusarium head blight resistance|text=Resistance to Fusarium head blight}} (FHB, Fusarium ear blight) is also an important breeding target. Marker-assisted breeding panels involving kompetitive allele specific PCR can be used. Singh et al. 2019 identify a KASP genetic marker for a pore-forming toxin-like gene providing FHB resistance.{{cite journal |last1=Kaur |first1=Bhavjot |last2=Mavi |first2=G. S. |last3=Gill |first3=Manpartik S. |last4=Saini |first4=Dinesh Kumar |title=Utilization of KASP technology for wheat improvement |journal=Cereal Research Communications |publisher=Springer Science+Business Media |volume=48 |issue=4 |date=2020-07-02 |doi=10.1007/s42976-020-00057-6 |pages=409–421 |s2cid=225570977}}

In 2003 the first resistance genes against fungal diseases in wheat were isolated.{{cite journal |last1=Feuillet |first1=Catherine |last2=Travella |first2=Silvia |last3=Stein |first3=Nils |last4=Albar |first4=Laurence |last5=Nublat |first5=Aurélie |last6=Keller |first6=Beat |title=Map-based isolation of the leaf rust disease resistance gene Lr10 from the hexaploid wheat ( Triticum aestivum L.) genome |journal=Proceedings of the National Academy of Sciences |volume=100 |issue=25 |date=2003-12-09 |issn=0027-8424 |pmid=14645721 |pmc=299976 |doi=10.1073/pnas.2435133100 |pages=15253–15258|doi-access=free |bibcode=2003PNAS..10015253F }}{{cite journal |last1=Yahiaoui |first1=Nabila |last2=Srichumpa |first2=Payorm |last3=Dudler |first3=Robert |last4=Keller |first4=Beat |title=Genome analysis at different ploidy levels allows cloning of the powdery mildew resistance gene Pm3b from hexaploid wheat |journal=The Plant Journal |volume=37 |issue=4 |date=2004 |issn=0960-7412 |doi=10.1046/j.1365-313X.2003.01977.x |pages=528–538|pmid=14756761 }} In 2021, novel resistance genes were identified in wheat against powdery mildew and wheat leaf rust.{{cite journal |last1=Sánchez-Martín |first1=Javier |last2=Widrig |first2=Victoria |last3=Herren |first3=Gerhard |last4=Wicker |first4=Thomas |last5=Zbinden |first5=Helen |last6=Gronnier |first6=Julien |last7=Spörri |first7=Laurin |last8=Praz |first8=Coraline R. |last9=Heuberger |first9=Matthias |last10=Kolodziej |first10=Markus C. |last11=Isaksson |first11=Jonatan |last12=Steuernagel |first12=Burkhard |last13=Karafiátová |first13=Miroslava |last14=Doležel |first14=Jaroslav |last15=Zipfel |first15=Cyril |last16=Keller |first16=Beat |display-authors=6 |title=Wheat Pm4 resistance to powdery mildew is controlled by alternative splice variants encoding chimeric proteins |journal=Nature Plants |volume=7 |issue=3 |date=2021-03-11 |issn=2055-0278 |pmid=33707738 |pmc=7610370 |doi=10.1038/s41477-021-00869-2 |pages=327–341|bibcode=2021NatPl...7..327S }}{{cite journal |last1=Kolodziej |first1=Markus C. |last2=Singla |first2=Jyoti |last3=Sánchez-Martín |first3=Javier |last4=Zbinden |first4=Helen |last5=Šimková |first5=Hana |last6=Karafiátová |first6=Miroslava |last7=Doležel |first7=Jaroslav |last8=Gronnier |first8=Julien |last9=Poretti |first9=Manuel |last10=Glauser |first10=Gaétan |last11=Zhu |first11=Wangsheng |last12=Köster |first12=Philipp |last13=Zipfel |first13=Cyril |last14=Wicker |first14=Thomas |last15=Krattinger |first15=Simon G. |last16=Keller |first16=Beat |display-authors=6 |title=A membrane-bound ankyrin repeat protein confers race-specific leaf rust disease resistance in wheat |journal=Nature Communications |volume=12 |issue=1 |date=2021-02-11 |page=956 |issn=2041-1723 |pmid=33574268 |pmc=7878491 |doi=10.1038/s41467-020-20777-x|bibcode=2021NatCo..12..956K }}

Modified resistance genes have been tested in transgenic wheat and barley plants.{{Cite journal |last1=Koller |first1=Teresa |last2=Camenzind |first2=Marcela |last3=Jung |first3=Esther |last4=Brunner |first4=Susanne |last5=Herren |first5=Gerhard |last6=Armbruster |first6=Cygni |last7=Keller |first7=Beat |display-authors=6 |date=2023-12-10 |title=Pyramiding of transgenic immune receptors from primary and tertiary wheat gene pools improves powdery mildew resistance in the field |journal=Journal of Experimental Botany |volume=75 |issue=7 |pages=1872–1886 |doi=10.1093/jxb/erad493 |issn=0022-0957 |doi-access=free|pmid=38071644 |pmc=10967238 }}

Because wheat self-pollinates, creating hybrid seed to provide the possible benefits of heterosis, hybrid vigor (as in the familiar F1 hybrids of maize), is extremely labor-intensive; the high cost of hybrid wheat seed relative to its moderate benefits have kept farmers from adopting them widelyMike Abram for Farmers' Weekly. 17 May 2011. [http://www.fwi.co.uk/articles/17/05/2011/126829/hybrid-wheat-to-make-a-return.htm Hybrid wheat to make a return]Bill Spiegel for agriculture.com 11 March 2013 [http://www.agriculture.com/crops/wheat/technology/hybrid-wheats-comeback_147-ar30398 Hybrid wheat's comeback] despite nearly 90 years of effort.{{cite web|url=http://www.hybridwheat.net/anglais/growing-hybrid-wheat-in-europe/history-of-hybrid-wheat/history-of-hybrid-wheat-627.aspx|title=The Hybrid wheat website|date=18 December 2013|url-status=dead|archive-url=https://web.archive.org/web/20131218051925/http://www.hybridwheat.net/anglais/growing-hybrid-wheat-in-europe/history-of-hybrid-wheat/history-of-hybrid-wheat-627.aspx|archive-date=18 December 2013}}Bajaj, Y.P.S. (1990) Wheat. Springer Science+Business Media. pp. 161–163. {{ISBN|3-540-51809-6}}. Commercial hybrid wheat seed has been produced using chemical hybridizing agents, plant growth regulators that selectively interfere with pollen development, or naturally occurring cytoplasmic male sterility systems. Hybrid wheat has been a limited commercial success in Europe (particularly France), the United States and South Africa.Basra, Amarjit S. (1999) Heterosis and Hybrid Seed Production in Agronomic Crops. Haworth Press. pp. 81–82. {{ISBN|1-56022-876-8}}.

Synthetic hexaploids made by crossing the wild goatgrass wheat ancestor Aegilops tauschii,{{Cite journal |last1=Aberkane |first1=Hafid |last2=Payne |first2=Thomas |last3=Kishi |first3=Masahiro |last4=Smale |first4=Melinda |last5=Amri|first5=Ahmed |last6=Jamora |first6=Nelissa |date=1 October 2020 |title=Transferring diversity of goat grass to farmers' fields through the development of synthetic hexaploid wheat |journal=Food Security |volume=12|issue=5 |pages=1017–1033 |doi=10.1007/s12571-020-01051-w |s2cid=219730099 |doi-access=free }} and other Aegilops,{{cite journal |last=Kishii |first=Masahiro |title=An Update of Recent Use of Aegilops Species in Wheat Breeding |journal=Frontiers in Plant Science |publisher=Frontiers Media SA |volume=10 |date=9 May 2019 |page=585 |doi=10.3389/fpls.2019.00585 |pmid=31143197 |pmc=6521781 |doi-access=free }} and various durum wheats are now being deployed, and these increase the genetic diversity of cultivated wheats.(12 May 2013) [https://www.bbc.co.uk/news/uk-22498274 Cambridge-based scientists develop 'superwheat'] BBC News UK, Retrieved 25 May 2013[http://www.k-state.edu/wgrc/Germplasm/synthetics.html Synthetic hexaploids] {{webarchive|url=https://web.archive.org/web/20111128114349/http://www.k-state.edu/wgrc/Germplasm/synthetics.html |date=28 November 2011 }}(2013) [http://www.niab.com/uploads/files/NIAB_Synthetic_Hexaploid_Wheat.pdf Synthetic hexaploid wheat] {{webarchive|url=https://web.archive.org/web/20140416183627/http://www.niab.com/uploads/files/NIAB_Synthetic_Hexaploid_Wheat.pdf |date=16 April 2014 }} UK National Institute of Agricultural Botany, Retrieved 25 May 2013

Modern bread wheat varieties have been cross-bred to contain greater amounts of gluten,{{Cite journal|last=Belderok|first=B.|s2cid=46259398|date=1 January 2000|title=Developments in bread-making processes |journal=Plant Foods for Human Nutrition |location=Dordrecht, Netherlands|volume=55 |issue=1|pages=1–86 |pmid=10823487 |doi=10.1023/A:1008199314267}} which affords significant advantages for improving the quality of breads and pastas from a functional point of view.{{cite journal|pmid=22224557|year=2012 |last1=Delcour |first1=J. A. |title=Wheat gluten functionality as a quality determinant in cereal-based food products|journal=Annual Review of Food Science and Technology |volume=3 |pages=469–492 |last2=Joye |first2=I. J. |last3=Pareyt |first3=B. |last4=Wilderjans |first4=E. |last5=Brijs |first5=K. |last6=Lagrain |first6=B. |doi=10.1146/annurev-food-022811-101303 |url=https://www.researchgate.net/publication/221728752}}{{open access}} However, a 2020 study that grew and analyzed 60 wheat cultivars from between 1891 and 2010 found no changes in albumin/globulin and gluten contents over time. "Overall, the harvest year had a more significant effect on protein composition than the cultivar. At the protein level, we found no evidence to support an increased immunostimulatory potential of modern winter wheat."{{cite journal |last1=Pronin |first1=Darina |last2=Borner |first2=Andreas |last3=Weber |first3=Hans |last4=Scherf |first4=Ann |title=Wheat (Triticum aestivum L.) Breeding from 1891 to 2010 Contributed to Increasing Yield and Glutenin Contents but Decreasing Protein and Gliadin Contents |journal=Journal of Agricultural and Food Chemistry |date=10 July 2020 |volume=68 |issue=46 |pages=13247–13256 |doi=10.1021/acs.jafc.0c02815 |pmid=32648759 |bibcode=2020JAFC...6813247P |s2cid=220469138 }}

Stomata (or leaf pores) are involved in both uptake of carbon dioxide gas from the atmosphere and water vapor losses from the leaf due to water transpiration. Basic physiological investigation of these gas exchange processes has yielded carbon isotope based method used for breeding wheat varieties with improved water-use efficiency. These varieties can improve crop productivity in rain-fed dry-land wheat farms.{{cite journal |last1=Condon |first1=AG |year=1990 |title=Genotypic variation in carbon isotope discrimination and transpiration efficiency in wheat. Leaf gas exchange and whole plant studies |journal =Australian Journal of Plant Physiology |volume=17 |pages=9–22 |doi=10.1071/PP9900009 |last2=Farquhar |first2=GD |last3=Richards |first3=RA |citeseerx=10.1.1.691.4942 }}

The complex genome of wheat has made its improvement difficult. Comparison of hexaploid wheat genomes using a range of chromosome pseudomolecule and molecular scaffold assemblies in 2020 has enabled the resistance potential of its genes to be assessed. Findings include the identification of "a detailed multi-genome-derived nucleotide-binding leucine-rich repeat protein repertoire" which contributes to disease resistance, while the gene Sm1 provides a degree of insect resistance,{{cite journal |last1=Walkowiak |first1=Sean |last2=Gao |first2=Liangliang |last3=Monat |first3=Cecile |last4=Haberer |first4=Georg |last5=Kassa |first5=Mulualem T. |last6=Brinton |first6=Jemima |last7=Ramirez-Gonzalez |first7=Ricardo H. |last8=Kolodziej |first8=Markus C. |last9=Delorean |first9=Emily |last10=Thambugala |first10=Dinushika |last11=Klymiuk |first11=Valentyna |last12=Byrns |first12=Brook |display-authors=5 |title=Multiple wheat genomes reveal global variation in modern breeding |journal=Nature |publisher=Nature Research/Springer Nature |volume=588 |issue=7837 |date=25 November 2020 |doi=10.1038/s41586-020-2961-x |pages=277–283 |pmid=33239791 |pmc=7759465 |bibcode=2020Natur.588..277W |doi-access=free }} for instance against the orange wheat blossom midge.{{cite journal |last1=Kassa |first1=Mulualem T. |last2=Haas |first2=Sabrina |last3=Schliephake |first3=Edgar |last4=Lewis |first4=Clare |last5=You |first5=Frank M. |last6=Pozniak |first6=Curtis J. |last7=Krämer |first7=Ilona |last8=Perovic |first8=Dragan |last9=Sharpe |first9=Andrew G. |last10=Fobert |first10=Pierre R. |last11=Koch |first11=Michael |last12=Wise |first12=Ian L. |display-authors=5 |title=A saturated SNP linkage map for the orange wheat blossom midge resistance gene Sm1 |journal=Theoretical and Applied Genetics |publisher=Springer Science+Business Media |volume=129 |issue=8 |date=9 May 2016 |doi=10.1007/s00122-016-2720-4 |pages=1507–1517 |pmid=27160855 |s2cid=14168477 }}

In 2010, 95% of the genome of Chinese Spring line 42 wheat was decoded.{{cite web|publisher= Biotechnology and Biological Sciences Research Council|url=http://www.bbsrc.ac.uk/news/food-security/2010/100827-pr-uk-researchers-release-draft-wheat-genome.aspx|title= UK researchers release draft sequence coverage of wheat genome |date=27 August 2010|archive-url=https://web.archive.org/web/20110611082525/http://www.bbsrc.ac.uk/news/food-security/2010/100827-pr-uk-researchers-release-draft-wheat-genome.aspx|archive-date=11 June 2011 }} This genome was released in a basic format for scientists and plant breeders to use but was not fully annotated.{{Cite web |url=http://www.bbsrc.ac.uk/web/FILES/Publications/1102_wheat_genome_case_study.pdf |title=UK scientists publish draft sequence coverage of wheat genome|publisher= Biotechnology and Biological Sciences Research Council |access-date=15 July 2011 |archive-date=15 July 2011 |archive-url=http://webarchive.nationalarchives.gov.uk/20110715204254/http://www.bbsrc.ac.uk/web/FILES/Publications/1102_wheat_genome_case_study.pdf |url-status=live }} In 2012, an essentially complete gene set of bread wheat was published.{{cite journal |last=Hall |title=Analysis of the bread wheat genome using whole-genome shotgun sequencing|journal=Nature|volume=491 |issue=7426 |doi=10.1038/nature11650 |pmid=23192148 |year=2012 |pages=705–10|pmc=3510651 |bibcode=2012Natur.491..705B }} Random shotgun libraries of total DNA and cDNA from the T. aestivum cv. Chinese Spring (CS42) were sequenced to generate 85 Gb of sequence (220 million reads) and identified between 94,000 and 96,000 genes. In 2018, a more complete Chinese Spring genome was released by a different team.{{cite web |title=U of S crop scientists help crack the wheat genome code |publisher=University of Saskatchewan, Canada |date=16 August 2018 |url=https://news.usask.ca/articles/research/2018/u-of-s-crop-scientists-help-crack-the-wheat-genome-code-.php |access-date=22 December 2020}} In 2020, 15 genome sequences from various locations and varieties around the world were reported, with examples of their own use of the sequences to localize particular insect and disease resistance factors.{{cite web |title=Landmark study generates first genomic atlas for global wheat improvement |publisher=University of Saskatchewan |date=25 November 2020 |url=http://news.usask.ca/articles/research/2020/landmark-study-generates-first-genomic-atlas-for-global-wheat-improvement.php |access-date=22 December 2020}} {{Visible anchor|Wheat Blast Resistance}} is controlled by R genes which are highly race-specific.

For decades, the primary genetic modification technique has been non-homologous end joining (NHEJ). However, since its introduction, the CRISPR/Cas9 tool has been extensively adopted, for example:

• To intentionally damage three homologs of TaNP1 (a glucose-methanol-choline oxidoreductase gene) to produce a novel male sterility trait, by Li et al. 2020{{cite journal |last1=Li |first1=Shaoya |last2=Zhang |first2=Chen |last3=Li |first3=Jingying |last4=Yan |first4=Lei |last5=Wang |first5=Ning |last6=Xia |first6=Lanqin |title=Present and future prospects for wheat improvement through genome editing and advanced technologies |journal=Plant Communications |publisher=Chinese Academy of Sciences, Center for Excellence in Molecular Plant Sciences and Chinese Society for Plant Biology (Cell Press) |volume=2 |issue=4 |year=2021 |doi=10.1016/j.xplc.2021.100211 |page=100211 |pmid=34327324 |pmc=8299080 |bibcode=2021PlCom...200211L }}
• Blumeria graminis f.sp. tritici resistance has been produced by Shan et al. 2013 and Wang et al. 2014 by editing one of the mildew resistance locus o genes (more specifically one of the Triticum aestivum MLO (TaMLO) genes)
• Triticum aestivum EDR1 (TaEDR1) (the EDR1 gene, which inhibits Bmt resistance) has been knocked out by Zhang et al. 2017 to improve that resistance
• Triticum aestivum HRC (TaHRC) has been disabled by Su et al. 2019 thus producing Gibberella zeae resistance.
• Triticum aestivum Ms1 (TaMs1) has been knocked out by Okada et al. 2019 to produce another novel male sterility
• and Triticum aestivum acetolactate synthase (TaALS) and Triticum aestivum acetyl-CoA-carboxylase (TaACC) were subjected to base changes by Zhang et al. 2019 (in two publications) to confer herbicide resistance to ALS inhibitors and ACCase inhibitors respectively

{{As of|2021}} these examples illustrate the rapid deployment and results that CRISPR/Cas9 has shown in wheat disease resistance improvement.

File:Vincent Van Gogh - Wheatfield with Crows.jpg, an 1890 painting by Vincent van Gogh. Van Gogh Museum, Amsterdam ]]

The Dutch artist Vincent van Gogh created the series Wheat Fields between 1885 and 1890, consisting of dozens of paintings made mostly in different parts of rural France. They depict wheat crops, sometimes with farm workers, in varied seasons and styles, sometimes green, sometimes at harvest. Wheatfield with Crows was one of his last paintings, and is considered to be among his greatest works.{{cite book |title=Cézanne to Picasso: Ambroise Vollard, Patron of the Avant-garde |page=11 |publisher=Metropolitan Museum of Art |date=2006 |isbn=1588391957 |url=https://books.google.com/books?id=B6JTCCBSZuoC&pg=PA11}}{{cite book |last=McKenna |first=Tony |title=Art, Literature and Culture from a Marxist Perspective |publisher=Springer |date=2015 |isbn=978-1137526618 |url=https://books.google.com/books?id=cqWFCwAAQBAJ&pg=PT101 |at=PT101}}

In 1967, the American artist Thomas Hart Benton made his oil on wood painting Wheat, showing a row of uncut wheat plants, occupying almost the whole height of the painting, between rows of freshly-cut stubble. The painting is held by the Smithsonian American Art Museum.{{cite web |title=Wheat |url=https://americanart.si.edu/artwork/wheat-32285 |publisher=Smithsonian Institution |access-date=28 January 2024}}

In 1982, the American conceptual artist Agnes Denes grew a two-acre field of wheat at Battery Park, Manhattan. The ephemeral artwork has been described as an act of protest. The harvested wheat was divided and sent to 28 world cities for an exhibition entitled "The International Art Show for the End of World Hunger".{{cite news |last=Hessel |first=Katy |title=A field of wheat on a $4.5bn patch of New York: the prophetic eco art of Agnes Denes |url=https://www.theguardian.com/artanddesign/2022/jul/18/a-field-of-wheat-on-a-45bn-patch-of-new-york-the-prophetic-eco-art-of-agnes-denes |access-date=28 January 2024 |work=The Guardian |date=18 July 2022}}

{{col div|colwidth=25em}}

• Effects of climate change on agriculture
• Gluten-free diet
• Peak wheat
• Intermediate wheatgrass: a perennial alternative to wheat
• Wheat germ oil
• Wheat production in the United States
• Wheat middlings
• Whole-wheat flour

{{col div end}}

{{reflist|30em}}

• {{cite book |last=Khan |first=K. |chapter=Wheat Classes − Producing Nations |chapter-url=https://books.google.com/books?id=Cc1XDAAAQBAJ&pg=PA109 |title=Wheat: Chemistry and Technology |publisher=Elsevier Science |series=American Association of Cereal Chemists International |year=2016 |isbn=978-0-12-810454-5}}

• The World Wheat Book : A History of Wheat Breeding

:* {{ Cite book |volume=1 |date=2001 |publication-place=London |publisher=Lavoisier |last1=Bonjean |first1=Alain P. |last2=Angus |first2=William J. |isbn=9781898298724 |oclc=59515318 |title=The World Wheat Book : A History of Wheat Breeding |ref=none}}

:* {{ Cite book |volume=2 |date=2011 |publication-place=Paris |publisher=Lavoisier |last1=Bonjean |first1=Alain P. |isbn=978-2-7430-1102-4 |oclc=707171112 |title=The World Wheat Book : A History of Wheat Breeding |ref=none}}

:* {{ Cite book |date=2016 |volume=3 |publication-place=Paris |publisher=Lavoisier-Tec & doc |last1=Bonjean |first1=Alain P. |last2=Angus |first2=William J. |last3=Ginkel |first3=Maarten van |isbn=978-2-7430-2091-0 |oclc=953081390 |title=The World Wheat Book : A History of Wheat Breeding |ref=none}}

• {{ Cite book |date=2016 |publication-place=London |publisher=Ashgate Publishing |first3=Alison |first2=Jennifer |first1=Lesley |last3=Gates |last2=Atchison |last1=Head |isbn=978-1-315-58854-4 |oclc=1082225627 |title=Ingrained: A Human Bio-geography of Wheat |ref=none}}
• Jasny Naum, The Wheats of Classical Antiquity. Johns Hopkins University Press, Baltimore, 1944. {{ S2CID |82345748}}.
• Nelson, Scott Reynolds (2022). Oceans of Grain: How American Wheat Remade the World. [https://www.amazon.com/dp/1541646460/ Excerpt].
• {{cite journal |last1=Shiferaw |first1=Bekele |last2=Smale |first2=Melinda |last3=Braun |first3=Hans-Joachim |last4=Duveiller |first4=Etienne |last5=Reynolds |first5=Mathew |last6=Muricho |first6=Geoffrey |title=Crops that feed the world 10. Past successes and future challenges to the role played by wheat in global food security |journal=Food Security |volume=5 |issue=3 |date=2013 |doi=10.1007/s12571-013-0263-y |pages=291–317 |doi-access=free |ref=none}}

• {{Commons-inline|Wheat}}
• [http://www.hort.purdue.edu/newcrop/crops/wheat.html Triticum species] at Purdue University (1971)

{{Wheat}}

{{Cereals}}

{{Bioenergy}}

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Wheat

Category:Crops

Category:Energy crops

Category:Poaceae genera

Category:Staple foods

Category:Taxa named by Carl Linnaeus