hulled wheat
What is hulled wheat?

Most people are very familiar with bread and durum (AKA pasta) wheats, but not quite as familiar with hulled wheats. 

Bread and durum wheats may be called ‘naked’ or ‘free-threshing’ which means that the seeds separate cleanly from the chaff during the threshing process.  Hulled wheats, on the other hand, have a hull (or husk) that adheres tightly to the seed and is difficult to remove from the seed.  Hulled wheat retains all parts of the seed, including the hull, which is comprised of rachis segments, glumes, the paleae and the lemmae.  Removing the hull requires extra processing.

Hulled wheats are used for both human consumption and animal feed.

Einkorn, emmer and spelt are hulled wheats.

einkorn and emmer wheats

For in-depth information please see companion fact sheet.

Why grow hulled wheats?

  • Hulled wheats offer the grower another crop to incorporate into their rotations or diversification efforts.
  • Hulled wheats often do very well under poor soil conditions and are tolerant to a range of fungal diseases.  Therefore, they may be well suited for land that naked wheats do not thrive on.
  • Hulled wheats were once widely grown on a global scale, but suffered a decline when high yielding bread and durum wheats rose to prominence in the world markets.  However, niche markets for hulled wheats have always existed.
  • Increased interest by consumers for variety, novel breads and food products, and more healthy food options have led to new research on hulled wheats. Hulled wheats can be used to make bread (both leavened and unleavened), porridge, gruel, cereal, soup, cracked wheat and beer.
  • Despite some reports to the contrary, hulled wheats contain gluten and are not suitable for consumption by those suffering from celiac disease or those wanting low-gluten or gluten free products.

comparison

Comparison of emmer, spelt and einkorn heads to those of bread wheat (BW) and durum.

General agronomic practises for hulled wheat versus conventional wheat

Seeding:

All hulled wheats

Hulled wheat varieties tend to be later maturing, similar to durum wheat, and should be sown earlier in the seeding cycle. If the hulled form is used for seeding, the intact spikelets need to be polished to remove awns and awnlets in order prevent bridging. The presence of hulls delays crop emergence by one day relative to naked seed without significantly affecting plant stands. Hull removal tends to reduce seed germination. A germination test followed by seeding rate adjustments are recommended.

Spelt

There are both spring and winter spelts.

Spring spelt is generally seeded the same way as spring wheats.  Spelt is able to grow in poorly-drained, low fertility, soils. Because the hulls are attached to the seed, germination is slower than for wheat. Grain drills should use the setting for oats. Aim for a plant stand similar to that of spring wheat. Plant at least 3 cm (1¼ inches) deep. Spelt can grow in a range of soil pH’s from 6.0 to 7.5.  Fertilizer application is similar to that of spring wheat. However, as with winter spelt (Northern Grain Growers 2011), over fertilization of spring spelt with nitrogen can result in increased stem elongation which may increase the chance of lodging. 

Maturity:

Spelt

 CDC Nexon typically matured 1 week after Katepwa (Ehsanzadeh 1999) in test plots in Saskatoon (U of S Field lab).  Results from early seeding are variable due to the unpredictability of the growing conditions in Western Canada (Hucl 1995). It produces lower yields when seeded late compared to wheat (Ehsanzadeh 1999). Because it is later maturing, in Saskatchewan spelt needs to be seeded late April to mid-May, approximately 2 weeks earlier than CWRS wheat (Ehsanzadeh 1999).

Insects and diseases:

Hulled wheat species are attacked by the same insects and diseases as conventional wheat.

Einkorn appears to be highly resistant to leaf, stem and stripe rust. Current spelt varieties are all susceptible to stem rust and leaf rust but resistant to stripe rust and common bunt. All three species of cultivated hulled wheat have hollow stems. Spelt wheat is less prone to ergot infection than most spring wheat types while einkorn appears to be more susceptible.

Harvest and storage:

The threshed product of einkorn and emmer wheat will be mostly hulled as these two crops have very tight hulls. Current spring spelt varieties vary in threshability. Threshability varies with growing and harvest conditions but rarely exceeds 50% for spring spelt. Hulled wheat will have a tendency to bridge during grain handling and storage.

Spelt can be either direct-combined or windrowed and threshed.  The combine should be set at a slower cylinder speed to avoid excessive seed cracking. Drying and storage requirements are similar to those of wheat. Unlike wheat however, the tough hull remains on the spelt kernel through harvest, shipping, and storage. Seed that is intended for animal feed must be ground or milled prior to use. Spelt processed for human consumption is mechanically de-hulled just prior to milling. This additional step makes spelt more difficult and expensive to process than wheat (2012 Kentucky Newsletter).

Spelt yields are presented as the seed with the hull attached.

Einkorn

einkorn

Emmer

emmer

 

Spelt

spelt

References:

Ehsandzadeh, Parviz 1998.  Agronomic and growth characteristics of spring spelt compared to common wheat.  Ph.D. Thesis.  University of Saskatchewan.

Hucl, P. 1995. Growth responses of four hard red spring wheat cultivars to date of seeding. Can. Plant Sci. 75:75-80.

Kentucky Extension Newsletter 2012.  https://www.uky.edu/Ag/CCD/introsheets/spelt.pdf

Northern Grain Growers, 2011. http://northerngraingrowers.org/wp-content/uploads/SPELT.pdf

drawing

 

 

intro

Introduction

What is hulled wheat?

There are many different species of wheat (Triticum spp.).  We are most familiar with bread wheat and durum (or macaroni) wheat.  Both these wheats are ‘naked’ or ‘free-threshing’ meaning that the seeds cleanly separate out from the chaff during threshing.  However, other species of wheat have a hull (or husk) that will adhere tightly to the seed making removal difficult.  Hulled wheat is therefore defined as wheat seed that retains all parts of the seed, including the hull (rachis segments, glumes, paleae and lemmae (Figure 1).

seed

Figure 1. Wheat seed anatomy.  N. A. Mohr 2018.

Hulled wheats also have a brittle rachis.  The brittle rachis of wild wheats have spikelets that readily disarticulate (come apart) when the plant is mature, aiding in seed dispersal, but hindering harvest.  Cultivated hulled wheat lines have a less brittle rachis which will remain intact until threshing, barring a wind storm resulting in spike shattering. If a hulled wheat spike shatters, the top 2/3 will break off causing significant yield losses.

However, the main characteristic that distinguishes a hulled wheat from a free-threshing wheat is the persistent enclosing hull. When bread, or durum, wheat is threshed, the rachis segments stay attached to each other and the glumes and other chaff break, releasing a free grain kernel.  When hulled wheat is threshed, it breaks up into component spikelets.  Each spikelet consists of glumes attached to a rachis segment and encloses one or more grains. In hulled wheat, the semi-brittle joints are between the rachis internodes and the toughened glumes which has major implications for processing. However, this hull also has other important characteristics. These thick, tough glumes provide protection to the grains in the field and in storage.  Hulled wheats often do very well under poor soil conditions and are tolerant to a range of fungal diseases (Nesbitt and Samuel 1995).

Due to lower yields and the difficulties in processing, hulled wheats saw a continued decline in global production from the early 1900s.  However, recent renewed interest in novel breads and food products has led to new research of hulled wheats and they retain a place in niche markets. 

The most commonly grown hulled wheats are einkorn, emmer and spelt (Figure 2).  In Europe, hulled wheats are often called farro. Specifically, einkorn is known as farro piccolo, emmer as farro medio and spelt as farro grande.

wheat heads
Figure 2.
Emmer, spelt and einkorn heads, 2017.

Recent history suggests that their uses are limited (in part reflected in the decreased in world production), however, the ethnographic and archaeological evidence points to an enormous historical range of uses including; bread (leavened and unleavened), porridge, gruel, soup, cracked wheat and beer (Nesbitt and Samuel 1995).   Other, newer processes are also being explored with hulled wheats, such as puffing (Hildago et al. 2016).

Renewed interest in promoting ‘novel’ foods and diversification of foods for health and nutrition (ex. biofortification) also drives current research into these ancient grains (Longin and Würschum 2016, Sharma et al. 2017).    Numerous recent newspaper articles, and a plethora of cooking and baking recipes attest to this growing consumer interest. Products made from hulled grains are often more expensive to produce, in part due to lower overall yields than modern wheat cultivars, however for the niche markets, such as artisanal baking, that are currently being developed the higher price is not a barrier to sales.

It is important to note that despite some reports, hulled wheats all contain gluten and are not suitable for the estimated 1% of the population suffering from celiac disease (Jnawali et al. 2016, Scherf et al. 2016).  Attempts to develop celiac-friendly wheats has not yet materialized (Shewry and Tatum 2016). Hulled wheats have been said to reduce IBS (irritable bowel syndrome) symptoms (affecting approximately 12% of Western population), although this may also be due to differences in baking processes (Zeigler et al. 2016).

Products made from ancient grains may also be friendlier for those suffering from Type II diabetes due to a downregulation of key regulatory genes in the liver (Thorup et al. 2014/2015). However, much more research is needed before definitive benefits of hulled wheats can be ascribed, and some research suggests that there is very little difference between ancient and modern grains altogether (Shewry and Hey 2015).

Background

How do hulled wheat cultivars differ from regular wheat cultivars?

Common wheat and durum were ‘cultivated’ during the Agricultural revolution some 10,000 years ago.  Bread wheat currently makes up 95% of global production (Feldman and Levy 2015).  The remainder of wheat production is comprised of durum, hulled wheats and a few other wheats such as Khorasan (similar to durum) (Figure 3).

Historically, farmers would have grown mixed (polymorphic) fields of wheat which had a highly variable genetic component.  Safety, in the form of a guaranteed harvest, was a key concern, rather than purely high yield.  A mixed field allowed for genetic variation and, catastrophes notwithstanding, farmers could count on at least some harvest at the end of each field season. Mixed fields also had high genetic diversity and natural hybridization was possible.  Different farmers, in different areas, would apply different selection pressures, depending on their needs which in turn led to the development of different landraces (Feldman and Levy 2015). 

Modern, planned scientific, breeding practices began at the end of the 19th century and have eroded this genetic variation in domesticated wheat by replacing the many landraces with a smaller number of high-yielding mega-varieties.  Fields of wheat are uniform and no longer conducive to spontaneous gene exchange.  The goal of the modern breeding practices was a high yield with the main limiting factor being water.  The second goal was to improve milling and baking qualities.  Less effort has been expended to improve nutritional value, such as increasing protein content and to remedy deficiencies in important constituents such as amino acids (Feldman and Levy 2015).

Hulled wheats have not been subject to intense modern breeding practices as have bread and durum wheats.  Landraces still exhibit large genetic variation. This large variation equates with poor and sometimes unpredictable yields contrary to what is expected from modern wheat cultivars.

compare
Figure 3.
Comparison of emmer, spelt and einkorn heads to those of bread wheat (BW) and durum, 2017.

Genetics

The genetics of wheat is complicated, but it helps to have a basic understanding to fully appreciate issues related to the genetics of the various wheat types.

As a point of reference, humans have a diploid chromosome compliment.  Each parent provides 23 chromosomes to their offspring, for a total of 46 chromosomes (n=23).  Therefore, humans are diploid and have one genome (or genetic compliment). 

The use of capital letters indicates an independent set of two genomes (Abdel-Aal et al., 1998), with the different letters indicating different genomes, or ploidy (Figure 4).

Einkorn is diploid (or AA) with n=7, or 14 chromosomes in total.

Emmer (and durum wheat) are tetraploid (AABB) with n=14, or 28 chromosomes in total.

In comparison, spelt (and bread wheat) have 3 distinct genomes (A, B and D) of 7 chromosomes, for a total of 42 chromosomes (n=21).  Wheat is therefore hexaploid (AABBDD).  This allopolyploidy (having more than two sets of haploid chromosomes, that are both different and derived from different species) has intrigued researchers for decades.

The A genome is derived from einkorn Triticum monococcum (or wild red einkorn T. urartu).

The B genome may be derived from the wild Aegilops speltoides (either an extinct, or a yet to be discovered extant species).

The D genome is derived from wild goat grass Aegilops tauschii.

Due to the complicated genetic make up of wheat, it has been hard to classify to the satisfaction of any one school of thought and therefore remains in flux.

chart
Figure 4.
Chart of basic wheat genetics.

Nutrition

Wheat has been part of the human diet for some 10,000 years and humans have consequently adapted to the consumption of wheat.  Wheat provides important nutritional components such as protein, vitamins and minerals. Wheat has also come under recent scrutiny by the public and has been linked to various gastrointestinal disorders. Hulled wheats have a slightly different nutritional composition compared to bread and durum wheats.  This difference has captured the interest of both the public and the research sector.

Gluten

All wheats contain gluten and these wheats include bread wheat, durum, einkorn, emmer, spelt, Khorasan, and triticale in addition to barley, rye and oats.

Gluten, which is derived from the Latin word for “glue”, has viscoelastic properties which give dough the elasticity it needs to be manipulated and formed into loaves.  Gluten also helps dough rise and provides for the chewy texture we appreciate in our bread products.  This texture is important.  Consumers will not purchase products that do not ‘feel’ right.

Gluten, together with starch, is found in the endosperm.  Gluten is a plant storage protein.  Storage proteins are the biological food reserve needed by seeds for sprouting and contain metal ions and amino acids. 

Glutenin and gliadin explained:

Gluten is comprised of glutenin and gliadin.  Glutenin is the major protein found in wheat and does not dissolve in water while gliadin is water-soluble. There are three types of gliadin, α, γ, and ω.  Individuals with celiac disease are allergic to gliadins.

Gliadin has a high proline (an imino acid [not amino]) content.  Proline is important in the human body.  It helps heal cartilage, cushion joints and aids the body in breaking down proteins for use in healthy cells and tissues.

It is the ratio of glutenin to gliadin that determines baking quality.  Glutenin contributes to the elastic character of gluten while gliadin contributes to extensibility, or the ability of bread to rise. A balance between elasticity and extensibility is necessary for optimum baking performance (see also: Grains Canada 2016).

Specifics of hulled wheats 

Einkorn

Einkorn (AKA farro or farro piccolo) (Figure 5) is an ancient wheat suitable for baking, although limited for bread production. Einkorn also is used to add flavor to foods. It has a higher lipid content than bread wheat (4.2 vs. 2.8 g/100g) and is high in minerals, except for cadmium. Einkorn is often higher in protein, riboflavin and Vitamin E than bread wheat.  It has a lower total phenol percentage.  Phenols are a large group of chemical compounds found in plants that are responsible for controlling enzyme activity and protecting plants from viral and bacterial infections in addition to UV radiation damage.  In human nutrition, phenols are considered to have positive antioxidant properties that are considered healthy, except for certain individuals sensitive to phenol content. Einkorn is also higher in lutein and carotenoids than bread wheat. Lutein is involved in the synthesis of vitamin A and carotenoids are a plant pigment that provides antioxidants and Vitamin A in human nutrition (Hidalgo and Brandolini 2014).

There is some inconsistency and confusion in the literature regarding the scientific naming of the einkorns, depending on the on-going changes in systematics.  However, the most straightforward explanation is:

Wild einkorn: this single-grain grass may be known as either a separate species, Triticum boeoticum or a subspecies, Triticum monococcum subsp. boeoticum.

Several other synonyms, or subspecies options for wild einkorns exist, i.e T. aegilopoides and T. thaoudar. (See Nesbitt and Samuel 1995, Lopez-Merino et al. 2015, Purdue website).

An example of a two-grained wild einkorn is T. urartu (AKA Red Wild einkorn).

Domesticated einkorn: similarly, domesticated einkorn may be known as a separate species T. monococcum L., or as a subspecies, T. monococcum subsp. monococcum

Einkorn has the smallest grains of the hulled wheats. Domesticated some 10,000 years ago in the Fertile Crescent (Tigres-Euphrates regions), it eventually fell out of favour as a staple wheat for human consumption but was always grown in small amounts, on marginal land, and used primarily for animal feed (Hidalgo and Brandolini 2014).  Einkorn is drought and disease resistant, especially to rust and mildew (Gras 1980, Anker and Rients 2001, Kling et al. 2006).

Einkorn is generally higher in protein content than bread, durum or spelt wheat (Weiser et al. 2009) but the quality is lower (Longin et al. 2016). It contains less dietary fibre, but is richer in micronutrients (Hidalgo and Brandolini 2014).

Despite reports that some gluten-sensitive individuals tolerate einkorn, it does contain gluten and cannot be recommended for celiac disease patients. There may be proteins present that prevent the einkorn glutens from causing the same issues in sensitive individuals, however it is certainly not gluten free. Einkorn, in general, has poor bread making qualities when compared to current standards.  However, einkorn lines with high glutenin contents and low gliadin to glutenin ratios compare more favourably (Wieser et al. 2009).

Einkorn can produce yields similar to that of durum wheat under adverse growing conditions in Italy (Perrino and Hammer 1984, Purdue website).  Protein content is also 10-26 % higher than durum (12.5-13.5%).  Due to negative agronomic traits, such as lodging, einkorn may be better suited to low moisture areas.

einkorn
Figure 5.
 Field of einkorn. University of Saskatchewan. 2017.

Emmer

Emmer (AKA farro or farro medio) is another ancient grain, also favoured for adding flavour to foods. Emmer has a high protein, mineral and fiber content.  It may have higher antioxidants (phenolics and flavonoids) than bread wheat. It is low in carotenoids.  Gluten varies from very low to higher than bread wheat. Bread making properties vary but are generally considered to be less acceptable than those of bread wheat. Emmer may be missing some gliadin proteins, which may make it more digestible for some individuals, but it is not gluten free.

The emmers include:

T. dicoccum (Schrank) Schübl. Domesticate AB

T. palaeocolchicum Menabde Domesticate AB

T. ispahanicum Heslot Domesticate AB

T. timopheevi (Zhuk.) Zhuk. Domesticate AG (Nesbitt and Samuel 1995).

T. diococcoides Wild Emmer

Emmer originated in the same areas as einkorn. Emmers mostly have awns and spikelets that contain two well developed kernels (Purdue website) (Figure 6).

Cultivated emmer has been utilized in the Middle East, Central and West Asia as well as in Europe (Marino et al. 2009, Zaharieva et al. 2010).  It has also been underutilized in favour of hulless grains, but is still common in India, Ethiopia and Yemen where it is important in the preparation of traditional foods (Damania 1998, Zaharieva et al. 2010).  Although it only covers 1% of the global wheat area (Stallknecht et al. 1996), it remains a valuable crop due to its ability to give good yields on poor soils and its resistance to fungal diseases such as stem rust.  Some populations are also very tolerant to drought and heat stress (Zaharieva et al. 2010).

Emmer is primarily grown as a human food but is also used as feed.  It has acceptable pasta qualities (Cubbada and Marconi 1996). Emmer wheat has different sensorial qualities compared to durum and bread wheat that is preferred by many consumers (Zaharieva et al. 2010). Current research suggests further potential for emmer-derived bread baking qualities (Bandla et al. 2010).

Emmer is also recognized to have health food qualities and may be considered easy on the digestive system in some cultures (Zaharieva et al. 2010).  Information however, remains contradictory and controversial.  It is diabetic-friendly, due to its low glycemic value and high satiety value (Annapurna 2000, Buvaneshwari et al. 2003). In India, it has also been used to make pasta for endurance athletes (Kavita 1999).

Emmer is lower in carotenoids than either wheat or durum (Abdel-Aal et al. 1998, Handelman 2001, Hughes 2001).

emmer
Figure 6
. Emmer dehiscing pollen. University of Saskatchewan 2017.

Spelt

Spelt (T. spelta, farro grande AKA dinkel wheat) is another ancient grain, but one that has been utilized more than einkorn or emmer (Figure 7).  Spelt has a higher lipid, unsaturated fatty acid and starch content than bread wheat. The endosperm and bran tend to have a higher mineral content with regards to Fe, Zn, Mg, P.  Protein content is similar or higher but fiber content may be lower in spelt than in bread wheat. Spelt has a lower lysine content than wheat. Lysine is the most deficient amino acid in our general diets, and is also found in very low amounts in cereal crops. 

Gluten and protein composition are similar to that of bread wheat but spelt has poorer bread making qualities.  It is also used as an animal feed. The hulls have almost the same nutritional value as the grain.  Feed value for dairy cattle and poultry showed that spelt was comparable to oats (Ascott and Harper 1962, Ingalls et al. 1963).

Spelt can be used in many of the same processed foods as soft red winter wheat such as pastas, high fiber cereals and crackers.

In Germany, roasted spelt is used in soups and since the 1970s the ‘rediscovery’ of spelt has led to bakeries that currently focus only on spelt products (Longin and Würschum 2016).

The lower baking quality (shorter dough development and poor mixing) results in a coarser bread.

spelt
Figure 7.  Field of spelt.  University of Saskatchewan 2017.

Spelt has a complex history that archeaobotanists have not come to an agreement on. The exact origin and the historic timing of spelt is not known, but is believed to come from either the Fertile Crescent or Europe (perhaps it emerged twice, independently) but its emergence can be traced all the way back to the beginning of agriculture (Helbaek 1960). Spelt was first described in 301 A.D.  and is believed to derive from Saxon origins (Percival 1921, McFadden and Sears 1946).  Its peak of popularity was during the Bronze and Medieval periods in Europe.

Spelt is believed to be an ancestor of our common naked wheat (Percival 1921, McFadden and Sears 1946, Nesbitt and Samuel 1995).  The current understanding is that spelt arose due to chromosome doubling in natural hybrids of tetraploid wheat, perhaps crossed with goat grass (Aegilops squarrosa).  Once it arrived and was grown in Europe, it came in contact with naked wheats to form a naked free-threshing tetraploid wheat through natural hybridization (McFadden and Sears 1946). Dvorak et al. 2012 believe spelt was derived from free-threshing hexaploid wheat through hybridization of free-threshing wheat with hulled emmer. If so, the tetraploid parent of hexaploid wheat was not a hulled emmer, but rather a free-threshing form of tetraploid wheat.

Unlike einkorn and emmer, the hexaploid hulled wheat spelt has no wild hexaploid ancestor. Once it was known that both Triticum and Aegilops existed in polyploid series of diploid (14 chromosomes), tetraploid (28) and hexaploid (42), it was clear by the 1920s that hexaploid wheats must be an allopolyploid of a tetraploid Triticum and a diploid Aegilops. The Aegilops species were narrowed down to those with the barrel-type breakage pattern, and then to A. tauschii because its square-shouldered glumes best matched spelt. Subsequent work using other techniques has confirmed the role of A. tauschii as an ancestor of both the hulled and free-threshing hexaploids (Kerby and Kuspira 1987). When wild or domesticated emmer wheat was crossed with A. tauschii, and chromosome doubling induced in the first generation, a fertile hybrid resulted that was very similar to cultivated spelt. McFadden and Sears (1946) reported that the hybrid had the domesticated, semi-tough rachis, which would select against survival in the wild. Further crosses between both naked and hulled domesticated tetraploid wheats and A. tauschii forms always resulted in hulled, spelt-type hexaploid wheats (Kerber and Rowland 1974). The first hexaploid wheat would, therefore, have been a hulled wheat (Nesbitt and Samuel 1995).

Current spelt crops are often grown in mountainous regions under poor growing conditions such as high altitude with high precipitation heavy soils and cold winters.  Spelt is also resistant to fungal pathogens (Kema 1992a, 1999b) although it is susceptible to loose smut (2012 Kentucky Newsletter).  Some lines also show resistance to stem rust (McVey 1990), smut and bunt (Percival 1921, Iordanskaya 1996). Due to renewed interest, there has been considerable research into agronomic practices (i.e. Biel et al. 2016).

Spelt is also taller, lodges more easily and threshed spelt produces more chaff than bread and durum wheat (Ruegger and Winzeler 1993, Percival 1921).  Despite reports of hardiness Cabeza et al. 1993 found a higher mortality of tillers compared to wheat.  Spelt might only be hardier when both low temperature and higher precipitation is present.

There is some contradictory nutritional information, but in general spelt has weaker gluten making it suitable for confectionaries and pastries (Percival 1921), but not low enough to factor as a player for low-gluten or gluten-free foods. Outside of the higher protein content, spelt varies greatly in chemical composition but in general it is similar to hard red spring wheat (Ranhorta et al. 1995) in nutritional make-up. 

Spring spelt is generally seeded the same way as spring wheats.  Spelt is able to grow in poorly-drained, low fertility, soils. Because the hulls are attached to the seed, germination is slower than for wheat.

Hulled seed generally has a higher germination rate (Riesen et al. 1986, Ruegger et al. 1990c) and a lower risk of fungal contamination (Riesen et al. 1986) than naked spelt seed leading researchers to conclude that that hull provides protection for the seed. However, Ehsanzadeh (1999) found no differences in emergence.

There are many cultivars of “spelt” available that are a result of crosses between common wheat and spelt.  Common wheat and spelt wheat have the same genomes (ABD) and form fully fertile hybrid plants. This may result in some confusion. However, there is now an increased demand for pure (not crossed with common bread wheat) spelt varieties and breeding efforts are focusing on producing pure spelt cultivars.

Spelt in North America

Of the three hulled wheats, spelt is the best known. Immigrants brought spelt seed with them and production peaked in the early 1900s (including emmer and einkorn). In the US, it was grown mainly in N. and S. Dakota, Kansas, Nebraska and Minnesota (Great Plains). Production decreased rapidly until the 1920s (Purdue website).  Most of the current winter spelt is grown in Ohio (2012 Kentucky newsletter).

Yields have been inconsistent.  The disadvantages of limited adapted cultivars, low test weight and added time and expense of dehulling also contributed to the loss of interest in spelt and the other hulled wheats (Purdue website). 

Importance of Hulled Wheat in Saskatchewan

Spelt, emmer and einkorn wheats are grown largely under organic conditions. Markets exist for all three of these wheat types. Organic food sales in the USA have grown to an estimated $35 billion (2014) and Canadian sales of organic products have followed the upward trend reaching $3.7 billion in 2013. Saskatchewan is the largest producer of organic wheat in Canada and has the potential to become the leader in hulled wheat production. In 2008 SK had  20% of the spelt wheat acreage in Canada (total= 10,848 ac). The release of three CDC spring spelt cultivars since 2007 should provide some impetus for increased production in SK. SADF project funding  led to the development of the spring spelt variety, CDC Origin (2010), which is shorter, stronger strawed and produces a higher grain protein content and significantly higher falling number values than CDC Zorba, released in 2007. Falling number measures the amount of the enzyme alpha-amylase in a sample.  This enzyme converts starch into the energy required for germination.  The greater the amount of alpha-amylase present in a sample, the greater the potential for sprouting of the grain. The falling number is measured in the seconds it takes for a plunger to fall through a heated slurry of the ground grain. The more alpha-amylase is present the faster the plunger falls and the lower the lower the number. A higher falling number means there is less sprouting damage.

The spring spelt variety CDC Silex released in 2013 was the earliest-maturing spring spelt released by the CDC at the time. CDC Silex has a Falling Number value approaching that of CWRS wheat.  CDC Origin and CDC Silex have a good disease resistance profile, with the exception of stem rust and leaf rust (CDC Silex).

There is  commercial interest in emmer as well.  Currently, most of the product sold in Canada is imported from either Italy or the USA.  Emmer produced in Italy has a winter growth habit while the US material tends to be similar to the feed emmer variety ‘Vernal’.

Processing of Hulled Wheats

Glume removal is difficult, but can be done efficiently in continuous operating traditional plants (Giambanelli et al. 2013).

General agronomy of hulled wheats

For more information regarding the agronomic practices for hulled wheat, and for cultivars developed at the University of Saskatchewan, Crop Development Centre, please see the companion fact sheet.

Conclusions

The three ancient hulled wheats, einkorn, emmer and spelt, have always had a presence in regional or niche markets.  However, while the global acreage devoted to these wheats has declined dramatically since the 1900s, recent enthusiasm for novel foods, nutrition and crop diversity has resulted in renewed interest in the development and production of these ancient wheats.

Literature cited

Abdel-Aal, E.S.M., Sosulski, F.W., P. Hucl. 1998.  Origins, characteristics and potentials of ancient wheats. Cereal Foods World. 43:708-715.

Anker, C.C. and E.N. Rients. 2001. Prehaustorial resistance to the wheat leaf rust fungus, Puccinia triticina in Triticum monococcum (s.s.). Euphytica. 117(3):209-215.

Annapurna, K. 2000. Comparative study on protein and storage quality of supplemented uppuma of diococcum and durum wheat. M.Sc. Thesis Univ. of Agri Sci Dharwad.

Ascott and Harper 1962. Refer to Purdue website.

Bandla, N.R., C.J. Pozniak, P.J. Hucl, C. Briggs. 2010. Baking quality of emmer-derived durum wheat breeding lines. J. Cereal Sci. 51:299-304.

Biel, W., S. Stankowski, A. Jaroszewska, S, Pużyński and P. Bośko. 2016. The influence of selected agronomic factors on the chemical composition of spelt wheat (Triticum aestivum ssp. spelta L.) grain. J. Integrative Ag. 15(8): 1763–1769.

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