Crop: Avena strigosa Schreb. (Lopsided oat)

Black oat is a wind pollinated annual landrace crop and was the main oat species grown on British islands until the 17th century (Podyma et al., 2019). It is now grown primarily on the Outer Hebrides as a forage crop, with some cultivation on a small scale across Orkney and Shetland. On the Outer Hebrides it is grown on the Machair habitat as part of traditional maintenance practices. Here it is grown as part of a mixed crop including one or both of two other species; barley (Hordeum vulgare L.) or rye (Secale cereale L.) (Scholten, Spoor and Green, 2009). This crop rotation and fallow system using small packages of land on the Machair makes an important contribution to the conservation of a unique environment (Owen, Kent and Dale, 2000). It is used for forage for cows and sheep and once harvested it can be used for silage.

Cultivation System: ND.

Geographical Information

Country: United Kingdom

As Avena strigosa Schreb. has been replaced by more lucrative commercial species, the areas in which it is still grown have shrunk. It is now grown as a clean crop in very small areas, often directly tied to craft reliant on its production – for example traditional oat back chairs made and sold on Orkney.

Oat is still widely grown as part of a mixed crop of barley (Hordeum vulgare L.), Rye (Secale cereale L.), and oat (Avena strigosa Schreb.) on the Machair habitats of the Outer Hebrides (Scholten, Spoor and Green, 2009). These are generally small packages of land associated with crofts, usually ranging between a few acres and a few hectares.

Farmer(s) description:

Black oat can be sown in early spring or in the autumn. Maintainers of this landrace describe it as an easy crop to work with owing to its tolerance to marginal soils due to cultivation in this area for centuries. Therefore, it has very low agricultural input needs. The main constraint described by most maintainers is issues with disease or pests such as geese or starling, which can decimate Avena strigosa Schreb. crop yields along with other cereal crops (Scholten, Spoor and Green, 2009). Like many other Avena species, black oat is susceptible to Puccinia coronate (, 2019.

Propagation system: Seed, self-pollination

Multiplication procedures and consequences on landrace diversity:

Black oat is a self-pollinating crop so does not rely on a healthy pollinator population. Seed is not always available from merchants so there is a need for islands in the Outer Hebrides to be self-reliant in terms of supply. For this reason, the impact of harvest failures due to disease is severe and has led to stock reintroduction in the past (Shaw, 1980). The need for famers to maintain seed stock and regulate quality themselves means that physical planting qualities may be prioritised over maintaining the genetic diversity of the population. In addition, there are some patterns of seed movement between maintainers on the Outer Hebrides, as is traditional to limit weed contamination (Scholten, Spoor and Green, 2009). This allows for increased local adaptation and aids maintenance of genetic diversity.

If the crop fails and maintainers have participated in SASA’s Scottish Landrace Protection Scheme, they may have submitted seed from previous years. In this case they can request their seed back from SASA. It will be their own seed and so locally adapted to their land.

Management plan existence:

Management currently relies on maintainers of this landrace, most of whom are found on the Outer Hebrides and in smaller numbers on Orkney and Shetland.

Added Values

Market - existing and novel:

Oat has been a traditional animal feed for centuries, and while it is still predominantly grown for animal feeds the health benefits associated with this grain have seen an increase in demand for oat products over the few decades (Wrigley, Batey and Miskelly, 2017). Despite this interest in oat products, Avena strigosa Schreb. is still grown on the Outer Hebrides exclusively as animal feed and as part of a traditional Machair maintenance method. Similarly, on Shetland, there are a few maintainers who grow oats for fodder, stray, hay and/ or silage. On Orkney there is at least one grower maintaining this landrace to use for production of traditional oat back chairs which are then sold.

There is also interest in oat flour products, such as bread, from those who suffer from a wheat allergy. It is not necessary for those with this allergy to avoid oats, so they may consume products made with oat flour in place of those made with wheat flour and avoid symptoms associated with their allergy (Pietzak, 2012).

Others (e.g. commercial/geographical brands or special traits):

Oats have attracted attention over the past few years because of compounds such as β-glucan and sterols, which along with other compounds contained in oat grains, have been linked to a number of health benefits (Martínez-Villaluenga and Peñas, 2017). β-glucan in particular can lower LDL cholesterol levels and reduce the risk of cardiovascular disease (Theuwissen and Mensink, 2008). It should be noted that much of the research surrounding oats and health benefits associated with them is not specific to Avena strigosa Schreb., instead focusing on commercial oat crop species. Increased research into the particular benefits associated with Avena strigosa Schreb. may lead to increased market interest in this landrace, thus increasing land area used.

Currently, according to the ICUN Red List, Avena Strigosa Schreb. is globally assessed as Data Deficient as knowledge on the abundance of this species is limited, and insufficient to assess the level of extinction threat (Rhodes, Bradley and Maxted, 2016). Any land used to grow black oat is eligible for rural payments from the UK government (GOV.UK, 2019).

The Scottish government is committed to protecting its plant genetic resources under various international treaties such as the Convention on Biological Diversity (CBD) 1992 and the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) 2004. As a result, the Scottish Landrace Protection Scheme was set up at SASA in 2006 and includes black oat in its collections to safeguard local adaptations in seed and prevent farmers having to buy in seed should a crop fail (, 2019). This means that local adaptations are retained. As of 2008 the SASA cereal landrace collection held 23 black oat accessions.

A potential renewal of interest in oat crops due to the health food movement could see hope for on-farm conservation efforts in the future.

Avena strigosa Schreb. is held in numerous collections in numerous gene banks globally, including the John Innes Centre in Scotland (, 2019). Despite this apparently large representation, it is likely that many of these accessions double up, potentially making the actual representation of the gene pool rather narrow (Podyma et al., 2019).

As described above, seed is also held by SASA. Access is limited, so for further information or to access seed please contact

Case study provided by University of Birmingham, United Kingdom.

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