The Scottish Government

« Previous | Contents | Next »

Listen

THE STATUS OF TRADITIONAL SCOTTISH ANIMAL BREEDS AND PLANT VARIETIES AND THE IMPLICATIONS FOR BIODIVERSITY

PART 2 - CROP VARIETIES

CHAPTER TEN: Introduction

10.1 The crop component of the project concentrated on barley and oats, with a brief overview of other crops. Scots Bere is given as a particular example of a traditional Scottish crop and is reviewed in some detail. Barley and oats were important components of pre-historic Scottish agriculture and, unlike other crops, had developed as "landraces". Historically, oats were the most widespread crop but have steadily declined since the 1950s and now are grown on less than 10% of the cereal area. In contrast, barley crops have a long history in Scottish agriculture but have been less important than oats until the rapid expansion of malting barley production in the 1960s. Winter wheat (Scottish barley and oat crops are mainly spring sown) was a minor crop until entry of the UK into the EU changed the economics of grain whisky distillation and provided a new market for soft milling wheat.

Historical Context

10.2 The early history of most crops, in detail, is obscure with older records being less reliable or more difficult to interpret than modern agricultural statistics (Agriculture in Scotland, Annual reports, HSMO). The most readily available early data on Scottish Agriculture "The New Statistical Account of Scotland" lists crops and "describes" methods but does not have the same information content as modern statistics. Many books and papers have been published on Scottish Agriculture since 1596 and older records can be accessed via Symon (1959), who records their location. Archaeological studies have established the succession of crops in the Middle East (Harlan, 1995) and more recently "genetical archaeology" has suggested centres of origin and dispersal routes of ancient agriculture (Badr et al, 2000; Heun et al, 2000).

10.3 Local landraces of cereals evolved from crops domesticated in the Middle East some 10,000 years BP, particularly in the Fertile Crescent. The development of local landraces involved genetic adaptation as the crops migrated north and west from the centres of their origin. The most significant factor determining adaptation is time of flowering. In barley, time of flowering is affected by a number of genes controlling response to vernalization and daylength as well as earliness per se (Laurie, 1997; Laurie et al, 1995; Bezant et al, 1996). With current knowledge it is obvious that the process of unconscious selection for date of heading and maturity would have had widespread effects on the genome. It is not possible, however, to be sure of the efficiency of "natural" selection as many land-races may have been sown in both autumn and spring.

10.4 Early flowering, conditioned by a day-length response and low vernalization requirement, is appropriate to Mediterranean latitudes. Typically, in dry, rain-fed, situations early flowering is important to exploit winter rainfall and avoid drought stress associated with high temperatures in mid-summer (van Oosterom and Acevedo, 1992). In contrast, the highest crop yields occur in moist, cool environments in which long days allow slow plant development (Ellis and Kirby, 1980; Kirby and Ellis, 1980; Ellis and Russell, 1984; Russell and Ellis, 1988). In this context it is useful to note that crops in North America and South Australia are grown in environments that resemble Mediterranean conditions more closely than North West European agriculture so that the relationship between grain composition and malting quality is not constant (Swanston et al, 1997). The contrast between the Mediterranean climate and that of North West Europe resulted in many changes within and between crops. It is, for example, suggested that oats started as a crop weed in the Middle East but in Northern France out-competed barley and predominated in the crop as a response to an increase in rainfall (Thomas, 1995).

10.5 In addition to day-length and rainfall, soil composition has a dramatic effect on crop growth. While barley is more tolerant of salt than wheat (Harlan, 1995), acidic soils cause greater stresses in barley because metal ions such as Mn++ and Al+++ are more toxic to barley than to wheat or oats (van Essen and Dantuma, 1962). In contrast to the majority of barleys, Scots Bere is relatively tolerant of acidic soils due to a single gene on chromosome 4H (Stølen and Andersen, 1986). The basic mechanism of aluminium tolerance is still obscure (Kidd et al., 2001) with the possibilities that vacuolar sequestration, exclusion from the root or immobilisation in the soil by root exudates may play a part.

10.6 Scottish agriculture has been reviewed extensively both separately and together with the rest of the UK. It is notable that the reviews by Britton (1969), Coppack (1976) and Food from Britain (1983), do not consider Scots Bere. This contrasts with local interest groups particularly from the Orkneys (Davidson, 1982) where the Orkney Biodiversity Record Centre runs courses in Wildlife Identification and the Birsay Heritage Trust maintains Barony Mills, a traditional watermill, that is still used to mill Scots Bere ( http://www.orkney.com/birsayheritage/mill.htm). An overview is needed of the effect of the traditional crops on tourism, the wider environment and local interests but, in detail, this is beyond the scope of this report.

Changes in the importance of crops

10.7 The pattern of cropping in Scotland has changed considerably with Scots Bere widely grown in the 18 ^th and 19 ^th centuries (Figure 10.1). The export of Scots Bere to Norway and the Netherlands, with subsidy support, was recorded as early as 1695 (Symon, 1959). In 1769 more Scots Bere than barley was grown on Highland farms but the area of barley was extended by progressively liming soils. A farm hand-book (McConnell, 1904) records four types of Scots Bere; Common Bere, Black Four-row, Victoria and Winter White Bere. It would appear that only the first type has been preserved in collections. Since 1856 the

Figure 10.1 A comparison of the records of bear (Scots Bere), barley, wheat and oats in The New Statistical Account of Scotland for 1791-99 and 1845. The references to the four crops change little but give no clear indication of the relative importance in terms of the area sown.

relative positions of the major crops has changed considerably (Figure 10.2). Oat crops have declined and barley increased in area while other crops have also decreased. It is difficult to compare major and minor crops on the same scale but the use of a log ₁₀ scale allows the decline of rye, beans and orchards in the 1950s to be observed. The area used to grow soft fruit remained constant until 1995 and has then declined.. The major changes in crop importance were reflected in programme changes at the Scottish Plant Breeding Station (Table 10.1) with barley breeding starting in 1968 and oat breeding ceasing in the late 1970s.

Figure 10.2 Areas of selected crops 1856 - 1997 plotted to illustrate the changes between the major crops (grass and oats) and crops of intermediate importance in total area (potatoes, barley, turnips).

Figure 10.3. Areas of selected crops 1940 - 1970 plotted on a log ₁₀ scale to illustrate the differences between major crops (grass and oats), minor crops (orchards, soft fruit, rye, beans) and intermediate crops (potatoes, barley, turnips).

Table 10.1 Selected events from the programme of the Scottish Plant Breeding Station

10.8 The recorded exchange throughout Europe of barley cultivars and breeding material has been extensive (Plarre and Hoffmann, 1963) with widespread development of cultivars selected from landraces. The main centres of barley and breeding were at Weihenstephan and Hadmersleben in Germany, Abed in Denmark, Svalof in Sweden and Cambridge in England. It is notable that Scottish barley landraces have made no genetic contribution of any sort to barley improvement i.e. are not represented in the pedigrees of modern cultivars. This is in great contrast to Sweden where landraces from Gothenburg made a substantial contribution to malting - quality barley development. This contrast reflects the localisation of activity in breeding programmes and differs greatly from the objective of modern commercial breeding programmes that aim to produce pan-European cultivars. The fact that adaptation of cultivars, produced by any breeding programme, is dependent on the geographical span of the in-built trialling system, was recognised after collaborative testing in Europe (Ellis and Schmuetz, 1981).

10.9 The need for wider adaptation was recognised in the publicly-funded cereal breeding programmes of the Plant Breeding Institute, Cambridge; the Welsh Plant Breeding Station, Aberyswyth and the Scottish Plant Breeding Station, Edinburgh. Local trials were latterly supplemented, particularly for barley, by an exchange of material at both the row selection and replicated-plot trial stages. The efficiency of improved trials technique (Robinson, Kershaw and Ellis, 1988) gave increased flexibility and efficiency in trials run by breeders and in National List and Recommended List testing. Close collaboration between workers at the Scottish Plant Breeding Station and member companies of the British Society of Plant Breeders resulted in setting up a system of national trials in parallel to National List Trials (NLT) (Talbot and England, 1984).

Traditional cereal cultivars

10.10 It is difficult to define what is meant by a traditional cultivar because older cultivars are often heterogeneous. Pragmatically, barley and oats that show particular adaptation to Scotland can be considered in three broad categories: 1) only present in germplasm collections, 2) still cultivated in traditional systems and 3) ex-Recommended List but no longer in main-stream commerce (Table 10.2). Newer cultivars may be as well adapted, particularly as global climate causes marked change in rainfall and/or temperature, but have not been assessed as completely as those listed below.

10.11 New cultivars are assessed in a system of National List Trials (NLT) in which good plot performance over the whole UK is the first hurdle that the candidate must exceed. A few of the entries for NLT reach Recommended List Trials (RLT) and succeed in being recommended. The rate of attrition of breeding material has been reviewed (Ellis, 1986) and appears to preclude the recognition of specific regional adaptation in a new cultivar.

10.12 The barley variety Golden Promise is an example of the ex-Recommended List category and is very well adapted to Scottish conditions, well liked by farmers, maltsters, brewers and distillers. It is no longer on the National List, so is not protected as a plant variety, but it is still used by brewers who prefer its malting performance. Golden Promise seed was sown on 481 ha in 2000 i.e. 1.6% of the total Scottish seed production (Figure 10.4). The equivalent figures for Tyne and Prisma were 2 % and 5% respectively. Consideration should be given to reviewing procedures for National List Trends to accommodate regional differences with a view to encouraging greater diversity in varieties used.

Table 10.2 Examples of barley and oat varieties adapted to Scottish conditions and their status.

Barley

Oats

¹Note that reference to a single variety name does not specify the number of samples that exist

Figure 10.4 Seed production in Scotland for spring barley in 2000 - areas accepted for certification. The cultivars (left to right) are Optic, Chalice, Decanter, Riviera, Chariot, Prisma, Maresi, Tyne, Static, Hart, Golden Promise, Delibes and Derkado.

10.13 The other "traditional" barleys are not represented in the formal seed production system and there are no records for informal seed production. Oat seed production is on a much smaller scale that barley (Figure 10.5). The area sown to produce seed of Dula in 2000 was 324 ha, somewhat less than Golden Promise. Again there is no certified seed production of other traditional cultivars of oats.

Figure 10.5 Areas of oat seed sown and accepted for certified seed production in Scotland in 2000.

Other crops

10.14 In the case of potatoes the traditional Scottish role has been the production and export of seed potatoes to England and Wales. Some traditional varieties such as Pink Fir Apple and Kerr's Pink have been grown for specialist purposes. The major European Potato collections have been catalogued (Kehoe, 1986) and the Scottish Agricultural Science Agency are currently compiling a European Community Potato Cultivar Database of some 4,500 accessions. Fruit production in Scotland has been limited by climate to localised areas that specialise in e.g. raspberry production. SCRI has collected and assessed the genetic diversity of wild Scottish raspberries (Graham et al, 1997).

« Previous | Contents | Next »