1. Introduction
Rye – the Latin name is Secale cereale – is still generally regarded
as the typical Germa bread cereal. Nevertheless, there is a continuous decline
in rye consumption. In the case of this bread cereal, too, it is chiefly winter
rye that is used for baking. Although over 90% of the world's rye is grown in
Europe, the cereal is by no means a uniform product. The main growing areas and
breeding centres are in eastern, central and northern Europe, although rye is also
grown and bred in North America, Australia and other regions.
Generally speaking, the objectives of breeding crop plants are to
achieve and maintain yield as an "agricultural value" and, where
necessary, to ensure good properties for a specific use as a "technological
value". Taken together, the two values ultimately determine the market value
of a variety. This also applies to rye as a bread cereal.
2. Yield as a Mark of Progress in
Breeding
The breeding of rye took a tremendous step forward with the
introduction of hybrid20 varieties around 1970. The importance of this
progress lay in the much greater yield of the hybrids as compared with pure
breeds and the fact that this yield was largely independent of soil quality.
Although the reliability of the yield depends on climatic conditions and is
therefore subject to certain annual fluctuations, the possibilities of increasing
the yield with hybrid varieties remain constant. A further advantage in years
with poor weather and in unfavourable locations is the hybrids' good resistance
to sprouting.
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| Fig. 92: Falling Number levels for the rye varieties approved in Germany since 1977 |
Fig. 92 shows the development of varieties over the past three decades
and the significance of the hybrids for the Falling Number as a criterion for
evaluation. Yield is an important factor in all forms of crop husbandry.
Rye is an interesting cereal from the point of view of ecologically
controlled and organic farming because it shows its advantages in respect of
yield and yield stability even with extremely little use of agricultural
inputs, including pesticides. For this reason rye and also dinkel are sometimes
regarded as the "health cereals".
Further advantages of rye are that its protein has greater biological
value for man than that of wheat, that it is less susceptible to mould – including
Fusarium – than many wheat varieties and that it is less inclined to form fusariotoxin.
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Tab. 69: Percentages of the main rye varieties grown in Germany (2004
harvest)
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However, the subject of ergot should be considered in connection with
rye. Possible differences in susceptibility to Claviceps purpurae infections
between the hybrid and pure breeds are still being discussed. Tab. 69 shows the
rye varieties most widely grown in Germany at present on the grounds of
regional decisions and yield. Hybrid varieties account for over 75% of the rye
grown.
Note :
20 Hybrid: offspring from two genetically dissimilar
parents. Two organisms are crossed with different desirable characteristics
with the premise that the offspring will possess more of the desirable
characteristics.
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