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.
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.
Tab. 69: Percentages of the main rye varieties grown in Germany (2004 harvest)
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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