Target traits in breeding

The huge improvements in crop yields observed during the latter half of the twentieth century were due to many factors, including the increased use of fertilisers and pesticides and improved mechanisation techniques to allow planting at optimum times. In addition to these factors, plant breeding has played a major part, not only influencing the harvestable yields (the harvest index ) of crops, but also, and very importantly, their physical characteristics, pest and disease resistance, maturity times and quality. 

The harvest index of wheat has been substantially increased by the breeding of semi-dwarf varieties, and a closely related trait, improved resistance to lodging, has resulted in improvements both to yield and crop quality. Improved yields have been an important trait in all of the other major crops. In some cases improvements have been obtained by plant breeders selecting for winter hardy types which can be autumn sown. Oilseed rape is an important example, others, less successful, have included linseed, peas and lupins. 

One of the main outcomes of the bovine spongiform encephalopathy (BSE) and Foot and Mouth Disease epidemics, in terms of livestock production methods, was a re-evaluation of the systems of production in favour of grass fed animals and some expansion of organic production. 

There has recently been a large increase in interest in the use of red clover and a much needed and very welcome reinstatement of the breeding programme for this legnme at IGER (now IBERS - the Institute of Biological, Environmental and Rural Sciences) Aberystwyth. Important objectives for the plant breeders will be increased longevity, coupled with improved resistaiKe to clover rot and stem eelworm. 

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