Analysis of breeding progress of sugarbeet

Breeding of new sugarbeet varieties allows a steady increase of yield and thereby contributes to meet the increasing demand for plant biomass. The aim of this study was to analyse the extent of the breeding progress of sugarbeet varieties and to show which characteristics were modified by breeding. Sugarbeets approved as varieties during the years 1964 to 2003 were cultivated under equal environmental conditions in field and greenhouse experiments, to exclude effects from changes in production technique and climatic conditions. Differences in beet yield are therefore regarded as breeding progress. The results showed that breeding caused an increase in the white sugar yield of about 0.6 to 0.9% a(-1). This progress was realized by an increased harvest-index (higher root/leaf ratio and higher sugar/marc ratio), an improved technical quality (decreased standard molasses loss) and an improved assimilation (higher chlorophyll content, improved efficiency of the photosynthesis) of the sugarbeets. To continue the increase of breeding progress in future it is essential to work on parameters like disease and pest resistance and stress tolerance. A sustainable improvement of sugarbeet yield by breeding can be achieved by modifying several traits.