Sugar beet

Sugar beet is a biennial crop, but the storage root used for sugar manufacture is formed in the first year. Development of leaf canopy and storage root is temperature driven and not separated by distinct growth stages. Most critical stages are emergence, plant establishment, and early development. Breeding has shifted assimilate partitioning towards sugar storage at the expense of leaf mass and beet structural compounds. As yield formation is sink-limited most of the growing season, factors affecting radiation interception (decreasing radiation and canopy cover in autumn, elevated CO2, N supply) have less effect on yield, whilst genotypic yield is stable in different environments. Consequently the correlation between yield and canopy cover is loose, and nutrient demand increases only slightly with increasing yield. Despite high water use efficiency (yield per unit evapotranspiration), an adequate water supply is demanding for high yielding crops. As sugar beet has already a high yield potential, closing the yield gap will be an important challenge in future.