Climatic impact on the productivity of sugar beet in Europe, 1961-1995

A recent study showed that drought stress was the major factor causing yiel d loss of the sugar beet crop in the UK. That study has been extended here by modelling potential and rain-fed yields (1961-1995) for European areas w here irrigation of sugar beet is uncommon. The inputs to this study are an improved crop growth model, the European monthly half-degree gridded meteor ological data time series, and a map of soil texture and available water ca pacity in sugar beet growing regions. Model outputs were scaled using a rat io of national mean to experimental plot yields to reflect commercial perfo rmance of a hypothetical 1998 variety for all years. The model was run on d aily weather data reconstructed from monthly values. Potential yields incre ased from north to south and from west to east due to increased radiation r eceipts. Drought losses were greatest in east Ukraine and southern Russia, at over 40% of potential yield (5 t ha(-1)). Losses were intermediate (15-3 0% or about 2 t ha(-1)) in central Ukraine, west Poland, east Gel-many and England (sandy soils) and lowest in NW Europe and west Ukraine. Increasing continentality decreases the number of rainy days per month during summer a nd the fraction of diffuse radiation; this reduces the radiation use effici ency by as much as 11%. Model output was also used to examine the efficienc y of sugar beet production across Europe; at the extremes, NW European farm ers deliver about 80% of the potential rain-fed yield while Polish farmers are only able to deliver 40%. This study demonstrates the importance of bre eding for drought stress tolerance in Europe. (C) 2001 Published by Elsevie r Science B.V.