‌‌Modeling yield potential and yield gap of sugar beet (Beta vulgaris L.) in Iran

Sugar beet is an industrial and strategic crop regarding sugar production in Iran, however, accurate information on its yield potential (Yp) and yield gap (Yg) is limited. The aim of this study was to estimate the yield potential of sugar beet using GYGA protocol according to the current conditions for the first time in Iran. Based on this protocol, agro-climatic zones (CZ), reference weather stations (RWs) and buffers within each meteorological station in each climatic zone as well as the type of soil texture in the buffer range were determined and yield potential, yield gap and production were evaluated using SSM-iCrop2 model. Finally, 28 weather stations were selected for sugar beet in 13 climatic zones which cover 92.7% of total sugar beet cultivation areas. The modeling results estimated the yield potential and yield gap to be 11.39 and 6.23 M t, respectively. Actual yield and the yield potential were 46.663 and 102.986 tha-1, respectively resulting in yield gap of 56.323 t ha-1 for sugar beet production in Iran with a relative yield (RY) of 45%. This indicates that current management practices produce only less than half of the performance potential.