The effect of transplanting, sowing and harvesting date on yield and water use efficiency of autumn-sown sugar beet

This study was conducted to evaluate the effect of transplanting on water use efficiency of autumn-sown sugar beet in Mehran, Ilam province. The experiment was carried out as factorial split-split plot based on randomized complete block design with four replication in two grwoing season 2015-16 and 2016-17. Sowing date (late September, early October, early November and late November) and cultivar (Sharif and Spartak) laid out in main plots, planting method (direct seed planting & transplanting) in sub-plots and harvest time (late April, mid-May and early June) as sub-sub-plots (split at time). The results of ANOVA based on expected mean of squares showed that effect of year on root yield, sugar content, sugar yield, and white sugar yield was significant. However, it had no effect on the water use efficiency based on sugar yield. The effect of planting time on root yield, sugar yield, and white sugar yield was significant. The effect of harvest time on root yield and sugar yield was significant. Water use efficiency based on white sugar yield in transplanting method was 1.60 kg/m3 which was 50% more than seed planting method. Root yield in transplanting method was 101 t/ha (54% increase compared with seed planting method). The highest white sugar with 14.08 t/ha was observed in transplanting, late September sowing, and at early June harvest (28% increase compared with seed planting). Considering the non-economic performance of seed planting method in autumn sugar beet sowing in the province, reduction of water resource , damage of migratory birds, and limitations of growing season, it seems that sugar beet transplanting can be a proper way to increase sugar production and water use efficiency which can be considered as a reliable method to replace seeding by completing mechanization facilities. According to the study results, Mehran city can also be considered as a region prone to the extension of autumn sugar beet sowing.