Evaluation of the Effects of Water Stress and Different Levels of Nitrogen on Sugar Beet (Beta Vulgaris)

In order to investigate the effects of water stress and different levels of N fertilizer on yield and water use
efficiency in sugar beet (Var. BP) a split plots based on randomized complete block design was carried out with
4 replications in Khorasan Agricultural and Natural Resources Research Center (KANRC) during cropping
season in 2006. Water treatments comprising three levels including control (without water stress), initial water
stress and continuous water stress as main plots and different amounts of N fertilizer in 4 levels vis: control (0),
50, 100 and 150 Kg net N. ha-1 as sub plots were assessed. Analysis of variation showed that effects of water
treatments on root yield and gross sugar content was significant (at 1% level). Different levels of N also have
significant effect on root yield, net and gross sugar percent at 1% level while didn't influence net sugar yield
significantly. Interaction of water and N wasn’t significant for all the traits. Water use efficiency for root
(WUEr) and for sugar (WUEs) were significant in irrigation amounts (P< 0.05) However, results showed that
increased root yield under no water stress conditions with increased N amount was much more than it in water
stress conditions. In terms of root yield, no water stress treatment using 150 Kg Net N.ha-1 had the highest yield.
But water stress treatment particularly constant water stress, caused the maximum water use efficiency.