عنوان مقاله [English]
In ordet to investigate economic efficiency of five cultural systems in sugar beet crop, including high input, medium input low input , high and medium inputs without 3 times irrigation after emergence, an experiment was conducted over two years (2002-2003) in Agricultural and Natural Resources Research Center of Khorasan. These systems were analysed by marginal analysis and linear programming methods. Results showed significant difference among treatments for root yield, sugar and white sugar yield, sugar and white sugar content, sodium, potassium, α - amino azote and molass sugar.The maximum yield (52.11 ton/ha), was obtained from high input treatment and the minimum yield 35.89 (ton/ha) was obtained for medium input traetment without 3 times irrigation . Economic analysis showed that, low input treatment had the highest water efficiency followed by medium input treatment which had the highest economic rate of return. Beside, change in price of water ,led to change the optimum treatment.