effect of water deficit on sugar beet quality and quantity in kabotarabad-esfahan

in some regions of isfahan, although there is no soil and water salinity limitations, quality of sugar beet root is very low because of using high amount of irrigation water. a study was conducted to determine the relation between low irrigation and quality and quantity of sugar beet. in this study, a line source irrigation system for six water use treatments (from 10770 to 8554 m3/hec) was used. the results showed that root yield, sugar yield, sodium of root and white sugar yield decreased significantly when water use was decreased but sugar content and α- amino- n increased significantly. maximum root yield (55 ton per hectar) was obtained at 10770 m3/hec water use treatment, where as root yield decreased to 20.10 ton per hectar at 8554 m3 irrigation water. sodium of root responded to water contents, in that higher amount of water increased the sodium of root and as a result sugar content of sugar beet decreased. the results showed that water content less than 97.5% of the total water requirement did not increase water use efficiency for sugar yield. also, white sugar yield responded to low irrigation and it was significantly decreased with water use deficit.