عنوان مقاله [English]
In semiarid regions of Iran, one of the crop production management methods is delayed irrigation after emergence. This is due to simultaneous water requirement of cereal and spring season crops. A field study was conducted in Kabootarabad research station to investigate the effect of delayed irrigation on root yield, quality and growth trend using a RCB with four replications. The irrigation treatments were (I1) 100 mm (check), (I2) 200 mm, (I3) 300 mm, (I4) 400 mm, (I5) 500 mm and (I6) 600 mm evaporation from class A evaporation pan from 1997-1998. In 1997, the effect of treatments was not significant on root and sugar yield, but sugar content increased when irrigation resumed after 300 mm evaporation from class A pan. In 1998, root and sugar yield decreased significantly by delaying irrigation. The increase of sugar content by delaying irrigation were higher in I4 and I5 compared with other treatments, however sugar yield in I6 treatment was not compensated. Based on the results obtained in this study, about 22 percentage of water consumption was saved without any yield reduction in treatments of delayed irrigation. Therefore, more research on this subject has to be done for making practical recommendations.