the effect of deficit irrigation by alternate furrow irrigation on growth stages of the potato

this research was conducted at the shahrood agricultural research center in 1382 and 1383 to study the effect of alternate furrow irrigation on potato yield and its economic evaluation. the experimental design was a randomize complete block design and the treatments were: every furrow irrigation (efi), fixed alternate furrow irrigation (fafi), variable alternate furrow irrigation (vafi), fixed alternate furrow irrigation to onset of tuber setting (fafib), fixed alternate furrow irrigation to end of tuber setting (fafie), variable alternate furrow irrigation to onset tuber setting (vafib), variable alternate furrow irrigation to end of tuber setting (vafie). the water requirement was calculated based on the penman-montith method at each irrigation time and the water was supplied to each treatment using a volumetric meter and polyethylene. results showed for fafi and vafi, plant height, tuber number for each plant, average weight of tubers and yield were considerably reduced. there was no difference between efi and the other treatments (fafib, fafie, vafib, vafie). water usage can be reduced at the first growth stages and the end of the tuber forming stage with suitable irrigation management without yield reduction. for the economic analysis, the partial budgeting method and marginal benefit-cost ratio were applied. economic analysis showed that the benefit-cost ratio was 3.03 for vafie and water usage was reduced from 8632 m3/ha (efi) to 7250 m3/ha (vafie), saving 1384.7 m3/ha water. as a result, it is recommended to irrigate a crop based on the vafie treatment. in this way, without significant yield reduction, water usage and labor cost are reduced.