摘要:In order to study water demand, vegetative growth and tuber grade of potato crop under water stress and different cultivation patterns in different drip irrigation regimes, a split plot experiment based on the randomized complete block design with three replications carried out at the Allarog Research Station, Ardebil, Iran, in 2004. Estimation of crop evapotranspiration was conducted by CROPWAT computer program based on the relationship between crop coefficient (Kc) and crop evapotranspiration. Different drip irrigation levels were 100, 80 and 60% of potato crop evapotranspiration. Different levels of cultivation patterns were: 1 row 75 cm on bed 75 cm (furrow to furrow), 2 rows 35 cm on bed 150 cm (furrow to furrow) and 2 rows 45 cm on bed 150 cm and sampling times were the third factor with 6 levels. It was found that yield and growth of aerial parts was significantly affected by water stress and sampling times. Cultivation patterns had only significant effect on above ground biomass. The maximum and the minimum values of most traits studied were observed at 100 and 60% crop evapotranspiration levels, respectively. Number of tubers with 28-50 mm and larger than 50 mm diameter in size were higher at 80 and 100% of full irrigation, respectively. Estimating of amount of water irrigation during irrigation period for 100, 80 and 60% of water irrigation were 558.7, 445.96 and 335.22 mm, respectively.