Study of water stress effects on the quality and qualitative characters of new stable potato CVs in Ardabil.

Regional experiments during the two years of 1999-2000, have been showed high quantity and stability of two new local cultivars, Satina and Bolsta, of potato crop. Evaluation reactions of these CVs against the environmental conditions were the necessity. In order to determine of water use efficiency of these CVs and distinguish of water stress effects on the tuber yield and agricultural traits, we carried out an experiment with the statistical design split plot in the basis of Randomized Complete Block Design which the irrigation as a main plot (I) with three levels (I1 : irrigation amount in the basis 100% of requirement water from planting until tuberization stage and 120% of requirement water from tuberization until harvest time ; I2 : irrigation amount in the basis 80% of requirement water from planting date until tuberization stage and 100% of requirement water from tuberization until harvest time and I3 : irrigation amount in the basis 60 % of requirement water from planting date until tuberization stage and 80% of requirement water from tuberization until harvest time) and the selected potato CVs as a sub plot (V) with three levels ( V1: Agria as a check ;V2: Satina and V3 : Bolsta ), totally with 9 treatments and 3 replications took place in the experiment. The statistical analysis of results showed that water stress reduces total yield and yield components of potato cultivars, and there were significant differences for the total yield of selected cultivars. (i.e. 27% reduction in total yield for I3 treatment). Also Satina with yield of 31.385 t/ha was tolerable cultivar. In the other hand, with respect to applied water amount to irrigation of different cultivars, the Satina (V2) had the maximum water use efficiency with 4.066 kg/m3. Furthermore it was found that water use efficiency with full irrigation is higher than deficit irrigation. Therefore in areas with limited water supply, deficit irrigation with medium water stress and Satina cultivar (V2I2 treatment) are been recommended.