Evaluation of different watering levels on potato yield

In order to evaluate different levels of irrigation on yield of potato varieties, experimental was done in Tabriz region during 2009. The experiment was arranged as split-plot based on RCBD with three replications. Treatment was different levels of water stress (irrigation after 70, 110 and 150 mm evaporation pan evaporation class A) and five potato cultivars (Agria, Satyna, Savalan, Kaiser and Markis).The results showed that different levels of water in height, number of stems, number of tubers larger than 60 mm, shoots and tuber dry weight, nitrate content in tubers and yield was significant at 1% level. And at 5% level significant were obtained for a percentage of dry matter of tubers. Varieties in height, number of tubers larger than 60 mm, shoot dry weight and yield at 1% and tuber dry weight at 5% level was significant. Also, interactions were significant in height, shoot number and yield at 1% and tuber dry weight 5% level. The highest plant height equivalent was 83 cm by irrigation after 70 mm evaporation from pan evaporation surface was irrigated with 150 mm of water evaporated from the pan surface and the lowest shoot length equal to 49.39% decrease in same Figure has been obtained. Maximum number stem was equivalent 5.497 in cultivar Agria by the control and lowest number stem was 2 numbers in Markis in the control that can be caused by genetic differences. Maximum yield was equivalent 3.598 kg/m2 in Agria by level control and least amount of yield reduction in this equivalent 46.11% by irrigation after 150 mm evaporation from pan evaporation levels are achieved. The purpose of this experimental was the resistance of different varieties of potatoes to different levels on growth and performance.