Estimation for potato products water requirement in Torbat Heidariyah region and determining the actual Evapotranspiration based on the reference Evapotranspiration

Potato is a tuberous product with important value in food supply for world and because of high efficiency per surface unit; it has higher energy and protein per surface unit than wheat and rice. In order to increase the plantation of potato prevention of water waste is essential. One effective way to the purpose of this investigation is a well programmed irrigation protocol which is achievable an exact estimation of the need of the plants for Water requirement. The applicable equation to estimate Evapotranspiration does not use the same climate parameters and due to the practical entity of this process they are not applicable for all climate conditions. Thereby, there has to be a suitable equation to be used in each region. To reach this goal, in this study, by the aid of data collected from Torbat Heidariyah weather station, the amount of real Evapotranspiration has been calculated using correlation coefficient and compared with the reference Evapotranspiration (F-P-M).The results show that the amount of Evapotranspiration is 2/63 times more than the mean precipitation in growing season. It means that the plants have been using their moisture storage to accomplish their Evapotranspiration. In order to replenish the moist content in plants irrigation is essential. Using the Cropwat method, potato need for water supply was estimated 803/1mm from the beginning of implantation to the end of harvesting and the estimation of the amount of water to supply this need is equal to 741/9mm.