Effect of Different Irrigation Management in Surface and Sub-Surface Drip Irrigation Systems on Yield and Water Productivity of Potato

In order to evaluate the effect of different irrigation management, a split-split plot design was carried out in a randomized complete block design in Shahrekord Agricultural and Natural Resources Research Center in the growing season of 2018. This experiment consists of two methods of irrigation (surface and subsurface drip irrigation) in the main plots and four irrigation levels (Full irrigation, FI; deficit irrigation, RDI-80; Regulated deficit irrigation, RDI-65; and Partial Root-zone Drying (PRD-75) in subplots, in three replications for potato (Bourren cultivar). The results showed that the effect of different irrigation management on tuber yield, number of tubers per plant, percentage of tubers size, dry matter percentage, normal harvest index, percentage of starch, percentage of soluble sugars, percentage of nitrate and water productivity were significant (P≤0.01). Surface drip irrigation, as compared to irrigation of subsurface drip, increased the yield and water productivity by 7%. For surface irrigation, by increasing the amount of irrigation water from 65% to 100%, the average of starch and nitrate increased 18.8% and 33.6%, respectively and the soluble sugars decreased by 13.8%. With Compared to different irrigation treatments in two irrigation systems, average of maximum yield and normal harvest index for complete irrigation were obtained 50.3 t/ha and 0.48, respectively. In surface irrigation and 〖RDI〗_80 treatment the highest water productivity was achived 12 kg/m^2 which is recommended as a water saving solution.