Effect of Deficit Irrigation on some Physiological Characteristics and Yield in Two Potato (Solanum tuberosum L.) Cultivars

Potato crop requires substantial amount of water and is extremely susceptible to water stress. Therefore, irrigation management is particularly important for its cultivation. In order to study of yield and biochemical properties of potato leaves under deficit irrigation, a field split-plot experiment was carried out based on a completely randomized block design with three replications. Main plot included six irrigation regimes [100%, 90%, 80%, 70%, 60%, and 50% of water requirement] and sub-plots included cultivars Sante and Savalan. Irrigation treatments had significant effects on leaf soluble proteins and sugar, leaf relative water content, and yields and dry weights of tubers per plant. Severe water deficit stress reduced leaf soluble proteins content, leaf relative water content, yields and dry weights of tubers per plant. Irrigation regime × cultivar interaction was significant for concentrations of leaf potassium and proline. Results also indicated that the highest values of soluble sugar (2.8 µmol.g-1of FW) and soluble proteins (3 µmol.gr-1of FW) were related to 50% and80% irrigation regimes, respectively. The lowest yield (204.9 gr.plant-1) and dry weight (46.8 gr.plant-1) of tubers were observed in 50% of complete irrigation. Maximum concentrations of potassium(43 mg.gr-1of DW) and proline (2.2 µmol.gr-1 of FW) in leaves belonged to 50% irrigation regime in cv. Sante. Result from the present research indicated that, under drought conditions, adverse effects of water stress can be reduced and desirable product can be attained by managing irrigation (deficit irrigation) appropriately.