Determination of Optimal Irrigation Scheduling for Potato Crop Under Furrow Irrigation Method in Eastern Hararghe Zone of Oromia

Applying water using appropriate irrigation scheduling is crucial for enhancing of irrigation water use efficiency. This activity was done with the objectives of developing optimum irrigation regimes (when and how much to irrigate) for potato crop and evaluate the effect different irrigation scheduling on water productivity and yield of potato crop. The results indicate that, maximum irrigation frequency was obtained by scheduling irrigation at 60% ASMDL treatment. Minimum irrigation frequency was obtained by 140% ASMDL treatment. The result indicates that, maximum yield (335.7 qt/ha) was obtained by scheduling irrigation at 80% ASMDL treatment. The next maximum potato yield was obtained by scheduling irrigation at 100% ASMDL. Minimum potato yield (208.1 qt/ha) was obtained by scheduling irrigation at 140%ASMD treatment. The result show that, yield response factor (Ky) was greater than one at both 120% ASMDL and 140% ASMDL treatments. When ky is greater than one, it mean that, there is significance reduction on potato yield due to treatments. The result on irrigation scheduling of potato indicate that, maximum water productivity (12.34 kg/m<sup>3</sup>) and optimum yield (321.4 qt/ha) was obtained by scheduling irrigation at 100% ASMDL treatment than others. So, based on obtained water productivity and optimum yield, scheduling irrigation at 100% ASMDL is recommended for Potato with 8 day, 9 day, 10 day 13 day irrigation interval at initial, development, mid and maturity stage of Potato respectively.