Abstract:
mong African countries, Ethiopia has possibly the greatest potential for potato production.
But its contribution to food security is less due to poor agronomic techniques and other
factors which require improving the ways of resources use and increasing farm return. This
experiment was conducted in JUCAVM greenhouse to study the effect of nitrogen rates and
irrigation regimes on water and nitrogen use efficiency of selected potato varieties (Jalenie,
Guassa and Degemegn), using three nitrogen rates (130, 110, 90 kg/ha), and three irrigation
regimes (full irrigation (100%), 80% and 60% of full irrigation) on clay textured fine top soil
filled to poly ethylene pot of 15 liter and 30 cm upper diameter. The experiment was 3x3x3
factorial with three replications laid down in a Randomized Complete Block Design.
Interaction of variety and irrigation significantly affected water use efficiency (WUE). Jalenie
variety recorded the highest WUE at 80% irrigation, but was on par with Guassa varieties at
100% irrigation. The lowest WUE was obtained from Degemegn variety at 100% irrigation
even though there was no significant difference among the three irrigations. Irrigation and
variety was significantly affected the nitrogen utilization efficiency while only irrigation highly
significantly influenced the nitrogen up take efficiency. Guassa and Jalenie produced
statistically similar maximum nitrogen utilization efficiency while Degemegn provided lowest.
Significantly the highest nitrogen utilization efficiency was recorded at 100% irrigation and
the least was obtained at 60% irrigation, while 80% irrigation statistically similar to both
irrigation effects. The highest nitrogen up take efficiency was recorded at 100% irrigation,
followed by 80 and 60%. From the results, it can be concluded that irrigation regimes and
variety were significantly affected water and nitrogen use efficiency of the potato varieties
while the nitrogen rates and interaction between or among factors holding nitrogen
combination were not influenced the water and nitrogen use efficiency of the potato varieties
significantly. As this is output of greenhouse condition, open field experiment is suggested to
be carried out to come up with conclusive results.
