Irrigation levels and their impact on water consumption of potato crop

The study was conducted in Hashimiya district, 15 km east of Babylon governorate -Iraq in the autumn season of 2016. A randomized completely block design ( RCBD) with three replicates have been used. The irrigation levels of 60%, 80%, 100% and 120% of evaporation calculated from the evaporation pan (EPAN), were randomly distributed to experimental units. Potato tubers (Solanum Tuberosum L.) Revera class (E rank) were used. The total actual water consumption was studied during the growth stages of plant , vegetative growth, emergence of tubers, filling tubers and completeness of the tubers growth. The efficiency of field water-use was measured. At the end of the experiment, some growth and production characteristics of the potato crop were measured as well.The following are the main findings:1- The highest total water consumption of potato crop at the level of 120% was 293 mm. On the other hand, it reached to 186 mm, 214mm and 255 mm at the levels of 60%, 80% and 100% of the evaporation calculated from evaporation pan, respectively.2- The results showed that the highest water consumption was 107 mm in the tubers filling stage and at the level of 120% , while it was 43.8, 65.2 and 85.6 mm at the levels of 60% and 80% and 100% of evaporation calculated from the evaporation pan, respectively.3- The irrigation level of 60% gave the highest efficiency of field water-use 25.7 kg / m3. Whereas the efficiency values of field water-use were 18.4, 15.5 and 12.3 kg / mᵌ at the levels of 80 %, 100% and 120% of evaporation calculated from the evaporation pan, respectively.4- The results showed that the highest production was 33.43 tons/ha at the level of 100%. Yet, the production values reached 27.52, 29.64 and 33.21 tons/ha at the levels of 60%, 80% and 120% of evaporation calculated from the evaporation pan, respectively.5- The irrigation levels made a clear impact on the plant characteristics. There were significant differences indicating that the values of such characteristics increased with increasing the level of irrigation. Nevertheless, tubers yield reached the highest value( 0.66 kg. plant -1) at the level of 100% but it declined to 0.63 when increasing the irrigation level to 120% of the evaporation calculated from the evaporation pan.

Keywords:

water consumption , moisture distribution , drip irrigation , irrigation levels