Effect of partial root-zone drying and deficit drip irrigation on yield and water use efficiency of corn under Cukurova conditions

This study was carried out to determine yield- water use relations of the second crop maize under traditional deficit irrigation and partial root zone drying on yield and yield components under Cukurova conditions in 2006.Experimental site is located at the Research Field of the Agricultural Structures and Irrigation Department on clay soils in Mutlu Soil series. Pioneer 3394 hybrid corn variety was used in this study.Irrigation water quantity based on cumulative evaporation from class A pan at 7 day irrigation interval was applied through drip system to full irrigation (TS?100) and deficit irrigation (KS?50) and PRD?100, PRD?75 and PRD?50. Full and traditional deficit irrigation treatments received 100 and 50 % of cumulative evaporation at 7 day interval. In PRD treatments 2 of the 4 laterals alternately provided irrigation water and PRD?100, PRD?75 and PRD?50 received 100, 75 and 50 % cumulative evaporation value, respectively. A total of 644 mm irrigation water was applied to TS?100 treatment, while KS?50 and PRD?100 treatment plots received 396 mm, PRD?75 received 333 mm and PRD?50 treatment received 271 mm of irrigation water.The highest grain yield was obtained from the TS?100 treatments as 1040.3 kg/da, while KS?50 and PRD?100 treatments resulted in yields of 772.3 and 774.3 kg/da respectively. There was significant difference among the treatment with respect to grain yields. Significant second degree polinomial relationships between grain yield (Y) vs irrigation water (I) and grain yield (Y) vs water use (ET) were found as Y=-0.0006I2 + 1.6213I + 296.99 (R2 =0.91**); Y=- 0.0027ET2+4.2591ET- 585.65 (R2=0.88**) and, respectively. Water use effeciencies (WUE) for the second crop maize varied from 1.77 kg/m3 to 1.54 kg/m3. The highest WUE was found in PRD?100 treatment as 1.77 kg/m3, the lowest one was found in TS?100 treatment as 1.54 kg/m3.Key Words: Partial root zone drying, Deficit irrigation, Yield, Water use efficiency, corn