干旱区生态环境知识资源中心

The study observed the effects of different watering regimes on yield and water use efficiency of N-84 cotton (Gossypium hirsutum L.) variety in the Aegean Region of Turkey during 2003 and 2004. Trials comprised two irrigation intervals (4-d and 8-d) within each of which three different watering regimes (100%, 67% and 33% of cumulative Class-A pan evaporation) were applied. The highest irrigation water level was applied to the full irrigation treatment (IR-100) for both irrigation intervals. Seasonal water use values in the treatments varied from 313-650 mm in 2003 and 249-603 mm in 2004. Seed cotton yield was significantly affected by irrigation intervals and irrigation levels. The maximum and minimum seed cotton yields were obtained from the 8-d IR-100 and the 8-d IR-33 treatments and averaged 5508 kg ha(-1) and 3419 kg ha(-1), respectively. Significant curvilinear relationships between seed cotton yield and crop water use were obtained for 2003 and 2004. Averaged across years, the highest water use efficiency (WUE) (1.21 kg m(-3)) was obtained in the 8-d IR-33 treatment and the lowest WUE (0.83 kg m(-3)) in the 4-d IR-100 treatment. The average yield response factor (k(y)) was 0.59 for the 4-d irrigation interval and 0.67 for the 8-d irrigation interval, respectively. Overall, the results of this research indicated that the 8-d irrigation interval with the IR-100 irrigation treatment could be used for cotton grown in semi-arid regions under no water shortage. Moreover, results obtained from the 8-d, IR-67 treatment could be used as a good basis for reduced drip irrigation strategy development underwater shortage because 33% of water saving was obtained with only a 6.0% yield loss averaged across years.