Effect of different irrigation water level on cotton yield and yield components

Abstract

Effects of different water level on yield and yield components of the drip irrigated cotton were evaluated in Amik 
Plain in the East Mediterranean Region of Turkey. Four levels of irrigation water were tested in 2003 and 2004. 
Treatments were 25 (I25), 50 (I50), 75% (I75) of the full irrigation treatment (I100) which received 100% class-A pan 
evaporation. Numbers of irrigation events were 5 and 8 in 2003 and 2004, respectively. Under I25, I50 and I75 
treatment conditions, evapotranspiration, total cotton seed yield, boll weight, lint percentage, number of 
sympodial branches and leaf area index decreased while some boll parameters such as boll weights and opened 
boll numbers increased. Increase of boll number per plant under water stress condition showed that cotton had 
high ability for adapting water stress conditions. The highest yield was obtained in the I100 treatment. A second 
degree polynomial relation could adequately describe the cotton seed yield response to the irrigation water 
amount. The highest irrigation water use efficiency (IWUE) was obtained with the I50 treatment.