M. Alikhasi - Department of Irrigation and Drainage, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
M. Kouchakzadeh - Department of Irrigation and Drainage, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
E. Baniani - Head of Agronomy Research Department, Cotton Research Institute, Varamin, Islamic Republic of Iran.

Shortage of irrigation water is a crucial problem especially in arid and semiarid regions; therefore, application of wastewater in agriculture in such regions seems to be an indispensable solution. A field experiment was conducted in non-agricultural soil to investigate the effect of Treated Municipal Wastewater (TMW) on the yield and fiber quality of cotton (Gossypium hirsutum L.) crop. The treatments consisted of surface irrigation by different mixtures and as well, through different intervals of freshwater plus TMW. Two additional treatments, namely, irrigation with freshwater and with TMW were considered as control. The experimental design was a randomized complete block one with eight treatments and three replications. The results indicated that cotton yield, number of bolls per m۲, Leaf Area Index (LAI) and plant height were significantly higher when the crop irrigated with TMW rather than with freshwater. The crop yields in TMW vs. freshwater treatments were about ۲,۲۰۰ and ۷۸۰ kg lint ha-۱, respectively. There were no significant differences observed between interval and mixture treatments when the same percentages of freshwater and TMW applied. Also there was no significant detrimental effect observed on the characteristics of cotton fiber quality when the crop irrigated with TMW.

Cotton, Crop yield, Effluent, Fiber quality, Reuse