University of Tabriz Water and Soil Science 2008-5133 26 1-1 2016 05 21 Applicability of CWSI Index for Irrigation Scheduling of Maize Using Saline Water in Ahvaz Applicability of CWSI Index for Irrigation Scheduling of Maize Using Saline Water in Ahvaz 173 185 4849 FA M Saeedinia S Broomand Nasab AR Hooshmand A Soltani Mohammadi B Andarzian Journal Article 2016 06 20 Irrigation scheduling under water and salinity stresses is more difficult than normal<br />conditions. To investigate the effect of water stress on crop growth, numerous indices have been<br />introduced which one of them is crop water stress index (CWSI). To evaluate the suitability of this<br />index for irrigation scheduling of corn (maize) with using saline water, a field experiment consisted<br />of irrigation water with five salinity levels (S0: Caroon River (EC= 2.3 dS m-1), S1: EC= 3.5 dS m-1,<br />S2: EC=4.5 dS m-1, S3: EC=5.5 dS m-1 and S4: EC=6.5 dS m-1) was conducted at the research station<br />of Shahid Chamran University, Iran. Results showed that the lower baseline equation (without<br />stress) for the summer corn was (Tc-Ta)ll=2.161-0.221 VPD and the upper baseline equation (with<br />full stress) was h=3.690C. The CWSI value as a base for irrigation scheduling was calculated to be<br />0.23. Also it was found that increasing water salinity caused to increase the foliage temperature.<br />Thus, CWSI may be used for irrigation scheduling under conditions of using saline water. By<br />increasing water salinity from 2.2 to 6.5 dS m-1, the temperature difference between the canopy and<br />air was increased by 30C, approximately. In this research, CWSI values at the day just before the<br />irrigation were 0.23 for S0, 0.35 for S1, 0.46 for S2, 0.58 for S3 and 0.73 for S4scenarios. Also results<br />showed by increasing water salinity from 2.3 to 6.5 dS m-1, CWSI increased about three times. Irrigation scheduling under water and salinity stresses is more difficult than normal<br />conditions. To investigate the effect of water stress on crop growth, numerous indices have been<br />introduced which one of them is crop water stress index (CWSI). To evaluate the suitability of this<br />index for irrigation scheduling of corn (maize) with using saline water, a field experiment consisted<br />of irrigation water with five salinity levels (S0: Caroon River (EC= 2.3 dS m-1), S1: EC= 3.5 dS m-1,<br />S2: EC=4.5 dS m-1, S3: EC=5.5 dS m-1 and S4: EC=6.5 dS m-1) was conducted at the research station<br />of Shahid Chamran University, Iran. Results showed that the lower baseline equation (without<br />stress) for the summer corn was (Tc-Ta)ll=2.161-0.221 VPD and the upper baseline equation (with<br />full stress) was h=3.690C. The CWSI value as a base for irrigation scheduling was calculated to be<br />0.23. Also it was found that increasing water salinity caused to increase the foliage temperature.<br />Thus, CWSI may be used for irrigation scheduling under conditions of using saline water. By<br />increasing water salinity from 2.2 to 6.5 dS m-1, the temperature difference between the canopy and<br />air was increased by 30C, approximately. In this research, CWSI values at the day just before the<br />irrigation were 0.23 for S0, 0.35 for S1, 0.46 for S2, 0.58 for S3 and 0.73 for S4scenarios. Also results<br />showed by increasing water salinity from 2.3 to 6.5 dS m-1, CWSI increased about three times. https://water-soil.tabrizu.ac.ir/article_4849_e590c0c3a77137daad4a97899c14df62.pdf