Water Use Efficiency of Common Sorghum and Grain Corn Cultivars and Comparing the Effect of Water Deficit on These Cultivars

Water Use Efficiency of Common Sorghum and Grain Corn Cultivars and Comparing the Effect of Water Deficit on These Cultivars    Nasrin Safian۱, Mohammadreza Naderidarbaghshahi۲*, Hamid Reza Salemi۳, Massoud Torabi۴, Ali Soleimani۵ ۱- PhD Student, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.     ۲- Associate Professor in Agronomy, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.  ۳- Assistant Professor, Isfahan Agriculture and Natural Resources Research Center, Isfahan, Iran.    ۴- Assistant Professor, Isfahan Agriculture and Natural Resources Research Center, Isfahan, Iran. ۵- Professor in Agronomy, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.    * Corresponding Author E-mail: mnaderi@khuisf.ac.ir   Received: ۲۰ October ۲۰۲۲                                                                                Accepted:  ۸  January  ۲۰۲۳   Abstract Drought stress is the most important abiotic factor which limits the growth and production of plants in arid and semi-arid regions. In order to investigate the effects of irrigation regimes (۱۰۰, ۸۰ and ۶۰% of the plant's water requirement based on the Penman-Monteith method) on grain yield of sorghum (Payam and Kimia) and corn (۷۰۴ and Maxima) cultivars under the hot and dry climate of Isfahan, a split plots experiment was carried out in the years ۲۰۱۸-۲۰۱۹ in randomized complete blocks design with three replications. Results showed that the highest index of chlorophyll and grain fat was obtained from cultivar ۷۰۴ and in ۱۰۰% of irrigation. Cultivar ۷۰۴ produced the highest grain lignin under ۶۰% and ۸۰% irrigation regimes. Kimia cultivar produced more lignin compared to Payam cultivar. Payam cultivar produced the most yield and the highest plants under irrigation regimes of ۱۰۰ and ۸۰. Compared to Payam cultivar, Kimia showed more ۱۰۰۰ grains weight under different irrigation regimes. The harvest indices of Kimia and Payam cultivars showed significant decreases by increasing the drought. Different cultivars have different mechanisms to tolerate drought stress. As a drought tolerant plant, Sorghum was less damaged by stress than corn. Biochemical traits of plants can be used as stress resistance indicators in breeding programs and the selection of resistant cultivars.