Effects of Water Stress on Vegetative and Reproductive Traits of Three Commercial Cotton Varieties in Field Conditions in Central Iran
Abstract Backgroundwater scarcity is one of the most important factors that restricts crop production specially, cotton which must planted in areas without cold temperature limitation. Most of such area in Iran encounters drought events, hot temperatures and high atmospheric evaporative demand. So, understanding of stress severity and cultivar responses will help to better management of crop in stress conditions. Our previous study showed that cultivar responses in view of some physiological and morphological aspects were highly different in water stress condition. In this study we focused on yield formatting traits.Results Three cotton commercial varieties; Khorshid, Khordad and Varamin studied in sever, mild and without water stress. In normal condition zero type cultivar, the khorshid, produced the highest seed cotton yield. Varamin cultivar had more and longer sympodial branches which could raise it’s yield. Also, Varamin cultivar’s seed cotton yield was higher than the others (3617 kg -1 ha compared with 2477 and 3060 for khordad and khorshid, respectively). Khorshid was superior to the others at sever water stress.ConclusionSeed cotton yield showed high correlation whit boll number and boll weight and vegetative aspects such as plant height, node number and sympodial branches number. Management for developing more sympodial branches results in higher bud and flower and will increase the yield. Totally, we recommend Khorshid and Varamin cultivars for normal condition and Khorshid for sever stress conditions.