Responses of yield and yield components of three safflower (Carthamus tinectorious L.) spring cultivars to salinity induced at different growth stages

Salinity stress is one of the most important environmental constraints that have been limited agricultural production in Iran. Therefore, introducing suitable cultivars having desirable yield under salinity stress will lead to increase of production efficiency. In order to study the response of spring safflower cultivars to salinity, an experiment was carried out at the Experimental Station of the University of Birjand during 2007. The study was done as a split-plot experiment based on a Completely Randomized Block Design with three replications. Treatments were three times of salinity application (at branching, budding, and flowering) as main plots and three cultivars (Mahali Isfahan (a local variety), PI, and IL111). Salinity stress was induced using well water with an EC equal to 8.6 dSm-1. Results showed salinity had non-significant effects on yield components of cultivars, but the effects followed by these small changes influenced seed and oil yields and oil percentage significantly by time of salinity exertion. There was a significant difference between cultivars in yield and also the most of yield components, with notable superiority of Mahali Isfahan over PI and IL11. Slicing of interactions of cultivars in each time of saline water application indicated that majority of differences between cultivars was related to their response to salinity induced at budding, with Mahali Isfahan had the highest seed weight and seed number. than others. In general, it seems that Mahali Isfahan cultivar had more adaptability to irrigation with saline water. If this cultivar is irrigating with fresh water during reproductive phase, especially between budding to full flowering, it can producea reasonable seed and oil yields.