Effects of Salinity on Oil Content, Protein, and Grain Yield of Safflower (Carthamus tinctorius L.) in Birjand Province.

Salinity and nitrogen deficiency are among most important limiting factors for crop production in eastern part of Iran In order to investigate effects of salinity and nitrogen on safflower's oil and protein content and grain yield, an experiment was conducted during 2008 in Research Field of Faculty of Agriculture, The University of Birjand, Birjand, Iran, as split-plot based on complete randomized block design with three replications Treatments were three different salinities of irrigation water (1, 5, and 9 dS m (1)) as main plots and four nitrogen fertilizer levels (46, 92, 138 and 184 kg N ha (1)) as subplots Results showed as salinity of irrigation water increased, grain yield, oil percentage and yield and also protein yield decreased significantly (p <= 0 05), but protein percentage was not affected The higher nitrogen applications increased protein yield and percent significantly, whereas applying 138 kg N ha (1) or more caused oil percentage to be decreased significantly compared to 46 kg N ha (1), however nitrogen had any effect on oil yield In general, severe salinity stress led to more reduction in protein yield of safflower, as a result of its impacts on grain yield