effect of plant growth promoting rhizobacteria, nitroxin and sulfur on quantity and quality of caster bean (ricinus commines l.) in sistan region

the caster bean oil is high value in industry around of world. plant nutrition and plant growth promoting rhizobacteria (pgpr) are important for crop production. an experiment was set up to investigate the effect of nitrogen (n), sulfur (s) fertilizers and pgpr on seed yield production of ricinus commines l. this experiment was carry out in factorial layout based on complete randomize block design with three replicates at research center of university of zabol during growing season of 2011-2012. the treatments were pgpr with three types of bacteria (control, nitroxin , and super nitroplas 2 l.ha-1), three levels of nitrogen (0, 150 and 200 kg.ha-1) and two levels of sulfur fertilizer (0 and 300 kg.ha-1). the results showed that grain weight, 1000-seed weight, number of capsule and number of seed per plant were not affected by studied treatments. the highest effect of pgpr was on dry weight of capsule, plant height, number of leaf per plant, oil percentage and amount of seed protein. number of inflorescence just affected by sulfur treatments and most of studied plant characters affected by n fertilizers. the highest and the lowest oil percentage were related to nitroxin and super nitroplas 51.89 and 47.85, respectively. also the highest and the lowest plant height were related to nitroxin and control treatments 82.29 and 53.33, respectively.