seed germination and growth improvement in heracleum persicum desf. by osmo-primming

background & aim: because of seed germination ability of medicinal plants seed is low and, generally exposed to problem. priming is one of the techniques that help seeds to be germinated faster and uniformly. experimental: a laboratory experiment was carried out on germination and growth improvement in heracleum persicum desf.  by seed osmo-primming in seed technology laboratory of faculty of agriculture in birjand university, iran. statistical design was factorial rcbd with three replications. factors were priming media (polyethylen glycol 6000 (peg), kno3 and cacl2), osmotic potential of solution (-0.5, -1 and -1.5 mpa) and time of treatment (12 and 24 h). results & discussion: the results showed that priming media had significant effect on all of evaluated characteristics. germination rate significantly was affected by osmotic potential of solutions. time of treatment was also effective on germination rate and mgt. however, cacl2 in 24h and -0.5 mpa, peg in 24h and -1 mpa, peg in 12h and -1.5 mpa and kno3 in 24h and -1 mpa were best treatments in germination percentage and rate, seedling vigor index and mgt respectively. therefore, suitable priming treatments are able to improve germination traits in heracleum persicum. industrial and practical recommendations: the findings showed that priming leads to increasing the traits of blossoming in hogweed. since cumarin is used in various industries and its seed is week in blossoming, using priming can be helpful for blossoming and fixating of this plant and can be increase the production.