qualitative and qualitative characteristics of milk thistle (silybum marianum l.) in response to organic, biological and chemical fertilizers

in order to evaluate the effects of organic, biological and chemical fertilizers on yield and yield components of milk thistle (silybum marianum l.), an experiment was conducted at the research station of ferdowsi university of mashhad based on complete randomized block design with three replications and six treatments during year 2007. treatments included inoculated seeds with azotobacter, compost, vermicompost, combination of both azotobacter and compost treatments, chemical npk fertilizer and control (without any fertilizer). the traits such as number of branches per plant, plant height, number of inflorescences per plant, inflorescence diameter, number of seeds per capitol, 1000 seed weight, seed yield, biological yield, harvest index, oil percentage, silymarin percentage, silybin percentage, oil yield and silymarin yield were measured. the results showed that application of different types of organic fertilizers had no effect on yield components, but had significant effect on oil percentage of oil, silymarin and silybin of seed. compost application resulted the highest oil percentage (20.1) compared to other treatments. there was no significant difference between control, chemical fertilizer, compost and azotobacter treatments on silymarin percentage. in terms of silybin percentage, there was no significant difference between control, compost, azotobacter and aztobacter+compost treatments. the chemical fertilizer treatment showed the lowest silybin percentage (16.4). there was a positive correlation between plant height and seed yield (r=0.68**). it seems that biofertilizers can consider as a replacement for chemical fertilizers in milk thistle medicinal plant production.