effects of different fertilizer treatments on quantitative and qualitative characteristics of isabgol (plantago ovata)

application of organic manures is one of the most important strategies for plant nutrition compared to chemical fertilizers, especially in organic management of medicinal plants. in order to evaluate the effects of different organic and chemical fertilizers on yield, yield components and qualitative characteristics of isabgol (plantago ovata), a field experiment was conducted based on randomized complete block design with three replications at the agricultural research station, college of agriculture, ferdowsi university of mashhad, during growing season of 2011-2012. treatments included three levels of nitrogen fertilizer (25, 50 and 75 kg.ha-1), three levels of cow manure (5, 10 and 15 t.ha-1) and three levels of vermicompost (2, 4 and 6 t.ha-1) and control.the results showed that the effectof different fertilizers was significant (p≤0.05) on all studied traits except swelling rate of isabgol. the maximum amounts were observed in 6 t.ha-1 vermicompost and 15 t.ha-1 cow manure. the highest seed yield (548.4 kg.ha-1) was observed in 6 t.ha-1 vermicompost that it enhanced up to 26% compared to control. by increasing in organic fertilizers enhanced mucilage content, swelling factor and swelling content of isabgol. the maximum mucilage content and swelling factor were observed in 15 t.ha-1 (with 35.3% and 13.4 ml, respectively). since, organic matters improved quantitative and qualitative yield of isabgol compared to chemical fertilizer, it concluded that these organic inputs could be regarded as a suitable alternative to enhance the growth and yield of medicinal plants such as isabgol especially in low input systems.