investigation of yield and germination qualitative characteristics of seeds of black cumin (nigella sativa l.), isabgol (plantago ovate forsk.) and fennel (foeniculum vulgare mill.) under organic cultivation

introduction during the last decades interest in organic production of seed specially for medicinal plants take into consideration because of higher quality of organic products (hermes, 2010). seed germination is one of the principal stages in the plant life cycle and seeds with higher quality and vigour resulted in more pronounced seedlings growth and development. therefore, investigation of agronomic practices specially nutrient management in the field is important because of its effective role in the promotion of plant growth, yield and consequently seeds with good quality criteria. materials and methods in order to investigate seed quantitative and qualitative criteria of black cumin (nigella sativa l.), isabgol (plantago ovate forsk.) and fennel (foeniculum vulgare mill.) under application of organic fertilizers including cow manure, spent mushroom compost, municipal waste compost and control, an experiment was conducted in a complete randomized block design with three replications at agricultural research station of ferdowsi university of mashhad, during two growing season of 2010-2011 and 2011-2012. consequently, their seed quality criteria were evaluated in a factorial experiment based on completely randomized design with three replications in laboratory of seed technology at college of agriculture and natural resources, university of tehran. criteria such as biological and seed yield, harvest index, 1000- seed weight, length, width and diameter of seed, seed germination percentage and rate, seed vigour index, length and weight of seedling were investigated. results and discussion results indicated that organic fertilizers caused a significant increase in seed yield and biological yield in which spent mushroom compost had the highest effect on mentioned criteria compared to control in both years of experiment. harvest index was not affected by fertilizers in isabgol and black cumin in both years while showing a significant effect in fennel. application of spent mushroom composts in the first year of experiment and municipal waste compost in the second year of the experiment affected 1000- seed weight of isabgol and black cumin, respectively. also, seed germination percentage and rate, seedling length and weight and seed vigour index were affected by organic fertilizers in three studied species, in which cow manure performed better and caused the highest amount of seed criteria compared to control. based on the results, application of cow manure, spent mushroom compost and municipal waste compost resulted in an increase of 43.75, 26.62 and 10.3 % in seed vigour index in comparison with control, respectively. non-application of organic fertilizers caused 23.5, 17.66 and 8.48% reduction of mean seedling length compared to using cow manure, spent mushroom compost and municipal waste compost, respectively. also, seedling dry weight had a similar trend like seedling length. interaction effect of species and organic inputs affected seed length significantly, in which, spent mushroom compost caused the highest amount of seed length in studied species. fennel seeds by using spent mushroom compost showed the highest seed length (6.19 mm) among different studied species and organic inputs. it seems black cumin, isabgol and fennel under organic nutrition showed more pronounce growth and yield in which resulted in production of seeds with higher vigour and germination criteria. probably adequate balance of nutrients in seeds caused better growth of seedlings and consequently increased their length and dry weight compared to non application of organic fertilizers. conclusion in general, the results of this experiment revealed that application of organic fertilizers such as cow manure, spent mushroom compost, municipal waste compost promoted both yield and seed quality characteristics of three studied species, black cumin, isabgol and fennel, which seems a promising result in production of organic medicinal plants. acknowledgments this project was supported by the fund provided by the vice chancellor for research and technology of ferdowsi university of mashhad for which the authorsare thankful.