the effect of application of nitrogen fertilizer and nano-organic manure on yield, yield components and essential oil of fennel (foeniculum vulgar mill.)

introduction since discovery of food, clothing and shelter, human wanted to improve their physical sufferings, and using experience separated toxic plants from non – toxic ones and medicinal herbs from non – medicine. medicinal herbs are agricultural products which have a very important role in the health of people in society. among the medicinal herbs, fennel with scientific name (foeniculum vulgare mill.) traditionally was used for treating problems such as inflammation and cramping. now, one of the main objectives of the modern agriculture is decreasing the consumption of fertilizers and greater the use of organic fertilizers especially livestock fertilizers. the use of organic fertilizers in nano-dimensions can absorb the nutrients needed to plant. better use of nano- technology for producing organic fertilizers, suitable for recruiting plant can help plants in variable environmental conditions and be effective in the growth, quantity and quality performance (sumner, 2000). by the considering the same management of organic and chemical fertilizers consumption especially nano–organic fertilizers, is of great importance and necessitate further research and consideration in all kinds of plants, medical and aromatic herbs and plants in particular. materials and methods a factorial experiment, arranged in a randomized complete blocks design with three replications, was conducted in the saffron research institute at torbat - heydarieh university in 2014. the geographical location of the experimental station was 35º 20´ n and 59º 13´ e with the altitude of 1450 m. factors, including utilization of nano-organic fertilizer in four levels (zero, 10, 20 and 30 tons per hectare) and nitrogen fertilizers application in four levels (0, 25 , 50 and 75 kg per hectare). each experimental plot was 3 m long and 2 m wide and contained 4 rows with 50 cm distance. seeds were directly sown by hand in late may. first irrigation was done 10 days after seedling emergence. the rest of irrigation was done every 5 days. the spacing between plants were 20 cm that was achieved by thinning plants in 3-4 leaves stage .weeding was done manually tree times. fennel harvesting was done in early september at the time of physiological maturity. at the first five plants harvested randomly from each plot for measurement of plant height, the number of lateral branches per plant, the number of umbels per plant, the number of seeds per umbel, the number of seeds per plant, weight of 1000 seed and fresh and dry weight of plant. then for measurement of biomass, grain yield and harvest index, one m-2 of center of each plot was harvested. seed and straw essence were measured using distillation method with distilled water by clevenger apparatus. the data was analyzed using the sas software. means comparisons were done with duncan’s multiple rang test at 5% probability. results and discussion results showed that height, the number of lateral branches, the number of umbels per plants, the number of seeds per plant, 1000 seed weight, dry weight, seed yield, straw yield, biological yield, harvest index, and essence yield were affected by nano-organic manure. nitrogen fertilizers had significant effect on height, the number of seeds per umbrella, the number of seeds per plant, plant fresh and dry weight, seed yield, straw yield, biological yield and essence yields while the number of lateral branches, umbels per plant, seed weight and harvest index was not affected by this factor. the interaction of nano- organic manure and nitrogen fertilizer had not significant effect on the measurement characteristics. while the application of 10 ton ha-1 of nano-organic manure or 25 kg ha-1 of nitrogen fertilizer could increase biological, seed, straw and essential oil yield, higher amount utilization values of each treatment had no effect .consumption of 25 kg ha-1 of nitrogen fertilizer increased seed yield by increasing the biological yield, while 10 tons ha-1 nano-organic manure increased yield by increasing the number of umbrellas per plant, number of seeds per plant and seed weight. conclusions in general it can be concluded that consumed 10 ton ha-1 of nano-organic manure can be an appropriate alternative for nitrogen fertilizers in fennel and probably has less adverse effects on environment.