42 Javaheri et al. Int. J. Biosci. 2014 RESEARCH PAPER OPEN ACCESS Evaluation agronomic traits of canola affected by organic and chemical nitrogen fertilizer Mohsen Javaheri 1 , Amir Hossein Shiranirad 2* , Jahanfar Daneshian 2 , Ebrahim Amiri 3 , Saeed Saifzadeh 1 1 Department of Agronomy, College of Agriculture, Takestan Branch, Islamic Azad University, Takestan, Iran 2 Seed and Plant Improvement Institute, Karaj, Iran 3 Department of water Engineering, College of Agriculture, Lahijan Branch, Islamic Azad University, Lahijan, Iran Key words: Canola, nitrogen, organic manure, yield. http://dx.doi.org/10.12692/ijb/5.11.42-50 Article published on December 08, 2014 Abstract Nitrogen is one of the most important element in crop production, so nitrogen deficit occurs almost every where except when the fertilizer is added to plants, therefore a field experiment was carried out a factorial split plot arranged in randomized complete blocks design with four replications in two planting date(PD) at one year. Main plots consisted of two level of organic manure, (OM1) and (OM2) and five level of chemical fertilizer, (CF1), (CF2), (CF3), (CF4), (CF5) and sub plots consisted of two cultivar(C) (Okapi and Zarfam). Results of composed variance analysis showed that organic manure had significant effect on seed yield and means comparison showed highest seed yield was observed from application of organic manure with 2165 kg/ha and in comparison between organic manure levels application of organic manure had highest oil percent with 40.4 percent this positive effect was attributed to indicate importance of application of organic manures, in continuance result showed third level of chemical fertilizer application had highest harvest index with 38.33 percent that caused to observed highest seed yield with 2492 (Kg/ha). * Corresponding Author: Amir Hossein Shiranirad  shirani.rad@gmail.com International Journal of Biosciences | IJB | ISSN: 2220-6655 (Print) 2222-5234 (Online) http://www.innspub.net Vol. 5, No. 11, p. 42-50, 2014