Berhan International Research Journal of Science and Humanities (BIRJSH), 2024, 8(1), 123-139 Journal homepage: www.journals.dbu.et ISSN: 2414-2794, eISSN: 3006-578X The International Research Journal of Debre Berhan University, 2024 123 Yield and Quality Evaluation of Linseed (Linum usitatissimum L.) Varieties by Nitrogen Fertilizer Application Sintayehu Tenaye 1 , Fresew Belete 1* , Mitiku Ashenafi 1 1 Department of Plant Science, Debre Berhan University, P.O. Box 445, Debre Berhan, Ethiopia Abstract Linseed (Linum usitatissimum L.) is among the most significant industrial oilseed crops in Ethiopia, and it is high in health-promoting fatty acids. However, its yield and quality are low owing to poor nitrogen fertilizer use and lack of improved cultivars. Hence, a field trial was conducted at Angolelana Tera District, Debre Berhan University research site, during the main cropping season of 2021, to evaluate yield and quality of three linseed varieties (Kulumsa-1, Tolle, and Bekoji-14) as affected by four nitrogen rates (0, 11.5, 23, and 34.5 kg ha -1 ). The study was conducted using a randomized complete block design in factorial arrangement with three replications. Significance differences were observed in the interaction effects of nitrogen rates and linseed varieties on seed yield, percentage of oil content and oil yield. However, only the varietal differences affected all the fatty acid profiles. The highest seed yield was obtained from the application of 11.5 kg N ha -1 on Bekoji-14 variety; while the lowest was produced from Tolle variety without applying nitrogen. Kulumsa-1 variety with no nitrogen application had the highest percentage of oil content, while Tolle variety with 34.5 kg N ha -1 had the lowest. At 23 N kg ha -1 , Bekoji-14 variety produced the most oil yield whereas Tolle variety produced the least when 0 kg ha -1 of nitrogen was applied. Bekoji-14 and Tolle variety had the highest and lowest fatty acid compositions, respectively. A correlation study also demonstrated that seed yield has a negative correlation with the percentage of oil content but a positive and significant correlation with oil yield. Thus, farmers in the research region should be recommended to utilize Bekoji-14 variety with 11.5 kg N ha -1 for higher seed and oil yields with optimal fatty acid profiles. Keywords: Linseed; nitrogen rates; Linseed varieties; Linseed yield; seed quality * Corresponding author email: beletefresew@gmail.com Article information: Received 09 October 2024; Revised 10 November 2024; Accepted on 26 December 2024 © 2024 Debre Berhan University. All rights reserved.