Sowing time is an important factor aff ecting crop yield and quality, especially in arid and semi-arid regions. The aim of this research was to investigate the eff ects of sowing time on the growth, yield, and quality of rapeseed genotypes and to determine genotype × sowing time interactions for grain yield and its related traits. | H. TURHAN, M. K. GÜL, C. Ö. EGESEL, F. KAHRIMAN Research Article Turk J Agric For 35 (2011) 225-234 © TÜBİTAK doi: Effect of sowing time on grain yield, oil content, and fatty acids in rapeseed (Brassica napus subsp. oleifera) Hakan TURHAN1,*, Muhammet Kemal GÜL2, Cem Ömer EGESEL1, Fatih KAHRIMAN3 1 Department of Agricultural Biotechnology, Faculty of Agriculture, Çanakkale Onsekiz Mart University, 17020 Çanakkale - TURKEY 2 COMPO GmbH Co. KG Turkey Liasion Office, Büyükdere Street, GIZ 2000 Plaza, 7th Floor, 34398 Maslak, İstanbul - TURKEY 3 Department of Field Crops, Faculty of Agriculture, Çanakkale Onsekiz Mart University, 17020 Çanakkale - TURKEY Received: Abstract: Sowing time is an important factor affecting crop yield and quality, especially in arid and semi-arid regions. The aim of this research was to investigate the effects of sowing time on the growth, yield, and quality of rapeseed genotypes and to determine genotype × sowing time interactions for grain yield and its related traits. The study was carried out using 8 winter rapeseed genotypes (H604049, H604038, H604041, Viking, Elan, Titan, Lorenz, and Trabant) and 4 sowing times (10 October, 20 October, 30 October and 10 November) during the 2005-2006 and 2006-2007 growing seasons. An NIRS system was used to determine oil, protein, glucosinolate and sinapic acid esters. Fatty acid analyses were done by the capillary gas chromatography method. Significant differences were found between sowing times for most of the traits measured. The lowest average seed yield ( kg ha–1) was obtained from the latest sowing time, whereas the highest average seed yield ( kg ha–1) was obtained from the earliest sowing time. The genotype H604038 produced the highest seed yield ( kg ha–1), and it was followed by Trabant ( kg ha–1) and Titan ( kg ha–1). The highest oil content, at , was obtained from genotype Lorenz at the first sowing time .
