Effect of Sowing Dates, Seeding Rates on Growth, Yield and its Component of Some Rapeseed (Brassica nupus L.) Genotypes.*


This study was conducted at Grdarasha Research Field / College of Agricultural Engineering Sciences - Salahaddin University - Erbil during the winter growing season (2014-2015), to investigate the effect of sowing dates, seeding rates on growth parameters, yield and its component of different rapeseed genotypes . A factorial experiment based on Randomized Complete Block Design (RCBD), with three replicates was applied, the first factor included three genotypes (Pactol, Raja and Rendy), the second factor included three sowing dates (15th October, 31st October, and 15th November), while the third factor represented two seeding rates (4 and 6 kg ha -1).The results indicated that the sowing on 15th October was superior and gave highest rate of leaf area (1986.34 cm 2), dry matter weight (23.86 g plant -1), plant height (208.63 cm), number of primary branches (8.05), number of secondary branch (5.75), stem diameter (11.04 mm), number of siliques plant -1 (218.75), number of seeds silique -1 (21.95), weight of thousand seeds (3.31 g), seed yield (3.39Mg ha -1). Increasing seeding rate from 4 to 6 kg ha -1 caused reduction in all growth characteristics of Rapeseed genotypes except plant height. While Pactol genotype obtained the highest seed yield (4.49 Mg ha -1) when sown on 15th October with seeding rate of 4 kg ha -1.