Effect of planting date on some phenological and morphological characteristics, yield and yield components of five rapeseed (Brassica napus L.) cultivars

This research was conducted to investigate the effect of sowing date on some phenological and morphological characteristics, yield and yield components of five rapeseed (Brassica napus L.) cultivars in research farm of Agriculture and Natural Resources Research Center of Tehran during 2008-2009. The experimental design consisted of four randomized complete blocks (CRDB) in a split-plot arrangement. Four sowing dates (11 September, 27 September, 12 October and 27 October) as main plots and five rapeseed cultivars (RGS003, Hayola401, Okapi, Sarigol and Zarfam) as sub-plots were evaluated. In this experiment, evaluated traits included germination period length, flowering period length, number of days to flowering and maturity, plant height, number of secondary stem, pod lengh per main and secondary stems, number of pod per plant, number of seed per pod and grain yield. The sowing date had significant effect on all characteristics, except number of days to maturity and pod lengh per main stem. There were significant difference between rapeseed cultivars (P