Abstract:

Effects of three cultural factors including seeding time, plant density and application amount of nitrogen on main traits and yield of direct\|seeding rapeseed Zheyou\|18 were studied using orthogonal test. The results showed that seeding time significantly affected the height, the number of primary affective branches, the total pods per plant, the grains per pod and the kilo-grain weight. Plant density significantly affected the number of primary affective branches, the total pods per plant and the grains per pod. Meanwhile, the application amount of nitrogen only influenced the branch height, and these three cultural factors had no significant effect on the other traits. The order of the three effect factors on rapeseed yield was seeding time>plant density>application amount of nitrogen based on the range of means and F test. The yield of Zheyou-18 increased at first and reduced later with the increasing application of nitrogen, but showed no significant difference. The yield markedly increased with appropriate earlier seeding time and higher plant density．

Key words: rapeseed (Brassica napus L.), Zheyou-18, direct-seeding, seeding time, plant density, application amount of nitrogen