Biotech Studies 2008, Vol 17, Num, 1-2

The Effects of Nitrogen Fertilizer Forms Applied at Different Growing Periods on Yield and Yield Components of Winter Rapeseed (Brassica napus ssp. oleifera L.)

Neslihan Duygu ÜSTÜNER 1 ,Özer KOLSARICI 2 ,Mehmet Demir KAYA 3

1 Ziraat Yüksek Mühendisi
2 Ankara Üniversitesi Ziraat Fakültesi Tarla Bitkileri Bölümü, Dıskapı-ANKARA
3 Tarla Bitkileri Merkez Arastırma Enstitüsü, Yenimahalle-ANKARA
- This research was conducted to investigate the effects of nitrogen fertilizer forms applied at different growing stages (rosette, jointing stage, pre-flowering and post-flowering) on yield and yield components of winter rapeseed. In the study, winter rapeseed cultivar Orkan and ammonium sulphate (26% N), ammonium nitrate (33% N) and urea (44% N) were used as material. Plant height, number of lateral branches, number of capsule in main branch, one thousand seed weight, seed yield and oil ratio were determined in the study. The results revealed that nitrogen fertilizer forms and fertilizer application stages significantly affected the investigated traits. The highest seed yield would be obtained if ammonium sulphate in rosette stage, urea in jointing stage and ammonium nitrate in preflowering stage were applied. However, urea should be advised to increase seed yield of rapeseed if nitrogen fertilizer is generally applied in jointing stage in rapeseed. Keywords : Rapeseed, Brassica napus L., nitrogen fertilizer forms, growth stage, yield, oil ratio