ABSTRACT A research is aimed to know the influence of bulb vernalization period on flower initiation and bulb forma- tion of several onion varieties (Allium cepa fa. ascalo- oum). This research is carried out at Purworejo village, District Temanggung, in the Regency of Temanggung from September 18, 1995 until November 26, 1995. The soil type is Latosol, it's elevation is 650 meter above sea …