在洋葱生产上由于栽培技术措施不当,使秧苗在低温季节发棵过大,造成在鳞茎形成前过早抽薹的现象,叫做洋葱先期抽薹。洋葱先期抽薹使鳞茎的膨大受到抑制,不能充分肥大,个头变小,产量低,品质变劣,易腐烂,耐贮性显著下降,经济效益低。因此,在洋葱栽培上必须控制先期抽薹。防止洋葱先期抽薹的栽培技术措施有以下几点。一、选用优良品种生产上应 In the onion production due to improper cultivation techniques, so that the seedlings in the cold season is too large, resulting in bulbs premature bolting phenomenon, called the pre-bolting onion. Onset bolting early bulb bulked suppressed, can not be fully hypertrophy, smaller head, low yield, poor quality, perishable, storability significantly reduced, low economic benefits. Therefore, in the onion cultivation must control the early bolting. Prevent the early bolting of onion cultivation techniques and measures have the following points. First, the selection of good varieties should be produced