一、种性退化 目前,大蒜生产中存在严重的种性退化现象,其表现为:植株日趋矮小,假茎变细,叶色变淡、变小,小瓣蒜和独头蒜增多,提早枯黄的植株增多,产量降低等。造成种性退化的原因主要有三方面:一是大蒜用蒜瓣进行无性繁殖,不经过有性世代,这是种性退化的主要原因。二是在生产中,如土壤贫瘠、缺乏有机肥料、土壤理化性状不良、缺少水肥、高度密植、采(?)过迟、茎叶损伤、选种不严或不当的栽培管理,均会引起大蒜种性退化。三是病毒病,大蒜体内普遍存在病毒,当病毒积累到一定程度后,种性就明显退化。在华北及南方地区,大蒜鳞茎膨大期时值高温干燥气 First, the degeneration of sex At present, there is a serious degenerative phenomenon of garlic production, which is manifested as: increasingly smaller plants, pseudostem thinning, leaf color fades, smaller, small petal garlic and single garlic increased early yellow More plants, lower yields and more. There are three main reasons for the degenerative species degeneration: First, vegetative propagation of garlic with garlic cloves is the main reason for degenerative sex without going through the sexual generation. Second, in the production, such as poor soil, lack of organic fertilizer, poor soil physical and chemical properties, lack of water and fertilizer, high density, harvesting (?) Too late, stems and leaves injury, inappropriate selection or inappropriate cultivation and management, will cause garlic Sexual degeneration. Third, the virus disease, garlic virus widespread in the body, when the virus accumulated to a certain extent, the species significantly deteriorated. In North China and South China, the value of high-temperature dry bulb when the bulb bulging period