临汾市县底镇某村,1995年3月栽植的一万余株M_(26)为中间砧的2001富士苹果树,其中80％的树体发生日灼。 经调查发现,在M_(26)砧木朝阳面出现黑斑,韧皮部坏死,严重的甚至整株死亡。这是因为冬季或早春树体朝阳面昼夜温差大,加之M_(26)不抗寒,树皮部昼夜冻融交替而造成日灼(实际是一种冻害)。许 Linfen City, a village at the end of the town, in March 1995 planted more than 10,000 strains of M_ (26) as the intermediate anvil 2001 Fuji apple trees, of which 80% of the tree sunburn occurs. After investigation, it was found that there were dark spots on the sun-facing surface of M_ (26) rootstock, necrosis of phloem, and even death of whole plant. This is because winter or early spring tree sunburst temperature difference between day and night, coupled with M_ (26) is not cold, bark day and night due to freeze-thaw alternating sunburn (actually a frost damage). Xu