1枝干日烧的发生及预防枝干日烧经常发生在寒冷地区的冬末春初。原因是白天气温在0℃以上,而树干向阳面受日光照射后,树皮增温快,常达10℃以上,夜间温度低于或等于0℃,昼夜温差大,这种冷热交替的温度变化,使枝干(尤其是树干)组织受损伤而发生。开始受害时树皮变色横裂,出现皮层 The occurrence of a branch of dry day and the prevention of branch dry day often occurs in late winter and early spring in cold areas. The reason is that during the daytime the temperature is above 0 ℃, and after the tree trunk is exposed to the sun by the sun, the bark increases rapidly, often up to 10 ℃, the nighttime temperature is lower than or equal to 0 ℃, and the temperature difference between day and night is large. Change, so that the branches (especially the trunk) tissue damage occurred. At the beginning of the damage bark discoloration and transverse cracking, there cortex